PROPOFOL-INDUCED ALTERATIONS IN THE MICROCIRCULATION OF HAMSTER STRIATED-MUSCLE

To investigate the effects of propofol on small vessels, we have measu red changes in diameter and blood flow in microcirculatory venules and arterioles. Studies were carried out in the dorsal skinfold chamber o f hamsters by intravital fluorescence microscopy. A bolus injection of propofol 25 mg kg(-1) dilated small and collecting venules by a mean value of 18% and arterioles by 13%. Blood flow in venules increased by up to 69%. Intralipid dilated arterioles and post-capillary venules b y 26% and 30%, respectively. After 4 h of continuous infusion (0.2-0.8 mg kg(-1)), only blood flow in postcapillary venules increased (66% p ropofol and 92% Intralipid). Post-capillary and collecting venules dil ated in both groups. Therefore, propofol and Intralipid induced venodi latation and enhanced blood flow after bolus administration. After 4 h , despite dilatation in both groups, only postcapillary venules showed enhanced blood flow. These observations suggest redistribution of blo od flow after prolonged administration of propofol.