[Awareness during general anesthesia for head and neck surgery--a case report].

We report a second case of awareness during general anesthesia with sevoflurane supplemented with fentanyl. A 58-year-old man, weighing 61 kg, underwent an 8.8-hour operation for a malignant tumor of the right mandible. His right eye was guarded with ointment but kept open for observation of facial movement following muscle stimulation by the surgeon. The intraoperative course and emergence from anesthesia were otherwise uneventful. The patient became agitated in the recovery room and could recall his visual memory during the operation. We speculated contribution of visual input through the open eye and/or the effects of cranial bone oscillation during the surgery to his intraoperative awareness.