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

Increasing ventilation in drowning resuscitation - A cross-over randomized simulation study of ventilation during automated external defibrillator analysis pauses

Objective

The aim of this study was to analyze the feasibility of a new resuscitation strategy in which breaths are provided during automated external defibrillator (AED) rhythm analysis, and to evaluate its impact on chest compressions (CC) quality and the peri-analysis time.

Method

A randomized simulation study, comparing two cardiopulmonary resuscitations strategies, has been conducted: the standard strategy (S1) with strategy involving ventilation during AED analysis (S2). Thirty lifeguards have performed both strategies in a cross-over study design during 10 min of CPR.

Results

The number of ventilations per 10 min increases from 47 (S1) to 72 (S2) (p < 0.001). This results in the delivery of an additional 17.1 L of insufflated air in S2 compared to S1 (p < 0.001). There have been no significant changes in frequency and total number of CC. These findings correspond to a reduction of the non-ventilation period from 176 s (S1) to 48 s (S2).

Conclusions

This simulation study suggests that it is feasible to increase the number of ventilations during resuscitation following drowning, without affecting the quantity and quality of chest compressions. The results of this study may serve as a foundation for further investigation into optimal ventilation strategies in this context.

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.

Cardiac Arrest in Special Populations

Best practices in cardiac arrest depend on continuous high-quality chest compressions, appropriate ventilatory management, early defibrillation of shockable rhythms, and identification and treatment of reversible causes. Although most patients can be treated according to highly vetted treatment guidelines, some special situations in cardiac arrest arise where additional skills and preparation can improve outcomes. Situations covered in this section involve cardiac arrest in context of electrical injuries, asthma, allergic reactions, pregnancy, trauma, electrolyte imbalances, toxic exposures, hypothermia, drowning, pulmonary embolism, and left ventricular assist devices.

Danish Drowning Formula for identification of out-of-hospital cardiac arrest from drowning

BACKGROUND

Accurate, reliable, and sufficient data is required to reduce the burden of drowning by targeting preventive measures and improving treatment. Today's drowning statistics are informed by various methods sometimes based on data sources with questionable reliability. These methods are likely responsible for a systematic and significant underreporting of drowning. This study's aim was to assess the 30-day survival of patients with out-of-hospital cardiac arrest (OHCA) identified in the Danish Cardiac Arrest Registry (DCAR) after applying the Danish Drowning Formula.

METHODS

This nationwide, cohort, registry-based study with 30-day follow-up used the Danish Drowning Formula to identify drowning-related OHCA with a resuscitation attempt from the DCAR from January 1st, 2016, through December 31st, 2021. The Danish Drowning Formula is a text-search algorithm constructed for this study based on trigger-words identified from the prehospital medical records of validated drowning cases. The primary outcome was 30-day survival from OHCA. Data were analyzed using multiple logistic regression.

RESULTS

Drowning-related OHCA occurred in 374 (1%) patients registered in the DCAR compared to 29,882 patients with OHCA from other causes. Drowning-related OHCA more frequently occurred at a public location (87% vs 25%, p < 0.001) and were more frequently witnessed by bystanders (80% vs 55%, p < 0.001). Both 30-day and 1-year survival for patients with drowning-related OHCA were significantly higher compared to OHCA from other causes (33% vs 14% and 32% vs 13%, respectively, p < 0.001). The adjusted odds ratio for 30-day survival for drowning-related OHCA and other causes of OHCA was 2.3 [1.7-3.2], p < 0.001. Increased 30-day survival was observed for drowning-related OHCA occurring at swimming pools compared to public location OHCA from other causes with an OR of 11.6 [6.0-22.6], p < 0.001.

CONCLUSIONS

This study found higher 30-day survival among drowning-related OHCA compared to OHCA from other causes. This study proposed that a text-search algorithm (Danish Drowning Formula) could explore unstructured text fields to identify drowning persons. This method may present a low-resource solution to inform the drowning statistics in the future.

REGISTRATION

This study was registered at ClinicalTrials.gov before analyses (NCT05323097).

Cardiac Arrest in Special Populations

Best practices in cardiac arrest depend on continuous high-quality chest compressions, appropriate ventilatory management, early defibrillation of shockable rhythms, and identification and treatment of reversible causes. Although most patients can be treated according to highly vetted treatment guidelines, some special situations in cardiac arrest arise where additional skills and preparation can improve outcomes. Situations covered in this section involve cardiac arrest in context of electrical injuries, asthma, allergic reactions, pregnancy, trauma, electrolyte imbalances, toxic exposures, hypothermia, drowning, pulmonary embolism, and left ventricular assist devices.

