Out-of-hospital cardiac arrest due to drowning: An Utstein Style report of 10 years of experience from St. Mary's Hospital

Development and validation of a clinico-biological score to predict outcomes in patients with drowning-associated cardiac arrest

BACKGROUND

While several scoring systems have been developed to predict short-term outcome in out-of-hospital cardiac arrest patients, there is currently no dedicated prognostic tool for drowning-associated cardiac arrest (DACA) patients.

METHODS

Patients experiencing DACA from two retrospective multicenter cohorts of drowning patients were included in the present study. Among the patients from the development cohort, risk-factors for day-28 mortality were assessed by logistic regression. A prediction score was conceived and assessed in patients from the validation cohort.

RESULTS

Among the 103 included patients from the development cohort, the day-28 mortality rate reached 51% (53/103). Identified independent early risk-factors for day-28 mortality included cardiopulmonary resuscitation duration longer than 20 min (OR 6.40 [95% CI 1.88-23.32]; p = 0.003), temperature at Intensive Care Unit admission <34 °C (OR 8.84 [95% CI 2.66-32.92]; p < 0.001), need for invasive mechanical ventilation (OR 6.83 [95% CI 1.47-40.87]; p = 0.02) and lactate concentration > 7 mmol/L (OR 3.56 [95% CI 1.01-13.07]; p = 0.04). The Area Under the ROC Curve (AUC) of the developed score based on those variables reached 0.91 (95% CI, 0.86-0.97). The optimal cut-off for predicting poor outcomes was 4 points with a sensitivity of 92% (95% CI, 82-98%), a specificity of 82% (95% CI, 67-91%), a positive predictive value (PPV) of 84% (95% CI, 72-95%) and a negative predictive value (NPV) of 91% (95% CI, 79-96%). The assessment of this score on the validation cohort of 81 patients exhibited an AUC of 0.82. Using the same 4 points threshold, sensitivity, specificity, PPV and NPV values of the validation cohort were: 81%, 67%, 72% and 77%, respectively.

CONCLUSION

In patients suffering from drowning induced initial cardiac arrest admitted to ICU with a DACA score ≥ 4, the likelihood of survival at day-28 is significantly lower. Prospective validation of the DACA score and assessment of its usefulness are warranted in the future.

Wilderness Medical Society Clinical Practice Guidelines for the Treatment and Prevention of Drowning: 2024 Update

The Wilderness Medical Society convened a panel to review available evidence supporting practices for acute management of drowning in out-of-hospital and emergency care settings. Literature about definitions and terminology, epidemiology, rescue, resuscitation, acute clinical management, disposition, and drowning prevention was reviewed. The panel graded available evidence supporting practices according to the American College of Chest Physicians criteria and then made recommendations based on that evidence. Recommendations were based on the panel's collective clinical experience and judgment when published evidence was lacking. This is the second update to the original practice guidelines published in 2016 and updated in 2019.

Drowning in the United States: Patient and Scene Characteristics using the novel CARES Drowning Variables

INTRODUCTION

Drowning results in more than 360,000 deaths annually, making it the 3rd leading cause of unintentional injury death worldwide. Prior studies examining drowning internationally have reviewed factors surrounding drowning however in the U.S. limited data exists. This study evaluated the novel drowning elements collected in the Cardiac Arrest Registry to Enhance Survival (CARES) during the first 2 years of data collection.

METHODS

A retrospective analysis of the CARES database identified cases of drowning etiology for the two years 2020 and 2021. Demographics and incident characteristics were collected. Characteristics included items such as body of water, precipitating event, and who extracted patients. Survival to hospital discharge and neurological outcomes were compared between groups based on who initiated CPR using Pearson's Chi-Squared tests.

RESULTS

Among 1,767 drowning cases, 69.7% were male, 47.1% white and 11.9% survived to hospital discharge. Body of water was often natural body (36.2%) or swimming pool (25.9%) and bystanders removed the patient in 42.7% of incidents. Swimming was the most common activity at time of submersion (18.6%) however in 50.2% of cases, activity was unknown or missing. When compared to EMS/First Responder initiating CPR, odds of neurologically favorable survival were significantly higher in the Bystander initiated CPR group (OR=2.85, 95% confidence interval [CI] 2.02-4.01).

CONCLUSION

In this national cohort of drowning patients in cardiac arrest, the novel CARES drowning elements provide additional detail of epidemiological factors. Bystander CPR was associated with improved neurological outcomes. Future studies utilizing the drowning elements can inform injury prevention strategies.

Pre-Existing Medical Conditions: A Systematic Literature Review of a Silent Contributor to Adult Drowning

Medical conditions can increase drowning risk. No prior study has systematically reviewed the published evidence globally regarding medical conditions and drowning risk for adults. MEDLINE (Ovid), PubMed, EMBASE, Scopus, PsycINFO (ProQuest) and SPORTDiscus databases were searched for original research published between 1 January 2005 and 31 October 2021 that reported adult (≥15 years) fatal or non-fatal drowning of all intents and pre-existing medical conditions. Conditions were grouped into the relevant International Classifications of Diseases (ICD) codes. Eighty-three studies were included (85.5% high-income countries; 38.6% East Asia and Pacific region; 75.9% evidence level III-3). Diseases of the nervous system (n = 32 studies; 38.6%), mental and behavioural conditions (n = 31; 37.3%) and diseases of the circulatory system (n = 25; 30.1%) were the most common categories of conditions. Epilepsy was found to increase the relative risk of drowning by 3.8 to 82 times, with suggested preventive approaches regarding supervised bathing or showering. Drowning is a common suicide method for those with schizophrenia, psychotic disorders and dementia. Review findings indicate people with pre-existing medical conditions drown, yet relatively few studies have documented the risk. There is a need for further population-level research to more accurately quantify drowning risk for pre-existing medical conditions in adults, as well as implementing and evaluating population-level attributable risk and prevention strategies.

Neurological outcomes in adult drowning patients in China

BACKGROUND

Drowning is the third leading cause of unintentional death worldwide. The epidemiological characteristics of adult drownings are rarely reported.

OBJECTIVE

Investigate factors associated with neurological prognosis in adult drowning inpatients.

DESIGN

Multicenter medical record review.

SETTING

Tertiary health care institutions.

