Mild hypothermia during advanced life support: a preliminary study in out-of-hospital cardiac arrest.

INTRODUCTION

Induction of mild hypothermia after cardiac arrest may confer neuroprotection. We assessed the feasibility, safety and effectiveness of therapeutic infusion of 2 l of normal saline at 4 degrees C before return of spontaneous circulation during cardiopulmonary resuscitation after out of hospital cardiac arrest.

METHODS

This was a prospective, observational, multicenter clinical trial conducted in Emergency Medical Services units and in a medical intensive care unit at Caen University Hospital, Cen, France.

RESULTS

In patients who had suffered out of hospital cardiac arrest, hypothermia was induced by infusing 2 l of 4 degrees C NaCl 0.9% over 30 minutes during advanced life support prior to arrival at the hospital. A total of 33 patients were included in the study. Eight patients presented with ventricular fibrillation as the initial cardiac rhythm. Mild hypothermia was achieved after a median of 16 minutes (interquartile range 11.5 to 25.0 minutes) after return of spontaneous circulation. After intravenous cooling, the temperature decreased by 2.1 degrees C (P < 0.0001) to a mean body temperature of 33.3 degrees C (interquartile range 32.3 to 34.3 degrees C). The only observed adverse event was pulmonary oedema, which occurred in one patient.

CONCLUSION

We concluded that prehospital induction of therapeutic hypothermia using infusion of 2 l of 4 degrees C normal saline during advanced life support was feasible, effective and safe. Larger studies are required to assess the impact that this early cooling has on neurological outcomes after cardiac arrest.