Comparison of the recovery and respiratory effects of aminophylline and doxapram following total intravenous anesthesia with propofol and remifentanil

Abstract Study Objective To compare the effects of aminophylline and doxapram on recovery, respiration, and bispectral index (BIS) values in patients after total intravenous anesthesia (TIVA) with propofol and remifentanil. Design Prospective, randomized, blinded clinical trial. Setting Operating room of a university hospital. Patients 90 adult, ASA physical status 1 and 2 patients scheduled for elective laparoscopic vaginal hysterectomy. Interventions TIVA was performed with the induction target of remifentanil 3 ng/mL and propofol 6 μg/mL, followed by the maintenance target of remifentanil 1–3 ng/mL and propofol 3–5 μg/mL at the effect site, and with BIS scores in 40–50 range. Patients were randomized to three groups to receive intravenous (IV) aminophylline 3 mg/kg (n = 30), IV doxapram 1 mg/kg (n = 30), or normal IV saline (control; n = 30). Measurements and Main Results After administration of the study drugs, return to spontaneous ventilation differed significantly among the three groups. The times to eye opening and hand squeezing on verbal command were similar. The time to extubation was shortened in both the doxapram and aminophylline groups ( P < 0.05). Tidal volumes were increased in the doxapram group at 5–14 minutes and the aminophylline group at 5–12 minutes ( P < 0.05). Respiratory rates were increased at 2 to 8 minutes and then showed a decrease at the 12 to 14-minute mark in both the doxapram and aminophylline groups ( P < 0.05). No difference was noted between the two groups. BIS values were increased in both the doxapram and aminophylline groups at 4–10 minutes ( P < 0.05). Heart rates were increased in the doxapram group for the first 8 minutes and at 1–2 minutes in the aminophylline group ( P < 0.05). Conclusion Aminophylline 3 mg/kg or doxapram 1 mg/kg shortened the time to spontaneous ventilation and improved early recovery from TIVA without appreciable side effects. The more rapid emergence correlates with higher BIS values when compared with the saline control group. The arousal and respiratory effects of aminophylline were comparable to those of doxapram.