Cooling children after cardiac arrest provides no significant benefit

Although body-cooling has long been a standard of care in treating adults after heart attacks, a recently published multi-center study has concluded that the same procedure - known as "therapeutic hypothermia" - does not confer any survival-with-quality-of-life benefit for children who are resuscitated after suffering out-of-hospital cardiac arrest. The study noted hypothermia is no more effective than maintaining normal body temperature by preventing fever in the children being treated.

These surprising results, published April 25, 2015, in the New England Journal of Medicine, have major implications for critical-care pediatricians who treat children in the wake of cardiac arrest that takes place outside the hospital.

"What this study tells us is that there's no significant advantage to using a lower-than-normal [body] temperature when caring for children who've experienced cardiac arrest," said Dr. Meert.

"I think the take-home message for clinicians is very important. This large study of nearly 300 children who were treated after cardiac arrest at 38 different pediatric health care facilities in the United States clearly indicates that lower-than-normal body temperature is not necessary," Dr. Meert added. "That finding is very helpful, because body-cooling is a time-consuming and complex therapy that can also put additional physical stress on the children being treated. Thanks to the study, we now know that such lower-than-normal body temperature is not necessary."

Because about two-thirds of the 6,000 U.S. children who undergo cardiac arrest (often from choking or near-drowning) each year die or suffer permanent neurologic damage, finding ways to improve their odds during treatment has been an urgent quest among pediatric critical-care providers. Until recently, however, there had been no large-scale multi-center studies aimed at determining whether the demonstrated positive effects of body-cooling in adults after heart arrest could also be counted on to help similarly affected children.

The trials, funded by the National Heart, Lung, and Blood Institute (NHLBI) U01-HL-094339 and U01-HL-094345 of the National Institutes of Health and titled "Therapeutic Hypothermia after Out-of-Hospital Cardiac Arrest in Children," were based on treatment data collected by dozens of investigators at 38 children's hospitals. The study included nearly 300 participants (two days to 18 years old) who were brought to hospitals after cardiac arrest.

Using specially designed, water-cooled blankets over a period of five days, the caregivers lowered body temperatures in half of the post-heart arrest subjects by about six degrees Fahrenheit below normal, on average. In the other half of the cohort, the normal body temperature of approximately 98.6 degrees was maintained during the same period.

Because maintaining normal body temperature required that the treating clinicians prevent fever, it now seems clear that effectiveness of body cooling among adult heart-arrest patients (documented during studies in the early 2000s) was likely the result of fever prevention, Dr. Meert said.