PATIENTS AND METHODS

We collected demographic and clinical data on patients who drowned but survived between September 2006 and January 2020. Neurological prognosis was compared in patients with and without cardiac arrest.

MAIN OUTCOME MEASURES

Neurological outcomes.

SAMPLE SIZE AND CHARACTERISTICS

142 patients with mean age of 50.6 (19.8) years, male/female ratio of 1.54:1.

RESULT

Forty-five patients (31.7%) received CPR, 90 patients (63.4%) experienced unconsciousness, and 59 patients (41.5%) received endotracheal intubation and mechanical ventilation. Multivariate logistic regression analysis showed that the initial blood lactic acid level (OR: 7.67, 95%CI: 1.23-47.82, P=.029) was associated with a poor neurological prognosis in patients without cardiac arrest. The incidence of ICU admission (OR: 16.604, 95%CI: 1.15-239.49, P=.039) was associated with a poor neurologic prognosis in patients with cardiac arrest.

CONCLUSIONS

For the drowning patients with cardiac arrest, ICU admission was associated with neurological function prognosis in these patients. Among the patients without cardiac arrest, the initial lactate value was associated with neurological function prognosis of these patients.

LIMITATIONS

Retrospective.

CONFLICT OF INTEREST

None.

2021 International Consensus on Cardiopulmonary Resuscitation and Emergency Cardiovascular Care Science With Treatment Recommendations: Summary From the Basic Life Support; Advanced Life Support; Neonatal Life Support; Education, Implementation, and Teams; First Aid Task Forces; and the COVID-19 Working Group

The International Liaison Committee on Resuscitation initiated a continuous review of new, peer-reviewed published cardiopulmonary resuscitation science. This is the fifth annual summary of the International Liaison Committee on Resuscitation International Consensus on Cardiopulmonary Resuscitation and Emergency Cardiovascular Care Science With Treatment Recommendations; a more comprehensive review was done in 2020. This latest summary addresses the most recently published resuscitation evidence reviewed by International Liaison Committee on Resuscitation task force science experts. Topics covered by systematic reviews in this summary include resuscitation topics of video-based dispatch systems; head-up cardiopulmonary resuscitation; early coronary angiography after return of spontaneous circulation; cardiopulmonary resuscitation in the prone patient; cord management at birth for preterm and term infants; devices for administering positive-pressure ventilation at birth; family presence during neonatal resuscitation; self-directed, digitally based basic life support education and training in adults and children; coronavirus disease 2019 infection risk to rescuers from patients in cardiac arrest; and first aid topics, including cooling with water for thermal burns, oral rehydration for exertional dehydration, pediatric tourniquet use, and methods of tick removal. Members from 6 International Liaison Committee on Resuscitation task forces have assessed, discussed, and debated the quality of the evidence, according to the Grading of Recommendations Assessment, Development, and Evaluation criteria, and their statements include consensus treatment recommendations or good practice statements. Insights into the deliberations of the task forces are provided in Justification and Evidence-to-Decision Framework Highlights sections. In addition, the task forces listed priority knowledge gaps for further research.

2021 International Consensus on Cardiopulmonary Resuscitation and Emergency Cardiovascular Care Science With Treatment Recommendations

The International Liaison Committee on Resuscitation initiated a continuous review of new, peer-reviewed published cardiopulmonary resuscitation science. This is the fifth annual summary of the International Liaison Committee on Resuscitation International Consensus on Cardiopulmonary Resuscitation and Emergency Cardiovascular Care Science With Treatment Recommendations; a more comprehensive review was done in 2020. This latest summary addresses the most recently published resuscitation evidence reviewed by International Liaison Committee on Resuscitation task force science experts. Topics covered by systematic reviews in this summary include resuscitation topics of video-based dispatch systems; head-up cardiopulmonary resuscitation; early coronary angiography after return of spontaneous circulation; cardiopulmonary resuscitation in the prone patient; cord management at birth for preterm and term infants; devices for administering positive-pressure ventilation at birth; family presence during neonatal resuscitation; self-directed, digitally based basic life support education and training in adults and children; coronavirus disease 2019 infection risk to rescuers from patients in cardiac arrest; and first aid topics, including cooling with water for thermal burns, oral rehydration for exertional dehydration, pediatric tourniquet use, and methods of tick removal. Members from 6 International Liaison Committee on Resuscitation task forces have assessed, discussed, and debated the quality of the evidence, according to the Grading of Recommendations Assessment, Development, and Evaluation criteria, and their statements include consensus treatment recommendations or good practice statements. Insights into the deliberations of the task forces are provided in Justification and Evidence-to-Decision Framework Highlights sections. In addition, the task forces listed priority knowledge gaps for further research.

Singapore Advanced Cardiac Life Support Guidelines 2021

Advanced cardiac life support (ACLS) emphasises the use of advanced airway management and ventilation, circulatory support and the appropriate use of drugs in resuscitation, as well as the identification of reversible causes of cardiac arrest. Extracorporeal cardiopulmonary resuscitation and organ donation, as well as special circumstances including drowning, pulmonary embolism and pregnancy are addressed. Resuscitation does not end with ACLS but must continue in post-resuscitation care. ACLS also covers the recognition and management of unstable pre-arrest tachy- and bradydysrhythmias that may deteriorate further.

A scoping review of female drowning: an underexplored issue in five high-income countries

BACKGROUND

Drowning is a significant public health issue, with females accounting for one third of global drowning deaths. The rate of female drowning has not decreased within high-income countries and presentations to hospital have increased. This scoping review aimed to explore adult female unintentional drowning, including risk factors, clinical treatment and outcomes of females hospitalised for drowning.

METHODS

A systematic search of the literature following the PRISMA-ScR framework was undertaken. The databases OVID MEDLINE, Embase, CINAHL, OVID Emcare, Web of Science, Informit and Scopus were accessed. Study locations of focus were Australia, Canada, New Zealand, the United Kingdom, and the United States. Studies from January 2003 to April 2019 were included. The quality of evidence of included studies was assessed using GRADE guidelines.

