Skills assessment in drowning incidents by rescuers

TESE DE DOUTORAMENTO SKILLS ASSESSMENT IN DROWNING INCIDENTS BY RESCUERS Roberto Jesús Barcala Furelos ESCOLA DE DOUTORAMENTO INTERNACIONAL DA UNIVERSIDADE DE SANTIAGO DE COMPOSTELA PROGRAMA DE DOUTORAMENTO EN INVESTIGACIÓN CLÍNICA EN MEDICINA SANTIAGO DE COMPOSTELA ANO 2021 DECLARACIÓN DO AUTOR/A DA TESE D./Dna. Roberto Jesús Barcala Furelos Título da tese: Skills assessment in drowning incidents by rescuers Presento a miña tese, seguindo o procedemento axeitado ao Regulamento, e declaro que: 1) A tese abarca os resultados da elaboración do meu traballo. 2) De ser o caso, na tese faise referencia ás colaboracións que tivo este traballo. 3) Confirmo que a tese non incorre en ningún tipo de plaxio doutros autores nin de traballos presentados por min para a obtención doutros títulos. 4) A tese é a versión definitiva presentada para a súa defensa e coincide a versión impresa coa presentada en formato electrónico E comprométome a presentar o Compromiso Documental de Supervisión no caso de que o orixinal non estea na Escola. En Santiago de Compostela, 29 de Maio de 2021. Sinatura electrónica AUTORIZACIÓN DO DIRECTOR/TITOR DA TESE D./Dna. Santiago Martínez Isasi En condición de: Director/a Título da tese: Skills assessment in drowning incidents by rescuers INFORMA: Que a presente tese, correspóndese co traballo realizado por D/Dna Roberto Jesús Barcala Furelos, baixo a miña dirección/titorización, e a utorizo a súa presentación , considerando que reúne os r equisitos esixidos no R egulamento de Estudos de Doutoramento da USC, e que como director/titor desta non incorre nas causas de abstención establecidas na Lei 40/2015. En Santiago de Compostela, 29 de Maio de 2021 Sinatura electrónica AUTORIZACIÓN DO DIRECTOR/TITOR DA TESE D./Dna. Antonio Rodríguez Núñez En condición de: Titor/a e director/a Título da tese: Skills assessment in drowning incidents by rescuers INFORMA: Que a presente tese, correspóndese co traballo realizado por D/Dna Roberto Jesús Barcala Furelos, baixo a miña dirección/titorización, e a utorizo a súa presentación , considerando que reúne os r equisitos esixidos no R egulamento de Estudos de Doutoramento da USC, e que como director/titor desta non incorre nas causas de abstención establecidas na Lei 40/2015. En Santiago de Compostela, 29 de Maio de 2021 Sinatura electrónica AUTORIZACIÓN DO DIRECTOR / TITOR DA TESE Skills assessment in drowning incidents by rescuers D. Antonio Rodríguez Núñez Santiago Martínez Isasi INFORMA/N: Que a presente tese, correspóndese co traballo realizado por D/Dna. Roberto Jesús Barcala Furelos, baixo a miña dirección/titorización, e a utorizo a súa presentación, considerando que reúne os r equisitos esixidos no R egulamento de Estudos de Doutoramento da USC, e que como director desta non incorre nas causas de abstención establecidas na Lei 40/2015. De acordo co indicado no Regulamento de Estudos de Doutoramento, declara tamén que a presente tese de doutoramento é idónea para ser defendida en base á modalidade de COMPENDIO DE PUBLICACIÓNS , nos que a participación do/a doutorando/a foi decisiva para a súa elaboración e as publicacións se axustan ao Plan de Investigación. En Santiago a 29 de 5 de 2021 CONTENTS Abbreviations………………………………………...…………. 10 List of figures…………..……….……………………..………… 14 List of publications…………..……………………..…………… 17 ABSTRACTS…………………………...………….…..………… 19 ABSTRACT……………………………………...……………..… 20 RESUMEN………………………………………………...……… 23 RESUMO……………..……………..…………….……………… 26 SUMMARY IN SPANISH……………………………….……… 29 SUMMARY IN GALICIAN…………………………….……… 55 1. INTRODUCTION………………..…………………..………. 80 2. HYPOTHESIS & OBJETIVES……….…...………………… 89 2.1 HYPOTHESIS………………..………...……………….…… 92 2.2 OBJETIVES……………………………………………….…. 93 3. METHODOLOGY..................................................................... 96 3.1 GENERAL METHODOLIGICAL DESCRIPTION................ 97 3.2 STUDY VARIABLES….…..……………….……………….. 99 3.3 ETHICAL ASPECTS………………..………………...…….. 99 4. RESULTS OF PUBLICATIONS……………..……….…….. 101 4.1 LAY-RESCUERS IN DROWNING INCIDENTS: A SCOPING REVIEW…………..………………...……….…….. 102 4.1.1 Evidence of Quality…………………………....................... 102 4.1.2 Article abstract…………………………………………..…. 103 4.2 IS IT FEASIBLE ‘SCOOP AND RUN WHILE PLAYING’ RESUSCITATION ON A RESCUE WATER CRAFT? A RANDOMIZED SIMULATION STUDY WITH LIFEGUARDS…………………………………………………… 106 4.2.1 Evidence of Quality…………………………...................... 106 4.2.2 Article abstract……………………………………..………. 107 4.3 IS LOW-FREQUENCY ELECTRICAL STIMULATION A TOOL FOR RECOVERY AFTER A WATER RESCUE? A CROSS-OVER STUDY WITH LIFEGUARDS………………. 110 4.3.1 Evidence of Quality…………….…………………............. 110 4.3.2 Article abstract………………..……………………………. 111 4.4 OCCUPATIONAL HEALTH RECOMMENDATIONS FOR LIFEGUARDS IN AQUATIC EMERGENCIES IN THE COVID-19 ERA: PREVENTION, RESCUE AND RESUSCITATION…………………….……………….………… 113 4.4.1 Evidence of Quality……………….…………...................... 113 4.4.2 Article abstract…………..…………………………………. 116 4.5. PLASTIC BLANKET DROWNING KIT: A PROTECTION BARRIER TO IMMEDIATE RESUSCITATION AT THE BEACH IN THE COVID-19 ERA. A PILOT STUDY.................. 116 4.5.1 Evidence of Quality…………………….……..................... 116 4.5.2 Article abstract………………………..……………………. 117 4.6 SAFE ON-BOAT RESUSCITATION BY LIFEGUARDS IN COVID-19 ERA………………..……….…………………….. 119 4.6.1 Evidence of Quality…………………………………........... 119 4.6.2 Article abstract………………………………….……….…. 120 5. DISCUSSION……………………………………..…..……… 122 5.1 LAY-RESCUERS, PROFILE AND TECHNIQUES……….... 124 5.2 LIFEGUARDS, PROFILE AND TECHNIQUES.………….... 129 5.3 SARS-COV-2 AND LIFEGUARDING…….....……………... 140 5.4 PRACTICAL IMPLICATIONS………………...............…… 153 5.5 LIMITATIONS………………………………………………. 155 6. CONCLUSIONS…………………………………...….……… 156 7. FUTURE RELATED OR DERIVED RESEARCH…...…… 160 8. REFERENCES…..…………………………………………… 163 APPENDIX I (LINK TO PUBLICATIONS)…………..……… 178 APPENDIX II (PERMISSION FOR REPRODUCTIONS).... 179 APPENDIX III (ETHICAL PERMISSION)…..…………….… 184 16 Salud Pública by Barcala-Furelos et al. under Creative Commons license and reproduced with their editorial permission. Figure 18 Laying the plastic blanket [1,2] and comparison of plastic vs. apron blanket [3]. (Own images). 151 Figure 19 Comparison of plastic blanket in IRB set [1] vs. full PPE with apron [2]. (Own images). 152 17 LIST OF PUBLICATIONS Thesis by compendium of publications indexed in the Journal Citation Report (article 41 of the Regulations for Doctoral Studies - USC). Barcala-Furelos R, Graham D, Abelairas-Gómez C, RodríguezNúñez A. Lay-rescuers in drowning incidents: A scoping review. Am J Emerg Med. 2021 Jan 31;44:38–44 https://pubmed.ncbi.nlm.nih.gov/33578330/ Barcala-Furelos R, Abelairas-Gomez C, Aranda-García S, LorenzoMartínez M, Martínez-Isasi S, Durán-Álvarez C, et al. Is it ‘scoop and run while playing’ resuscitation feasible on a rescue water craft? A randomized simulation study with lifeguards. Am J Emerg Med. 2020 Mar; 38(3):618–23. https://pubmed.ncbi.nlm.nih.gov/31982219/ Barcala-Furelos R, González-Represas A, Rey E, MartínezRodríguez A, Kalén A, Marques O, et al. Is Low-Frequency Electrical Stimulation a Tool for Recovery after a Water Rescue? A Cross-Over Study with Lifeguards. Int J Environ Res Public Health. 2020 Aug 12;17(16). https://pubmed.ncbi.nlm.nih.gov/32806727/ Barcala-Furelos R, Aranda-García S, Abelairas-Gómez C, Martínez-Isasi S, López-Mesa F, Oleagordia-Aguirre A, et al. Occupational health recommendations for lifeguards in aquatic emergencies in the COVID-19 era: prevention, rescue and resuscitation. Rev Esp Salud Publica. 2020 Jun 30;94. https://pubmed.ncbi.nlm.nih.gov/32601267/ 18 Barcala-Furelos R, Szpilman D, Abelairas-Gómez C, AlonsoCalvete A, Domínguez-Graña M, Martínez-Isasi S, et al. Plastic blanket drowning kit: A protection barrier to immediate resuscitation at the beach in the COVID-19 era. A pilot study. Am J Emerg Med. 2020 Nov;38(11):2395–9. https://pubmed.ncbi.nlm.nih.gov/33039225/ Barcala-Furelos R, Abelairas-Gómez C, Alonso-Calvete A, CanoNoguera F, Carballo-Fazanes A, Martínez-Isasi S, et al. Safe OnBoat Resuscitation by Lifeguards in COVID-19 Era: A Pilot Study Comparing Three Sets of Personal Protective Equipment. Prehosp Disaster Med. 2021 Apr;36(2):163–9. https://pubmed.ncbi.nlm.nih.gov/33500008/ 19 ABSTRACTS 20 ABSTRACT Background and purpose Drowning is one of the leading causes of unintentional death worldwide. Prevention is the best strategy but it is not always sufficient to avoid the incident. When a person starts drowning, survival and prognosis will depend largely on the assistance of a rescuer. The objectives of this thesis were to analyze the interventions that both bystanders and professional rescuers have been known to use until now, in order to study the different strategies for the improvement of physiological conditions on the basis of simulation-controlled studies and to evaluate the optimization of resuscitation techniques on board rescue boats, both before and during the COVID-19 pandemic. Material and methods Six scientific publications make up this thesis. The first two papers are conceptual and descriptive, namely: a systematic literature review (PRISMA) and an expert consensus guide based on the COVID-19 literature review. The remaining 4 articles are controlled simulation studies with lifeguards, innovative in methodology, in which physiological, perceptual and skill aspects were analyzed during cardiopulmonary resuscitation (CPR) in case of drowning. 21 Results Four profiles of lay rescuers have been identified, with different skill levels, and risk gradation has been established according to the rescue technique used. In professional lifeguards, the effect of electrostimulation (ES) on the recovery process after a rescue was found to be better than passive recovery. The feasibility of cardiopulmonary resuscitation maneuvers has been verified by navigating on a rescue water craft (RWC). In situations with risk of airborne transmission of aerosols containing infectious agents, the use of plastic blankets improves intervention start times without reducing the quality of CPR. Conclusions The conclusions related to the hypotheses are summarized in the following three paragraphs: There are different profiles of lay-rescuers. There is no scientific description of recommended water rescue techniques for lay-people; therefore in general the lay-rescuer should not enter the water to attempt a rescue. However, lay-rescuers with aquatic experience who are in the water (e.g. surfers) can be a great asset in drowning mitigation. 22 In relation to professional lifeguards, initiating CPR of the drowning victim early is possible on land and on a rescue vessel by adapting known techniques to the space, rescuer position and sea conditions. The use of personal protective equipment (PPE) has a number of advantages as well as limitations in aquatic environments. The use of a plastic blanket may be an alternative to delay the start of maneuvers without diminishing the CPR quality. Active recovery methods designed for professional rescuers promote faster physiological readjustment. Electrostimulation may be an alternative for recovery after a physically demanding rescue. Key words Drowning, bystander, lifeguards, cardiopulmonary resuscitation, physiological recovery, rescue boats, COVID-19. 23 RESUMEN Antecedentes y propósito El ahogamiento es una de las principales causas de muerte no intencional a nivel mundial. La prevención es la mejor estrategia pero no siempre es suficiente para evitar el incidente. Cuando una persona comienza a ahogarse, la supervivencia y pronóstico van a depender en gran medida del auxilio de un rescatador. Los objetivos de esta tesis fueron analizar las intervenciones conocidas hasta el momento de testigos (rescatadores legos) y socorristas profesionales, y analizar en base a estudios controlados las diferentes estrategias de recuperación tras el rescate, estudiar la viabilidad de técnicas de reanimación a bordo de embarcaciones de rescate y evaluar diferentes equipos de protección personal para la reanimación cardiopulmonar (RCP) durante la pandemia COVID-19. Material y métodos Seis publicaciones científicas conforman esta tesis. Los dos primeros trabajos son conceptuales y descriptivos: una revisión sistemática de la literatura (PRISMA) y una guía de consenso de expertos basada en la revisión de la literatura en tiempos de COVID-19. Los restantes cuatro artículos son estudios controlados de simulación con socorristas. Estos trabajos son metodológicamente innovadores, en los que se analizaron aspectos fisiológicos, perceptivos y de habilidades durante la RCP en ahogamiento. 