Sevoflurane and propofol anaesthesia differentially modulate the effects of epinephrine and norepinephrine on microcirculatory gastric mucosal oxygenation

BackgroundAdequate gastrointestinal mucosal oxygenation is regarded to be crucial in the prevention and therapy of critical illness. Epinephrine and norepinephrine are used for perioperative haemodynamic support. However, their per se effects on gastromucosal haemoglobin oxygenation (HbO2) remain unclear. Moreover, respective effects of epinephrine and norepinephrine may be affected by the type of underlying anaesthesia. Thus, we studied the effects of epinephrine and norepinephrine during anaesthesia with sevoflurane or propofol on regional gastromucosal HbO2 and systemic O2-derived variables.MethodsIn a double-randomized cross-over study, chronically instrumented dogs (n=6 per group) were anaesthetized randomly with sevoflurane or propofol, ventilated, and then randomly received either epinephrine or norepinephrine (0, 0.05, 0.1, and 0.2 g kg-1 min-1). We measured gastromucosal HbO2, systemic haemodynamics, and O2-derived variables.ResultsDuring sevoflurane anaesthesia, norepinephrine markedly increased HbO2 (P<0.0001) and systemic oxygen transport (DO2) (P=0.0006). In contrast, epinephrine failed to increase HbO2, despite doubling DO2 (P=0.0002). During propofol anaesthesia, in contrast to sevoflurane, neither epinephrine nor norepinephrine affected HbO2, although epinephrine, but not norepinephrine, again resulted in markedly increased DO2 (P<0.0001).ConclusionsThe effects of epinephrine and norepinephrine depended on the type of anaesthesia. In addition, regional effects (i.e. HbO2) were not predictable from systemic effects (i.e. DO2). © The Author 2010. Published by Oxford University Press on behalf of the British Journal of Anaesthesia. All rights reserved.