Effect of pethidine premedication and halothane anaesthesia on upper limb blood flow

Forearm blood flow (FBF), hand blood flow (HBF) and arterial pressure were measured in 12 patients, before and after premedication with pethidine and during halothane anaesthesia. After pethidine there was a significant (P less than 0.01) increase in HBF (180%) and decreased hand vascular resistance; heart rate also increased significantly (P less than 0.05), whilst mean arterial pressure (MAP) did not change. The large increase in HBF without hypotension suggests a local effect. With halothane, there was a significant (P less than 0.05) decrease in MAP, increase in HBF and decrease in hand vascular resistance compared with either control or effects produced by pethidine; there was a significant decrease in FBF and reversal of the action of pethidine on forearm vascular resistance.