A comparison between head cooling begun during cardiopulmonary resuscitation and surface cooling after resuscitation in a pig model of cardiac arrest.
OBJECTIVE
Employing transnasal head-cooling in a pig model of prolonged ventricular fibrillation, we compared the effects of 4 hrs of head-cooling started during cardiopulmonary resuscitation with those of 8 hrs of surface-cooling started at 2 hrs after resuscitation on 96-hr survival and neurologic outcomes.


METHODS
Prospective controlled animal study.


METHODS
University-affiliated research laboratory.


METHODS
Domestic pigs.


METHODS
Twenty-four male pigs were subjected to 10 min of untreated ventricular fibrillation followed by 5 min of cardiopulmonary resuscitation. In the head-cooling group, hypothermia was started with cardiopulmonary resuscitation and continued for 4 hrs after resuscitation. In the surface-cooling group, systemic hypothermia with a cooling blanket was started, in accord with current clinical practices, at 2 hrs after resuscitation and continued for 8 hrs. Methods in the control animal studies were identical except for temperature interventions.


RESULTS
All animals were resuscitated except for one animal in each of the surface-cooling and control groups. After 5 min of cardiopulmonary resuscitation, jugular vein temperature was significantly decreased in the head-cooled animals. However, there were no differences in pulmonary artery temperatures among the three groups at that time. Nevertheless, both head-cooled and surface-cooled animals had an improved 96-hr survival after resuscitation. Significantly better neurologic outcomes were observed in early head-cooled animals in the first 3 days after resuscitation.


CONCLUSIONS
Early head-cooling during cardiopulmonary resuscitation continuing for 4 hrs after resuscitation produced favorable survival and neurologic outcomes in comparison with delayed surface-cooling of 8 hrs duration.
Guan
Jun
J
Well Institute of Critical Care Medicine, Rancho Mirage, CA, USA.
Barbut
Denise
D
Wang
Hao
H
Li
Yongqin
Y
Tsai
Min-Shan
MS
Sun
Shijie
S
Inderbitzen
Becky
B
Weil
Max Harry
MH
Tang
Wanchun
W
D000818:Animals; D016887:Cardiopulmonary Resuscitation / Q000379:methods*; D003326:Coronary Circulation; D006257:Head; D006323:Heart Arrest / Q000150:complications / Q000401:mortality / Q000628:therapy*; D007036:Hypothermia, Induced / Q000379:methods*; D008297:Male; D012121:Respiration, Artificial; D013552:Swine; D013997:Time Factors; D014693:Ventricular Fibrillation / Q000209:etiology / Q000401:mortality / Q000628:therapy*