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 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.

Low-dose combined spinal-epidural anesthesia for a patient with a giant hiatal hernia who underwent urological surgery.

A hiatal hernia refers to herniation of the abdominal organs through the esophageal hiatus of the diaphragm. A giant hiatal hernia affects digestive and cardiopulmonary function by compressing the organs. We report a patient who had low-dose combined spinal and epidural anesthesia (CSEA) for safe and effective anesthesia for conservative treatment of a giant hiatal hernia. An 84-year-old woman who had a giant hiatal hernia was scheduled for ureteroscopic removal of a ureteral stone. CSEA was performed at the L4 to L5 lumbar interspace and an epidural catheter tip was placed 5 cm cephalad from the inserted level. The T12 block was checked after 10 minutes of intrathecal injection of 6 mg of 0.5% bupivacaine. The T10 block was checked after additional injection of 80 mg of 2% lidocaine through the epidural catheter. During anesthesia and surgery, the patient's vital signs remained stable and the operation was completed within 1 hour without any problems. In conclusion, low-dose CSEA may be safely used without any cardiopulmonary and gastrointestinal problems in patients with a giant hiatal hernia undergoing urological surgery.