Influence of premedication with alprazolam on the occurence of obstructive apneas. A prospective randomized double-blind study

: Postoperative development or worsening of obstructive sleep apnea is a potential complication of anesthesia. The objective of this study was to study the effects of a premedication with alprazolam on the occurrence of apneas during the immediate postoperative period. Fifty ASA 1 - 2 patients undergoing a colonoscopy were recruited. Patients with a history of obstructive sleep apnea (OSA) were excluded. Recruited patients were randomly assigned to one of two groups: in Group A, they received 0.5 mg of alprazolam orally one hour before the procedure; and in Group C, they received placebo. Anesthesia technique was identical in both groups. Patients were monitored during the first two postoperative hours to establish their AHI (apnea hypopnea index, the number of apneas and hypopneas per hour). Nine patients were excluded (4 in group A and 5 in group C) due to technical problems or refusal. Interestingly, premedication by alprazolam did not change intra-operative propofol requirements. During the first two postoperative hours, the AHI was significantly higher in group A than in group C (Group A: 20.33 ± 10.97 h-1, C: 9.63 ± 4.67 h-1). These apneas did not induce significant arterial oxygen desaturation, or mandibular instability. Our study demonstrates that a premedication with 0.5 mg of alprazolam doesn't modify intra-operative anesthetic requirements during colonoscopy, but is associated with a higher rate of obstructive apneas during at least three and a half hours after ingestion. No severe side effects were observed in our non-obese population. Our results must be confirmed on a larger scale.