Secondary analysis of a multicenter, prospective, observational study ICE-CRASH study in Japan including adult patients admitted with moderate-to-severe accidental hypothermia between 2019 and 2022.
Some structural generalizability (median age 81 years!) issues with this study but well done overall.
Authors undertook some rather complex modeling to predict outcomes related to rapid rewarming, showing that “the rewarming rate and predicted probability of each outcome increased significantly up to 3°C/hr, but when the rewarming rate exceeded 3°C/hr, the predicted probability of each outcome was almost constant.”
Suggests that for those with severe hypothermia that an initially rapid rate of up to 3C/hr is a good target for a ceiling, but above this may be associated with less favorable risk:benefit ratio. Benefit in moderate hypothermia was not as clear.
Conclusion: The mode of rewarming in severe hypothermia should still be based on local protocols and capabilities (e.g. external, intravascular, extracorporeal rewarming) but the rate of rewarming up to 3C/hr is associated with better outcomes.
