Effects of propofol on haemodynamics and on regional blood flows in dogs submitted or not to a volaemic expansion

This study was designed to examine the effect of volume loading on haemodyn amic responses and regional cardiac function in dogs subjected to two infus ion rates of propofol. Instrumentation was established to measure aortic an d left ventricular pressures, cardiac output and myocardial segmental lengt hs. Measurements were taken during two successive infusion rates of propofo l: 0.2 (P0.2) and 0.4 (P0.4) mg kg(-1) min(-1). One group (VL+) (n=6) recei ved volume loading (dextran 40, 10 mL kg(-1) h(-1)), the other group (VL-) (n=6) received only basal perfusion (Ringer solution, 2 mL kg(-1).h(-1)). R egional blood flows were measured by radio-labelled microspheres. P0.4 indu ced a decrease in cardiac output and in dP/dt(max). End-diastolic length de creased with propofol without any difference between groups. Regional contr actility was not modified by propofol or by volume loading. P0.4 decreased endocardial and epicardial blood flow in the VL-group only. Renal, small in testine and large intestine blood flows decreased in both groups with P0.4. P0.2 did not alter regional blood flows significantly. It was concluded th at in this model, propofol infusion at 0.4 mg kg(-1) min(-1) induced splanc hnic, renal and myocardial hypoperfusion in animals not submitted to a mild fluid loading. Fluid loading allowed myocardial perfusion to be maintained but could not prevent a marked decrease in splanchnic and renal perfusion.