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.

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: 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.

Clinical spectrum and risk factors for mortality among seawater and freshwater critically ill drowning patients: a French multicenter study

Background

Drowning is a global threat and one of the leading causes of injury around the world. The impact of drowning conditions including water salinity on patients’ prognosis remains poorly explored in Intensive Care Units (ICUs) patients.

Methods

We conducted a retrospective multicenter study on patients admitted to 14 ICUs in the west of France from January 2013 to January 2020. We first compared demographic and clinical characteristics at admission as well as clinical courses of these patients according to the salinity of drowning water. Then, we aimed to identify variables associated with 28-day survival using a Cox proportional hazard model.

Results

Of the 270 consecutive included patients, drowning occurred in seawater in 199 patients (73.7%) and in freshwater in 71 patients (26.3%). Day-28 mortality was observed in 55 patients (20.4%). Freshwater was independently associated with 28-day mortality (Adjusted Hazard Ratio (aHR) 1.84 [95% Confidence Interval (CI) 1.03–3.29], p = 0.04). A higher proportion of freshwater patients presented psychiatric comorbidities (47.9 vs. 19.1%; p < 0.0001) and the etiology of drowning appeared more frequently to be a suicide attempt in this population (25.7 vs. 4.2%; p < 0.0001). The other factors independently associated with 28-day mortality were the occurrence of a drowning-related cardiac arrest (aHR 11.5 [95% CI 2.51–52.43], p = 0.0017), duration of cardiopulmonary resuscitation (aHR 1.05 [95% CI 1.03–1.07], p < 0.0001) and SOFA score at day 1 (aHR 1.2 [95% CI 1.11–1.3], p < 0.0001).

Conclusions

In this large multicenter cohort, freshwater drowning patients had a poorer prognosis than saltwater drowning patients. Reasons for such discrepancies include differences in underlying psychiatric comorbidity, drowning circumstances and severities. Patients with initial cardiac arrest secondary to drowning remain with a very poor prognosis.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13054-021-03792-2.

Prehospital Cross-Sectional Study of Drowning Patients Across the United States

INTRODUCTION

Every year drowning is responsible for 7% of injury-related deaths worldwide, making it the third leading cause of unintentional injury-related death. However, in the United States, little is known regarding the prehospital presentation and management of these patients. The purpose of this study was to describe the drowning population in the United States, with a focus on prehospital time intervals, transport, and cardiac arrest frequency.

METHODS

A retrospective cross-sectional study was performed querying records from emergency medical services encounters across the United States over 30 mo (January 2016 to July 2018) using the ESO (Austin, TX) national emergency medical services data registry. Patients with a dispatch or chief complaint of drowning were included. Descriptive statistics, binomial proportion tests, and general linear and logistic regression models were used.

RESULTS

There were 1859 encounters that met the study criteria. Median age was 18 y (n=1855, LQ-UQ 4-46). Pediatric patients accounted for 50% (n=919, 95% CI 47-52). Cardiac arrest occurred in 29% (n=537, 95% CI 27-31), and return of spontaneous circulation occurred in 37% (n=186, 95% CI 32-41). Times were 8±5, 19±17, and 15±10 min (mean±SD) for arrival, on-scene, and transport times, respectively.

CONCLUSIONS

This national prehospital drowning study demonstrated that despite an 18% fatality rate in drowning encounters, patients were more likely to have return of spontaneous circulation when compared to the overall prehospital national average, with rates higher in pediatric patients. Future studies with outcomes data should focus on identifying factors that improve cardiopulmonary resuscitation success rates.

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.

Incidence and characteristics of drowning in Sweden during a 15-year period

AIM

Drowning is a global health problem and deeper knowledge about the extent and causes is of utmost importance for implementing preventative actions. The aim of this study was to describe the incidence and characteristics of drowning in Sweden over time, including both non-fatal and fatal cases.

METHODS

All cases identified as drowning (ICD-10 coding) at a national level in Sweden between 2003-2017 were collected. Three sources of data from the Swedish National Board of Health and Welfare were extracted via the Cause of Death Register and the National Patient Register.

