Intra-arrest selective brain cooling improves success of resuscitation in a porcine model of prolonged cardiac arrest☆
Received 5 October 2009; received in revised form 9 December 2009; accepted 17 January 2010. published online 08 March 2010.
Abstract
Aims of study
We have previously demonstrated that early intra-nasal cooling improved post-resuscitation neurological outcomes. The present study utilizing a porcine model of prolonged cardiac arrest investigated the effects of intra-nasal cooling initiated at the start of cardiopulmonary resuscitation (CPR) on resuscitation success. Our hypothesis was that rapid nasal cooling initiated during “low-flow” improves return of spontaneous resuscitation (ROSC).
Methods
In 16 domestic male pigs weighing 40±3kg, VF was electrically induced and untreated for 15min. Animals were randomized to either head cooling or control. CPR was initiated and continued for 5min before defibrillation was attempted. Coincident with starting CPR, the hypothermic group was cooled with a RhinoChill™ device which produces evaporative cooling in the nasal cavity of pigs. No cooling was administrated to control animals. If ROSC was not achieved after defibrillation, CPR was resumed for 1min prior to the next defibrillation attempt until either successful resuscitation or for a total of 15min.
Main results
Seven of eight animals in the hypothermic group (87.5%) and two of eight animals in control group (25%) (p=0.04) were successfully resuscitated. At ROSC, brain temperature was increased from baseline by 0.3°C in the control group, and decreased by 0.1°C in the hypothermic animals. Pulmonary artery temperature was above baseline in both groups.
Conclusion
Intra-nasal cooling initiated at the start of CPR significantly improves the success of resuscitation in a porcine model of prolonged cardiac arrest. This may have occurred by preventing brain hyperthermia.
dDepartment of Critical Care Medicine, Peking Union Medical College Hospital, Chinese Academy of Medical Science, Beijing, China
Corresponding author at: Weil Institute of Critical Care Medicine, 35100 Bob Hope Drive, Rancho Mirage, CA 92270, United States. Tel.: +1 760 778 4911; fax: +1 760 778 3468.
ABSTRACT