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.
Trial registration: ClinicalTrials.gov NCT01022151.