[Responses of hemodynamics and splanchnic organ blood flow to esmolol during inhalation of volatile anesthetics in dogs].

Background: Because the hemodynamic alterations due to sympathetic suppression by the interaction of esmolol with volatile anesthetics may alter the blood flow to the splanchnic organs, this study was designed to investigate whether esmolol might modify the hemodynamics and splanchnic organ blood flow in anesthetized dogs.

Methods: Anesthesia was maintained with 0.9% halothane, 1.3% isoflurane or 2.4% sevoflurane (1MAC, n=8, each) in oxygen. Esmolol was infused at a constant rate of 400 microg * kg(-1) x min(-1) during a 60 min-infusion period. The renal, hepatic, and pancreatic blood flows (RBF, HBF, and PBF) were measured by using the hydrogen clearance method.

Results: Mean arterial pressure in all three groups decreased without any changes in heart rate or systemic vascular resistance. Cardiac index in all three groups decreased with reductions in cardiac contractility. The RBF, HBF, and PBF in all three groups were reduced during the esmolol infusion.

Conclusions: The splanchnic organ blood flow reductions caused by esmolol may be due to cardiac depression, whereas there appears to be no differences in there change regarding the kind of the volatile anesthetics. These findings suggest that hypotension induced by esmolol may impair the maintenance of splanchnic organ blood flow during anesthesia by volatile agents.