Is hypothermia indicated during cardiopulmonary resuscitation and after restoration of spontaneous circulation?

PURPOSE OF REVIEW

Targeted temperature management (TTM) after cardiac arrest has become a standard therapy in postresuscitation care. However, many questions addressing the optimum treatment protocol remain unanswered.

RECENT FINDINGS

The positive influence of intra-arrest cooling on survival and neurologic outcome, seen in animal studies, was not revealed in clinical trials so far. By contrast, the evidence of TTM after restoration of circulation is based on both experimental and clinical data. The mechanisms of cerebral injury unfold different time windows for cooling initiation. Immediate cooling and early achievement of a target temperature less than 34°C seems to be beneficial, although clinical data on preclinical cooling failed to detect a positive correlation. Despite previous beneficial experimental and clinical data, the benefit of a lower body temperature was recently called into question by a recent study. Regardless of the preferred temperature range, the main focus must lie in active cooling and prevention of hyperthermic conditions. There are many factors that influence the effect of TTM, which should therefore be tailored to the specific patient's needs.

SUMMARY

To maximize its beneficial potential, TTM should be customized to resuscitation covariates. Despite open questions on the optimum treatment protocol, active cooling should be started as soon as possible and hyperthermic conditions should be prevented in any case. To answer the question if intra-arrest cooling or prehospital cooling induction is indicated, additional studies are needed.