The influence of deliberate hypotension on splanchnic perfusion balance with use of either isoflurane or esmolol and nitroglycerin

Various techniques to induce deliberate hypotension PR have different influ ences on splanchnic perfusion. The aim of our study was to determine whethe r splanchnic perfusion is clinically impaired during DH by using either iso flurane (ISO) or a combination of esmolol and nitroglycerin (E/N). We rando mized 16 patients undergoing elective maxillofacial surgery to receive eith er ISO (0.7%-1.8%) or E (105 g . kg(-1) . min(-1)) and N (1-6 mg/h) to indu ce DH. General anesthesia was performed in both groups by IV midazolam 0.07 mg/kg, fentanyl 0.003 mg/ kg, propofol 1.5 mg/kg, and vecuronium. 0.1 mg/k g followed by a propofol infusion with 6 mg . kg-1 . h(-1). After the induc tion of anesthesia, a gastric tonometer (TRIP (R) NGS Catheter) and a radia l artery catheter were inserted. Baseline values of gastric intramucosal pH (pl-li) were determined 60 min after placement of the catheter and before the induction of DH. The pHi values were calculated every 60 min until DH w as discontinued. h-L both groups, DH was satisfactorily established. None o f the pl-Ii values calculated was less than 7.37 in the E/N or 7.41 in the ISO group. Arterial blood lactate levels did not increase in any of the pat ients. We conclude that neither method of producing DH compromises splanchn ic tissue oxygen balance in healthy patients. Furthermore, overall organ pe rfusion was sufficient in both groups, because none of the patients showed an increase in blood lactate.