[The effect of pentobarbital on the microcirculation of skeletal muscles and the subcutis. An animal-experimental study].

The effects of pentobarbitone anaesthesia on the macrohaemodynamics and the microvasculature of subcutaneous tissue and skin muscle were studied in hamsters (n = 14) utilizing intravital microscopy, quantitative video techniques and a platinum multiwire electrode for local PO2 measurements. After achieving anaesthesia with 35 mg/kg b.w. pentobarbitone, changes in macrohaemodynamic parameters, blood cell velocity and vessel diameters were not observed. However, after 30 min of pentobarbitone anaesthesia, 25% of the arteriolar blood volume coursed through arteriovenous shunts. The increase in a-v shunting was accompanied by a significant decrease of functional capillary density. As a result, local PO2 values decreased slightly after 30 min of pentobarbitone anaesthesia. These findings provide evidence that 35 mg/kg b.w. pentobarbitone cause alterations in capillary density and perfusion. It is concluded that with a dose of up to 35 mg/kg b.w. pentobarbitone, these changes have little effect on local tissue oxygenation.