The direct effects of propofol on pial microvessels in rabbits.

摘要: Propofol is widely used for neurosurgical anesthesia; however, its effects on the pial microvasculature are unknown. We therefore evaluated direct of propofol microvessels in rabbits. Pial microcirculation was visualized using a closed cranial window technique 20 Japanese white In first experiment (n=14), after baseline hemodynamic measurements, superfused with 5 increasing concentrations (10−8, 10−7, 10−6, 10−5, 10−4 mol/L; n=8) or intralipid (at comparable concentrations; n=6) dissolved artificial cerebrospinal fluid 7 minutes each. A typical anesthetic concentration 5 μg/mL corresponds to 10−6 mol/L. second (n=6), phenylephrine 10−6 mol/L and nitroglycerin were applied topically under pentobarbital anesthesia. third (n=3), electroencephalogram bispectral index measured Diameters selected arterioles venules microscope-video capture unit combination subsequently digital video analyzer. Topical application at 10−8, 10−5 mol/L did not alter diameters microvessels; 10−4 mol/L induced dilation large small arterioles, along venular dilation. Intralipid alone have any significant effect vessel diameters. Phenylephrine produced arteriolar constriction dilation, respectively. constricted dilated venules. Pentobarbital produce either burst suppression an isoelectric electroencephalogram. The results confirm our hypothesis: clinically relevant propofol, that is, approximately 10−6 mol/L, do dilate