RESULTS

Over 15 years, a total of 6609 cases occurred, resulting in an annual incidence of 4.66 per 100 000. The median age was 49 years (IQR 23-67) and 67% were males. Non-fatal drownings represented 51% (n = 3363), with an overall non-fatal to fatal ratio of 1:1, this being 8:1 for children (0-17 years of age). Non-fatal cases were more often female (36% vs. 30%; p < 0.001), younger 30 (IQR 10-56) vs. 60 (IQR: 45-72) (p < 0.001) and of unintentional nature (81% vs. 55%; p < 0.001). The overall incidence decreased over time from 5.6 to 4.1 per 100 000 (p < 0.001). The highest rate of 30-day survival was found in females 0-17 years (94%, 95% CI 91.1-95.5) and the lowest in males >66 years (28.7%, 95% CI 26.2-31.2). Although the incidence in children 0-4 years increased from 7.4 to 8.1 per 100 000 (p < 0.001), they demonstrated the highest non-fatal to fatal ratio (13:1).

CONCLUSION

Drowning is declining but remains a consistent and underestimated public-health problem. Non-fatal drowning cases represent about half of the burden and characteristics differ from fatal drowning cases, being younger, more often female and of unintentional nature.

Out-of-Hospital Cardiac Arrest due to Drowning in North America: Comparison of Patient Characteristics between Survival and Mortality Groups

Out-of-hospital cardiac arrest (OHCA) due to drowning carries high morbidity and mortality. There are a few studies on drowning-related out-of-hospital cardiac arrest (OHCA), in which patients are followed from the scene to hospital discharge. This study aims to compare patient characteristics between the survival group and mortality group of OHCA due to drowning. OHCA due to drowning cases were selected from the North America Termination of Resuscitation Association database between 2011 and 2015. The retrospective analysis of epidemiological characteristics and clinical features of all OHCA patients were performed. Of the 17,094 OHCA cases in the registry, 54 cases of OHCA due to drowning were included in this study. Among the 54 OHCAs due to drowning, 7 (13.0%) survived, while 47 (87.0%) died. Compared to the mortality group, the survival group had a higher bystander witness rate (57.1% versus 17.0%, p < 0.05), higher asystole rate (42.9% versus 78.7%, p < 0.05), and higher mild therapeutic hypothermia rate (28.6% versus 2.1%, p < 0.05). In addition, a large proportion of survivors were children (71.4%) and males (71.4%). Survival among OHCA's due to drowning was found to be improved with a higher bystander rate, higher asystole rate, and higher mild hypothermia rate. In addition, children and males comprised the majority of survivors.

Adult Basic Life Support: International Consensus on Cardiopulmonary Resuscitation and Emergency Cardiovascular Care Science With Treatment Recommendations

This 2020 International Consensus on Cardiopulmonary Resuscitation (CPR) and Emergency Cardiovascular Care Science With Treatment Recommendations on basic life support summarizes evidence evaluations performed for 20 topics that were prioritized by the Basic Life Support Task Force of the International Liaison Committee on Resuscitation. The evidence reviews include 16 systematic reviews, 3 scoping reviews, and 1 evidence update. Per agreement within the International Liaison Committee on Resuscitation, new or revised treatment recommendations were only made after a systematic review.

Systematic reviews were performed for the following topics: dispatch diagnosis of cardiac arrest, use of a firm surface for CPR, sequence for starting CPR (compressions-airway-breaths versus airway-breaths-compressions), CPR before calling for help, duration of CPR cycles, hand position during compressions, rhythm check timing, feedback for CPR quality, alternative techniques, public access automated external defibrillator programs, analysis of rhythm during chest compressions, CPR before defibrillation, removal of foreign-body airway obstruction, resuscitation care for suspected opioid-associated emergencies, drowning, and harm from CPR to victims not in cardiac arrest.

The topics that resulted in the most extensive task force discussions included CPR during transport, CPR before calling for help, resuscitation care for suspected opioid-associated emergencies, feedback for CPR quality, and analysis of rhythm during chest compressions. After discussion of the scoping reviews and the evidence update, the task force prioritized several topics for new systematic reviews.