RESULTS

The final search results included 14 studies from Australia (n = 4), Canada (n = 1), New Zealand (n = 1), United States (n = 6), United Kingdom (n = 1), and one study reporting data from both Australia and United States. Nine studies reported risk factors for female drowning including age, with the proportion of female drowning incidence increasing with age. Although females are now engaging in risk-taking behaviours associated with drowning that are similar to males, such as consuming alcohol and swimming in unsafe locations, their exposure to risky situations and ways they assess risk, differ. Females are more likely to drown from accidental entry into water, such as in a vehicle during a flood or fall into water. This review found no evidence on the clinical treatment provided to females in hospital after a drowning incident, and only a small number of studies reported the clinical outcomes of females, with inconsistent results (some studies reported better and some no difference in clinical outcomes among females).

CONCLUSION

Adult females are a group vulnerable to drowning, that have lacked attention. There was no single study found which focused solely on female drowning. There is a need for further research to explore female risk factors, the clinical treatment and outcomes of females hospitalised for drowning. This will not only save the lives of females, but also contribute to an overall reduction in drowning.

Rewarming From Hypothermic Cardiac Arrest Applying Extracorporeal Life Support: A Systematic Review and Meta-Analysis

Introduction: This systematic review and meta-analysis aims at comparing outcomes of rewarming after accidental hypothermic cardiac arrest (HCA) with cardiopulmonary bypass (CPB) or/and extracorporeal membrane oxygenation (ECMO). Material and Methods: Literature searches were limited to references with an abstract in English, French or German. Additionally, we searched reference lists of included papers. Primary outcome was survival to hospital discharge. We assessed neurological outcome, differences in relative risks (RR) of surviving, as related to the applied rewarming technique, sex, asphyxia, and witnessed or unwitnessed HCA. We calculated hypothermia outcome prediction probability score after extracorporeal life support (HOPE) in patients in whom we found individual data. P < 0.05 considered significant. Results: Twenty-three case observation studies comprising 464 patients were included in a meta-analysis comparing outcomes of rewarming with CPB or/and ECMO. One-hundred-and-seventy-two patients (37%) survived to hospital discharge, 76 of 245 (31%) after CPB and 96 of 219 (44 %) after ECMO; 87 and 75%, respectively, had good neurological outcomes. Overall chance of surviving was 41% higher (P = 0.005) with ECMO as compared with CPB. A man and a woman had 46% (P = 0.043) and 31% (P = 0.115) higher chance, respectively, of surviving with ECMO as compared with CPB. Avalanche victims had the lowest chance of surviving, followed by drowning and people losing consciousness in cold environments. Assessed by logistic regression, asphyxia, unwitnessed HCA, male sex, high initial body temperature, low pH and high serum potassium (s-K+) levels were associated with reduced chance of surviving. In patients displaying individual data, overall mean predictive surviving probability (HOPE score; n = 134) was 33.9 ± 33.6% with no significant difference between ECMO and CPB-treated patients. We also surveyed 80 case reports with 96 victims of HCA, who underwent resuscitation with CPB or ECMO, without including them in the meta-analysis. Conclusions: The chance of surviving was significantly higher after rewarming with ECMO, as compared to CPB, and in patients with witnessed compared to unwitnessed HCA. Avalanche victims had the lowest probability of surviving. Male sex, high initial body temperature, low pH, and high s-K+ were factors associated with low surviving chances.

Resuscitation and emergency care in drowning: A scoping review

BACKGROUND

The ILCOR Basic Life Support Task Force and the international drowning research community considered it timely to undertake a scoping review of the literature to identify evidence relating to the initial resuscitation, hospital-based interventions and criteria for safe discharge related to drowning.

METHODS

Medline, PreMedline, Embase, Cochrane Reviews and Cochrane CENTRAL were searched from 2000 to June 2020 to identify relevant literature. Titles and abstracts and if necessary full text were reviewed in duplicate. Studies were eligible for inclusion if they reported on the population (adults and children who are submerged in water), interventions (resuscitation in water/boats, airway management, oxygen administration, AED use, bystander CPR, ventilation strategies, ECMO, protocols for hospital discharge (I), comparator (standard care) and outcomes (O) survival, survival with a favourable neurological outcome, CPR quality, physiological end-points).

RESULTS

The database search yielded 3242 references (Medline 1104, Pre-Medline 202, Embase 1722, Cochrane reviews 12, Cochrane CENTRAL 202). After removal of duplicates 2377 papers were left for screening titles and abstracts. In total 65 unique papers were included. The evidence identified was from predominantly high-income countries and lacked consistency in the populations, interventions and outcomes reported. Clinical studies were exclusively observational in nature.

CONCLUSION

This scoping review found that there is very limited evidence from observational studies to inform evidence based clinical practice guidelines for drowning. The review highlights an urgent need for high quality research in drowning.

Impact of prehospital airway interventions on outcome in cardiac arrest following drowning: A study from the CARES Surveillance Group

INTRODUCTION

Drowning results in more than 360,000 deaths annually, making it the 3rd leading cause of unintentional injury death worldwide. Prior studies have examined airway interventions affecting patient outcomes in cardiac arrest, but less is known about drowning patients in arrest. This study evaluated the outcomes of drowning patients in the Cardiac Arrest Registry to Enhance Survival (CARES) who received advanced airway management.

METHODS

A retrospective analysis of the CARES database identified cases of drowning etiology between 2013 and 2018. Patients were stratified by airway intervention performed by EMS personnel. Demographics, sustained return of spontaneous circulation [ROSC], survival to hospital admission, survival to hospital discharge, and neurological outcomes were compared between airway groups using chi-squared tests and logistic regression.

RESULTS

Among 2388 drowning patients, 70.4% were male, 41.8% white, and 13.1% survived to hospital discharge. Patients that received supraglottic airways [SGA] had statistically significantly lower odds of survival to hospital admission compared to endotracheal tube [ETT] use (adjusted odds ratio [aOR] = 0.56, 95% confidence interval [CI] 0.42-0.76) as well as lower odds of survival to discharge compared to bag valve mask [BVM] use (aOR = 0.40, 95% CI 0.19-0.86) when accounting for relative ROSC timing.

CONCLUSION

In this national cohort of drowning patients in cardiac arrest, SGA use was associated with significantly lower odds of survival to hospital admission and discharge. However, survival to discharge with favorable neurological outcome did not differ significantly between airway management techniques. Further studies will need to examine if airway intervention order or time to intervention affects outcomes.

