Hemodynamic and oxygen transport patterns in surviving and nonsurviving postoperative patients

Invasive hemodynamic monitoring was performed on 220 critically ill surgical patients judged by clinical evaluation to have a high likelihood of surgical complications or death. Patients with markedly abnormal preoperative hemodynamic values were excluded from analysis. Data were separated into preoperative, intraoperative and postoperative time intervals and the mean value of each variable for each patient at each time period was computed. In comparison to survivors, the nonsurvivors generally had: (a) reduced myocardial performance as judged by lower cardiac index and left ventricular stroke work in the presence of high right and left ventricular filling pressures, (b) reduced pulmonary function (increased alveolar-arterial oxygen content difference and pulmonary shunt fraction), (c) pulmonary vasoconstriction (increased pulmonary artery pressure and pulmonary vascular resistance), and (d) decreased oxygen delivery despite maintenance of normal arterial blood gases and comparable hemoglobin values. Both survivors and nonsurvivors had vital signs usually within the normal range (until the terminal state of nonsurvivors).