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 μg/ml after the target concentration of remifentanil was reached. In both groups, the concentration of propofol was increased by 0.5 μg/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 μg/ml in the remifentanil-propofol group, which was lower than that in the propofol alone group (3.38 ± 0.72 μg/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 (SpO2) during polysomnography showed no statistical difference between groups (P > 0.05). The lowest SpO2 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.
Keywords: Drug-induced sleep endoscopy; Obstructive sleep apnea; Propofol; Remifentanil.