24 Resultados Se han identificado cuatro perfiles de rescatadores legos, con diferentes niveles de habilidad y se ha establecido una clasificación del riesgo en función de la técnica de rescate utilizada. En socorristas profesionales, el efecto de la electro-estimulación(ES) logró mejores resultados en el proceso de recuperación después del rescate que la recuperación pasiva. Se ha verificado la viabilidad de las maniobras de RCP en una moto acuática de rescate. La calidad de las maniobras fue aceptable, rondando el 60% navegando a 20 nudos. En la situación de riesgo de contagio por aerosoles durante la RCP en tiempos de COVID-19, el uso de mantas plásticas puede ser una alternativa a considerar por los socorristas, ya que acorta el tiempo de inicio de las maniobras sin disminuir la calidad de la RCP. Este sistema de protección puede ser usado tanto en la arena como en las embarcaciones de rescate. Conclusiones Las conclusiones relacionadas con las hipótesis se sumarizan en los siguientes tres párrafos: Existen cuatro perfiles de rescatadores legos. No existe descripción ni recomendación científica sobre las técnicas de rescate empleadas por rescatadores legos, por lo tanto, de forma genérica el testigo sin 25 experiencia no debe entrar en el agua para intentar un rescate, sin embargo, aquellos rescatadores que sin entrenamiento formal cuentan con experiencia acuática, están dentro del agua en el momento del incidente y disponen de material de flotación (ej. surfistas), pueden ser un gran activo en la mitigación del ahogamiento. En relación a los socorristas profesionales, iniciar la RCP del ahogado de forma precoz es posible en tierra y en una embarcación de rescate, adaptando las técnicas al espacio, posición del rescatador y condiciones marítimas. El uso de equipos de protección personal (EPI) supone una serie de ventajas y también limitaciones en entornos acuáticos. El uso de mantas de plástico puede ser una alternativa real para no demorar el inicio de las maniobras y no supone una disminución de la calidad de la RCP. Los métodos de recuperación activos diseñados para socorristas, promueven un reajuste fisiológico más rápido. La ES puede ser una gran alternativa de recuperación después de un rescate acuático con gran demanda física. Palabras Clave Ahogamiento, testigo, socorristas, reanimación cardiopulmonar, recuperación fisiológica, embarcaciones de rescate, COVID-19. 32 En cambio, los socorristas son personas que han completado un entrenamiento formal y son competentes para prevenir incidentes, rescatar y aplicar primeros auxilios en entornos acuáticos. Tanto testigos como profesionales son parte de la solución, por tanto evaluar las capacidades y limitaciones de cada perfil, y proponer las mejores prácticas fue el origen de esta tesis doctoral. Estos propósitos se han visto alterados y por tanto modificados con la nueva situación de salud. En el año 2019 se produce una de las mayores alertas epidemiológicas de los últimos cien años. El Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2). El mundo viviría en Europa el primer verano de la Era-Covid en 2020. La problemática para los socorristas es que sus intervenciones raramente se dan en otros contextos médicos, y en este momento todavía se ha complicado más por la COVID-19. Esta tesis pretende compilar las características, condiciones y efectos de las habilidades de los socorristas (legos o profesionales) y mostrar las nuevas aportaciones adaptadas a tiempos de COVID-19. HIPÓTESIS H1. Los rescatadores legos tienen características, motivaciones y habilidades específicas que pueden ser identificadas en la literatura científica. 33 H2. Las técnicas para la reanimación en caso de ahogamiento pueden ser adaptadas y optimizadas para situaciones todavía más especiales (en embarcación de rescate o con uso de Equipos de Protección Individual (EPI) durante la era COVID-19). H3. La recuperación fisiológica del socorrista tras el rescate acuático puede acortarse con estrategias utilizadas en el deporte profesional. OBJETIVOS O1. Identificar los diferentes perfiles rescatadores legos descritos en la literatura científica. O1.1. Clasificar las diferentes técnicas realizadas por rescatadores legos. O1.2. Identificar el perfil y competencia de los rescatadores legos. O2. Evaluar las habilidades de los rescatadores en diferentes contextos y situaciones de la reanimación en ahogamiento. O2.1. Evaluar la viabilidad y calidad de la reanimación en Moto Acuática de Rescate Acuática (MAR). O2.2. Analizar las habilidades de reanimación con EPI. O2.3. Comparar diferentes sets de EPI durante la reanimación a bordo de una embarcación. 34 O3. Analizar estrategias de recuperación fisiológica tras la intervención del socorrista. O3.1. Analizar la recuperación pasiva tras un rescate acuático. O3.2. Comparar el efecto de la electro-estimulación (ES) sobre la recuperación tras el rescate acuático. METODOLOGÍA Esta tesis doctoral está compuesta de 6 publicaciones que han seguido diferentes metodologías, adaptadas a los objetivos establecidos en cada subestudio. El conjunto de artículos y el ámbito del socorrismo que abarca, puede apreciarse en la figura 1a. Figura 1a. Diagrama de flujo del contenido de la Tesis. Evaluación de las habilidades de los rescatadores en los incidentes acuáticos. 35 Dos de los artículos son revisiones, basados en evidencias y proponiendo una síntesis de los resultados. El estudio titulado “Layrescuers in drowning incidents: A scoping review” es una revisión sistemática de la literatura siguiendo la metodología PRISMA. El estudio titulado “Occupational health recommendations for socorristas in aquatic emergencies in the Covid-19 era: prevention, rescue and resuscitation” se presenta en forma de recomendaciones basadas en evidencias. La metodología para realizar este artículo también siguió una metodología PRISMA, pero la forma de presentar el manuscrito, por la propia finalidad del contenido, sigue la estructura de recomendación científica. Los cuatro restantes estudios “Is it feasible ‘scoop and run while playing’ resuscitation on a rescue water craft? A randomized simulation study with socorristas”, “Plastic blanket drowning kit: A protection barrier to immediate resuscitation at the beach in the Covid19 era. A pilot study”, “Safe on-boat resuscitation by socorristas in Covid-19 Era. A pilot study comparing three sets of protective personal equipment”, “Is low-frequency Electrical Stimulation a tool for recovery after a Water Rescue? A Cross-Over Study with Socorristas”, siguen una metodología cuasi-experimental. Son estudios cuantitativos, aleatorizados y transversales. El análisis de los datos fue realizado con el software estadístico SPSS (IBM Corp., Chicago, IL, USA). Mediante comparaciones por pares (pruebas paramétricas –TTest/Anovao no paramétricas –Wicolxon test-) de dos o más factores. Los estudios 36 presentan medias, desviaciones típicas, intervalos de confianza (95%), frecuencias y tamaño del efecto. Se estableció un nivel de significatividad de p<0.05 para todos los análisis. RESULTADOS DE LAS PUBLICACIONES Artículo 1. Lay-rescuers in drowning incidents: a scoping review. [Rescatadores legos en incidentes acuáticos: una revisión de la literatura] Objetivo. Muchas víctimas de incidentes acuáticos son legos que tratan de rescatar a otro. Esta revisión tiene como objetivo identificar las técnicas y materiales más seguros (improvisados o diseñados específicamente) para que un testigo no capacitado los use cuando intente un rescate acuático. Método. Una muestra de 249 trabajos fue incluida en la búsqueda bibliográfica, en los que finalmente se seleccionaron 19 siguiendo la metodología PRISMA y se añadieron 3 trabajos presentados en congresos internacionales y revisados por pares. Se incluyeron un total de 22 documentos a la síntesis cualitativa. Resultados. La ubicación geográfica, el nivel económico, la condición física o la experiencia pueden variar el perfil de los rescatadores legos y la forma de realizar un rescate acuático de manera segura. Se 37 identificaron cuatro perfiles de rescatadores legos: 1) Niños que rescatan a niños en países con bajos y medios ingresos, 2) Adultos que rescatan a adultos o niños, 3) Testigos con alguna experiencia y entrenamiento en rescate, 4) Testigos con motivaciones culturales o profesionales. Tres tipos de técnicas utilizadas por los diferentes perfiles de rescatadores legos: a) técnicas sin contacto para rescates desde tierra: lanzamiento y alcance, b) técnicas sin contacto para rescate mediante material con flotación y, c) técnicas de rescate con contacto dentro del agua: nadar y remolcar con o sin aletas. Conclusión. La recomendación de los expertos es que la técnica más segura para rescatadores legos es intentar un rescate usando una rama, ropa o algún material de flotación, sin entrar en el agua. Sin embargo, aún con la recomendación de rescates sin contacto desde tierra, existe una tendencia global a intentar rescates desde el agua, sin que hasta el momento haya evidencia de cuál técnica o procedimiento puede contribuir a un rescate seguro. Deben considerarse estrategias de formación para legos. Artículo 2. Is it feasible ‘scoop and run while playing’ resuscitation on a rescue water craft? a randomized simulation study with lifeguards. [Es posible rescatar y trasladar reanimando en una moto de agua. un estudio aleatoriazado de simulación con socorristas] 38 Objetivo: El tiempo de respuesta es un factor predictivo para la supervivencia de las víctimas de ahogamiento. Las motos acuáticas de rescate (MAR) son embarcaciones muy habituales en las operaciones de salvamento. El objetivo de este estudio fue analizar la viabilidad de administrar ventilaciones boca a boca y / o resucitación cardiopulmonar (RCP) efectivas en MAR mientras se navega a diferentes velocidades. Método: Se utilizó un diseño cuasi-experimental cruzado para evaluar durante un minuto la viabilidad de la ventilación Boca a Boca (BB) y la RCP tanto en tierra (playa) como navegando a dos velocidades diferentes 5 y 10 nudos con mar en calma. Las referencias de RCP de calidad (Q-RCP) fueron las directrices del ERC de 2015. Resultados: Se incluyeron los datos obtenidos de 13 socorristas que completaron 78 test de RCP. Las habilidades de ejecución de solo BB alcanzaron 69,7% ± 40,4 para 5 nudos y 60,0% ± 41,8 para 10 nudos (p = 0,59). Para la RCP estándar (compresiones y ventilaciones), el resultado fue 74,4% ± 24,2 y 68,5% ± 23,9 respectivamente. La calidad de la BB y la RCP disminuyó no significativamente, mientras navegaba a 5 nudos y 10 nudos [(Q-BB; 5 nudos: 59,9% ± 37,8 vs.10 nudos: 43,2% ± 41,4, p = 0,42) (Q-RCP ; 5 nudos: 64,8% ± 21,2 y 10 kn: 60,6% ± 21,0, p = 0,44)]. Las variables de solo BB y compresiones torácicas fueron significativamente peores en MAR en comparación con la reanimación en la playa (p <0,05). Se observó una tendencia a mejores resultados por parte de los socorristas que se entrenaron previamente en MAR. 39 Conclusiones: Las técnicas de reanimación a bordo de MAR son factibles y por tanto podrían ser una opción para los socorristas cuando su formación, las condiciones del mar, la distancia y las características de la víctima lo permitan. Las maniobras de RCP pueden ser muy efectivas a 10 nudos, tanto para MM solo como para RCP; sin embargo, la calidad de las ventilaciones empeora drásticamente al aumentar la velocidad. Artículo 3. Is low-frequency electrical stimulation a tool for recovery after a water rescue? a cross-over study with lifeguards. [¿Es la electro-estimulación de baja frecuencia una herramienta para la recuperación después de un rescate acuático? un estudio cruzado con socorristas] Este estudio tuvo como objetivo evaluar en qué grado la electroestimulación (ES) transcutánea mejoró la recuperación después de un rescate acuático simulado. En este estudio participaron veintiséis socorristas. El rescate consistió en nadar 100 m con aletas y tubo de rescate: 50 m de aproximación de nado y 50 m de remolque de una víctima simulada. La concentracion de lactato en sangre, el esfuerzo percibido (RPE) y las propiedades contráctiles de los músculos se evaluaron al inicio del estudio, después del rescate en el agua y después del protocolo de recuperación pasiva (PR) o activa con ES. La tensiomiografía, el RPE y los niveles basales de lactato en sangre indicaron equivalencia entre ambos grupos antes del rescate. No hubo 40 cambios en la tensiomiografía antes y después de la recuperación y no hubo diferencias entre los protocolos de recuperación (pasivo o con ES). El RPE general, el RPE de piernas y el RPE de brazos después de ES (media ± DE; 2,7 ± 1,53, 2,65 ± 1,66 y 2,30 ± 1,84, respectivamente) fueron moderadamente más bajos que después de PR (3,57 ± 2,4, 3,71 ± 2,43 y 3,29 ± 1,79, respectivamente) (p = 0,016, p = 0,010, p = 0,028, respectivamente). Hubo un nivel de lactato en sangre significativamente más bajo después de la recuperación con ES que en PR (media ± DE; 4,77 ± 1,86 mmol • L-1 frente a 6,27 ± 3,69 mmol • L-1; p = 0,045). La ES de baja frecuencia inmediatamente después de un rescate en el agua es una estrategia de recuperación eficaz para eliminar la concentración de lactato en sangre. Artículo 