Prognosis of coma after cardiac arrest in the era of hypothermia.

PURPOSE OF REVIEW: Outcome prediction is more difficult in comatose survivors of cardiac arrest who are treated with hypothermia than in those who are kept normothermic. This article compares prognostication measures in these two groups of patients.

RECENT FINDINGS: The introduction of therapeutic hypothermia for cardiac arrest has resulted in reduced mortality and better neurologic outcomes among survivors. However, it has also introduced greater uncertainty into the process of prognostication. For guidance on predicting outcome, most neurologists have relied on the 2006 AAN practice parameter. The studies on which the practice parameter was based, however, were performed before the advent of hypothermia. Data from posthypothermia era studies suggest a change in the predictive power of some markers that are regularly used to assess prognosis in post-cardiac arrest patients. It is unclear whether the same rules apply when predicting outcomes after cardiac arrest in cooled patients. In this new era of hypothermia, caution must be exercised when using the current AAN practice parameter to predict prognosis in post-cardiac arrest comatose survivors.

SUMMARY: This article compares and contrasts prognostication before and after the introduction of hypothermia in an attempt to provide new guidance on predicting outcomes.