Propofol and hypothermic cardiopulmonary bypass

Publisher Website
Google Scholar
Abstract
Summary: The effects of propofol during low flow (1.6 l.min−1.m−2) hypothermic (27–29°C) cardiopulmonary bypass on systemic haemodynamic and metabolic variables were studied in 20 patients in a parallel group comparison. Patients in the control group underwent two consecutive control periods, whereas those in the propofol group underwent a control period followed by a ‘propofol’ period during which they received an intravenous bolus of propofol 5 mg.kg−1 followed by an infusion at a rate of 20 mg.kg−1.h−1. Haemodynamic and metabolic variables were measured at the end of each period. The propofol group showed a significant reduction in both systemic vascular resistance (p < 0.001) and systemic oxygen uptake (p < 0.05). There was a small but significant fall in lactate in the control group (p < 0.02); however, there was no significant change in the propofol group. These findings could indicate impaired tissue perfusion, although they more likely indicate systemic metabolic depression with washout of lactate from previously hypoperfused tissues.