4. Occupational health recommendations for lifeguards in aquatic emergencies in the covid-19 era: prevention, rescue and resuscitation. [Recomendaciones de salud laboral para socorristas ante emergencias acuáticas en la era covid-19: prevención, rescate y reanimación] El síndrome respiratorio agudo severo (SARS-CoV-2), que causa la enfermedad por coronavirus 2019 (Covid-19), es altamente contagioso. Los socorristas son la primera línea de respuesta en las emergencias acuáticas y van a sufrir una fuerte exposición al riesgo este primer verano de la era Covid-19, por lo que su salud laboral debe ser replanteada en su práctica profesional durante la nueva normalidad. La 41 principal medida de salud pública para evitar ahogamientos es la prevención, pero cuando esta falla y se requiere la asistencia o el rescate, en la mayor parte de las intervenciones el distanciamiento no será posible. La limitación de los equipos de protección personal (EPI) para el rescate es una realidad que debe conocerse y que puede afectar a la salud del socorrista. Se realizó una revisión de la literatura actual orientada a evitar o minimizar el riesgo de contagio en las intervenciones realizadas por rescatadores en la era Covid-19. Este artículo ofrece una información estructurada sobre la prevención del contagio en los socorristas, los riesgos potenciales, los EPI disponibles y las recomendaciones para su adecuado uso durante los rescates o la atención prehospitalaria en los entornos acuáticos. Artículo 5. Plastic blanket drowning kit: a protection barrier to immediate resuscitation at the beach in the covid-19 era. a pilot study. [kit de manta de plástico para ahogamiento: una barrera de protección para la reanimación inmediata en la playa durante la era covid-19. un estudio piloto] Objetivo: Presentación de un nuevo equipamiento para socorristas simple y económico, compuesto por una mascarilla facial preensamblada a una manta de plástico y a un filtro HEPA, lo que puede ofrecer un significativo ahorro de tiempo y otras ventajas para reducir el riesgo de transmisión del COVID-19 en los primeros minutos de la 48 Uno de los retos de esta tesis, fue analizar cómo se puede atenuar el efecto de la fatiga aguda en los socorristas, buscando estrategias que ayuden a su recuperación sin que supongan una interrupción de sus labores profesionales. Es en este momento, basado en un equipo multidisciplinar de trabajo con socorristas, médicos, enfermeros, educadores físicos y fisioterapeutas, cuando se plantea la electroestimulación para ser usada tras el rescate acuático. Se realizó un estudio controlado colaborativo entre la Universidad de Vigo, la Universidad de Santiago de Compostela y la Universidad de Coimbra, en la localidad del litoral portugués de Figueira da Foz. Tras un rescate de 100m, se aplicó una corriente de onda bifásica a 5 Hz, con una duración de 0.25 milisegundos. El tiempo de electroestimulación fue de 20min. La localización de los electrodos fue en los cuádriceps de ambas piernas, basado en que los socorristas realizaron el rescate con aletas, y la literatura científica muestra que durante la patada de crol con aletas, el músculo con mayor implicación es el recto femoral. Los resultados obtenidos, mostraron valores fisiológicos a tener en cuenta. La electro estimulación redujo significativamente la disminución de la concentración de lactato y mostró una tendencia hacia una menor fatiga percibida aunque no logró valores significativos (p>0.05). 49 SARS-COV-2 y socorrismo Tras el confinamiento decretado por el Gobierno de España, y mientras se empezó a doblegar la primera ola, entramos en mayo/junio, justo el comienzo de la temporada de verano y nadie había pensado en los socorristas, ni en su entrenamiento para afrontar el primer verano de la Era COVID-19, ni en el uso de EPI en la playa, ni en las modificaciones técnicas que requieren los procedimientos de salvamento y reanimación del ahogado. Desde el grupo de trabajo de socorrismo de la Sociedad Española de Medicina de Emergencias (SEMES) junto con otros investigadores del ahogamiento, se creó un grupo de trabajo para promover unas recomendaciones de autoprotección e intervención para socorristas, que finalmente fue publicado en junio del 2020 en la Revista Española de Salud Pública, del Ministerio de Sanidad. Este grupo elaboró una guía organizada en cuatro apartados: 1) Prevención del contagio, cribado de positivos y riesgos para el socorrista, 2) Equipo de protección individual (EPI). Posibilidades y limitaciones, 3) Reacción ante el ahogamiento. Rescate acuático. 4) Mitigación: atención prehospitalaria y soporte vital básico en ahogados. La nueva situación pandémica requeriría incluir todo el material de protección (EPI), sin embargo, la utilización en los entornos acuáticos puede ir de dificultoso a imposible. 50 El primer estudio con manta plástica pretendió analizar la viabilidad de su uso en la playa. Nuestra hipótesis es que la manta plástica es un método alternativo de protección que no afecta a la calidad de la RCP, además de permitir una colocación rápida sin demorar el inicio de las ventilaciones. Otras ventajas son el bajo coste y la facilidad de uso, algo necesario para profesionales que no tienen un entrenamiento específico ni usan a diario EPI para la reanimación. Nuestro diseño consistió en un plástico transparente de 250 cm de largo por 150 cm de ancho, en una parte se pre-ensambló una a una máscara facial (pocket mask) con un filtro HEPA. El kit lo componen de 4 a 6 piquetas. Este plástico integrado en el maletín de primeros auxilios permite cubrir la víctima y comenzar las ventilaciones en 82s de media. En nuestro estudio, la calidad de RCP no se vio afectada, con un valor del 91% en 10 min. Otro aspecto relevante fue que una gran parte de los socorristas consideraron que usar este kit plástico era simple, en comparación con usar EPI completo (con bata impermeable). Este sistema de manta de plástico, tiene una especial importancia a bordo de una embarcación de rescate. Bajo esta premisa comparamos tres set de EPIs en un bote semirrígido de socorristas, navegando a 20km/h, comparando nuevamente la Q-RCP, y analizando el tiempo de preparación del kit hasta el inicio de la primera ventilación. El primer hallazgo importante, fue que el tiempo hasta la primera ventilación fue de 17s con nivel de protección básica, 34s con 51 protección basada en manta plástica y 69s con el EPI completo. Es decir, vestir EPI completo lleva 30s más, además el 43% de los socorristas, lo usaron mal o su colocación fue incorrecta, con amplias zonas corporales expuestas. En el test de reanimación no hubo diferencias significativas con ninguno de los tres sets y los valores fueron alrededor del 90% de Q-CPR. Implicaciones prácticas de los estudios Esta tesis ha pretendido aportar claves para resolver numerosas situaciones prácticas en un entorno especial y con eventos difícilmente comparables a otros entornos clínicos. Nuestros estudios se han centrado en los rescatadores (legos y profesionales) y deben servir para: Rescatadores legos: - Establecer campañas de prevención adecuadas para cada tipo de rescatador lego. - Promover el entrenamiento de habilidades de rescate desde fuera del agua y auto-rescate para los rescatadores legos con mayor riesgo. - Promover entrenamiento de habilidades de rescate y reanimación para rescatadores legos que por sus características, tienen la experiencia, el entrenamiento y la fortuna de encontrarse en el agua cuando realizan el rescate (surfistas). 52 Socorristas profesionales: - Implementar nuevas posibilidades para iniciar la reanimación cuanto antes, especialmente proveer ventilaciones desde el primer momento de la parada respiratoria durante el ahogamiento. - Mejorar las condiciones físicas de los socorristas, con la finalidad de que puedan recuperarse lo más rápido posible. - Ofrecer recomendaciones y protocolos de reanimación para tratar el ahogamiento, analizando los diferentes medios de autoprotección basados en las características del entorno acuático. CONCLUSIONES A continuación se presentan las conclusiones de esta tesis doctoral. Conclusiones de la H1 Existen diferentes perfiles de rescatadores legos, con variabilidad en sus capacidades y diferentes riesgos durante sus intentos de rescate. De forma genérica los testigos no debe entrar en el agua, sin embargo, los rescatadores legos con conocimiento y gran experiencia acuática que están dentro del agua pueden ser un gran activo en la mitigación del ahogamiento. No existe descripción de técnicas específicas para el rescate dentro del agua en legos, más allá de que los surfistas pueden usar su tabla como ayuda. Fuera del agua no hay reportes de cuánta 53 gente ha sido rescatada por lanzamientos de material de flotación, en cambio, existen numerosas evidencias de personas ahogadas intentando rescatar a otras víctimas. Conclusiones de la H2 Iniciar la reanimación del ahogado de forma precoz es posible, tanto en MAR como en IRB, adaptando las técnicas conocidas al espacio disponible, posición del rescatador y condiciones marítimas. En MAR la calidad de las ventilaciones y las compresiones es aceptable. La experiencia del socorrista es un factor determinante para una buena aplicación de la RCP. La protección (EPI) en tiempos de COVID-19 es posible, especialmente usando una manta de plástico. El uso de mantas plásticas ha sido testado con éxito tanto en tierra como navegando en una embarcación de rescate semi-rigida, no ha influido en la calidad de la RCP y ha recortado el tiempo en el inicio de las maniobras. Conclusiones de la H3 Los métodos de recuperación activos promueven un reajuste fisiológico más rápido. La ES puede ser una alternativa de recuperación tras un rescate permitiendo al socorrista continuar con su trabajo de vigilancia. 54 55 SUMMARY IN GALICIAN SUMARIO EN GALEGO 56 SUMMARY IN GALICIAN Nota. Este sumario é unha versión reducida do documento principal en lingua inglesa. As referencias bibliográficas foron citadas no manuscrito en inglés. INTRODUCIÓN O afogamento é un problema importante de saúde pública e é responsable directo de case 300.000 mortes anuais en todo o mundo. Afecta especialmente a nenos e ten un especial impacto nos países de baixos ou medios recursos. A nivel global representa a terceira causa de morte por dano non intencional e supón o 7% de todas as mortes relacionadas con lesións. En España estímase que 400 persoas falecen por afogamento cada ano. O afogamento defínese como “o proceso polo que se experimenta unha imposibilidade para respirar por sumersión ou inmersión nun fluído”, e de forma xenérica, o seu resultado pode ser a morte ou supervivencia con ou sen morbilidade. Considérase que o afogamento está infravalorado e a miúdo referiuse a a “Metáfora do Iceberg”. Un exemplo desta metáfora reflíctese nos datos comparativos; por cada persoa afogada que requiriu de atención médica, outras seis tiveron que ser rescatadas. A prevención é a estratexia máis importante e a máis efectiva no balance custo/beneficio, por iso numerosas publicacións recomendan focar os 57 esforzos nas tarefas preventivas do afogamento, con todo, os datos epidemiolóxicos indican que aínda queda un longo camiño cara a unha prevención o suficientemente efectiva. É necesario estudar, entender e comprender os mecanismos desencadenantes, os perfís dos afogados e as habilidades e estratexias dos socorristas profesionais para atender ás persoas que sofren un incidente no medio acuático. As circunstancias que envolven ao afogamento a miúdo adoitan ser multifactoriales, pero xenéricamente teñen que ver coa omisión das medidas de prevención ou asumir condutas de risco. Aínda así, o proceso de afogamento é silencioso, sutil e aínda non está suficientemente estudado, de aí a importancia da investigación en todos os aspectos do afogamento. Neste punto, coñecer como os rescatadores (legos ou profesionais) afrontan un incidente acuático, debe ser un dos retos da ciencia do afogamento. Unha testemuña que presencia un afogamento e decide prestar auxilio é o que coñecemos como “rescatador lego” e defínese como a persoa que sen ser profesional ou ter un coñecemento específico intenta un rescate acuático. Poden existir diferentes tipos de rescatadoré legos en función do seu coñecemento e competencias. En cambio, os socorristas son persoas que completaron un adestramento formal e son competentes para previr incidentes, rescatar e aplicar primeiros auxilios en contornas acuáticas. 