Wilderness Medical Society Clinical Practice Guidelines for the Treatment and Prevention of Drowning: 2019 Update

The Wilderness Medical Society convened a panel to review available evidence supporting practices for acute management and treatment of drowning in out-of-hospital and emergency medical care settings. Literature about definitions and terminology, epidemiology, rescue, resuscitation, acute clinical management, disposition, and drowning prevention was reviewed. The panel graded available evidence supporting practices according to the American College of Chest Physicians criteria and then made recommendations based on that evidence. Recommendations were based on the panel's collective clinical experience and judgment when published evidence was lacking. This is the first update to the original practice guidelines published in 2016.

Long-Term Survival After Drowning-Related Cardiac Arrest

BACKGROUND

Long-term outcomes after drowning-related cardiac arrest are not well characterized.

OBJECTIVE

Our aims were to estimate long-term survival and identify prognostic factors in a large, population-based cohort of drowning victims with cardiac arrest.

METHODS

We conducted a population-based prospective cohort study (1974-1996) of Western Washington Drowning Registry (WWDR) subjects with out-of-hospital cardiac arrest and attempted professional resuscitation. The primary outcome was long-term survival through 2012. We tabulated Utstein-style exposure variables, estimated Kaplan-Meier curves, and identified prognostic factors with Cox proportional hazard modeling.

RESULTS

Of 2824 WWDR cases, 407 subjects (median age 17 years [interquartile range 3-33 years], 81% were male) were included. Only 54 (13%) were still alive after 1663 person-years of follow-up. Most deaths occurred after termination of initial resuscitation or during initial hospitalization. Risk of subsequent death after hospital discharge was 9.6 (95% confidence interval [CI] 5.7-15.9) per 1000 person-years. Long-term survival differed by Utstein variables (older age, illicit substance use, pre-drowning activity, submersion duration, cardiopulmonary resuscitation duration, intubation, defibrillation, and medications) and inpatient markers of illness severity (vital signs, Glasgow Coma Scale, laboratory values, shock). In adjusted analyses, older age (hazard ratio [HR] 1.01; 95% CI 1.01-1.02), epinephrine administration (HR 1.92; 95% CI 1.31-2.80), antiepileptic administration (HR 0.53; 95% CI 0.35-0.81), initial arterial pH (HR 0.49; 95% CI 0.26-0.92), and shock (HR 2.19; 95% CI 1.16-4.15) were associated with higher risk of death.

CONCLUSIONS

Most cases of drowning-related cardiac arrest were fatal, but survivors to hospital discharge had a low risk of subsequent death that was independently associated with older age and clinical evidence of shock.

Unmanned aerial vehicles (drones) to prevent drowning

BACKGROUND

Drowning literature have highlighted the submersion time as the most powerful predictor in assessing the prognosis. Reducing the time taken to provide a flotation device and prevent submersion appears of paramount importance. Unmanned aerial vehicles (UAVs) can provide the location of the swimmer and a flotation device.

OBJECTIVE

The objective of this simulation study was to evaluate the efficiency of a UAV in providing a flotation device in different sea conditions, and to compare the times taken by rescue operations with and without a UAV (standard vs UAV intervention). Several comparisons were made using professional lifeguards acting as simulated victims. A specifically-shaped UAV was used to allow us to drop an inflatable life buoy into the water.

RESULTS

During the summer of 2017, 28 tests were performed. UAV use was associated with a reduction of time it took to provide a flotation device to the simulated victim compared with standard rescue operations (p < 0.001 for all measurements) and the time was reduced even further in moderate (81 ± 39 vs 179 ± 78 s; p < 0.001) and rough sea conditions (99 ± 34 vs 198 ± 130 s; p < 0.001). The times taken for UAV to locate the simulated victim, identify them and drop the life buoy were not altered by the weather conditions.

CONCLUSION

UAV can deliver a flotation device to a swimmer safely and quickly. The addition of a UAV in rescue operations could improve the quality and speed of first aid while keeping lifeguards away from dangerous sea conditions.

Review of 14 drowning publications based on the Utstein style for drowning

BACKGROUND

The Utstein style for drowning (USFD) was published in 2003 with the aim of improving drowning research. To support a revision of the USFD, the current study aimed to generate an inventory of the use of the USFD parameters and compare the findings of the publications that have used the USFD.

METHODS

A search in Pubmed, Embase, the Cochrane Library, Web of Science and Scopus was performed to identify studies that used the USFD and were published between 01-10-2003 and 22-03-2015. We also searched in Pubmed, Embase, the Cochrane Library, Web of Science, and Scopus for all publications that cited the two publications containing the original ILCOR advisory statement introducing and recommending the USFD. In total we identified 14 publications by groups that explicitly used elements of the USFD for collecting and reporting their data.

RESULTS

Of the 22 core and 19 supplemental USFD parameters, 6-19 core (27-86%) and 1-12 (5-63%) supplemental parameters were used; two parameters (5%) have not been used in any publication. Associations with outcome were reported for nine core (41%) and five supplemental (26%) USFD parameters. The USFD publications also identified non-USFD parameters related to outcome: initial cardiac rhythm, time points and intervals during resuscitation, intubation at the drowning scene, first hospital core temperature, serum glucose and potassium, the use of inotropic/vasoactive agents and the Paediatric Index of Mortality 2-score.

CONCLUSIONS

Fourteen USFD based drowning publications have been identified. These publications provide valuable information about the process and quality of drowning resuscitation and confirm that the USFD is helpful for a structured comparison of the outcome of drowning resuscitation.

2015 revised Utstein-style recommended guidelines for uniform reporting of data from drowning-related resuscitation: An ILCOR advisory statement

BACKGROUND

Utstein-style guidelines use an established consensus process, endorsed by the international resuscitation community, to facilitate and structure resuscitation research and publication. The first "Guidelines for Uniform Reporting of Data From Drowning" were published over a decade ago. During the intervening years, resuscitation science has advanced considerably, thus making revision of the guidelines timely. In particular, measurement of cardiopulmonary resuscitation elements and neurological outcomes reporting have advanced substantially. The purpose of this report is to provide updated guidelines for reporting data from studies of resuscitation from drowning.