Adult Basic Life Support: 2020 International Consensus on Cardiopulmonary Resuscitation and Emergency Cardiovascular Care Science With Treatment Recommendations

This2020 International Consensus on Cardiopulmonary Resuscitation(CPR)and Emergency Cardiovascular Care Science With Treatment Recommendationson basic life support summarizes evidence evaluations performed for 22 topics that were prioritized by the Basic Life Support Task Force of the International Liaison Committee on Resuscitation. The evidence reviews include 16 systematic reviews, 5 scoping reviews, and 1 evidence update. Per agreement within the International Liaison Committee on Resuscitation, new or revised treatment recommendations were only made after a systematic review.

Systematic reviews were performed for the following topics: dispatch diagnosis of cardiac arrest, use of a firm surface for CPR, sequence for starting CPR (compressions-airway-breaths versus airway-breaths-compressions), CPR before calling for help, duration of CPR cycles, hand position during compressions, rhythm check timing, feedback for CPR quality, alternative techniques, public access automated external defibrillator programs, analysis of rhythm during chest compressions, CPR before defibrillation, removal of foreign-body airway obstruction, resuscitation care for suspected opioid-associated emergencies, drowning, and harm from CPR to victims not in cardiac arrest.

The topics that resulted in the most extensive task force discussions included CPR during transport, CPR before calling for help, resuscitation care for suspected opioid-associated emergencies, feedback for CPR quality, and analysis of rhythm during chest compressions. After discussion of the scoping reviews and the evidence update, the task force prioritized several topics for new systematic reviews.

Management for the Drowning Patient

Drowning is "the process of experiencing respiratory impairment from submersion or immersion in liquid." According to the World Health Organization, drowning claims the lives of > 40 people every hour of every day. Drowning involves some physiological principles and medical interventions that are unique. It occurs in a deceptively hostile environment that involves an underestimation of the dangers or an overestimation of water competency. It has been estimated that > 90% of drownings are preventable. When water is aspirated into the airways, coughing is the initial reflex response. The acute lung injury alters the exchange of oxygen in different proportions. The combined effects of fluid in the lungs, loss of surfactant, and increased capillary-alveolar permeability result in decreased lung compliance, increased right-to-left shunting in the lungs, atelectasis, and alveolitis, a noncardiogenic pulmonary edema. Salt and fresh water aspirations cause similar pathology. If the person is not rescued, aspiration continues, and hypoxemia leads to loss of consciousness and apnea in seconds to minutes. As a consequence, hypoxic cardiac arrest occurs. The decision to admit to an ICU should consider the patient's drowning severity and comorbid or premorbid conditions. Ventilation therapy should achieve an intrapulmonary shunt ≤ 20% or Pao₂:Fio₂ ≥ 250. Premature ventilatory weaning may cause the return of pulmonary edema with the need for re-intubation and an anticipation of prolonged hospital stays and further morbidity. This review includes all the essential steps from the first call to action until the best practice at the prehospital, ED, and hospitalization.

Fatal intentional drowning in Australia: A systematic literature review of rates and risk factors

INTRODUCTION

Unintentional drowning deaths are only part of the drowning profile, with little attention being paid to intentional drowning in Australia. Strategies for the prevention of intentional drowning deaths are likely to be different from unintentional. Quality documentation, analysis and dissemination of intentional deaths data is crucial for developing appropriate strategies for prevention.

OBJECTIVE

To conduct a systematic literature review to investigate the mortality rates and risk factors of intentional drowning deaths in Australia.

METHODS

A systematic search guided by PRISMA was performed using Ovid MEDLINE, CINAHL, PsycINFO (ProQuest), Scopus, Google Scholar, and BioMed Central databases to locate relevant original research articles published between 2007 and 2018.

RESULTS

Ten papers reporting the mortality rates and risk factors of intentional drowning deaths in Australia published between 2007 and 2018, with study periods of the included articles spanning from 1907 to 2012, were reviewed. Most studies investigated suicidal drowning deaths in Australia, none reported homicidal drowning deaths. The downward trend of fatal suicide drowning was identified in Australia. The annual rate of intentional drowning between 1994 and 2012 can be inferred from eight studies, ranging from 0.06 to 0.21 for nation-wide mortality rates. The highest annual state-wide mortality rate was identified in the state of Queensland, ranging from 0.02 to 0.11 per 100,000 individuals. Of four studies examining the risk factors of fatal intentional drowning in Australia, being of older age groups, being female, and the presence of substance use were identified as important factors for suicidal drowning deaths. The national-scale proportion of suicide drowning in Australia, ranging from 2% to 3% of all intentional self-harm deaths, was also identified.