64 Método: Utilizouse un deseño cuasi-experimental cruzado para avaliar durante un minuto a viabilidade da ventilación Boca a Boca (BB) e a RCP tanto en terra (praia) como navegando a dúas velocidades diferentes 5 e 10 nós con mar en calma. As referencias de RCP de calidade (Q-RCP) foron as directrices do ERC de 2015. Resultados: Incluíronse os datos de 13 socorristas que completaron 78 test de RCP . As habilidades de execución de só BB alcanzaron 69,7% ± 40,4 para 5 nós e 60,0% ± 41,8 para 10 nós (p = 0,59). Para a RCP estándar (compresións e ventilacións), o resultado foi 74,4% ± 24,2 e 68,5% ± 23,9 respectivamente. A calidade da BB e a RCP diminuíu non significativamente, mentres navegaba a 5 nós e 10 nós [(Q-BB; 5 nós: 59,9% ± 37,8 vs.10 nós: 43,2% ± 41,4, p = 0,42) (Q-RCP ; 5 nós: 64,8% ± 21,2 e 10 kn: 60,6% ± 21,0, p = 0,44)]. As variables de só BB e compresiones torácicas foron significativamente piores en MAR en comparación coa reanimación na praia (p <0,05). Observouse unha tendencia a mellores resultados por parte dos socorristas que se adestraron previamente en MAR . Conclusións: As técnicas de reanimación a bordo de MAR son factibles e xa que logo poderían ser unha opción para os socorristas cando a súa formación, as condicións do mar, a distancia e as características da vítima permítano. As manobras de RCP poden ser moi efectivas a 10 nós, tanto para MM só como para RCP; con todo, a calidade das ventilaciones empeora drásticamente ao aumentar a velocidade. 65 Artigo 3. Is low-frequency electrical stimulation a tool for recovery after a water rescue? a cross-over study with lifeguards. [É a electro-estimulación de baixa frecuencia unha ferramenta para a recuperación logo dun rescate acuático? un estudo cruzado con socorristas] Este estudo tivo como obxectivo avaliar en que grado a electroestimulación (ES) transcutánea mellorou a recuperación logo dun rescate acuático simulado. Neste estudo participaron vinte e seis socorristas. O rescate consistiu en nadar 100 m con aletas e tubo de rescate: 50 m de aproximación de nado e 50 m de remolque dunha vítima simulada. A concentracion de lactato en sangue, o esforzo percibido (RPE) e as propiedades contráctiles dos músculos se avaliaron ao comezo do estudo, despois do rescate na auga e despois do protocolo de recuperación pasiva (PR) ou activa con ES. A tensiomiografía, o RPE e os niveis basales de lactato en sangue indicaron equivalencia entre ambos grupos antes do rescate. Non houbo cambios na tensiomiografía antes e despois da recuperación e non houbo diferenzas entre os protocolos de recuperación (pasivo ou con ES). O RPE xeral, o RPE de pernas e o RPE de brazos logo de ES (media ± DE; 2,7 ± 1,53, 2,65 ± 1,66 e 2,30 ± 1,84, respectivamente) foron moderadamente máis baixos que logo de PR (3,57 ± 2,4, 3,71 ± 2,43 e 3,29 ± 1,79, respectivamente) (p = 0,016, p = 0,010, p = 0,028, respectivamente). Houbo un nivel de lactato en sangue significativamente máis baixo logo da recuperación con ES que en PR 66 (media ± DE; 4,77 ± 1,86 mmol • L-1 fronte a 6,27 ± 3,69 mmol • L-1; p = 0,045). A ES de baixa frecuencia inmediatamente tras o rescate na auga é unha estratexia de recuperación eficaz para eliminar a concentración de lactato en sangue. Artigo 4. Occupational health recommendations for lifeguards in aquatic emergencies in the covid-19 era: prevention, rescue and resuscitation. [Recomendaciones de saúde laboral para socorristas ante emerxencias acuáticas en era covid-19: prevención, rescate e reanimación] A síndrome respiratoria aguda severa (SARS-CoV-2), que causa a enfermidade por coronavirus 2019 (Covid-19), é altamente contaxiosa. Os socorristas son a primeira liña de resposta nas emerxencias acuáticas e van sufrir unha forte exposición ao risco este primeiro verán de era Covid-19, polo que o seu saúde laboral debe ser reformulada na súa práctica profesional durante a nova normalidade. A principal medida de saúde pública para evitar afogamentos é a prevención, pero cando esta falla e requírese a asistencia ou o rescate, na maior parte das intervencións o distanciamiento non sexa posible. A limitación dos equipos de protección persoal (EPI) para o rescate é unha realidade que debe coñecerse e que pode afectar á saúde do socorrista. Realizouse unha revisión da literatura actual orientada a evitar ou minimizar o risco de contaxio nas intervencións realizadas por rescatadores en era Covid19. Este artigo ofrece unha información estructurada sobre a prevención 67 do contaxio nos socorristas, os riscos potenciais, os EPI dispoñibles e as recomendaciones para o seu adecuado uso durante os rescates ou a atención prehospitalaria nas contornas acuáticas. Artigo 5. Plastic blanket drowning kit: a protection barrier to immediate resuscitation at the beach in the Covid-19 era. A pilot study. [kit de manta de plástico para afogamento: unha barreira de protección para a reanimación inmediata na praia durante era Covid-19. Un estudo piloto] Obxectivo: Presentación dun novo equipamiento para socorristas simple e económico, composto por unha mascarilla facial preensamblada a unha manta de plástico e a un filtro HEPA, o que pode ofrecer un significativo aforro de tempo e outras vantaxes para reducir o risco de transmisión do COVID-19 nos primeiros minutos da RCP tras un rescate acuático, eliminando o impacto negativo na demora da ventilación. Método: Realizouse un estudo piloto para determinar a viabilidade do kit premontado de mascarilla e filtro HEPA adaptado sobre unha manta plástica. O primeiro paso consistiu en lavarse as mans, poñerse lentes e luvas de seguridade como primeiro equipo de protección persoal (EPI) e logo cubrir á vítima cunha manta plástica montada. O segundo paso consistiu en 10 min de reanimación cardiopulmonar (RCP) con EPI e 68 manta plástica, seguindo as recomendaciones técnicas para a ventilación durante o Covid-19. Resultados: Dez socorristas participaron no estudo piloto. O tempo promedio para usar EPI e colocar o kit premontado sobre a vítima foi de 82 s [IC 58-105]. Logo de 10 min, a calidade da reanimación (QRCP) foi do 91% [87-94]. As calidade das compresións torácicas foi dun 22% mellores que as ventilacións. A maioría dos socorristas (60%) consideraron que colocar a manta de plástico sobre a vítima na praia era algo simple ou moi simple. Conclusións: As técnicas de reanimación na praia durante era COVID19 incrementaron a complexidade para o uso correcto de EPI. A manta plástica engade un plus para a ventilación o que podería ser unha nova alternativa a considerar polos socorristas para realizar ventilaciones mentres reducen o risco de transmisión. Artigo 6. Safe on-boat resuscitation by lifeguards in Covid-19 era. a pilot study comparing three sets of protective persoal equipment. [Reanimación segura a bordo realizada por socorristas en era Covid-19. un estudo piloto comparando tres sets de equipamiento persoal de protección] Introdución: A reanimación a bordo pode ser aplicada por socorristas en embarcacións de rescate. A raíz da aparición do Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-COV-2) e as recomendacións para o uso de equipo de protección persoal (EPI), os 69 procedementos prehospitalarios foron reevaluados. O obxectivo deste estudo foi determinar como o uso de EPI inflúe no tempo de preparación necesario antes de comezar a reanimación (RCP) e na calidade da reanimación cardiopulmonar (Q-RCP) nunha embarcación de rescate semirríxida. Métodos: Realizáronse tres probas de RCP con 14 socorristas, agrupados en parellas, con diferentes EPI: (1) EPI Básico (B-EPI): luvas, mascarilla e lentes protectoras; (2) EPI completo (F-EPI): B-EPI + un delantal impermeable; e (3) EPI básico + manta plástica (B + EPI). Realizouse unha RCP a bordo utilizando unha bolsa-válvula-máscara (BVM) e un filtro de aire de partículas de alta eficiencia (HEPA) navegando a 20 km / hora. Resultados: o uso de B-EPI leva menos tempo e é significativamente máis rápido que o F-EPI (B-EPI 17 [SD = 2] segundos versus F-EPI 69 [SD = 17] segundos; P = 0,001), e o uso de B + EPI é lixeiramente superior (B-EPI 17 [SD = 2] segundos fronte a B + EPI 34 [SD = 6] segundos; P = 0,002). O QCPR mantívose similar nos tres escenarios (P>.05), alcanzando valores superiores ao 79%. Conclusión: O uso de EPI durante a reanimación a bordo é factible e non interfere coa calidade cando é realizado por socorristas adestrados. O uso dunha manta de plástico podería ser unha alternativa rápida e fácil para ofrecer protección adicional aos socorristas durante a RCP nun bote de rescate. 70 DISCUSIÓN Esta tese realizada segundo a modalidade de compendio de publicacións tivo como principais obxectivos, analizar os perfís de rescatadores (tanto legos como socorristas), e afondar en diferentes estratexias educativas, fisiolóxicas e de reanimación, ademáis de implementar condutas seguras mediante unha serie de recomendacións adaptadas a tempos de Covid-19. Os seus principais achados foron: d) Existen catro perfiles dominantes de rescatadores legos, con diferente risco en función da súa idade, procedencia, motivacións e experiencia. e) O rescate acuático é fisiolóxicamente moi esixente. Supón gran demanda física e require xa que logo unha recuperación adecuada. Esta recuperación pode ser acelerada con métodos procedentes do deporte profesional (p.ex. foam roller/electroestimulación). f) O uso de mantas de plástico pode ser unha alternativa rápida e eficaz na RCP realizada por socorristas, tanto en terra como en embarcacións de rescate, sen demorar o inicio das ventilacións. Rescatadores legos, perfís e técnicas Para as testemuñas non profesionais, ata agora recomendouse que ante un incidente acuático non deben entrar na auga para intentar un rescate, 71 con todo esta recomendación entra en conflito con numerosas circunstancias; a) localización do incidente (a maioría entre os 50 e 100 m), b) relación de parentesco coa vítima e c) aspectos culturais por exemplo o caso dos surfistas australianos que contribúen notablemente aos salvamentos en praias non vixiadas. O consenso de expertos apoia que si é lego, só se recomenda o auxilio desde fóra da auga seguindo a secuencia “reach, throw and don´t go [alcanzar, lanzar e non ir]”. Ainda así, a conduta humana máis repetida é intentar o rescate, o que en numerosas ocasións provoca o que se definiu como síndrome Aquatic-Victim-Instead-of-Rescued(AVIR) [vítima acuática en lugar de rescatador ], que consiste no intento de rescate dunha persoa que se está afogando, converténdose o rescatador tamén en vítima durante o intento. Ante esta conduta impulsiva e para mitigar as consecuencias dun rescate inexperto, algúns científicos australianos suxiren que todo bañista teña no seu material de praia “tools for heroic acts”[ferramentas para actos heroicos]. Este posicionamiento é ciertamente discutible, aínda que tamén moi realista. Para os rescatadores rescatadores legos(P) en que medida existen técnicas de rescate(I), en comparación con non intentar o rescate (C), e que non poña o risco nin expoña a un maior perigo ao rescatador(O)? É precisamente esta PICO question a que tratou de responder o primeiro artigo desta tese de doutoramento. Atopáronse catro tipos de rescatadores legos. Para dous dos perfís: 1) Nenos rescatando nenos e 2) Adultos rescatando adultos ou nenos, é 72 posible que a educación xogue un papel fundamental para afrontar o risco coa maior seguridade posible. Ata agora as propostas científicas baseáronse na prevención do incidente, pero non hai referencias de como controlar os impulsos e tomar decisións correctas no momento do rescate. A revisión mostra outros dous tipos de rescatadores legos con motivacións culturais, con experiencia ou con educación na seguridade do medio acuático como os surfistas, que contribúen notablemente aos rescates de bañistas en apuros, especialmente en praias non vixiadas. Socorristas profesionais; Rescate, reanimación e recuperación. Os socorristas son os profesionais encargados da prevención, vixilancia e intervención en caso de incidente acuático. O seu cometido é prover uns altos estándares en calidade asistencial, co obxectivo de evitar e/ou tratar calquera continxencia no medio acuático e a súa contorna. Dentro deste campo da literatura, hai un estudo que ten un valor especial, xa que abordou por primeira vez a viabilidade para realizar a reanimación boca a boca a bordo dunha MAR. Este estudo parte de dous conceptos vitais: gañar tempo e tratar a hipoxia, polo que se propón unha resposta a un debate clásico sobre o tratamento pre-hospitalario en situacións especiais de “stay and play” [tratar no sitio] or “scoop and run” [evacuar rápidamente]. 