Negative outcomes were seen in drowned children who couldn't be resuscitated within 30 minutes, according to a retrospective, population-based study.
In children presenting with cardiac arrest and hypothermia who received resuscitation for more than 30 minutes, 87 of 98 died (89%, 95% CI 83%-95%), wrote J.K. Kieboom, of Beatrix Children's Hospital at the University Medical Centre Groningen in the Netherlands, and colleagues.
Outcomes were also largely dependent on the season when the child drowned, with warmer weather associated with poorer outcomes, they added.
Of the children who drowned in spring, summer, or fall, only 12 out of 143 (8%, 95% CI 4%-13%) had a good outcome, while five out of 17 (29%, 95% CI 8%-51%) who drowned in the winter recovered (odds ratio 4.6, 95% CI 1.4-15.1, P=0.013). Results of this study showed a lower core body temperature (difference 3.7°C, P<0.001) for children who drowned in the winter compared with other seasons.
The large difference the seasons played in outcomes was an important reason for the study, because "most children drown in the summer," Kieboom told MedPage Today.
Previous studies had found "good neurological recovery" for children after drowning in cold or icy water (≤6°C/42.8°F). "Drowning in ice water could induce rapid cooling, both because of the large temperature gradient and, in the case of hypothermia, induced muscle rigidity and areflexia because of the relative absence of panic," the authors wrote.
Because cardiac arrest is often associated with hypothermia, the "current practice is to continue resuscitation until a core body temperature of 32-34 degrees C [89.6-93.2°F] has been achieved," the authors wrote, but they questioned the validity of those guidelines after drowning has occurred in more temperate water.
Kieboom said that when hypothermia occurs before asphyxia ("accidental hypothermic cardiac arrest"), it provides "cerebral protection from asphyxial damage," but when cardiac arrest is caused by asphyxia in non-icy water, the hypothermia occurs later.
"This explains the extremely poor outcome of prolonged resuscitation in children with cardiac arrest and hypothermia after drowning in non-icy water we found in this study and questions the value of prolonged resuscitation in these children," Kieboom added.
They looked at data on 784 children, ages 16 and under, who were identified by the ICD-9 code for drowning (994.1). These children were admitted to the emergency department (ED), the general pediatric ward, and admitted or transferred to the pediatric intensive care unit in eight university medical centers from Jan. 1, 1993 to Jan. 1, 2012.
The analysis focused on the 160 children "who experienced cardiac arrest with hypothermia after drowning outside, which was not associated with a motor vehicle or boat incident." Of those 160, 98 (61%) were resuscitated for more than 30 minutes. The median age for children in the study was 2, and 73% were boys.
For long-term results, in the 62 children who did not have prolonged resuscitation, 27% survived with a PCPC score of ≤3 after 1 year. A good neurological outcome (PCPC score 1) was seen in 6% of the children at 1 year, while 3% had mild neurological disability (PCPC score 2), and 1% had moderate neurological disability (PCPC score 3).
Of the 160 children, 44 were alive at 1 year with any outcomes, the authors reported.
Seasonal effect was evident even when it took less than 30 minutes to resuscitate a child. All five children who were resuscitated in less than 30 minutes during winter were associated with "significantly better outcomes" (100%, 95% CI 55%-100%) than children who were resuscitated in less than 30 minutes during all other seasons (12 out of 57 or 21%, 95% CI 10%-32%) for an OR of 4.8 (95% CI 2.9-7.9, P=0.01).
Limitations of the study include the potential missed complications of children drowning in stagnant water, (such as meningitis or sepsis) and the lack of exact water temperature in each case -- extrapolating the "season" to determine temperature, as well as the fact that Dutch seasons do not necessarily correlate to other climates throughout the globe. Other limitations include missed cases, such as children who recovered fully after resuscitation, who did not require treatment in the ED, and children in two of the eight medical centers who may have died in the ED after resuscitation attempts failed.
While the authors stated that "we propose a decision tree to be used in children experiencing cardiac arrest with hypothermia after drowning outside in a temperate climate," they did caution that in children who drown in winter or under "exceptional circumstances" (car or boat accident), continuing resuscitation until the patient is rewarmed is still advisable.
Kieboom and co-authors disclosed no relevant relationships with industry.
- Reviewed by Henry A. Solomon, MD, FACP, FACC Clinical Associate Professor, Weill Cornell Medical College and Dorothy Caputo, MA, BSN, RN, Nurse Planner