Twenty cirrhotic patients with bleeding from esophageal varices were studied before, during, and after portacaval shunt. There were 12 survivors and eight nonsurvivors. Preoperative determination of hepatic function and classification by Child's criteria correctly predicted outcome only in those with very good and those with very poor hepatic function. However, the majority of patients had intermediate liver function, and their operative survival could not be predicted on this basis. Other parameters, however, did distinguish between survivors and nonsurvivors. Survivors had better preoperative cardiac contractility, shorter operations, less severe preoperative and intraoperative blood loss, and fewer emergency operations. Intraoperatively, survivors maintained cardiac index and oxygen delivery while nonsurvivors did not. After operation, survivors had increased cardiac index, oxygen delivery, and oxygen consumption above preoperative values, while nonsurvivors failed to attain this. Analysis of these data suggests that determination of preoperative hepatic function alone will not provide accurate prediction of outcome from portacaval shunt, because there are multiple factors that determine outcome. The determinants identifed in this study were 1) preoperative hepatic function, 2) degree of hemodynamic compensation from preoperative bleeding and shock, 3) magnitude of the intraoperative oxygen deficits, 4) hemodynamic reserve allowing for the compensatory postoperative state, and 5) nutritional status.