Differential effects of propofol, ketamine, and thiopental anaesthesia on the skeletal muscle microcirculation of normotensive and hypertensive rats in vivo

This study utilized the dorsal microcirculatory chamber (DMC) model to determine differential effects of i.v. propofol, ketamine, and thiopental anaesthesia on the skeletal muscle microcirculation (10–180 μm) of normotensive (Male Wistar Kyoto, WKY) and hypertensive (spontaneously hypertensive Harlan, SHR) rats, importantly, comparing responses to a conscious baseline. Three weeks following implantation of the DMC in WKY (n=8) and SHR (n=6) (130 g) 0.25 ml 100 g−1 FITC–BSA (i.v.) was administered and the microcirculation viewed using fluorescent in vivo microscopy for a 30 min baseline (t=0–30 min). This was followed by either propofol, thiopental, ketamine, or saline (i.v. bolus induction over 5 min (t=30–35 min)), then maintenance step-up infusion for 60 min (t=45–105 min), so that animals received all four agents 1 week apart (56 experiments). Dilation of A3 arterioles (15–30 μm) and V3 venules (20–40 μm) with propofol was greater in SHR (t=95 min, A3 36.7 (12)%, V3 15.5 (2.3)%) than WKY (t=95 min, A3 19.4 (7.4)%, V3 8.0 (2.3)%) (P