Effects of aminophylline on cognitive recovery after sevoflurane anesthesia

Purpose Aminophylline accelerates the recovery from sevoflurane anesthesia. We studied the effects of escalating doses of aminophylline on cognitive and clinical recovery after sevoflurane anesthesia. Methods After ethical approval and informed consent, 150 patients scheduled for elective surgery under sevoflurane-fentanyl anesthesia were randomly allocated to receive saline or 2, 3, 4 or 5 mg/kg of aminophylline (n = 30 for each) at the end of anesthesia (T (0)). Short Orientation Memory Concentration Test (SOMCT) scores, entropy values, end-tidal sevoflurane concentrations (EtSevo), times to eyes opening and extubation, respiratory rate (RR) and tidal volume (TV) were recorded. Results Compared to placebo, patients receiving 2, 3, 4 and 5 mg/kg of aminophylline had higher SOMCT scores [median (25th percentile/75th percentile) 20.6 (19/23), 21.5 (21/22), 24.5 (24-25), 25.5 (25/26), respectively, vs. 13.5 (13/14) at 30 min after extubation, and 24 (22/26), 25 (24/26), 27.5 (27-28), 27.5 (27/28), respectively, vs. 18.5 (18/19) at 45 min after extubation], higher entropy values for the first 10 min after T (0), lower EtSevo for the first 4 min after T (0), shorter times to eyes opening [5 (4.0/6.0), 5 (4.0/6.0), 4 (2.0/5.5), and 4 (2.0/6.0), respectively, vs. 9.8 (8.0/11.0) min], shorter times to extubation, shorter times to home discharge (P < 0.001), and higher RR and larger TV values. Patients who received 4 and 5 mg/kg of aminophylline showed higher SOMCT scores, 6 min shorter times to eyes opening and to extubation, and 58 min shorter times to home discharge. Conclusion The administration of escalating doses of aminophylline accelerates postoperative cognitive recovery from sevoflurane anesthesia, as measured by the SOMCT, due to increased ventilatory elimination of sevoflurane.