Open-chest CPR improves survival and neurologic outcome following cardiac arrest.
OBJECTIVE
To determine if 15 min of open-chest cardiac massage (OC-CPR) versus closed-chest compressions (CC-CPR) improves 72-h survival and neurologic outcome (behavioral and histologic) after 5 min of untreated cardiac arrest.


METHODS
Mongrel dogs were anesthetized and instrumented. Cardiac arrest was induced by KCl injection and after a 5-min period of non-intervention, dogs were randomized to receive either CC-CPR (N = 7) or OC-CPR (N = 5) performed for 15 min. The dogs were then resuscitated and physiologic data was recorded. Surviving dogs were scored at 72 h using canine neurodeficit score of Safar et al. (NDS; 0 = behaviorally normal, 500 = brain death). Dogs that could not be resuscitated or died before 72 h were assigned a score of 500. Brain histology was performed on all survivors.


RESULTS
All OC-CPR dogs were successfully resuscitated and were behaviorally normal at 72 h (NDS = 0). Histology in OC-CPR dogs showed little to no injury. Only three out of the seven CC-CPR dogs survived to 72 h. Of the survivors, one dog exhibited minor ataxia (NDS = 15), and two had incapacitating deficits (both NDS = 180). Two dogs died within 24 h after extubation, and one could not be resuscitated and the other could not be weaned from the ventilator (each NDS = 500). Histology of the CC-CPR survivors revealed moderate to severe lesions. NDS between groups was statistically significant (p < 0.0079).


CONCLUSIONS
In our canine model of cardiac arrest, OC-CPR significantly improved 72-h survival and neurologic outcome when compared to CC-CPR.
Benson
Don M
DM
Department of Emergency Medicine, St. John Hospital and Medical Center, 22101 Moross Road, Detroit, MI 48236, USA.
O'Neil
Brian
B
Kakish
Edward
E
Erpelding
John
J
Alousi
Sarah
S
Mason
Reginald
R
Piper
David
D
Rafols
Jose
J
D000818:Animals; D001831:Body Temperature; D001921:Brain / Q000473:pathology; D016887:Cardiopulmonary Resuscitation / Q000379:methods*; D004195:Disease Models, Animal; D004285:Dogs; D006323:Heart Arrest / Q000150:complications* / Q000503:physiopathology / Q000628:therapy*; D006336:Heart Massage / Q000379:methods*; D006439:Hemodynamics; D009422:Nervous System Diseases / Q000209:etiology* / Q000473:pathology / Q000503:physiopathology / Q000517:prevention & control*; D020127:Recovery of Function; D016019:Survival Analysis; D016896:Treatment Outcome