CONCLUSION

Limited publications reporting the mortality rates and risk factors of intentional drowning deaths in Australia were identified. Being of older age groups and being female were recognised as factors for suicide drowning deaths, and psychoactive substances were widely identified amongst cases. Future research on improving death reporting systems and the legal framework for medico-legal death investigation, along with the investigation of the risk factors of intentional drowning, are required to inform the planning, implementation, and evaluation of prevention interventions for intentional drowning deaths in Australia.

Pediatric Post–Cardiac Arrest Care: A Scientific Statement From the American Heart Association

Successful resuscitation from cardiac arrest results in a post–cardiac arrest syndrome, which can evolve in the days to weeks after return of sustained circulation. The components of post–cardiac arrest syndrome are brain injury, myocardial dysfunction, systemic ischemia/reperfusion response, and persistent precipitating pathophysiology. Pediatric post–cardiac arrest care focuses on anticipating, identifying, and treating this complex physiology to improve survival and neurological outcomes. This scientific statement on post–cardiac arrest care is the result of a consensus process that included pediatric and adult emergency medicine, critical care, cardiac critical care, cardiology, neurology, and nursing specialists who analyzed the past 20 years of pediatric cardiac arrest, adult cardiac arrest, and pediatric critical illness peer-reviewed published literature. The statement summarizes the epidemiology, pathophysiology, management, and prognostication after return of sustained circulation after cardiac arrest, and it provides consensus on the current evidence supporting elements of pediatric post–cardiac arrest care.

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.

Characteristics of drowning victims in a surf environment: a 6-year retrospective study in southwestern France

Background

Drowning is the third cause of non-intentional injury death worldwide. Beaches of Gironde, in southwestern France, are exposed to strong environmental conditions, leading to rip currents and shore breaks. Bathing season usually lasts from April to October and is supervised from June till mid-September. The objective of this study was to study the characteristics of drowning victims along Gironde surf beaches and to identify peculiarities compared to national figures.

Methods

All calls originating from beaches to the emergency call center of Gironde from 2011 to 2016 were analyzed. Patient data, filled by a physician based on information given by pre-hospital care team (lifeguards, paramedics or emergency physicians), were extracted from the emergency call center database. We used Szpilman classification (0 = rescue to 6 = cardiac arrest) to assess severity. Rescues are patients without respiratory impairment who needed lifeguards or helicopter intervention. We compared our findings with national studies carried every three years (2012 and 2015).

Results

We analyzed 5680 calls from beaches and included 4398, 576 of which were rescued from the water, including 352 without respiratory impairment (stage 0). Among drownings, 155 had cough only (stage 1), 26 pulmonary rales (stage 2), 9 pulmonary edema (stage 3) and 1 had pulmonary edema with hypotension (stage 4). Five rescued people were in respiratory arrest and 28 were in cardiac arrest. 77.5% were bathers, others were mainly surfers or body-boarders. Drowning victims median age was 24 (quartiles: 17–40), and sex-ratio was 1.44 Male/Female. Men were significantly older than women (34 vs. 26 years old), and severity from stage 1 to 4 was positively associated with age. Compared to national data, Gironde drownings had a higher proportion of 15–44 year-old victims, and the case-fatality was lower in Gironde (11.5%) than at the national level (27.4%, p < 0.001).

Conclusion

Along Gironde coast, drowning is rarely severe, concerns mostly young men; the age distribution could explain the different case-fatality. Further study is needed to identify environmental predictors of drowning.

Outcome after pre-hospital cardiac arrest in accordance with underlying cause

AIM

In terms of treatment options, the underlying cause of out-of-hospital cardiac arrest (OHCA) has an impact on survival. This study aimed to examine the frequencies of different causes of OHCA and their outcomes using data from a national resuscitation registry.

METHODS

All pre-hospital cardiopulmonary resuscitations (CPR) documented in the German Resuscitation Registry between 2007 and 2017 were retrospectively investigated with regard to cause of cardiac arrest, return of spontaneous circulation (ROSC), and hospital discharge rate with good neurological outcome. To avoid selection bias, only rescue services with a return rate in the form 'further clinical treatment' of >30% were included, this resulted in a total return rate of 84% of the included data.

