Computer controlled induced hypothermia in victims of out-of-hospital cardiac arrest

Out-of-hospital cardiac arrest is a condition with high mortality and devastating morbidity. Until most recently there was no specific therapy apart from strict monitoring and supportive care. Results from animal studies and a few recent clinical trials suggest a beneficial effect of induced mild hypothermia on the neurologic outcome. We treated 22 successive patients with 24 hours of induced hypothermia to 34.5°C and compared their outcome to our last 16 patients who were hospitalized before we started the project. Patients were connected to a microprocessor-based heat pump that supplied warmed or cooled water to the ThermoWrap™ garment worn by the patient. The cooling system we used lowered patients´ temperature to a mean of 34.5 ± 0.7°C at a mean time of 6.2 ± 2.5 hours. 59% of the hypothermia patients were discharged conscious as compared to 25% of the patients who were treated conservatively p<0.03. The mortality rate was 29% in the hypothermia group and 37% in the conservative care group P=NS. We conclude that the computerized cooling system we used, adequately lowered and stabilized our patients´ temperature on the desired target level. Induced mild hypothermia is beneficial in victims of out-of-hospital cardiac arrest. The issue of controlled cooling of patients is complex and should be further investigated.