METHODS

An international group with scientific expertise in the fields of drowning research, resuscitation research, emergency medical services, public health, and development of guidelines met in Potsdam, Germany, to determine the data that should be reported in scientific articles on the subject of resuscitation from drowning. At the Utstein-style meeting, participants discussed data elements in detail, defined the data, determined data priority, and decided how data should be reported, including scoring methods and category details.

RESULTS

The template for reporting data from drowning research was revised extensively, with new emphasis on measurement of quality of resuscitation, neurological outcomes, and deletion of data that have proved to be less relevant or difficult to capture.

CONCLUSIONS

The report describes the consensus process, rationale for selecting data elements to be reported, definitions and priority of data, and scoring methods. These guidelines are intended to improve the clarity of scientific communication and the comparability of scientific investigations.

2015 Revised Utstein-Style Recommended Guidelines for Uniform Reporting of Data From Drowning-Related Resuscitation: An ILCOR Advisory Statement

BACKGROUND

Utstein-style guidelines use an established consensus process, endorsed by the international resuscitation community, to facilitate and structure resuscitation research and publication. The first "Guidelines for Uniform Reporting of Data From Drowning" were published over a decade ago. During the intervening years, resuscitation science has advanced considerably, thus making revision of the guidelines timely. In particular, measurement of cardiopulmonary resuscitation elements and neurological outcomes reporting have advanced substantially. The purpose of this report is to provide updated guidelines for reporting data from studies of resuscitation from drowning.

METHODS

An international group with scientific expertise in the fields of drowning research, resuscitation research, emergency medical services, public health, and development of guidelines met in Potsdam, Germany, to determine the data that should be reported in scientific articles on the subject of resuscitation from drowning. At the Utstein-style meeting, participants discussed data elements in detail, defined the data, determined data priority, and decided how data should be reported, including scoring methods and category details.

RESULTS

The template for reporting data from drowning research was revised extensively, with new emphasis on measurement of quality of resuscitation, neurological outcomes, and deletion of data that have proved to be less relevant or difficult to capture.

CONCLUSIONS

The report describes the consensus process, rationale for selecting data elements to be reported, definitions and priority of data, and scoring methods. These guidelines are intended to improve the clarity of scientific communication and the comparability of scientific investigations.

Bystander CPR is associated with improved neurologically favourable survival in cardiac arrest following drowning

BACKGROUND

Cardiac arrest associated with drowning is a major public health concern with limited research available on outcome. This investigation aims to define the population at risk, and identify factors associated with neurologically favourable survival.

METHODS

The Cardiac Arrest Registry for Enhanced Survival (CARES) database was queried for patients who had suffered cardiac arrest following drowning between January 1, 2013 and December 31, 2015. The primary outcomes of interest were for favourable or unfavourable neurological outcome at hospital discharge, as defined by Cerebral Performance Category (CPC).

RESULTS

A total of 919 drowning patients were identified. Neurological outcome data was available in 908 patients. Neurologically favourable survival was significantly associated with bystander CPR (Odds Ratio (OR)=2.94; 95% Confidence Interval (CI) 1.86-4.64; p<0.001), witnessed drowning (OR=2.6; 95% CI 1.69-4.01; p<0.001) and younger age (OR=0.97, 95% CI 0.96-0.98; p<0.001). Public location of drowning (OR=1.17; 95% CI 0.77-1.79; p=0.47), male gender (OR=0.9, 95% CI 0.57-1.43; p=0.66), and shockable rhythm (OR=1.54; 95% CI 0.76-3.12; p=0.23), were not associated with favourable neurological survival. AED application prior to EMS was associated with a decreased likelihood of favourable neurological outcome (OR=0.38; 95% CI 0.28-0.66; p<0.001). In multivariate analysis, bystander CPR (adjusted OR 3.02, 95% CI 1.85-4.92, p<0.001), witnessed drowning (adjusted OR 3.27, 95% CI 2.0-5.36, p<0.001) and younger age (adjusted OR 0.97, 95% CI 0.96-0.98, p<0.001) remained associated with neurologically favourable survival.

CONCLUSIONS

Neurologically favourable survival after drowning remains low but is improved by bystander CPR. Shockable rhythms were uncommon and not associated with improved outcomes.

Can we identify termination of resuscitation criteria in cardiac arrest due to drowning: results from the French national out-of-hospital cardiac arrest registry

RATIONALE, AIMS AND OBJECTIVES

The aim of this study was to describe the cohort of persons having experiences fatal and non-fatal drowning events, registered in the French cardiac arrest registry and to identify termination of resuscitation criteria.

METHODS

We performed a prospective multicenter study based on data from French cardiac arrest registry database. All patients with cardiac arrest after drowning (CAD) recorded between July 2011 and November 2014 were included. The population description was carried out by medians [interquartile ranges (IQR)] or frequencies. The characteristics were compared in terms of the primary endpoint (alive vs dead at hospital admission) using chi-square or Fisher's exact and the Mann-Whitney U test. The predictive model was carried out using the multivariate logistic regression.

RESULTS

The analysis included 234 CAD. The majority of patients were adults (83.6%) and males (64.5%). Most of the submersions occurred out of home (75.6%). We recorded 66.7% of incidents in fresh water. About a third of CAD was witnessed of which 33.8% had an immediate basic life support. Most of CAD patients received an advanced cardiac life support (87.2%). The median Mobile Medical Team response time was 22 [15-30] minutes. At hospital, 40.6% of patients were alive. Twenty one patients (9.0%) were discharged alive. Among them, 17 had a good neurological outcome. Faster interventions generally resulted in higher survival chances (Mobile Medical Team response time OR: 0.960[0.925; 0.996]; P = 0.0.031; no flow duration OR: 0.535[0.313; 0.913]; P = 0.022) if associated with ventilation (OR: 6.742[2.043; 22.250]; P = 0.002). Age (OR: 0.971[0.955; 0.988]; P = 0.001) and location outside (OR: 0.203[0.064; 0.625]; P = 0.007) are the other criteria of our model.

CONCLUSIONS

The model is helpful to highlight explanative variables concerning CAD patients' outcome. The next step is the validation of these five factors by a larger study. Prevention and public training to lifesaving behaviours must be considered as priorities in French public health programmes.

