Temperature control after cardiac arrest: friend or foe

Area of Science:

• Critical Care Medicine
• Neurology
• Cardiology

Background:

• Comatose patients resuscitated from cardiac arrest often require intensive care unit (ICU) support.
• Traditionally, therapeutic hypothermia (cooling to 32-36°C) for at least 24 hours was standard practice.
• The evidence supporting this practice is increasingly being questioned.

Purpose of the Study:

• To review the current evidence regarding temperature management in comatose patients post-cardiac arrest.
• To evaluate the efficacy of targeted temperature control versus fever prevention.

Main Methods:

• Systematic review and meta-analysis of existing studies, including the Targeted Temperature Management 2 (TTM-2) trial.
• Analysis of observational studies examining outcomes related to different temperature targets.
• Assessment of evidence from the Advanced Life Support (ALS) Task Force of the International Liaison Committee on Resuscitation (ILCOR).

Main Results:

• The TTM-2 trial found no significant difference in 6-month mortality between patients cooled to 33°C and those managed with targeted normothermia.
• A meta-analysis by ILCOR's ALS Task Force concluded that temperature control (32-34°C) did not improve survival or functional outcomes.
• Observational studies suggest potential benefits of 33-34°C over 35-36°C in patients with predicted hypoxic-ischaemic brain injury.

Conclusions:

• The certainty of evidence supporting strict cooling protocols (32-36°C) for comatose postcardiac arrest patients is diminishing.
• Active fever prevention, targeting temperatures ≤37.5°C, is recommended for comatose patients after return of spontaneous circulation (ROSC).
• Further research may refine optimal temperature management strategies based on individual patient factors and injury severity.