Cold saline infusion and ice packs alone are effective in inducing and maintaining therapeutic hypothermia after cardiac arrest

Abstract

Aim of the study: Hypothermia treatment with cold intravenous infusion and ice packs after cardiac arrest has been described and used in clinical practice. We hypothesised that with this method a target temperature of 32-34 degrees C could be achieved and maintained during treatment and that rewarming could be controlled.

Materials and methods: Thirty-eight patients treated with hypothermia after cardiac arrest were included in this prospective observational study. The patients were cooled with 4 degrees C intravenous saline infusion combined with ice packs applied in the groins, axillae, and along the neck. Hypothermia treatment was maintained for 26 h after cardiac arrest. It was estimated that passive rewarming would occur over a period of 8h. Body temperature was monitored continuously and recorded every 15 min up to 44 h after cardiac arrest.

Results: All patients reached the target temperature interval of 32-34 degrees C within 279+/-185 min from cardiac arrest and 216+/-177 min from induction of cooling. In nine patients the temperature dropped to below 32 degrees C during a period of 15 min up to 2.5h, with the lowest (nadir) temperature of 31.3 degrees C in one of the patients. The target temperature was maintained by periodically applying ice packs on the patients. Passive rewarming started 26 h after cardiac arrest and continued for 8+/-3h. Rebound hyperthermia (>38 degrees C) occurred in eight patients 44 h after cardiac arrest.

Conclusions: Intravenous cold saline infusion combined with ice packs is effective in inducing and maintaining therapeutic hypothermia, with good temperature control even during rewarming.