Intra-arrest rapid head cooling improves postresuscitation myocardial function in comparison with delayed postresuscitation surface cooling.
OBJECTIVE
To compare resuscitation outcomes and myocardial function among intra-arrest head cooling, delayed surface cooling, and uncooled controls.


METHODS
Prospective animal study.


METHODS
University-affiliated animal research laboratory.


METHODS
Twenty-four male domestic pigs.


METHODS
Ventricular fibrillation remained untreated for 10 mins after which animals were assigned into three groups: 1) intra-arrest head cooling, 2) postresuscitation surface cooling, and 3) uncooled controls. Head cooling by evaporative perfluorochemical began coincident with the start of cardiopulmonary resuscitation and continued for a total of 4 hrs. Surface cooling using a cooling blanket began at 2 hrs after return of spontaneous circulation and continued for 8 hrs. Control animals were treated identically with the exception for cooling.


RESULTS
Return of spontaneous circulation was achieved in eight of eight head-cooled animals, in seven of eight surface-cooled animals, and in seven of eight of controls. Myocardial functions measured by transthoracic echocardiography were significantly better in the head-cooled animals than in surface-cooled and controls. All head-cooled animals survived for more than 96 hrs. This contrasted with six of eight survivors after surface cooling, and only two of eight among controls.


CONCLUSIONS
Both intra-arrest head cooling and delayed surface cooling improved postresuscitation myocardial dysfunction. The beneficial effects were greatest with head cooling initiated with cardiopulmonary resuscitation.
Tsai
Min-Shan
MS
Weil Institute of Critical Care Medicine, Rancho Mirage, CA, USA.
Barbut
Denise
D
Wang
Hao
H
Guan
Jun
J
Sun
Shijie
S
Inderbitzen
Becky
B
Weil
Max Harry
MH
Tang
Wanchun
W
D000818:Animals; D016887:Cardiopulmonary Resuscitation / Q000379:methods*; D003326:Coronary Circulation; D004452:Echocardiography; D004554:Electric Countershock / Q000379:methods*; D004562:Electrocardiography; D004837:Epinephrine / Q000008:administration & dosage; D006257:Head; D006323:Heart Arrest / Q000150:complications; D007036:Hypothermia, Induced / Q000379:methods*; D008297:Male; D012121:Respiration, Artificial; D013552:Swine; D014662:Vasoconstrictor Agents / Q000008:administration & dosage; D014693:Ventricular Fibrillation / Q000209:etiology / Q000503:physiopathology / Q000628:therapy*
D014662:Vasoconstrictor Agents; D004837:Epinephrine