Low-flow desflurane and sevoflurane anesthesia minimally affect hepatic integrity and function in elderly patients

Hepatic blood flow is reduced in a dose-related manner by all inhaled anest hetics now in use. We assessed hepatic function in elderly patients anesthe tized with desflurane or sevoflurane. We measured the cytosolic liver enzym e alpha glutathione S-transferase (alpha GST), the formation of the lidocai ne metabolite monoethylglycinexylidide (MEGX), and gastric mucosal tonometr y-derived variables as sensitive markers of hepatic function and splanchnic perfusion. Thirty patients, 70 to 90 yr old, were allocated randomly to re ceive desflurane or sevoflurane anesthesia. Anesthetic exposure ranged from 2.1-4.5 minimum alveolar concentration hours. No significant changes in st andard liver enzyme markers were seen throughout the study. In both anesthe tic groups, tonometric measurements showed a significant decrease from base line in regional PCO2, regional to arterial difference in PCO2, and intramu cosal pH at 90 min after skin incision, alpha GST concentrations increased significantly in both groups (desflurane: median peak concentrations 5.8 mu g/L [25th, 75th percentile 5.3 mu g/L, 7.2 mu g/L]; sevoflurane: 7.0 mu g/ L [5.8 mu g/L, 7.3 mu g/L]) without showing differences between both anesth etic groups. A return to baseline values in tonometric values and alpha GST levels was seen 24 h postoperatively. MEGX formation did not change signif icantly after surgery. Median MEGX concentrations postoperatively were 70.0 ng/mL (56.2 ng/mL, 102.0 ng/mL) and 70.0 ng/mL (60.0 ng/mL, 94.2 ng/mL) in the desflurane and sevoflurane groups, respectively. We conclude that, ove rall, liver function in elderly patients is well preserved during desfluran e and sevoflurane anesthesia. Increased serum levels of alpha GST and chang es of gastric tonometry-derived variables imply a reduction in splanchnic p erfusion, leading to a temporary Impairment of hepatocyte oxygenation..