Use of BIS monitor in a child with congenital insensitivity to pain with anhidrosis.

We describe a case of a 14-year-old boy with congenital insensitivity to pain and anhidrosis (CIPA) who underwent tarsal tunnel release for tarsal tunnel syndrome. Because of abnormal pain perception, the patient's response to normally painful surgical stimuli is severely impaired and not adequately reflected in a corresponding rise in blood pressure or heart rate. This lack of autonomic feedback to pain stimuli may make it more difficult to assess whether anesthetic depth is adequate to prevent intraoperative awareness and thus to safely conduct anesthesia, especially if muscle paralysis is required for surgical indications. We describe for the first time the use of processed EEG monitoring with a BIS A-2000 monitor to gauge anesthetic depth in a patient with CIPA. Initial forehead bispectral index (BIS) values prior to induction were normal (98) and then ranged between 23 and 79 during the whole surgical procedure. Propofol and lidocaine were used for induction and deep extubation; isoflurane was used as the sole anesthetic for maintenance with concentrations ranging from 0.21% to 0.92% to maintain a target BIS of 40-60. Volatile anesthetic requirements remained low throughout the procedure and no narcotics were necessary during surgery. The BIS monitor served as an adequate tool to help avoid excessive use of volatile anesthetic while assuring a processed EEG consistent with unconsciousness and amnesia. After the patient had recovered and was oriented to place and time in the recovery room, he was asked whether he remembered anything about the surgery and the presence of a breathing tube in his mouth. He denied any recall of such events.