1. In this study, no child with hypothermia and cardiac arrest following a drowning accident survived with good neurological outcome if circulation was not reestablished within 30 minutes of resuscitation.
2. Children had a better prognosis if they drowned in winter, and hence in colder water, versus in other seasons.
Evidence Rating Level: 2 (Good)
Study Rundown: Drowning remains the primary cause of mortality worldwide in children 2-5 years old in developed countries. While children who regain circulation after cardiac arrest quickly with basic life support tend to have good neurological outcomes, evidence is less clear for situations where as to whether prolonged resuscitation over 30 minutes is required. This Danish study examined the outcomes of 160 pediatric patients who had cardiac arrest and hypothermia after drowning over a 20 year period. The 98 patients who received resuscitation for over 30 minutes either died, were in a vegetative state, or had severely impaired neurological outcomes. However, 17 of the 62 patients who required less than 30 minutes of resuscitation had good outcomes. Of all the patients reported on, those who drowned in the winter season had an average of 3.7°C lower body temperature on first measurement and better outcomes than those who drowned in any other months.
This study makes a strong argument for stopping resuscitative efforts after 30 minutes in pediatric drowning victims with cardiac arrest and hypothermia in the non-winter months, but it is still unclear if prolonged resuscitation may have benefit for patients who drowned in winter, mostly due to the small sample size in this cohort. Further, while this paper shows that drowning in winter leads to a better prognosis, it is difficult to discern whether this difference is due to colder water temperatures or the speed at which the body reaches hypothermia, which would be much quicker in the winter months.
Click to read the study in the BMJ
Click to read an accompanying editorial in the BMJ
Relevant Reading: Impact of age, submersion time and water temperature on outcome in near-drowning
In-Depth [retrospective cohort]: 160 out of 784 total pediatric drowning patients (≤16 years) had cardiac arrest and hypothermia in this Danish study based on inclusion of patients with ICD-9 diagnoses of drowning from a national database from 1993 to 2012. Good neurological outcomes were based on a pediatric cerebral performance category (PCPC) score ≤3. The total mortality rate was 73% (CI95 66-80%), and only 17 (11% CI95 6-16%) patients had good neurological outcomes a year later. 98 of the 160 children did not reestablish circulation after 30 minutes of prolonged resuscitation, and none of these children survived without being in a vegetative state or without having severe neurological damage. Those who drowned in the winter had a better outcome than those who drowned in other months (OR = 4.8 CI96 2.9-7.9). Other prognostic markers corroborated previous results in other studies, including worse prognosis with asystole, increasing adrenaline doses, and low pH and better prognosis with bradycardia. The outcomes at the beginning of the study period were unchanged from the outcomes at the end of the study period, demonstrating that the change in treatment paradigms over the 20 year study period had little or no effect on outcomes.
Image: PD
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