73 A mellora de habilidades ten como base o adestramento, tanto técnico como físico, xa que o salvamento ten unha alta demanda fisiolóxica. Un achado común en todos os estudos sobre socorristas é a fatiga ocasionada polas súas intervencións. Isto ocorre tanto en embarcacións como especialmente tras rescates acuáticos a nado. Os socorristas deben estar en boa forma física para afrontar os rescates, e a diferenza do salvamento deportivo, no socorrismo profesional tras realizar un rescate débese seguir traballando. Un dos retos desta tese, foi analizar como se pode atenuar o efecto de fatiga aguda nos socorristas, buscando estratexias que axuden á súa recuperación sen que supoñan unha interrupción das súas labores profesionais. É neste momento, baseado nun equipo multidisciplinar de traballo con socorristas, médicos, enfermeiros, educadores físicos e fisioterapeutas, cando se suscita a electroestimulación para ser usada tralo rescate acuático. Realizouse un estudo controlado colaborativo entre a Universidade de Vigo, a Universidade de Santiago de Compostela e a Universidade de Coimbra, na localidade do litoral portugués de Figueira dá Foz. Tras un rescate de 100m, aplicouse unha corrente de onda bifásica a 5 Hz, cunha duración de 0.25 milisegundos. O tempo de electroestimulación foi de 20min. A localización dos electrodos foi nos cuádriceps de ambas pernas, baseado en que os socorristas realizaron o rescate con aletas, e 80 1. INTRODUCTION 81 1. INTRODUCTION Drowning is a major public health problem(1) and is directly responsible for almost 300,000 deaths annually worldwide (2). It particularly affects children and has an especially severe impact on low and middle-income countries (LMIC)(1). Globally, it is the third leading cause of unintentional injury death and accounts for 7% of all injury-related deaths (3). In Spain, an estimated 400 people die from drowning each year (4). It should be noted that these statistics do not include migrants who die in Spanish waters. Drowning is defined as “the process of experiencing respiratory impairment from submersion/immersion in liquid”(5), and generically, its outcome may be death or survival with or without morbidity (5–7). Drowning is considered to be underrated and has often been referred to as the "Iceberg Metaphor."(8,9). An example of this metaphor is reflected in the comparative data; for every drowning person who required medical attention, six others had to be rescued (10). Prevention is the most important strategy and the most effective in the cost/benefit balance, which is why numerous publications recommend focusing efforts on drowning prevention tasks. (4,10–14). However, 82 epidemiological data indicate that there is still a long way to go towards sufficiently effective prevention (2). It is therefore necessary to study, understand and comprehend the mechanisms that trigger this incident, the profiles of drowning victims and the skills and strategies of professional rescuers to care for the victims. The Drowning Chain of Survival (11), is the first international consensus document that structured the phases of drowning in a logical time sequence. The main algorithm is composed of 5 links: 1. Prevention, 2-4. Sequence occurring in the water; 2. Recognition of the victim, 3. Provide flotation, 4. Rescue (remove from water), 5. Provide care as needed. More recently, the so-called Drowning Timeline was published (12), and it is a systematic model that includes four groups of actions: a. Prepare the community to prevent drowning b. Prevent drowning actively or reactively c. Reacting to the incident 83 d. Mitigate the effects of drowning in the post-event. Drowning differs by gender, age and location. (1–3,6,14,15). Males, children and citizens of LMIC are at increased risk of drowning. The triggers are often multifactorial (16), but in general they have to do with the omission of preventive measures or assuming risky behaviors. Prior to entering the water, triggers such as ignoring alerts or warnings about the state of the sea, alcohol consumption, lack of knowledge of the environment or low level of aquatic competence are triggers for drowning (6,17–20). In swimming pools, the absence of perimeter fences (figure 1) or continuous supervision is also strong triggers for drowning, especially in children. (17,21). Figure 2. Prevention mechanism. Perimeter fence preventing free access to the pool (own photograph). The second link in the chain of drowning survival is to recognize socalled "distress" (11). The term aquatic stress/distress includes the two 84 processes related to emotional control that can occur sequentially or in parallel. The recently published definition, which has an important consensus is that “two processes that occur when a person feels at risk of drowning. Stress evokes the person to try to find ways to get out of the situation. If the ability to rationally cope with the stressful condition is overwhelmed, a distress situation follows”(22). The drowning process is silent, subtle and not yet sufficiently studied, hence the importance of research into all aspects of drowning (23). Avramidis et al. presented the 4 W-model in which videos of aquatic incidents were analyzed as well as the behaviors of people who were experiencing a drowning and this provided some of the drowning outcome, such as rescuer characteristics, location or type of incident. (24). The drowning process can last from a few seconds to a few minutes (6) and by means of recent video analysis, Carballo-Fazanes & Bierens produced a study which found that the average time in which a victim became unconscious in a drowning process was 92s and the disappearance under water was 106s.(23). At this time, submergence time is the key factor, with the association between shorter submergence time and rapid response by Emergency Medical Services (EMS) being a key factor for survival (25). The final part of dealing with drowning or minimizing its consequences is described in the Drowning Timeline as mitigation (12) and in the Drowning Chain of Survival it is in the last link; that is, providing the necessary care (11). 85 On this point, knowing how rescuers (lay or professional) deal with an aquatic incident should be one of the challenges of drowning science. A Layperson is a person without professional or specialized knowledge in a subject area (in this case aquatic rescue) and there may be varying levels of knowledge depending on a person´s background (22). In contrast, Lifeguards are individuals who have completed training and have the necessary competence to prevent incidents, rescue and apply first aid in aquatic environments (22). In relation to lay rescuers, identifying their profiles, motivations, location (whether in or out of the water) and the techniques they use will help us to establish prevention campaigns to prevent drowning and also deaths when trying to rescue another person, i.e. aquatic victiminstead-of-rescuer syndrome (AVIR)-(26). It will also help us to better understand how lay-rescuers with experience in the aquatic environment (e.g. surfers)(27) can contribute to water rescues. Surfers may fall into the category of lay-rescuer with water rescue training and a certain level of competence to perform a rescue (22). In relation to professional lifeguards, analyzing their behavior and carrying out research with the aim of optimizing their performance should be a priority. This could greatly improve their capabilities and the effectiveness of their rescues. Nowadays, it is a fact that on beaches where lifeguards are present, the incidence of fatal drownings is indeed very low (6). However, the proportion of preventive or rescue 86 interventions is an important asset in the prevention of drowning (10). In the area of rescuers and their actions, research is still very limited. Some studies have addressed the effect of fatigue following rescue (28– 34) or the different rescue materials used (30,31,35,36). Others have examined competence in sand resuscitation (29,30,30,31), in-water resuscitation (37–40), on-boat resuscitation(41–46), or even simulation studies and cohorts of real interventions have also been studied. Drowning is a time-dependent event, so every second counts. Lifeguards must not only be proficient in the water. The lifeguard is actually a hybrid between an athlete and a paramedic. Sports science and health science must work together to prevent drowning and mitigate its consequences. Lifeguards must be treated as sports professionals and be given all available resources to help them get there faster and recover sooner. In short, to be in the best condition to deal with an imminent rescue. In recent years, research on the performance of professional lifeguards has increased with the analysis of their physical capabilities (32,35,47,48) or the consequences of their interventions(49) and novel strategies for recovery after rescues(50). However, the physiological conditioning of the rescuer is a field which has still barely been explored in sport sciences. Research is a living and oftentimes changing process, in which a new finding or a modification of reality can change any paradigm. This often happens in a period of years, but recently we have experienced it in a matter of months. 87 The year 2019 witnessed one of the biggest health alerts in the last hundred years. The Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2), appeared for the first time in the city of Wuhan (China). This type of coronavirus is responsible for the disease called COVID-19 (51). The World Health Organization (WHO) granted this disease pandemic status on March 11, 2020 (52). This highly infective coronavirus spread via fomites and especially aerosols, meant that all protocols for EMS had to be rethought. In an accelerated sprint of science worldwide, changes were addressed from multiple sectors: virologists learning and providing more precise evidence every week, vaccine development in record time (the fastest vaccine in history) and strong research for self-protection during health care. In Europe, the world experienced the first summer of the COVID era in 2020, following a large scale lockdown internationally. The problem for rescuers is that their interventions rarely occur in other medical contexts (53). In this regard, scientific societies related to drowning such as the International Drowning Research Alliance (IDRA) (54), the International Life Saving Federation (ILS)(54) through the medical commission, and the Spanish Society of Emergency Medicine (SEMES)(55) through the lifeguard working group, offered the first recommendations for lifeguards to meet the challenges of the new era. At present, and with the end of the health emergency on the horizon thanks to vaccination, some protocols will return to their previous state but others will endure and should therefore be evaluated scientifically. 88 This thesis aims to compile the characteristics, conditions and effects of the skills of first responders (lay or professional) and to show the new contributions adapted to COVID-19 times. For this purpose, the narrative discourse of this thesis will follow each of the Drowning Timeline actions (pre-event, event and post-event). In Europe, the world will experience the first summer of the COVID era in 2020, following a generalized lockdown. The problem for rescuers is that their interventions rarely occur in other medical contexts (53). This thesis aims to compile the characteristics, conditions and effects of the skills of first responders (lay or professional) and to show the new contributions adapted to COVID-19 times. For this purpose, the narrative discourse of this thesis will follow each of the Drowning Timeline actions (pre-event, event and post-event). 89 2. HYPOTHESIS & OBJETIVES 96 3. METHODOLOGY 97 3. METHODOLOGY 3.1 GENERAL METHODOLOGICAL DESCRIPTION This doctoral thesis is composed of 6 publications that have followed different methodologies, adapted to the objectives established in each sub-study. The set of articles and the scope of lifeguarding covered can be seen in Figure 2. Two of the articles are narrative, evidence-based and propose a synthesis of the results. The study entitled "Lay-rescuers in drowning incidents: A scoping review"(14) is a systematic review of the literature following PRISMA methodology (56). The initial literature review was provided by a librarian from the Belgian Red Cross Reference Center and checked by a drowning expert (Linda Quan). Following the systematic review procedure, two authors (Roberto Barcala-Furelos and Daniel Grahan) analyzed the literature separately, coincidentally including a total of 22 papers. The qualitative analysis performed by RBF and DG was reviewed by another pair of co-authors (Cristian Abelairas-Gómez and Antonio Rodríguez-Núñez). 98 The study entitled "Occupational health recommendations for lifeguards in aquatic emergencies in the Covid-19 era: prevention, rescue and resuscitation"(55) is presented in the form of evidencebased guidelines. The methodology for this paper also followed a PRISMA (56) methodology, but the way of presenting the manuscript, due to its practical purpose and the novelty of the content, follows the structure of a scientific recommendation. The remaining four studies, "Is 'scoop and run while playing' resuscitation feasible on a rescue water craft? A randomized simulation study with lifeguards"(57), "Plastic blanket drowning kit: A protection barrier to immediate resuscitation at the beach in the Covid-19 era. A pilot study"(58), "Safe on-boat resuscitation by lifeguards in Covid-19 Era. A pilot study comparing three sets of protective personal equipment"(44), "Is low-frequency Electrical Stimulation a tool for recovery after a Water Rescue? A Cross-Over Study with Lifeguards"(59), followed a quasi-experimental methodology. They are quantitative, randomized, cross-sectional studies. Data analysis was performed with SPSS statistical software (IBM Corp., Chicago, IL, USA) by means of pairwise comparisons (parametric tests -Test/Anova, or the non-parametric Wilcoxon test) of two or more factors. The studies present mean, standard deviation, confidence intervals (95%), frequencies and effect size. A significance level of p<0.05 was established for all analyses. 