Relationship between drowning location and outcome after drowning-associated out-of-hospital cardiac arrest: nationwide study

PURPOSE

Accidental drowning can cause out-of-hospital cardiac arrest (OHCA). We investigated the effect of drowning location on outcomes of individuals who experienced drowning-OHCA.

METHODS

All cases of emergency medical service-treated drowning-OHCA in South Korea from January 2006 to December 2013 were analyzed. Cases were excluded if there was a preceding injury, no information on event location, or suicide. Cases were divided into 4 groups: recreational water with mandatory safety regulations (group 1, public swimming pool; group 2, beach) and nonrecreational water without mandatory safety regulations (group 3, natural freshwater; group 4, seawater). The main outcome was survival to hospital discharge. Multiple logistic regression analysis was conducted using natural freshwater as the reference location.

RESULTS

We analyzed 1691 drowning-OHCAs (public swimming pools, 3.4%; public beaches, 5.2%; unsupervised seawater, 33.8%; and unsupervised open freshwater, 57.6%). The rate of survival to discharge was 4.6% for all cases, 17.5% for cases in public swimming pools, 9.1% for cases in public beaches, 4.9% for cases in unsupervised seawater, and 3.3% for cases in unsupervised open freshwater (p<0.01). The adjusted odds ratios (95% confidence intervals [CIs]) for survival relative to natural freshwater were 3.97 (95% CI, 1.77-8.89) for public swimming pools, 2.81 (95% CI, 1.22-6.45) for public beaches, and 1.54 (95% CI, 0.88-2.70) for unsupervised seawater.

CONCLUSION

Individuals who experience drowning-OHCA in public locations with safety regulations had a better rate of survival. There should be improved public awareness of the significantly greater risk of drowning-OHCA in locations that have no safety regulations.

Wilderness Medical Society Practice Guidelines for the Prevention and Treatment of Drowning

The Wilderness Medical Society convened a panel to review available evidence supporting practices for the prevention and acute management of drowning in out-of-hospital and emergency medical care settings. Literature about definition and terminology, epidemiology, rescue, resuscitation, acute clinical management, disposition, and drowning prevention was reviewed. The panel graded evidence supporting practices according to the American College of Chest Physicians criteria, then made recommendations based on that evidence. Recommendations were based on the panel's collective clinical experience and judgment when published evidence was lacking.

Drowning: an overlooked cause of out-of-hospital cardiac arrest in Canada

INTRODUCTION

Drowning is a major public health concern, yet little is known about the characteristics of drowning patients. The objectives of this study were to describe the demographic and clinical characteristics of out-of-hospital cardiac arrest (OHCA) attributed to drowning in Ontario and to compare the characteristics of OHCA attributed to drowning to those of presumed cardiac etiology.

METHODS

A retrospective, observational study was carried out of consecutive OHCA patients of drowning etiology in Ontario between August 2006 and July 2011. Bivariate analysis was used to evaluate differences between drowning and presumed cardiac etiologies.

RESULTS

A total of 31,763 OHCA patients were identified, and 132 (0.42%) were attributed to drowning. Emergency medical services treated 98 patients, whereas the remaining 34 met the criteria for legislative death. Overall, 5.1% of drowning patients survived to hospital discharge. When compared to patients of presumed cardiac etiology, drowning patients were younger and their arrest was more likely to be unwitnessed, present with a nonshockable initial rhythm, occur in a public location, and receive bystander cardiopulmonary resuscitation (CPR). A nonsignificant trend was noted for drowning cases to more frequently have a public access AED applied. There were no significant differences in the gender ratio or paramedic response times. Drowning patients were more likely to be transported to hospital but had a trend to be less likely to arrive with a return of spontaneous circulation. They were also more likely to be admitted to hospital but had no difference in survival to hospital discharge.

CONCLUSIONS

Significant differences exist between OHCA of drowning and presumed cardiac etiologies. Most drownings are unwitnessed, occur in public locations, and present with nonshockable initial rhythms, suggesting that treatment should focus on bystander CPR. Future initiatives should focus on strategies to improve supervision in targeted locations and greater emphasis on bystander-initiated CPR, both of which may reduce drowning mortality.

Comparison of clinical characteristics of intentional vs accidental drowning patients

PURPOSES

Drowning may happen by accident or as a method of committing suicide. The aim of this study was to determine some characteristics of drowning patients who committed intentionally.

METHODS

A retrospective review was performed on 462 patients who visited the emergency department complaining of drowning between January 1998 and October 2011. Of these patients, we only included the patients for whom the cause could be identified. Age, sex, cause, time of drowning, season, mechanism, cardiopulmonary resuscitation performance, body temperature, alcohol ingestion, history of previous suicide attempts, outcome, and other characteristics were collected.

RESULTS

A total of 380 patients were included. Among them, 282 (74.2%) had drowned themselves intentionally, and they were older than those who had drowned accidentally (median age, 35.0 years [25.0-49.0 years] vs 26.5 years [19.0-35.5 years], P < .001) and showed lower body temperature (below 34°C, 32.1% vs 12.2%, P = .027). Ninety-four cases (33.3%) jumped off the river from a bridge, and 185 (65.6%) walked into the river from the riverside. In the intentional group, 59 (20.9%) had depressive disorder in their history. The rate of death showed no clinical difference (19.5% vs 16.3%, P = .487), but more males died in the accidental group (61.8% vs 93.8%, P = .015).

CONCLUSIONS

Intentional drowning happened more in older subjects and presented lower initial body temperature. Walking from the riverside happened more often than jumping off a bridge. More males died of drowning regardless of intentionality.

Drowning in children: Utstein style reporting and outcome

BACKGROUND

We report the incidence and mortality of paediatric drowning incidents according to 'Utstein Style for Drowning' guidelines.

METHODS

Retrospective study including all the drowned children under 16 years of age who were hospitalised or died with or without attempted cardiopulmonary resuscitation (CPR) between 1997 and 2007 in the province of Uusimaa, Finland. Survival rates provided at hospital discharge and after 1-year follow-up period are reported.

