[Anesthetic management of a case of craniotomy using TCI of remifentanil with intraoperative monitoring of motor evoked potential].

We experienced anesthetic management using target-controlled infusion (TCI) of remifentanil for craniotomy in which monitoring of motor evoked potential (MEP) was performed. Anesthesia was induced and maintained by TCI of propofol and remifentanil. Vecuronium bromide was not administered except for facilitating tracheal intubation. Target effect-site concentrations (ESCs) of remifentanil during intubation, exposure, dura incision, microsurgery and closure were 6, 10, 8, 5 and 8 ng x ml(-1), respectively. Myogenic MEP was sufficiently elicited throughout the microsurgery without patient's body movement. Extubation was completed 10 min after the end of surgery with administration of remifentanil continued at a target ESC of 2 ng ml(-1) after surgery. Emergence from anesthesia was good without complaint of pain or respiratory disorder or new neurological deficit. It has been reported that remifentanil is suitable because of its wide dosage window with respect to recording MEP. ESC of remifentanil was fixed during continuous infusion, but its absolute value varies depending on lean body mass and/or age. The use of TCI enabled easy elimination of the above effects, adjustment of ESC to the expected value and maintenance of ESC of remifentanil at a constant level. TCI of remifentanil might be suitable for anesthesia with monitoring of MEP.