Arousal time from sedation during spinal anaesthesia for elective infraumbilical surgeries: Comparison between propofol and midazolam

BACKGROUND AND AIMS: Studies have already compared propofol and midazolam as sedatives during regional anaesthesia. A few studies have focused on recovery characteristics and very few have utilised both instrumental and clinical sedation monitoring for assessing recovery time. This study was designed primarily to compare arousal time from sedation using propofol with that of midazolam during spinal anaesthesia for infraumbilical surgeries, while depth of sedation was monitored continuously with bispectral index (BIS) monitor. The correlation between the BIS score and observer's assessment of awareness/sedation (OAA/S) score during recovery from sedation was also studied. METHODS: A total of 110 patients were randomly assigned to receive either propofol (Group P, n = 55) or midazolam (Group M, n = 55). Patients in the Group P received bolus of propofol (1 mg/kg), followed by infusion at 3 mg/kg/h; Group M received bolus of midazolam (0.05 mg/kg), followed by infusion at 0.06 mg/kg/h and titration until BIS score 70 was achieved and maintained between 65 and 70. OAA/S score was noted at BIS 70 and again at BIS 90 during recovery. The time to achieve OAA/S score 5 was noted. Spearman's correlation was calculated between the arousal time from sedation and the time taken to reach an OAA/S score of 5 in both the study groups. RESULTS: Arousal time from sedation was found lower for Group P compared to Group M (7.54 ± 3.70 vs. 15.54 ± 6.93 min, respectively, P = 0.000). The time taken to reach OAA/S score 5 was also found to be lower for Group P than Group M (6.81 ± 2.54 min vs. 13.51 ± 6.24 min, respectively, P = 0.000). CONCLUSION: A shorter arousal time from sedation during spinal anaesthesia can be achieved using propofol compared with midazolam, while depth of sedation was monitored with BIS monitor and OAA/S score. Both objective and clinical scoring correlate strongly during recovery from sedation.