RESULTS

A total of 58 drowned children were either admitted to the paediatric intensive care unit or died during the study period. The median (interquartile range) age was 5.9 (3.1, 7.8) years. The annual incidence of drowning was 1.9/100,000 and was highest, 2.8/100,000, in children aged between 1 and 4 years. The annual mortality rate was 0.9/100,000. Of all the 58 patients, 14 (24%) died at the scene, 22 (38.1%) before the hospital discharge, and 26 (45%) within the 1 year. The number of non-fatal drownings was 1.2-fold that of fatal drownings. The survival rate of the 26 patients for whom CPR was initiated by emergency medical service (EMS) personnel was 42% at hospital discharge, with the 1-year survival rate being 27%.

CONCLUSIONS

The incidence of drowning in children and the survival rate of those children in whom CPR was initiated by EMS personnel was in line with the previously reported. However, the overall mortality rate in drowned children was higher than estimated in previous studies.

Out-of-hospital cardiac arrest due to drowning among children and adults from the Utstein Osaka Project

BACKGROUND

Children have better outcomes after out-of-hospital cardiac arrest (OHCA) than adults. However, little is known about the difference in outcomes between children and adults after OHCA due to drowning.

OBJECTIVES

The aim of this study is to assess the outcome after OHCA due to drowning between children and adults. Our hypothesis is that outcomes after OHCA due to drowning would be in better among children (<18 years old) compared with adults (≥18 years old).

METHOD

This prospective population-based, observational study included all emergency medical service-treated OHCA due to drowning in Osaka, Japan, between 1999 and 2010 (excluding 2004). Outcomes were evaluated between younger children (0-4 years old), older children (5-17 years old), and adults (≥18 years old). Major outcome measures were one-month survival and neurologically favorable one-month survival defined as cerebral performance category 1 or 2. Multivariate logistic regression analyses were used to account for potential confounders.

RESULTS

During the study period, 66,716 OHCAs were documented, and resuscitation was attempted for 62,048 patients (1300 children [2%] and 60,748 adults [98%]). Among these OHCAs, 1737 (3% of OHCAs) were due to drowning (36 younger children [2%], 32 older children [2%], and 1669 adults [96%]). The odds of one-month survival were significantly higher for younger children (28% [10/36]; adjusted odds ratio [AOR], 20.20 [95% confidence interval {CI} 7.45-54.78]) and older children (9% [3/32]; AOR, 4.47 [95% CI 1.04-19.27]) when compared with adults (2% [28/1669]). However, younger children (6% [2/36]; AOR, 5.23 [95% CI 0.52-51.73]) and older children (3% [1/32]; AOR, 2.53 [95% CI 0.19-34.07]) did not have a higher odds of neurologically favorable outcome than adults (1% [11/1669]).

CONCLUSION

In this large OHCA registry, children had better one-month survival rates after OHCA due to drowning compared with adults. Most survivors in all groups had unfavorable neurological outcomes.

Brain resuscitation in the drowning victim

Drowning is a leading cause of accidental death. Survivors may sustain severe neurologic morbidity. There is negligible research specific to brain injury in drowning making current clinical management non-specific to this disorder. This review represents an evidence-based consensus effort to provide recommendations for management and investigation of the drowning victim. Epidemiology, brain-oriented prehospital and intensive care, therapeutic hypothermia, neuroimaging/monitoring, biomarkers, and neuroresuscitative pharmacology are addressed. When cardiac arrest is present, chest compressions with rescue breathing are recommended due to the asphyxial insult. In the comatose patient with restoration of spontaneous circulation, hypoxemia and hyperoxemia should be avoided, hyperthermia treated, and induced hypothermia (32-34 °C) considered. Arterial hypotension/hypertension should be recognized and treated. Prevent hypoglycemia and treat hyperglycemia. Treat clinical seizures and consider treating non-convulsive status epilepticus. Serial neurologic examinations should be provided. Brain imaging and serial biomarker measurement may aid prognostication. Continuous electroencephalography and N20 somatosensory evoked potential monitoring may be considered. Serial biomarker measurement (e.g., neuron specific enolase) may aid prognostication. There is insufficient evidence to recommend use of any specific brain-oriented neuroresuscitative pharmacologic therapy other than that required to restore and maintain normal physiology. Following initial stabilization, victims should be transferred to centers with expertise in age-specific post-resuscitation neurocritical care. Care should be documented, reviewed, and quality improvement assessment performed. Preclinical research should focus on models of asphyxial cardiac arrest. Clinical research should focus on improved cardiopulmonary resuscitation, re-oxygenation/reperfusion strategies, therapeutic hypothermia, neuroprotection, neurorehabilitation, and consideration of drowning in advances made in treatment of other central nervous system disorders.

Drowning related out-of-hospital cardiac arrests: characteristics and outcomes

AIM

There are few studies on drowning-related out-of-hospital cardiac arrest (OHCA) in which patients are followed from the scene through to hospital discharge. This study aims to describe this population and their outcomes in the state of Victoria (Australia).

METHODS

The Victorian Ambulance Cardiac Arrest Registry was searched for all cases of OHCA with a precipitating event of drowning attended by emergency medical services (EMS) between October 1999 and December 2011.

RESULTS

EMS attended 336 drowning-related OHCA during the study period. Cases frequently occurred in summer (45%) and the majority of patients were male (70%) and adult (77%). EMS resuscitation was attempted on 154 (46%) patients. Of these patients, 41 (27%) survived to hospital arrival and 12 (8%) survived to hospital discharge (5 adults [6%] and 7 [12%] children). Few patients were found in a shockable rhythm (6%), with the majority presenting in asystole (79%) or pulse-less electrical activity (13%). An initial shockable rhythm was found to positively predict survival (AOR 48.70, 95% CI: 3.80-624.86) while increased EMS response time (AOR 0.73, 95% CI: 0.54-0.98) and salt water drowning (AOR 0.69, 95% CI: 0.01-0.84) were found to negatively predict survival.

CONCLUSIONS

Rates of survival in OHCA caused by drowning are comparable to other OHCA causes. Patients were more likely to survive if they did not drown in salt water, had a quick EMS response and they were found in a shockable rhythm. Prevention efforts and reducing EMS response time are likely to improve survival of drowning patients.

Outcome analysis of cardiac arrest due to hanging injury

OBJECTIVE

The aim of this study was to review patient characteristics and analyze the outcomes in patients who have had cardiac arrest from hanging injuries.

