Out-of-hospital surface cooling to induce mild hypothermia in human cardiac arrest: a feasibility trial.

AIM: The earliest initiation of mild hypothermia after resuscitation from cardiac arrest is crucial. This study aimed to evaluate the feasibility and safety of out-of-hospital surface cooling in such cases.

METHODS: Cooling pads stored below 0 degrees C in the ambulance were applied as soon as possible after restoration of spontaneous circulation in the out-of-hospital setting. This continued in the emergency department until an oesophageal temperature of 34 degrees C was reached, when the pads were removed. A target temperature of 33 degrees C was maintained for 24 h. Results are given as median and interquartile range.

RESULTS: From September 2006 to January 2007, 15 victims of cardiac arrest were included. Cooling was initiated at 12 (8.5-15) min after restoration of spontaneous circulation. Oesophageal temperatures decreased from 36.6 (36.2-36.6) degrees C to 33 degrees C within 70 (55-106) min. Hospital admission was at 45 (34-52) min, with oesophageal temperatures of 35.4 (34.6-35.9) degrees C; the target 33 degrees C was achieved 50 (29-82) min after admission. No skin lesions were observed.

CONCLUSION: Non-invasive surface cooling immediately after resuscitation from cardiac arrest, in the out-of-hospital setting, proved to be feasible, fast and safe. Whether early cooling will improve neurological outcome needs to be determined in future studies.