99 3.2 STUDY VARIABLES The set of dependent variables generically encompassed the following variables: 1) Quality of CPR reported using the Little Anne QCPR manikin software (Laerdal, Norway). Recording partial variables of chest compression (CC): Rate, Depth and Chest Recoil. Ventilations (V): V with effective air intake and V with adequate volume. The programming parameters were under the 2015 European Resuscitation Council Guidelines for Resuscitation (ERCG2015) (60). 2) Time of skills: Rescue time or time to intervention. It was measured in seconds (s). 3) Physiological parameters: Rating of Perceived Effort (RPE) according to Borg's Scale (61,62). Blood lactate (BL) measured in millimoles/liter (mmol/l) of lactic acid, recorded with LactateScout device (SensLab GmbH, Leipzig, Germany). Maximal radial musclebelly displacement (Dm) and Contraction time (CT) recorded with Tensiomyography (TMG-S1). 3.3 ETHICAL ASPECTS All the work has respected the ethical principles of the Declaration of Helsinki and has been authorized by an ethics committee. The data was anonymized and complied with current legislation on data protection. 100 Those experimental studies that required an ethics committee were included in the scientific publication. Figure 1b. Flow chart of Thesis content: Skills assessment in drowning incidents by rescuers 101 4. RESULTS OF PUBLICATIONS 102 4. RESULTS OF PUBLICATIONS 4.1.ARTICLE 1. LAY-RESCUERS IN DROWNING INCIDENTS: A SCOPING REVIEW Figure 3. Screenshot of the article identification, available at https://www.sciencedirect.com/science/article/pii/S0735675721000723?via%3Dihu b. 4.1.1 Evidence of Quality This article published in the The American Journal of Emergency Medicine has an impact factor of 1.911 in the Journal Citation Report (JCR). 103  Category: Science Edition - EMERGENCY MEDICINE  Indexed in JRC: Quartile 2 (Q2) and in SJR (Q1).  Repositories: Web of Science and Scopus.  This journal is a reference in the field of pre-hospital medicine and emergency triggers. Full citation of the manuscript Barcala-Furelos R, Graham D, Abelairas-Gómez C, Rodríguez-Núñez A. Lay-rescuers in drowning incidents: A scoping review. Am J Emerg Med. 2021 Jan 31;44:38-44. doi: 10.1016/j.ajem.2021.01.069. Epub ahead of print. PMID: 33578330. Publication contribution. Leadership in writing the manuscript (first author). Being one of the peers in the literature analysis in the review. Elaboration of the qualitative analysis. Preparation of tables and conceptualization of figures. Submission of the manuscript and resubmission of the revised version. 4.1.2 Article abstract Objective. Many victims of drowning fatalities are lay-people attempting to rescue another person. This review aims to identify the 104 safest techniques and equipment (improved or purpose made) for an untrained bystander to use when attempting a water rescue. Method. A sample of 249 papers were included after the bibliographic search, in which 19 were finally selected following PRISMA methodology and 3 peer review proceedings presented at international conferences. A total of 22 documents were added to the qualitative synthesis. Results. Geographical location, economic level, physical fitness, or experience may vary the profile of the lay-rescuers and how to safely perform a water rescue. Four lay-rescuers profiles were identified: 1) Children rescuing children in lowand middle-income countries (LMICs) 2) Adults rescuing adults or children 3) Lay-people with some level of experience and rescue training 4) Lay-people with cultural or professional motivations. There are three types of techniques used by those lay-rescuers profiles: a) Non-contact techniques for rescues from land: i.e. throw and reach b) Non-contact techniques for rescue using a flotation device c) Contact techniques for rescue in the water: swim and tow with or without fins. 105 Conclusion. The expert recommendation of the safest technique for a lay-rescuer is to attempt rescue using a pole, rope, or flotation equipment without entering the water. However, despite the recommendations of non-contact rescues from land, there is an overall tendency to attempt contact rescues in the water, despite a lack of evidence on which technique, procedure or equipment contributes to a safer rescue. Training strategies for lay-people should be considered. Highlights: 1) The safest technique for a lay-rescuer is to attempt rescue from the land or a boat, throwing a pole, rope, or flotation equipment without entering the water. 2) Four different lay-rescuer profiles were found. Prevention strategies should be adjusted to target each profile. 3) If lay-rescuers are already in the water when the incident occurs (e.g., surfers), and they have good knowledge of the aquatic environment, experience in water rescue skills, good physical fitness, and floatation equipment, they could consider attempting a rescue only if it's safe. 112 rescue consisted of swimming 100m with fins and a rescue-tube: a 50m swim approach and a 50m tow-in with a simulated victim. Blood lactate clearance, rated perceived effort (RPE), and muscle contractile properties were evaluated at baseline, after the water rescue, and after ES or passive-recovery control condition (PR) protocol. Tensiomiography, RPE, and blood lactate basal levels indicated equivalence between both groups. There was no change in tensiomiography from pre to post-recovery and no difference between recovery protocols. Overall-RPE, legs-RPE and arms-RPE after ES (mean ± SD; 2.7 ± 1.53, 2.65 ± 1.66, and 2.30 ± 1.84, respectively) were moderately lower than after PR (3.57 ± 2.4, 3.71 ± 2.43, and 3.29 ± 1.79, respectively) (p = 0.016, p = 0.010, p = 0.028, respectively). There was a significantly lower blood lactate level after recovery in ES than in PR (mean ± SD; 4.77 ± 1.86 mmol·L−1 vs. 6.27 ± 3.69 mmol·L−1; p = 0.045). Low-frequency ES immediately after a water rescue is an effective recovery strategy to clear out blood lactate concentration. 113 4.4.ARTICLE 4. OCCUPATIONAL HEALTH RECOMMENDATIONS FOR LIFEGUARDS IN AQUATIC EMERGENCIES IN THE COVID19 ERA: PREVENTION, RESCUE AND RESUSCITATION Figure 6. Screenshot of item identification, available at https://www.mscbs.gob.es/biblioPublic/publicaciones/recursos_propios/resp/revis ta_cdrom/VOL94/C_ESPECIALES/RS94C_202006074.pdf. 4.4.1 Evidence of Quality This article published in the journal Revista Española de Salud Pública has an impact factor of 0.76 in the Journal Citation Report (JCR).  Category: Science Edition - PUBLIC, ENVIRONMENTAL AND OCCUPATIONAL  Indexed in JRC: Quartile 4 (Q4) and in SJR (Q3).  Repositories: Web of Science (WOS) and Scopus. 114  It is the official journal of the Spanish Society of Public Health and Health Administration (SESPAS), published since 1987. Full citation of the manuscript Barcala-Furelos R, Aranda-García S, Abelairas-Gómez C, MartínezIsasi S, López-Mesa F, Oleagordia-Aguirre A, Palacios-Aguilar J, Szpilman D. Recomendaciones de salud laboral para socorristas ante emergencias acuáticas en la era Covid-19: prevención, rescate y reanimación [Occupational health recommendations for lifeguards in aquatic emergencies in the Covid-19 era: prevention, rescue and resuscitation.] Rev Esp Public Health. 2020 Jun 30;94:e202006074. Spanish. PMID: 32601267. Contribution to the publication Leadership in writing the manuscript (first author). Development of the idea. Elaboration of tables and conceptualization of figures. Elaboration of the manuscript. Submission of the manuscript and resubmission of the revised version. 4.4.2 Article abstract Severe acute respiratory syndrome (SARS-CoV-2), which causes coronavirus disease 2019 (COVID-19), is highly contagious. Lifeguards are the first line of response in aquatic emergencies and they were seriously exposed to risk during the first summer of the Covid-19 115 era, so their occupational health must be rethought in their professional practice during the new normal. The main public health measure to prevent drowning is actual prevention, but when this fails and assistance or rescue is required, in most interventions, distancing will not be possible. The limitation of personal protective equipment (PPE) for rescue is a reality that must be known and it can seriously affect the health of the lifeguard. A review of the current literature aimed at avoiding or minimizing the risk of contagion in the interventions carried out by rescuers in the Covid-19 era was performed. This article provides structured information on the prevention of contagion in lifeguards, the potential risks, the available PPE, and the recommendations for its proper use during rescue or prehospital care in aquatic settings. 116 4.5.ARTICLE 5. PLASTIC BLANKET DROWNING KIT: A PROTECTION BARRIER TO IMMEDIATE RESUSCITATION AT THE BEACH IN THE COVID-19 ERA. A PILOT STUDY Figure 7. Screenshot of item identification, available at https://www.sciencedirect.com/science/article/pii/S0735675720307695. 4.5.1 Evidence of Quality This article published in the The American Journal of Emergency Medicine has an impact factor of 1.911 in the Journal Citation Report (JCR).  Category: Science Edition - EMERGENCY MEDICINE  Indexed in JRC: Quartile 2 (Q2) and in SJR (Q1).  Repositories: Wos of Science and Scopus. 117 Full manuscript citation Barcala-Furelos R, Szpilman D, Abelairas-Gómez C, Alonso-Calvete A, Domínguez-Graña M, Martínez-Isasi S, Palacios-Aguilar J, Rodríguez-Núñez A. Plastic blanket drowning kit: A protection barrier to immediate resuscitation at the beach in the Covid-19 era. A pilot study. Am J Emerg Med. 2020 Nov; 38(11):2395-2399. doi: 10.1016/j.ajem.2020.08.101. Epub 2020 Sep 16. PMID: 33039225; PMCID: PMC7492152. Publication contribution. Leadership in writing the manuscript (first author). Co-conception of the idea together with Antoni Rodríguez-Núñez. Data collection processing. Elaboration of tables and conceptualization of figures. Elaboration of the final version of the manuscript and the revised version. 4.5.2 Article abstract Objective: Introducing a new, simple and inexpensive type of portable equipment for lifeguards, consisting of a pre-assembled full-size plastic blanket with a mask and HEPA filter, which could offer significant time-saving advantages to reduce COVID-19 risk transmission in the first few minutes of CPR after water rescue, thus avoiding the negative impact of delayed ventilation. 118 Method: A pilot study was carried out to determine the feasibility of the pre-assembled kit of face-mask and HEPA filter adapted on a preset plastic-blanket. The first step consisted of washing hands, putting on safety glasses and gloves as the first personal protection equipment (PPE) elements and then covering the victim with an assembled plastic blanket. The second step consisted of 10 minutes of cardiopulmonary resuscitation (CPR) with PPE and plastic blanket, following the technical recommendations for ventilation during COVID-19. Results: Ten rescuers took part in the pilot study. The average time to put on PPE and place the pre-assembly kit on the victim was 82 s [IC 58-105]. After 10 min the quality of the resuscitation (QCPR) was 91% [87-94]. Quality chest compressions (CC) were 22% better than ventilations (V). Most of the rescuers (60%) thought that placing the plastic blanket over the victim on the beach was somewhat simple or very simple. Conclusions: Resuscitation techniques in the COVID-19 era on the beach have added complexities for the correct use of PPE. The plastic blanket plus basic ventilation equipment resources could be a new alternative to be considered for lifeguards to continue ventilation while reducing risk transmission. 119 4.6.ARTICLE 6. SAFE ON-BOAT RESUSCITATION BY LIFEGUARDS IN COVID-19 ERA. A PILOT STUDY COMPARING THREE SETS OF PROTECTIVE PERSONAL EQUIPMENT Figure 8. Screenshot of item identification, available at https://www.mscbs.gob.es/biblioPublic/publicaciones/recursos_propios/resp/revis ta_cdrom/VOL94/C_ESPECIALES/RS94C_202006074.pdf. 4.6.1 Evidence of Quality This article published in the journal Prehospital and Disaster Medicine has an impact factor of 1.911 in the Journal citation Report (JCR).  Category: Science Edition - EMERGENCY MEDICINE  Indexed in JRC: Quartile 3 (Q3) and in SJR (Q1).  Repositories: Wos of Science and Scopus. 