Objectives: 

Accidental hypothermia has high mortality. Rewarming is the initial primary management strategy. However, detailed evidence on rewarming management is limited, that is, rewarming rate is unclear, particularly with noncardiac arrest. Here, we evaluated the association between rewarming rate in the early phase of rewarming and survival and neurologic outcomes in patients with accidental hypothermia.

Design: 

A secondary analysis of a nationwide, multicenter, prospective, observational study—the Intensive Care with ExtraCorporeal membrane oxygenation Rewarming in Accidentally Severe Hypothermia (ICE-CRASH) study—including adult patients admitted with moderate-to-severe accidental hypothermia between 2019 and 2022.

Setting: 

Emergency medical facilities in Japan (n = 36).

Patients: 

Patients whose body temperature less than 32°C on arrival at the emergency department.

Interventions: 

None.

Measurements and Main Results: 

The early phase of rewarming was defined as the time from arrival at the emergency department to achieving a body temperature of 33°C. Primary and secondary outcomes included 28-day survival after admission and favorable neurologic status at discharge (Cerebral Performance Category score of 1–2). The median rewarming rates in the early phase was 1.35°C/hr (interquartile range, 0.91–2.03°C/hr). Overall, the 28-day survival rate was 82.0% (n = 324), and the proportion of favorable neurologic outcome was 66.6% (n = 263). Multivariable logistic regression analysis showed that the rewarming rate was significantly associated with 28-day survival and favorable neurologic outcomes in the early phase (odds ratio [OR], 1.51; 95% CI, 1.10–2.09; p = 0.011 and OR, 1.32; 95% CI, 1.06–1.64; p = 0.015).

Conclusions: 

In the early phase, the rewarming rate was associated with survival and favorable neurologic outcomes.