Abstract
AIM: 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". METHODS: 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. RESULTS: 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). CONCLUSIONS: Compared to rewarming, hypothermia aggravates coagulation parameters, but does not hasten death during untreated hemorrhagic shock presenting as the triad of death.