120 Full citation of the manuscript Barcala-Furelos R, Abelairas-Gómez C, Alonso-Calvete A, CanoNoguera F, Carballo-Fazanes A, Martínez-Isasi S, Rodríguez-Núñez A. Safe On-Boat Resuscitation by Lifeguards in COVID-19 Era: A Pilot Study Comparing Three Sets of Personal Protective Equipment. Prehosp Disaster Med. 2021 Apr; 36(2):163-169. doi: 10.1017/S1049023X2100011X. Epub 2021 Jan 27. PMID: 33500008; PMCID: PMC7900657. Contribution in publication Conceptualization of the idea. Manuscript writing leadership (first author). Data collection processing. Preparation of tables and conceptualization of figures. Preparation of the final version of the manuscript and the revised version. 4.6.2 Article abstract Introduction: On-boat resuscitation can be applied by lifeguards in an inflatable rescue boat (IRB). Due to Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-COV-2) and recommendations for the use of personal protective equipment (PPE), prehospital care procedures need to be re-evaluated. The objective of this study was to determine how the use of PPE influences the amount of preparation 121 time needed before beginning actual resuscitation and the quality of cardiopulmonary resuscitation (CPR; Q-CPR) on an IRB. Methods: Three CPR tests were performed by 14 lifeguards, in teams of two, wearing different PPE: (1) Basic PPE (B-PPE): gloves, a mask, and protective glasses; (2) Full PPE (F-PPE): B-PPE + a waterproof apron; and (3) Basic PPE + plastic blanket (B+PPE). On-boat resuscitation using a bag-valve-mask (BVM) and high efficiency particulate air (HEPA) filter was performed sailing at 20km/hour. Results: Using B-PPE takes less time and is significantly faster than FPPE (B-PPE 17 [SD = 2] seconds versus F-PPE 69 [SD = 17] seconds; P = .001), and the use of B+PPE is slightly higher (B-PPE 17 [SD = 2] seconds versus B+PPE 34 [SD = 6] seconds; P = .002). The QCPR remained similar in all three scenarios (P >.05), reaching values over 79%. Conclusion: The use of PPE during on-board resuscitation is feasible and does not interfere with quality when performed by trained lifeguards. The use of a plastic blanket could be a quick and easy alternative to offer extra protection to lifeguards during CPR on an IRB. 128 The fourth profile identified in the literature consists of surfers who rescue bathers (27,66). The question arises as to whether these athletes can be classified as lay-rescuers, since as a result of their physical conditions and experience, they may have developed adequate knowledge to respond to rescue situations, even adverse ones. Attar et al. estimated that in Australia, rescues performed by surfers are on a par with rescues performed by volunteer rescuers, and their actions are performed both in places monitored by rescuers (45%) and in unmonitored places (53%)(27). A relevant aspect of this study is that surfers attribute their rescue expertise to the number of years of surfing experience (not to their training in rescue techniques). One aspect to highlight is that surfers use their surfboards as a rescue tool. This equipment has been shown to be the most efficient in terms of time/effort (31,81). It therefore seems reasonable that this profile of layrescuer who is already in the water and has flotation equipment can act as a lifeguard when encountering a victim in distress. As a synthesis of this first part of the discussion, Figure 9 summarizes the technical recommendations for lay-people rescues in and out of the water, related to their training and experience. 129 Figure 9. Theoretical risk. Vs. Benefits rescue techniques for lay-rescuers. Original figure published in Barcala-Furelos R, Graham D, Abelairas-Gómez C, RodríguezNúñez A, Lay-rescuers in drowning incidents: A scoping review. Am J Emerg Med. 2021 Jan 31;44:38–44. Reproduction with editorial permission. 5.2 LIFEGUARDS, PROFILE AND TECHNIQUES Lifeguards are the professionals who are in charge of prevention, surveillance and intervention in the event of an aquatic incident. Their task is to provide high standards of quality care, with the aim of avoiding any contingency in the aquatic environment and its surroundings. Drowning is a time-dependent critical event (6,25), so it must be attended to quickly and hypoxia must be treated early. It is for this reason that in recent years, research with lifeboats has taken special interest. The recent review promoted by the International Liaison Committee on Resuscitation (ILCOR) has identified seven studies of 130 clinical interest (82), one of which is part of this doctoral thesis; Is “scoop and run while playing” resuscitation feasible on a rescue water craft? A randomized simulation study with lifeguards. Out of these lifeboat studies, only two articles presented clinical results with real patients (41,83), while the rest show results from simulation scenarios with manikins (43,45,46,57,84). Simulation studies addressed the ability of lifeguards and fishermen to perform on-board CPR in different conditions (with waves, wind, and at different speeds) as well as the use of the Automated External Defibrillator (AED). Within this field of literature, there is one study that has a special feature, as it addressed for the first time the feasibility to perform mouth-to-mouth resuscitation or on-boat CPR on a Rescue Water Craft (RWC). Figure 10. Mouth-to-mouth resuscitation and CPR on the RWC. (Own photographs) This study is based on two vital concepts: buying time and treating hypoxia, and therefore proposes a response to a classic debate on prehospital treatment in special "stay and play" or "scoop and run" situations (85). We start with the assumption that an aquatic scenario is not a safe place or a controlled environment and thus always involves risk (86), so the 131 "stay and play" option always involves greater exposure both for the rescuer and the victim. Even so, the scientific literature shows examples in which "stay and play" is a vitally important alternative, as in the technique known as in-water resuscitation (39). Specifically, this technique has also been analyzed in the ILCOR review, which analyzed five studies that met the inclusion criteria (82). Only one Brazilian study presented retrospective data on actual patients, comparing those who received in-water resuscitation vs. those who did not receive in-water resuscitation. The survival of the in-water resuscitated cohort was significantly better (57% higher) than those who received CPR after being removed from the water (39). On the other hand, being in the water has many other disadvantages in relation to the safety and prognosis of the victim; maritime phenomena, cold water or the difficulty in adequately assessing the damage, have made the "scoop and run" option the usual one in lifeguarding. Our proposal is based on the principle of not delaying resuscitation while the victim is being evacuated and we have called it "scoop and run while playing" (57). Before arriving at this conclusion, there are some antecedents that should be mentioned. The study by Tipton et al. analyzed the quality of CPR by comparing different boat sizes and sea states (waves etc.) (46). However, this type of boat is not used by beach lifeguards. The usual model on beaches is the Inflatable Rescue Boat (IRB). Five articles have been identified on IRBs, two Dutch ones (41,45) and three Spanish ones (42-44). 132 The set of Spanish studies conducted entirely by our research team showed how the quality of CPR in an IRB could be included in the "stay and play" option. This pilot study developed on the beach of Coroso (Ribeira-A Coruña, Spain) by means of a related samples test, compared the quality of CPR both on land and on board the ship (42). The next step was to test the feasibility of CPR when sailing, and the first tests were performed on fishing boats at different speeds and with changing wind conditions (84,87). Figure 11 The second relevant study of our research group, entitled "Can surflifeguards perform a quality cardiopulmonary resuscitation sailing on a lifeboat? A quasi-experimental study" published in Emerg Med J. 2017 Jun;34(6):370-5.(43) aimed to evaluate the influence of speed on Q-CPR. It was performed in Santiago del Teide (Canary Islands, Spain), with summer conditions and no adverse weather phenomena. This study showed that Q-CPR at 10 knots (18.52 km/h) was acceptable and although it meant an increase in rescuer fatigue and a slight decrease in quality, it is reasonable to think that it is a viable option and should be taken into account with real patients. Figure 11. 133 Figure 11. Image 1: First pilot study on Quality CPR sailing on a fishing boat. Figure 2: Second study in IRB (own photographs). This study is connected with Section 4 of the European Resuscitation Council Guidelines for Resuscitation 2015 (ERCGR2015), which recommends the use of lifeboats for greater rescuer safety (60). However these guidelines do not currently propose any type of onboard treatment. This study provided novel data on this possibility and introduced the idea of what we would later refer to as "scoop and run while playing on-boat" (57). IRBs are maneuverable, fast and used all over the world by different rescue agencies (42,43), but there is also another type of lifeboat which is even more maneuverable and is also common in surveillance and rescue operations (57). RWCs are used both on large beaches and in wild areas, and are very common in surfing competitions and other nautical sports. RCWs usually have a sled of variable dimensions, and 134 can operate with a skipper-surfer alone, or with two operators; skippersurfer and lifeguard. Our research hypothesis aimed to evaluate for the first time the feasibility of CPR and its quality in RWC, in two different forms of resuscitation; 1) mouth-to-mouth resuscitation [emulating in-water resuscitation] and 2) Standard CPR (CC and V). In order to compare the results with those obtained in IRB, the study was designed at the same speed (10 knots), the same duration (2 min) and the same sea conditions (no waves and a summer environment). In this case, the CPR technique had to involve bow riding, as this is the way the rescuer navigates on the sled. To avoid bias in the use of the technique, a brief training was conducted to familiarize the lifeguards with this new way of performing CPR. The findings in relation to Q-CPR were similar to other studies in IRB (43). In this investigation, the experience of the rescuers differed. Those rescuers with experience in RWC barely suffered a decrease in Q-CPR compared to those on the beach, but for less experienced rescuers, the quality decreased significantly. In any case, all lifeguards, regardless of their education or training, were able to perform both techniques (MMonly and CPR). This study differentiated ventilations in two variables: a) effective ventilation (i.e., when air enters and the chest is visibly raised) and b) quality of ventilation, when the volume recommended by the 135 ERCGR2015(60) between 500 and 600 ml is introduced. Lifeguards manage to introduce air in one out of two ventilations and insufflate adequate volume in 1 out of 3 ventilations. Difficulty ventilating during navigation is increased with speed and although this study has not tested this, it is also likely to be affected by wave size. Ventilation is the key factor in reversing hypoxia (6), and lifeguards should systematize training processes to optimize these results. While said results are not bad (doing nothing would be the worst scenario), they can definitely be improved significantly. The improvement of skills is based on both technical and physical training, since lifesaving puts high physiological demands on people (35). A common finding in all studies on lifeguards is fatigue in their interventions. This occurs both in IRB (43) and especially after swimming rescues (28,30,31,34,50). Some studies have found that physical fatigue can influence the quality of post-rescue CPR(28,29,34) and several articles have focused on the need for physical fitness standards for rescuers (35,88-90). An aquatic rescue must be fast and vigorous (30), and even at relatively short distances (75 to 100 m), it will invariably generate a submaximal physiological load, consisting of a production of lactic acid greater than 10 millimoles of lactic acid per liter (mmol/l) (30,31,50) along with perceived exertion values qualified as "extremely tough" after aquatic rescues (31,59). Lifeguards must be in good physical shape to perform rescues (35,88) and unlike in sports rescue, in professional lifeguarding they must 136 continue working after performing a rescue. Working hours in Spain are usually eight hours a day, and sometimes rescuers must perform more than one rescue in the same day (66). Such a demanding effort requires a recovery period. This physiological restoration process can take up to 48 hours. One of the challenges of this thesis was to analyze how to attenuate the effect of acute fatigue on rescuers, by looking for strategies to aid their recovery without interrupting their professional work. A previous study by our research group compared the effect of three recovery strategies (passive recovery: sitting while watching the beach, active recovery: running and active recovery: with foam roller Figure 12), after a high intensity aquatic rescue (50). Figure 12. Active recovery technique with Foam Roller (own image). 