The effects of desflurane on splanchnic hemodynamics and oxygenation in the anesthetized pig.

This study was designed to investigate the effects of desflurane on systemic and splanchnic hemodynamics, O2 delivery and O2 uptake, tissue oxygenation (as monitored by surface PO2 electrodes), and hepatic oxygen-dependent intermediary metabolism (hepatic lactate uptake, intestinal lactate production, ketone-body ratio) in the pig. We studied 11 anesthetized (i.e., ketamine, flunitrazepam, vecuronium) and ventilated domestic pigs (17-23 kg). After instrumentation, desflurane was administered randomly at 0.5 minimum alveolar anesthetic concentration (MAC) (4.2 vol %) and 1.0 MAC (8.3 vol %). Desflurane caused dose-dependent decreases in heart rate, mean arterial blood pressure, and cardiac output. Hepatic arterial blood flow was not affected at 0.5 MAC but decreased at 1.0 MAC. In contrast, portal and superior mesenteric arterial blood flow decreased at 0.5 MAC but did not show any further significant decrease at 1.0 MAC. Total hepatic blood flow decreased dose-dependently. Although O2 deliveries of whole body, liver, and small intestine were markedly reduced at both concentrations, respective O2 uptakes did not change significantly. The decreases in O2 deliveries were reflected by moderate disturbances in hepatic and small intestinal surface PO2. No evidence for severe tissue hypoxia could be detected. Desflurane had no adverse effects on hepatic and small intestinal metabolic function. These data indicate that hepatic and small intestinal O2 reserve capacity is impaired by desflurane.