[Case of obstructive sleep apnea possibly having led to postoperative appearance of generalized convulsion].

Adverse surgical outcomes appear to be more frequent in patients with known obstructive sleep apnea (OSA). However, OSA patients may present for surgery without a prior diagnosis. A 37-year-old man underwent craniotomy for surgical direct neck clipping of the right ruptured internal carotid aneurysm. His intraoperative and early postoperative courses were uneventful. At night, about 48 hr after surgery, he developed sudden generalized tonic-clonic convulsion and temporary depressed consciousness resulting in marked hypercapnea (Pa(CO2)>100 mmHg). His respiration was transiently supported by PSV mode via LMA. He soon got well without neurologic deficits. At night, about 74 hr postoperatively, a generalized convulsion was again observed with hypercapnea. Aside from the respiratory support, percutaneous cricothyroidotomy was performed using Minitrach II system for his airway control, leading to no further recurrence of seizure. He was suspected to have unrecognized OSA due to such characteristic findings of sleep apnea as obesity (BMI>30) and witnessed apneas by his family. Postoperative rapid eye movement (REM) sleep rebound has been suggested to contribute to two consecutive night appearance of seizure. Clinical suspicion for OSA should be required preoperatively and perioperative heightened awareness is recommended.