Abstract 9: Surface Cooling With a New Cooling-blanket for Rapid Induction of Mild Hypothermia in Humans After Cardiac Arrest: A Feasibility Trial
Purpose of the study: Mild hypothermia (33–36°C) proved to be beneficial when induced during or after cardiac arrest in humans. Reaching the target temperature rapidly in patients inside and outside hospitals remains a challenge. Therefore, a novel cooling-blanket (EMCOOLS®), independent of an energy source during use, was developed. The primary objective was to evaluate the efficacy and safety of surface cooling with this novel cooling-blanket in patients successfully resuscitated from cardiac arrest.
Materials and Methods: Between 09/05 and 12/05, 8 patients with restoration of spontaneous circulation after cardiac arrest, admitted to our department, were included. The cooling-blanket consists of multiple cooling units, filled with a combination of graphite/water. These cooling units were cooled to −20°C before use. Cooling was started as soon as feasible until an esophageal temperature (Tes) of 34°C was reached, when the cooling blanket was removed. Target-temperature of Tes 33°C was kept for 24 hours, and then re-warming was started. Data are presented as median and interquartile range (25–75%).
Results: The cooling-blanket decreased Tes from 35.8 (35.0–36.0)°C at baseline to 34.0°C within 37 (30–45) min, and to target temperature Tes 33°C within 56 (51–62) min after initiation of cooling, resulting in a cooling rate of 3.3 (2.6–3.5)°C/h. Parts of the cooling-blanket (30% of total size) had to be re-applied at various time points to maintain the target temperature of Tes 33°C in all 8 patients. Mean arterial pressures and heart frequencies remained within normal ranges. In one patient, a minor adverse reaction was observed (frost bites II° with complete healing, due to mistakenly storage of the blanket at −35°C).
Conclusions: The novel cooling blanket showed to rapidly induce and maintain mild hypothermia in patients after cardiac arrest in the hospital setting. The feasibility and efficacy of this device in the out-of-hospital setting (ambulance service) is under investigation.