Monitored anesthesia care using remifentanil and propofol for awake craniotomy

Adequate analgesia and sedation with adequate respiratory and hemodynamic c ontrol are needed during brain surgery in awake patients. In this study, a protocol using clonidine premedication, intraoperative propofol, remifentan il, and labetalol was evaluated prospectively in 25 patients (aged 50 +/- 1 6). In all but one patient, no significant problems regarding cooperation, brain swelling, or loss of control were noticed, and it was not necessary t o prematurely discontinue any of the procedures. One patient, who was uncoo perative and hypertensive, became apneic with increasing sedation, and need ed a laryngeal mask airway inserted. Patients were hemodynamically stable; elevated systolic blood pressure (greater than or equal to 150 mm Hg) was m easured infrequently, and there were no events of significant hypotension, tachycardia, or bradycardia. Events of hypoxemia (SAO(2) less than or equal to 95%), severe hypoxemia (SaO(2) less than or equal to 90%), or hypoventi lation (respiratory rate less than or equal to8 minute), were frequent in t he first ten patients, but the incidence decreased significantly in subsequ ent patients (P < .001). Three patients developed a focal neurologic defici t, and two patients experienced intraoperative seizures. Nausea and vomitin g were not recorded in any of the patients. Although these findings attest to the safety of awake craniotomy, they demonstrate the difficulty of achie ving adequate sedation without compromising ventilation and oxygenation. Th e learning curve of using a new protocol and a new potent anesthetic drug i s emphasized.