Effect of remifentanil during drug-induced sleep endoscopy in patients with obstructive sleep apnea

Purpose During drug-induced sleep endoscopy (DISE) in patients with obstructive sleep apnea, the increased depth of propofol anesthesia is related to the increased collapsibility of the upper airway with dose-dependent. We examined the effect of remifentanil on propofol concentration during DISE. Methods In a prospective randomized trial, 56 adult patients were divided into remifentanil-propofol (n = 28) and propofol alone (n = 28) groups. Anesthesia was administered using a target-controlled infusion system. In the remifentanil-propofol group, 0.5 ng/ml remifentanil was administered prior to propofol infusion and its concentration maintained; thereafter, in the propofol alone group, normal saline was injected instead of remifentanil. Propofol was infused at a concentration of 1.5 mu g/ml after the target concentration of remifentanil was reached. In both groups, the concentration of propofol was increased by 0.5 mu g/ml if the degree of sedation was not sufficient. The sedation level was targeted at observer's assessment of alertness/sedation (OAA/S) scale 3. Results The mean propofol concentration was 2.87 +/- 0.60 mu g/ml in the remifentanil-propofol group, which was lower than that in the propofol alone group (3.38 +/- 0.72 mu g/ml, P < 0.001). The time until sufficient sedation to perform DISE was shorter in the remifentanil-propofol group (P < 0.001). Apnea-hypopnea index and the lowest peripheral capillary oxygen saturation (SpO(2)) during polysomnography showed no statistical difference between groups (P > 0.05). The lowest SpO(2) and VOTE classification during DISE were also not statistically different (P > 0.05). Conclusions Use of remifentanil during DISE reduces the target concentration of propofol required for patient sedation to perform DISE without respiratory depression.