Prophylactic hypothermia for traumatic brain injury: a quantitative systematic review

Area of Science:

• Neuroscience
• Critical Care Medicine
• Trauma Surgery

Background:

• Growing evidence supports prophylactic hypothermia for traumatic brain injury (TBI).
• Existing studies categorize cooling strategies into short-term (24-48 hours) and long-term or goal-directed (until intracranial pressure normalization).
• A comprehensive systematic review including recent evidence was lacking.

Purpose of the Study:

• To systematically review and meta-analyze randomized controlled trials (RCTs) on therapeutic hypothermia for TBI.
• To compare the efficacy of short-term versus long-term/goal-directed cooling strategies.
• To evaluate the impact of hypothermia on mortality and neurologic outcomes.

Main Methods:

• Systematic review and meta-analysis following Cochrane Handbook and QUOROM guidelines.
• Comprehensive literature search across multiple databases (Embase, MEDLINE, Web of Science, etc.) and hand-searching.
• Studies analyzed based on cooling strategy (short-term vs. long-term/goal-directed); outcomes assessed were mortality and good neurologic outcome (Glasgow Outcome Scale 4-5).

Main Results:

• Twelve RCTs with 1327 participants were included.
• Overall hypothermia reduced mortality (RR 0.73) and improved neurologic outcome (RR 1.52).
• Long-term/goal-directed cooling significantly reduced mortality (RR 0.62) and improved neurologic outcome (RR 1.68), while short-term cooling showed no significant benefit.

Conclusions:

• Early mild-to-moderate hypothermia is supported by evidence for severe TBI (GCS ≤ 8) to reduce mortality and improve recovery.
• Long-term or goal-directed cooling protocols (≥72 hours or until ICP normalization) demonstrated maximal benefit.
• Hypothermia should be initiated promptly after injury, regardless of initial ICP, with further research in prehospital and ED settings recommended.