METHODS

A retrospective review was performed that examined the victims of out-of-hospital cardiac arrest (OHCA) due to hanging who presented to a tertiary general hospital from January 2000 to December 2009. Utstein style variables were evaluated, and patient outcomes were assessed at the time of hospital discharge using the cerebral performance category (CPC) scale.

RESULTS

Fifty-two patients with OHCA due to hanging were enrolled in this study from the aforementioned 10-year inclusion period. Resuscitation attempts were performed in 31 patients (60%), and 21 patients were pronounced dead. In all cases, the first monitored cardiac rhythms were either asystole or pulseless electrical activity (PEA) and were therefore nonshockable rhythms. Of the patients for whom resuscitation was attempted, 13 (42%) experienced a return of spontaneous circulation and 1 revealed cervical spine fracture. Of the 13 return-of-spontaneous-circulation patients, 5 survived to be discharged. The mean age of these 5 surviving patients was 36 years. All 5 patients were graded as cerebral performance category 4 at discharge.

CONCLUSION

The first monitored cardiac rhythms of patients presenting with OHCA due to hanging were nonshockable rhythms wherein the survival rate of these patients was 9.6%. All of the survivors were relatively young and demonstrated poor neurologic outcomes at discharge. Physicians must consider cervical spine fracture in patients who had cardiac arrest from hanging.

Therapeutic hypothermia in adult cardiac arrest because of drowning

BACKGROUND

Therapeutic hypothermia in adult victims who suffer cardiac arrest following drowning has been applied in only a small number of cases. In the last 4 years, we have employed therapeutic hypothermia to decrease hypoxia-induced brain injury in these patients. The purpose of the present study was to report the results of the treatment of these patients.

METHODS

This study investigated the utilisation of therapeutic hypothermia on consecutive patients with cardiac arrest because of drowning between 2005 and 2008. The study was conducted retrospectively, collecting data by reviewing medical records. Hypothermia, with a target temperature of 32-34°C, was induced for 24 h. Neurological outcomes were classified using the cerebral performance categories (CPCs). The primary outcome was neurological function at discharge.

RESULTS

Twenty patients were treated with therapeutic hypothermia. Four patients (20%) exhibited a favourable neurological outcome (CPC 1-2). Two patients (10%) remained in a vegetative state at discharge (CPC 4), and 14 patients (70%) died (CPC 5). The most common complications during therapeutic hypothermia were pancreatitis and rhabdomyolysis. A longer duration of advanced cardiac life support (P = 0.035), an absence of motor response to pain after 3 days (P = 0.003), an abnormal brain imaging (P = 0.005) and a lack of cortical response to somatosensory evoked potential (P = 0.008) were related to an unfavourable outcome (CPC 3-5).

CONCLUSION

The present study did not demonstrate an advantage of therapeutic hypothermia in adult cardiac arrest after drowning compared with previous studies treated with conventional therapy. Further prospective studies are needed to evaluate the effects of therapeutic hypothermia.

Diagnosis and management of environmental thoracic emergencies

Physiologic sequelae from increasing ambient pressure in underwater activities, decreasing ambient pressure while at altitude, or the consequences of drowning present a unique set of challenges to emergency physicians. In addition, several environmental toxins cause significant respiratory morbidity, whether they be pulmonary irritants, simple asphyxiants, or systemic toxins. It is important for emergency physicians to understand the pathophysiology of these illnesses as well as to apply this knowledge to the clinical arena either in the prehospital setting or in the emergency department. Current treatment paradigms and controversies within these regimens are discussed.

Toddler parents training, understanding, and perceptions of CPR

BACKGROUND

Little is known about parent CPR skills and their perceptions of its use, especially in the context of drowning incidents among young children where parents are often the first responder. The primary objective of the study was to examine parental understanding of child and adult CPR, extent of CPR training, and parental confidence to perform CPR.

METHOD

Survey research using a self-complete questionnaire was used to gather data from parents (n = 1716) whose 2-4-year-old toddlers were either attending early childhood centres (n = 781) or enrolled in swim schools (n = 935). Differences in parental CPR training, knowledge, levels of confidence in ability to perform CPR, and perceptions were measured by frequency, with regression tests used to discern differences by institution, gender, ethnicity, length of residency, and recency of CPR training.

RESULTS

Almost two-thirds (64%) of parents reported that they had received formal CPR training in the past, yet few correctly reported the current ratios for either adult CPR (19%) or child CPR (12%). Most parents correctly agreed that, in child CPR, you must always give initial breaths before starting compressions (74%), but the majority incorrectly believed you should seek help before starting CPR (61%) and continue CPR for 5 min before stopping (59%). Most parents (56%) felt anxious about their ability to perform CPR on an adult, and even more (62%) felt anxious about their ability to perform child CPR.

CONCLUSION

Our findings highlight the need for education interventions to address the substantial gaps in knowledge of CPR for all parents of young children.

The role of bystanders during rescue and resuscitation of drowning victims

BACKGROUND

Bystanders make a critical difference in the survival of drowning victims. Little information on their role before arrival of the Emergency Medical Services (EMS) is available in the scientific literature. In a descriptive study, this role is investigated.

METHODS AND RESULTS

We studied 289 rescue reports (1999-2004) available from the Dutch Maatschappij tot Redding van Drenkelingen (Society to Rescue People from Drowning), an organisation that, since 1767, acknowledges awards to bystanders who have contributed to the survival of a drowning victim. There were 138 variables retrieved from these reports. The Utstein Style for Drowning (USFD) was used as a guideline. Of the 26 USFD parameters on victim and scene information, 21 were available for analysis. Eight non-USFD parameters, defined by the authors of this research, were available in >60% of the cases. There were 343 victims, rescued by 503 rescuers. 109 victims were resuscitated by bystanders. Of the 18 victims who first received resuscitation from bystanders and then consequently from pre-hospital professionals, 14 survived. Rescues often occurred in dangerous circumstances: multiple victims (n=90/343), cold or ice-cold water (n=295/341), deep water (n=316/334), swimming to the victims (n=262/376), young age of rescuers (the youngest rescuer was 5 years of age).

CONCLUSIONS

Bystander rescue and resuscitation of drowning victims seems to contribute to a positive outcome. Bystanders are prepared to take responsibility to rescue a drowning victim in spite of significant dangers. The USFD is helpful in understanding the role of bystanders in drowning situations, but may need modification to become more instrumental.