Hypothermia does not hasten death during uncontrolled hemorrhagic shock presenting as the "triad of death" in rats.

The aim of this study was to investigate the effect of hypothermia on survival and coagulopathy in hemorrhagic shock presenting as the "triad of death".

Sixteen rats were lightly anesthetized with halothane while maintaining spontaneous breathing. The triad of death was simulated by inducing hypothermia (32.0°C) with surface body cooling and hemodilution with replacement of 20 mL blood with 50 mL normal saline. Then, rats were randomly assigned to one of two rectal temperature groups (n = 8/group: group 1, rewarming to 37.0°C; group 2, maintenance at 32.0°C) and subjected to hemorrhagic shock initiated by amputation of the tail at 75% of its length. The rats were then observed for survival time without fluid resuscitation. Blood coagulability with Sonoclot analysis was also assessed.

The triad of death status was considered as being induced at a rectal temperature of 32°C, arterial pH of 7.22, and deteriorating coagulating values. At 45 min after randomization, Sonoclot analysis revealed prolonged activated clotting times of 355 ± 131 s and "time to peak" of 23 ± 9 min in group 2, compared to 228 ± 64 s and 12 ± 1 min (P < 0.05) in group 1, respectively. Kaplan-Meier curves showed longer survival in group 2 than group 1 (P = 0.06).

Compared to rewarming, hypothermia aggravates coagulation parameters, but does not hasten death during untreated hemorrhagic shock presenting as the triad of death.