Effects of desflurane and isoflurane on splanchnic microcirculation during major surgery

Isoflurane has been considered the agent of choice where preservation of splanchnic blood flow is required. Liver blood flow and the hepatic artery buffer response are maintained better in the presence of isoflurane than with other volatile anaesthetic agents. The effects of desflurane have not been assessed in humans. Therefore, we have compared the effects of isoflurane and desflurane anaesthesia on small bowel and hepatic microcirculatory flow during major surgery using laser Doppler flowmetry in a prospective, randomized, single-blind, crossover study. Patients were allocated randomly to receive desflurane or isoflurane (1 MAC) in oxygen-enriched air. Steady-state jejunal and liver blood flow in segment III were assessed by laser Doppler flowmetry. Volatile anaesthetics were then interchanged, and measurements repeated at steady state. Desflurane anaesthesia at 1 MAC was associated with significantly greater gut blood flow than 1 MAC of isoflurane. These differences could not be explained by systemic haemodynamic differences. The similarity in total hepatic flow between groups implies an intact hepatic artery buffer response with desflurane and isoflurane.