Okay – rather than ‘therapeutic hypothermia’, the recommended phrase now is ‘targeted temperature management’. Several critical care authorities got together to produce clinical recommendations on this topic. Here are a few interesting points from the document:
Hypothermia affects platelet function and prolongs the prothrombin time and partial thromboplastin time. These effects are masked when laboratory analysis is performed at 37°C, suggesting that any risk will be mitigated by rewarming.
Although not mentioned in the abstract, the authors examined the role of TTM in raised intracranial pressure (ICP):
Sufficient evidence exists to conclude that TTM does decrease ICP compared to unstructured temperature management. However, there is no sufficient evidence to make a recommendation regarding the use of targeted hypothermia to control elevated ICP to improve patent-important outcomes in TBI. The jury makes NO RECOMMENDATION regarding the use of TTM as an ICP control strategy to improve outcomes in brain injuries regardless of cause (trauma, hemorrhage, or ischemic stroke).
Regarding acute liver failure with severe cerebral edema:
there are currently no RCTs. There is a case series suggesting a strongly favorable effect. This is a powerful argument for support of an RCT evaluating TTM alone or in combination with hepatic dialysis strategies
OBJECTIVE: Representatives of five international critical care societies convened topic specialists and a nonexpert jury to review, assess, and report on studies of targeted temperature management and to provide clinical recommendations.
DATA SOURCES: Questions were allocated to experts who reviewed their areas, made formal presentations, and responded to questions. Jurors also performed independent searches. Sources used for consensus derived exclusively from peer-reviewed reports of human and animal studies.
STUDY SELECTION: Question-specific studies were selected from literature searches; jurors independently determined the relevance of each study included in the synthesis.
CONCLUSIONS AND RECOMMENDATIONS:
- The jury opines that the term “targeted temperature management” replace “therapeutic hypothermia.”
- The jury opines that descriptors (e.g., “mild”) be replaced with explicit targeted temperature management profiles.
- The jury opines that each report of a targeted temperature management trial enumerate the physiologic effects anticipated by the investigators and actually observed and/or measured in subjects in each arm of the trial as a strategy for increasing knowledge of the dose/duration/response characteristics of temperature management. This enumeration should be kept separate from the body of the report, be organized by body systems, and be made without assertions about the impact of any specific effect on the clinical outcome.
- The jury STRONGLY RECOMMENDS targeted temperature management to a target of 32°C-34°C as the preferred treatment (vs. unstructured temperature management) of out-of-hospital adult cardiac arrest victims with a first registered electrocardiography rhythm of ventricular fibrillation or pulseless ventricular tachycardia and still unconscious after restoration of spontaneous circulation (strong recommendation, moderate quality of evidence).
- The jury WEAKLY RECOMMENDS the use of targeted temperature management to 33°C-35.5°C (vs. less structured management) in the treatment of term newborns who sustained asphyxia and exhibit acidosis and/or encephalopathy (weak recommendation, moderate quality of evidence).
Targeted temperature management in critical care: A report and recommendations from five professional societies
Crit Care Med. 2011 May;39(5):1113-1125