Effect of aminophylline on bispectral index

Abstract

Background: The aim of the present study was to investigate the effects of aminophylline on BIS as well as clinical recovery in patients anesthetized with sevoflurane.

Methods: Sixty patients with status of ASA I-II scheduled for elective surgery were enrolled in this study. Anesthesia was induced by 2 mg kg(-1) of propofol and 0.5 mg kg(-1) of atracurium, maintained with 1:1 ratio of oxygen and nitrous oxide and 2-2.5% sevoflurane, keeping BIS values at 50 +/- 5. During the last 30 min of the operation no muscle relaxant was given and anesthesia was continued without decreasing anesthetic concentration. After sevoflurane discontinuation, saline was given to Group P, and 5 mg kg(-1) of aminophylline was given to Group A. Bispectral index values, heart rate, blood pressure and oxygen saturation were determined in all the patients before and every min after injection of the test drug for 15 min. The following variables were measured in both groups: eye opening, extubation time, response to command, Aldrete scores, and performing three simple arithmetic calculations.

Results: Between groups there was no statistically significant difference in mean arterial blood pressure, SpO2 and anesthesia time. Heart rate was found to be statistically higher (P < 0.001) at 2 to 6 min in Group A when compared with group P. Eye opening, verbal response, extubation and arithmetic calculation times were significantly shorter (P < 0.001) in Group A. Bispectral index scores were significantly higher in Group A at 1 to 12 min after aminophylline injection when compared with placebo (P < 0.001).

Conclusion: Recovery from sevoflurane anesthesia and BIS scores are improved in early period when aminophylline is given at emerging from anesthesia.