RESULTS

In total, 33,772 patients were included. The most common causes of OHCA were cardiac events (62.2%), hypoxia (11.1%) and trauma (3.2%), in 17.2% no or unknown cause were documented. Overall, 44.8% of patients achieved ROSC, 13.1% of patients were discharged alive from hospital and 68.3% of these were in good neurological condition (9.0% of all patients). ROSC rates differed between 8.9% (sudden infant death syndrome) and 64.4% (intracranial bleeding), while discharge rates with good neurological outcome ranged between 0.9% (sepsis) and 14.0% (intoxication).

CONCLUSION

The most common causes of OHCA are cardiac events and hypoxia. Depending on the underlying cause, outcome after pre-hospital CPR varies widely with a survival rate with good neurological outcome ranging from 0.9 to 14%.

Comparison of presumed cardiac and respiratory causes of out-of-hospital cardiac arrest

AIMS OF THE STUDY

Most interventional and observational studies include cardiac arrest from cardiac origin. However, an increasing proportion of cardiac arrest results from an extra-cardiac origin, mainly respiratory. The aim of our study was to compare the characteristics and outcome of cardiac arrest patients according to the presumed cardiac or respiratory causes.

METHODS

This retrospective multicenter observational study included out-of-hospital cardiac arrest patients from presumed cardiac and respiratory origin treated with therapeutic hypothermia. Demographic data (age, sex, initial rhythm as shockable or non-shockable, durations of no-flow and low-flow), clinical evolution in ICU, lactate and outcome (CPC scale at ICU discharge) were compared between patients according to the presumed cardiac or respiratory origin of the cardiac arrest.

RESULTS

Two hundred and fifty-one cardiac arrest patients were included, 156 from presumed cardiac origin (62%) and 95 from presumed respiratory origin (38%). Patients with presumed cardiac cause presented more frequently a shockable rhythm (68% vs. 5%, p < 0.001), received more defibrillations attempts (2 [1-5] vs. 0 [0-0], <0.001) and needed less adrenaline (3 mg [0-5] vs. 4 mg [2-7], p = 0.01). The arterial lactate concentration on admission was higher in patients with presumed respiratory causes (6.3 mmol/L [4.2-9.8] vs. 3.2 mmol/L [1.6-5.0], p < 0.001). The proportion of patients presenting a favorable outcome was higher in the population with presumed cardiac causes, compared to its respiratory counterpart (42% vs. 19%, p < 0.001).

CONCLUSIONS

Compared to presumed cardiac origin, a worse outcome and a different mode of death are associated with the presumed respiratory origin, resulting from a greater insult preceding cardiac arrest. The presumed cause of cardiac arrest could be integrated in the multimodal prognostication process.

The Relationship between Emergency Response Time and Out-Of-Hospital Cardiac Arrest Prognosis: A Meta-Analysis

Objective

To assess the relationship between emergency response time and prognosis of patients with out-of-hospital cardiac arrest.

Design

Systematic review.

Methods

Relevant observational studies were identified by a search of PubMed and ISI databases to 30 January 2014. Primary outcome was survival to discharge. The weighted mean differences (WMD) for response time were calculated for those survivals to discharge and death in hospital. We also carried out a dose response meta-analysis for assessing summary odds ratio (OR) of survival by response time.

Results

A total of 13 studies with 804,998 patients included in the meta-analysis. The WMD of response time between survivals to discharge group and death in hospital group was 1.976 (95% confidence interval [CI] = 1.161-2.792; p<0.001). Sensitivity analyses by only included prospective cohorts showed the WMD of response time between two groups was 1.115 (95% CI=0.508-1.723; p<0.001). Dose-response relationship between response time and survival to discharge risk was observed statistically significant (χ2=39.86, p<0.001). In linear model, the summary OR was 0.914 (95% CI=0.889-0.940) for every 1 minutes delay in response time. In spline model, the survival OR decreased along with the response time, especially when response time less than 7 minutes.