137 The results showed that the passive type of recovery (the rescuer watching in a chair) was the least efficient, since the rate of decrease in lactate concentration was significantly lower (p<0.05), so the dilemma arose as to what would be more appropriate: to recover actively to quickly decrease the high lactacidemia or to continue with the surveillance even if the passive method takes longer in the recovery process? There is no single answer to this question, as it will depend on the number of rescuers on duty and the resources available. The use of foam roller for the recovery of lifeguards was something new and low cost, never tested until then, and it enabled the ability to maintain relative attention while watching the beach, and this was the reason why we experimented with this new, inexpensive cylinder. The use of foam roller focused on self-massage of the lower limb musculature: quadriceps, iliotibial tract, hamstrings, adductors, and gluteus and the protocol lasted approximately 25 min (50). We focused only on the lower limbs because this is the part of the rescue in which only the legs are involved (victim to-in). This phase lasts 3 times longer than the first part of the rescue in which hands and legs are used propulsively as the swimmer approaches the victim (30). This formula offered an alternative for the first time, so that rescuers could now perform active recovery while maintaining a relative focus on their surveillance tasks. 144 This group prepared a guide organized in four sections: 1) Prevention of contagion, screening of positives and risks for the lifeguard, 2) Personal protective equipment (PPE). Possibilities and limitations, 3) Reaction to drowning. Water rescue. 4) Mitigation: pre-hospital care and basic life support for drowning. 1) Prevention of contagion, screening of positives and risks for the rescuer. In the early stages of the pandemic, in addition to high community transmission of the virus, there was also a high rate of infection of health providers (93,99). A protective factor for lifeguards is that they work outdoors on the beaches and that the average age of lifeguards in Spain is less than 30 years; however, other risk factors should be considered, such as wind, the flow of tourists from places with a high incidence of COVID-19 and asymptomatic persons infected by COVID-19. The working group proposed the following general recommendations for first aid workers. - Hand washing before and after contact with the patient, and in general, whenever deemed necessary. - Permanent protection during assistance with FFP mask and use of sunglasses. - Inform users or hold conversations upwind of people. 145 - Disinfection of communication equipment, and distribute to each lifeguard their own communication equipment. Failing that, use personal cell phones. - COVID-19 screening is proposed, outside the watchtower or first aid station. The lifeguard will be fully clothed, behind a vinyl screen or upwind of the user and for minor treatments selfindications will be given. - The division of spaces is recommended for both health care and surveillance. The main measures can be found in figure 14. Figure 14. Diagram on adaptations of the first aid module and patient care by the lifeguard. Published in Revista Española de Salud Pública by Barcala-Furelos et al. (55) under Creative Commons license and reproduced with their editorial permission. 146 1) Personal protective equipment (PPE). Possibilities and limitations and 3) Reaction to drowning. After the first wave, it was decided to consider that any person requiring assistance is a potential SARS-CoV-2(94) carrier, until proven otherwise. Therefore, for the safest possible assistance, it was necessary to rethink the ideal PPE with the actual PPE that can be used by first responders. This section presented another new challenge, since there is no previous experience in the use of PPE among first responders, but there are also a number of additional difficulties that were noted by the working group that developed these recommendations. Prehospital care on land (the beach), and prehospital care in the water were differentiated. The aquatic part had the following conditioning factors: - Little or no likelihood of maintaining the safety distance. - Aquatic rescues with surrounding aerolizations (due to not being able to maintain the safety distance). - Habitual coughing and secretions from the early stages of drowning (6). By consensus of experts, with the information available at that time and with the adaptation to the work of the rescuer, figure 15 was proposed, which includes the feasibility of the use of PPE in relation to the type of intervention. 147 Figure 15. Feasibility of the use of PPE and other protective equipment in the different lifeguard interventions. Published in Revista Española de Salud Pública by Barcala-Furelos et al.(55) under Creative Commons license and reproduced with their editorial authorization. In this analysis of the material, and knowing the difficulties of its use, as well as the cost/benefit of the intervention, a hypothetical grading 148 was made of the risk related to the rescue material used. The materials with the lowest risk are those that involve non-contact flotation, such as drones, rescue bags, poles and other non-contact approaches or flotation materials. Medium risk was considered for rescues with less close contact, but without the possibility of maintaining safe distance, as in IRBs. High risk was considered for non-motorized vessels (canoes and paddle surfboards), where space is more limited and exposure time is longer. Finally, the highest risk was for rescue techniques that require direct contact with the victim, such as body-to-body water rescue (Figure 16). Thecnique Noncontact methods Short-term contact with possibility of using PPE Longer contact time with limited use of PPE Full contact, no PPE possible Risk LOW MEDIUM HIGH VERY HIGH Figure 16: Gradation of the risk of contagion in relation to the rescue procedure used. (Figure prepared by the authors). 4) Mitigation: pre-hospital care and basic life support in drowning. This section was particularly controversial. Researchers in the field of drowning reacted quickly to the new recommendations for Basic Life Support (BLS) in which ventilations took second place (94). The challenge of the new recommendations was to avoid aerosol transmission during CC, and in the administration of V it was necessary to ensure safety by using barrier materials, HEPA filters and PPE. 149 Both IDRA and our working group proposed resuscitation algorithms to provide the best drowning care. Our working group's algorithm maintained the essence of the ERCG2015 drowning recommendations, adding the use of PPE (60) Figure 17. The IDRA recommendations were less conservative, as they included the bag-valve-mask, pocket mask or passive ventilation as alternatives (54). These recommendations are intended for a more global audience. Figure 17. Adaptation of the drowning basic life support algorithm according to ERC2015 (60) recommendations to the Covid-19 era according to ERC2020 (94) recommendations. Published in the Revista Española de Salud Pública by BarcalaFurelos et al. (55) under the Creative Commons license and reproduced with their editorial permission. The use of PPE requires training, as well as experience, concentration and assistance in its use. This is not possible in most rescue procedures, especially after a rescue (58), when the rescuer emerges wet and fatigued (31), usually at a location away from the first aid station. After rescue, the ABCDE approach should be initiated, and basic CPR 150 initiated if necessary. Rescuers often have a portable emergency bag (PEB) for first aid, with essential equipment: Airway: Oropharyngeal airway, suction equipment, Breathing: Oxygen, bag-mask, face-mask, Circulation: Automated external defibrillator, wound dressing, hemostatic dressing, tourniquet. Disability: None, Exposure: Warning blanket (100). The new pandemic situation would require the inclusion of all protective equipment (PPE). However, its proper use in aquatic environments can range from difficult to impossible. Based on the hospital experience of anesthesiologists during intubation and extubation, using plastics for extra protection during airway interventions (101), as well as the study by Chan et al. showed the use of HEPA filter in bag-valve-mask dos not prevent 100% air leakage (102), which motivated us to look for the application of plastic blankets as a protective alternative in BLS performed by lifeguards. The first pilot study with plastic blanket in this thesis aimed to analyze the feasibility of its use on the beach (58). Our hypothesis is that the plastic blanket is an alternative method of protection that does not affect the quality of CPR, in addition to allowing rapid placement without delaying the start of ventilations. Other advantages are low cost and ease of use, which is necessary for professionals who do not have specific training or use PPE for resuscitation on a daily basis. 151 Our design consisted of transparent plastic 250 cm long by 150 cm wide, in one part of which a face-mask with a HEPA fligrotor was preassembled. The kit is composed of 4 to 6 horseshoe spikes. This plastic integrated in the first aid case allows rescuers to cover the victim and start ventilations in 82 sec. on average. Figure 18. Figure 18: Placement of the plastic blanket [1,2] and comparison of plastic vs. apron blanket [3]. (Own images). CPR quality was of high quality, with a value of 91% in 10 min resuscitation. Compressions were better than ventilations, as is usual in other simulation studies with rescuers using the same Laerdal Q-CPR measurement system (30,31,34). Another relevant aspect was that a large proportion of the rescuers considered that using this plastic kit was simple, compared to using full PPE (with an apron). In the arena it may be more or less debatable to use full PPE or to use alternative PPE (i.e. the plastic blanket), as the availability of resources, training, victim location or quick EMS assistance may offer different 152 alternatives. However, at the first moment of IRB rescue there are not many alternatives. The rescuer must choose between starting ventilations as soon as possible or delaying them, depending on the level of protection of each set. Even so, based on our background, we consider that the ideal PPE model (with apron) may be unfeasible in IRB, generate a false sense of protection and delay the start of resuscitation. Under this premise, we compared three PPE sets in an IRB sailing at 20km/h, again comparing the Q-CPR, and analyzing the set preparation time until the start of the first ventilation (44). Figure 19. Figure 19. Comparison of plastic blanket set on IRB [1] vs. full PPE with apron [2]. (Own images). The first important finding was that the time to first ventilation was 17s with a basic protection level, 34s with protection based on a plastic blanket and 69s with full PPE equipment. That is, wearing full PPE takes 30s more, 43% of the rescuers used it incorrectly or its placement was incorrect, with large exposed body areas. In the resuscitation test 153 there were no significant differences with any of the three sets and the values were around 90% Q-CPR. It is now accepted that a value equal to or greater than 70% in simulation could be considered quality CPR (103). Protection during emergencies has become essential, but recommendations focus on the most common "medical" settings (i.e. hospitals or ambulances), in which the means, experience and scenario is usually controlled (44). Protection is important, but so is treatment. An IRB is the fastest means at sea to interrupt the drowning process (43). Speed contributes to reducing submergence time, which is the most important determinant of drowning victim outcomes (25). Lifeguard agencies should consider the local incidence of the virus in their protocols, the age of their rescuers (usually young), vaccinated rescuers and the local vaccination rate or those rescuers who have already had COVID-19, for the choice of the level of protection during on-boat resuscitation. If maximum protection is chosen, it should be noted that the full use of PPE requires training (55,104,105) and a stable and safe place for its placement. 5.4. PRACTICAL IMPLICATIONS This thesis has sought to provide clues to resolve numerous practical situations in a special environment and with events that are difficult to