Sequential Cardiorespiratory Events During and After Dextran-4O Infusion in Normal and Shock Patients

Abstract

Sequential measurements of cardiac output, intravascular pressures, blood gases, pH, blood volume, and oxygen consumption were made in normal subjects and patients in shock before, during, and after infusions of dextran-40. In eight normal subjects the responses were: increased central venous pressure, increased cardiac index, decreased peripheral resistance, and decreased hemoglobin concentrations. These changes were of short duration and were attributed largely to increased plasma volume from the infusion. Nineteen of 26 patients in shock responded to administration of dextran-40 with increased central venous pressure, cardiac index, plasma volume, and central blood volume, as well as decreased mean transit time and total peripheral resistance. Lesser increases in blood pressure, stroke index, and left ventricular stroke work were observed. The increase in cardiac index was preceded by increased central venous pressure and decreased peripheral resistance. The hemodynamic changes were more marked and of longer duration than those of the normal subjects. In addition to these hemodynamic changes, dextran increased oxygen consumption in all but one of the patients whose major problem was hemorrhage and trauma. Increased oxygen consumption suggests that tissue perfusion improved after dextran possibly because of increased small vessel flow as well as increased plasma volume. In patients who were in shock because of sepsis, no change in oxygen consumption was observed despite hemodynamic improvement. As in the normal subjects, these hemodynamic changes were attributable to plasma expansion. In seven patients, dextran increased central venous pressure without improving cardiac index or other hemodynamic parameters. It is suggested that these patients were functioning with limited cardiac reserve.