Cerebral and systemic arteriovenous oxygen monitoring after cardiac arrest. Inadequate cerebral oxygen delivery.
BACKGROUND
After prolonged cardiac arrest, under controlled normotension, cardiac output and cerebral blood flow are reduced for several hours. This dog study documents for the first time the postarrest reduction in oxygen (O2) delivery in relation to O2 uptake for brain and entire organism.


METHODS
In eight dogs we used our model of ventricular fibrillation (VF) cardiac arrest of 12.5 min, reperfusion with brief cardiopulmonary bypass, and controlled normotension, normoxemia, and mild hypocapnia to 24 h.


RESULTS
Between 4 and 24 h after cardiac arrest, cardiac output decreased by about 25% and the systemic arteriovenous O2 content difference doubled, while the calculated systemic O2 utilization coefficient (O2 UC) increased and the systemic venous PO2 decreased, both not to critical levels. The cerebral arteriovenous O2 content difference however, which was 5.6 +/- 1.7 ml/dl before arrest, increased between 1 and 18 h, to 10.8 +/- 3.2 ml/dl at 4 h. The cerebral O2 UC increased and the cerebral venous PO2 decreased, both to critical levels.


CONCLUSIONS
After prolonged cardiac arrest in dogs with previously fit hearts, the reduction of O2 transport to the brain is worse than its reduction to the whole organism. Monitoring these values might help in titrating life-support therapies.
Oku
K
K
Department of Anesthesiology and Critical Care Medicine, University of Pittsburgh, Pittsburgh Medical Center, PA 15260.
Kuboyama
K
K
Safar
P
P
Obrist
W
W
Sterz
F
F
Leonov
Y
Y
Tisherman
S A
SA
D000818:Animals; D001921:Brain / Q000378:metabolism*; D002302:Cardiac Output / Q000502:physiology; D016887:Cardiopulmonary Resuscitation / Q000379:methods; D002560:Cerebrovascular Circulation / Q000502:physiology; D004285:Dogs; D005260:Female; D006323:Heart Arrest / Q000097:blood* / Q000503:physiopathology / Q000628:therapy; D002534:Hypoxia, Brain / Q000209:etiology* / Q000503:physiopathology; D008297:Male; D008991:Monitoring, Physiologic / Q000379:methods; D010100:Oxygen / Q000097:blood*; D010101:Oxygen Consumption / Q000502:physiology*; D013997:Time Factors; D014693:Ventricular Fibrillation / Q000097:blood* / Q000503:physiopathology / Q000628:therapy
D010100:Oxygen