Conclusions

Emergency response time is an important risk factor for prognosis after OHCA in adults. The EMS team must arrive as soon as possible to the site of the event. (Hong Kong j.emerg.med. 2015;22:345-351)

Therapeutic Hypothermia for Asphyxial Out-of-Hospital Cardiac Arrest Due to Drowning: A Systematic Review of Case Series and Case Reports

The objective of this review was to summarize published evidence of the effectiveness of therapeutic hypothermia in patients with drowning-associated asphyxial out-of-hospital cardiac arrest (OHCA) and to explore any preliminary favorable factors in the management of therapeutic hypothermia to improve survival and neurological outcome. Drowning may result in asphyxial OHCA or hypothermic OHCA, but the former does not provide any potential neuroprotective effect as the latter may do. Electronic literature searches of Ovid Medline, Embase, Cochrane Library, and Scopus were performed for all years from inception to July 2016. Primary studies in the form of case reports, letters to the editor, and others with higher quality are included, but guidelines, reviews, editorials, textbook chapters, conference abstracts, and nonhuman studies are excluded. Non-English articles are excluded. Relevant studies are then deemed eligible if the drowning OHCA patient's initial temperature was above 28°C, which implies asphyxial cardiac arrest, and intentional therapeutic hypothermia was instituted. Because of the narrow scope of interest and strict definition of the condition, limited studies addressed it, and no randomized controlled trials (RCT) could be selected. Thirteen studies covering 35 patients are included. No quantitative synthesis, assessment of study quality, or assessment of bias was performed. It is conjectured that extended therapeutic hypothermia of 48-72 hours might help prevent reperfusion injury during the intermediate phase of postcardiac arrest care to benefit patients of drowning-associated asphyxial OHCA, but this finding only serves as preliminary observation for future research. No conclusive recommendation could be made regarding the duration of and the time of onset of therapeutic hypothermia. Future research should put effort on RCT, particularly the effect of extended duration of 48-72 hours. Important parameters should be reported in detail. Asphyxial and hypothermic OHCA should be differentiated.

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.

Accidental hypothermia-an update : The content of this review is endorsed by the International Commission for Mountain Emergency Medicine (ICAR MEDCOM)

BACKGROUND

This paper provides an up-to-date review of the management and outcome of accidental hypothermia patients with and without cardiac arrest.

METHODS

The authors reviewed the relevant literature in their specialist field. Summaries were merged, discussed and approved to produce this narrative review.

RESULTS

The hospital use of minimally-invasive rewarming for non-arrested, otherwise healthy, patients with primary hypothermia and stable vital signs has the potential to substantially decrease morbidity and mortality for these patients. Extracorporeal life support (ECLS) has revolutionised the management of hypothermic cardiac arrest, with survival rates approaching 100 % in some cases. Hypothermic patients with risk factors for imminent cardiac arrest (temperature <28 °C, ventricular arrhythmia, systolic blood pressure <90 mmHg), and those who have already arrested, should be transferred directly to an ECLS-centre. Cardiac arrest patients should receive continuous cardiopulmonary resuscitation (CPR) during transfer. If prolonged transport is required or terrain is difficult, mechanical CPR can be helpful. Delayed or intermittent CPR may be appropriate in hypothermic arrest when continuous CPR is impossible. Modern post-resuscitation care should be implemented following hypothermic arrest. Structured protocols should be in place to optimise pre-hospital triage, transport and treatment as well as in-hospital management, including detailed criteria and protocols for the use of ECLS and post-resuscitation care.

CONCLUSIONS

Based on new evidence, additional clinical experience and clearer management guidelines and documentation, the treatment of accidental hypothermia has been refined. ECLS has substantially improved survival and is the treatment of choice in the patient with unstable circulation or cardiac arrest.

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.

Predicting outcome of drowning at the scene: A systematic review and meta-analyses

OBJECTIVE

To identify factors available to rescuers at the scene of a drowning that predict favourable outcomes.

DESIGN

Systematic review and meta-analysis.

DATA SOURCES

PubMed, Embase and Cochrane Library were searched (1979-2015) without restrictions on age, language or location and references lists of included articles.

STUDY SELECTION

Cohort and case-control studies reporting submersion duration, age, water temperature, salinity, emergency services response time and survival and/or neurological outcomes were eligible. Two reviewers independently screened articles for inclusion, extracted data, and assessed quality using GRADE. Variables for all factors, including time and temperature intervals, were categorized using those used in the articles. Random effects meta-analyses, study heterogeneity and publication bias were evaluated.

