[Changes in arterial oxygen tension during and after enflurane or halothane anesthesia as well as epidural analgesia].

Recovery from inhalation anesthesia is often marked by the occurrence of postoperative hypoxemia. In this study, we compared the effects of enflurane or halothane anesthesia and epidural analgesia on arterial oxygen tension during and after the operation in 60 ASA physical status 1-2 patients who underwent cholecystectomy. Anesthesia was induced with thiopental and maintained with 66% N2O and -enflurane (1.5%), -halothane (1%), or -epidural lidocaine (1% solution, 17.5 ml) in oxygen. Blood gas analysis was done before and 10, 30, 60 min after induction. PaO2 was measured on 1st and 3rd postoperative days in all patients breathing air spontaneously. PaO2 decreased during operation in all three groups of anesthesia. PaO2 values on first postoperative day were significantly lower than those before operation, and PaO2 value in enflurane group (PaO2 = 67 +/- 1 mmHg) was significantly lower than that in halothane group (PaO2 = 72 +/- 2 mmHg, P less than 0.05).