Synergistic sedation with midazolam and propofol versus midazolam and pethidine in colonoscopies: a prospective, randomized study

OBJECTIVE: The aim of our study was to compare the safety and efficacy of the synergistic sedation with a low dose of midazolam combined with propofol versus the standard regimen of midazolam and pethidine for conscious sedation in colonoscopy in a group of patients that included a sufficient number of elderly patients with several comorbidities. METHODS: A total of 120 consecutive patients undergoing colonoscopy in a prospective study were randomly assigned to one of two medication regimens (55 patients were over 65 yr). Patients in group A (n = 64) received i.v. 2 mg (<70 kg b.w.) or 3 mg (>70 kg b.w.) of midazolam and a median dose of 80 mg of propofol (range 40-150). Patients in group B (n = 56) received i.v. a median dose of 5 mg of midazolam (range 3-7) and 75 mg of pethidine (range 50-125). The patient's comfort level was assessed by a 4-point scale 24 h after the procedure. The time to recover from sedation was assessed at 5, 10, and 30 min after the procedure by using the Aldrete score. RESULTS: Multivariate stepwise logistic regression analysis revealed that among sex, age, duration of the test, American Society of Anesthesiologists' Physical Status Classification grade, and the sort of sedation, the synergistic sedation with midazolam and propofol was the only factor associated with a higher level of patient comfort (chi2 = 5.5, p < 0.05). Additional multivariate stepwise logistic regression analysis revealed that among sex, age, duration of the test, American Society of Anesthesiologists' Physical Status Classification grade, and the sort of sedation, the synergistic sedation with midazolam and propofol was the only factor associated with a quicker patient recovery time (chi2 = 24.5, p < 0.01; chi2 = 51.7, p < 0.01; chi2 = 148.4, p < 0.01 for Aldrete in 10 min, 20 min, and 30 min, respectively). The endoscopist's evaluation of patient sedation and cardiorespiratory parameters were similar in both groups and in all age groups. CONCLUSIONS: Our data suggest that the synergistic sedation with a low dose of midazolam combined with propofol was superior to a standard combination of midazolam and the opioid pethidine for colonoscopies as far as the patient comfort and recovery times are concerned.