RESULTS

Twenty-four cohort studies met the inclusion criteria. The strongest predictor was submersion duration. Meta-analysis showed that favourable outcome was associated with shorter compared to longer submersion durations in all time cutoffs evaluated: ≤5-6min: risk ratio [RR]=2.90; (95% confidence interval [CI]: 1.73, 4.86); ≤10-11min: RR=5.11 (95% CI: 2.03, 12.82); ≤15-25min: RR=26.92 (95% CI: 5.06, 143.3). Favourable outcomes were seen with shorter EMS response times (RR=2.84 (95% CI: 1.08, 7.47)) and salt water versus fresh water 1.16 (95% CI: 1.08, 1.24). No difference in outcome was seen with victim's age, water temperatures, or witnessed versus unwitnessed drownings.

CONCLUSIONS

Increasing submersion duration was associated with worse outcomes. Submersion durations <5min were associated with favourable outcomes, while those >25min were invariably fatal. This information may be useful to rescuers and EMS systems deciding when to perform a rescue versus a body recovery.

Extracorporeal life support for victims of drowning

AIM

Unintentional drowning is a significant public health concern in the United States and represents a leading cause of death in the pediatric population. Extracorporeal life support (ECLS) may be used to support drowning victims, but outcomes have not been well defined. This study examined survival rates and risk factors for death in this population.

METHODS

Retrospective data from the Extracorporeal Life Support Organization registry was examined to determine outcomes of ECLS and risk factors for death in drowning victims.

RESULTS

Two hundred forty-seven patients who received ECLS following a drowning event between 1986 and 2015 were identified. Eighty-four (34%) did not experience cardiac arrest prior to ECLS, whereas 86 (35%) experienced a pre-ECLS cardiac arrest but had return of spontaneous circulation prior to ECLS, and 77 (31%) were placed on ECLS during cardiopulmonary resuscitation (ECPR). Overall survival was 51.4%; 71.4% in patients who did not experience a cardiac arrest, 57.0% in patients who required cardiopulmonary resuscitation prior to ECLS, and 23.4% in patients who received ECPR (p<0.001). Logistic regression analysis identified ECPR, venoarterial mode of ECLS, renal failure, and cardiopulmonary resuscitation during ECLS as risk factors associated with mortality.

CONCLUSIONS

Outcomes in drowning victims supported with ECLS are encouraging; particularly in patients who do not experience cardiac arrest. These data suggest that early initiation of ECLS in drowning patients with respiratory insufficiency may be beneficial to reduce the likelihood of complete cardiopulmonary failure and ECPR. Additionally, ECLS appears to improve survival in patients who experience post-drowning cardiac arrest.

Part 3: Adult Basic Life Support and Automated External Defibrillation: 2015 International Consensus on Cardiopulmonary Resuscitation and Emergency Cardiovascular Care Science With Treatment Recommendations

This review comprises the most extensive literature search and evidence evaluation to date on the most important international BLS interventions, diagnostics, and prognostic factors for cardiac arrest victims. It reemphasizes that the critical lifesaving steps of BLS are (1) prevention, (2) immediate recognition and activation of the emergency response system, (3) early high-quality CPR, and (4) rapid defibrillation for shockable rhythms. Highlights in prevention indicate the rational and judicious deployment of search-and-rescue operations in drowning victims and the importance of education on opioid-associated emergencies. Other 2015 highlights in recognition and activation include the critical role of dispatcher recognition and dispatch-assisted chest compressions, which has been demonstrated in multiple international jurisdictions with consistent improvements in cardiac arrest survival. Similar to the 2010 ILCOR BLS treatment recommendations, the importance of high quality was reemphasized across all measures of CPR quality: rate, depth, recoil, and minimal chest compression pauses, with a universal understanding that we all should be providing chest compressions to all victims of cardiac arrest. This review continued to focus on the interface of BLS sequencing and ensuring high-quality CPR with other important BLS interventions, such as ventilation and defibrillation. In addition, this consensus statement highlights the importance of EMS systems, which employ bundles of care focusing on providing high-quality chest compressions while extricating the patient from the scene to the next level of care. Highlights in defibrillation indicate the global importance of increasing the number of sites with public-access defibrillation programs. Whereas the 2010 ILCOR Consensus on Science provided important direction for the “what” in resuscitation (ie, what to do), the 2015 consensus has begun with the GRADE methodology to provide direction for the quality of resuscitation. We hope that resuscitation councils and other stakeholders will be able to translate this body of knowledge of international consensus statements to build their own effective resuscitation guidelines.

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.