Abstract: Objective To investigate the optimal TCI target concentrations of remifentanil with propofol at different anesthetic and neurosurgical stages. Methods 100 ASAⅠ~Ⅲ patients scheduled for elective craniotomy were anesthetized with target controlled infusion of propofol and remifentanil. The initial plasma target-concentrations of propofol and remifentanil for induction of anesthesia were 5 mg·L^-1 and 3 μg·L^-1,respectively. When patients lost consciousness,the plasma target-concentration of propofol was decreased and maintained to 3 mg·L^-1 and vecuronium with the dose of 0.1 mg·kg^-1 was administrated.3 min later intubation was performed.The plasma target-concentration of remifentanil was adjusted to maintain the mean arterial pressure within(+10%～-20%) of baseline.The calculated plasma target-concentration and effect-site concentration were recorded at different stages of operation.Before the dura was sutured,lornoxicam 8 mg was administrated intravenously.The hemodynamics and anesthetic recovery profiles were observed. Results The plasma target-concentrations of remifentanil were ((2.98±)0.39)μg·L^-1,(3.44±0.86)μg·L^-1,(3.55±1.00)μg·L^-1 and(3.33±1.08)μg·L^-1 before skin incision,during skull opening,intracranial procedure and skull closing,respectively,and the upper limit of 95% confidences were 3.01 μg·L^-1,3.52 μg·L^-1,3.63 μg·L^-1,3.43 μg·L^-1,respectively.The calculated effect-site concentrations of remifentanil were(2.83±0.53)μg·L^-1,(3.43±0.85)μg·L^-1,(3.54±0.99)μg·L^-1 and(3.31±1.09)μg·L^-1,and the upper limit of 95% confidences were 2.87 μg·L^-1,3.50 μg·L^-1,3.62 μg·L^-1,3.41 μg·L^-1,respectively.The postoperative recovery times of spontaneous breathing,opening eyes,extubation and orientation were(10±6)min,(13±8)min,(16±7)min and(21±8)min,respectively.Conclusion The target-controlled infusion of propofol with remifentanil used for neurosurgery has advantages of rapid induction of anesthesia, stable hemodynamics and better recovery profile.With 3 mg·L^-1 of propofol TCI,the optimal plasma target-concentrations of remifentanil are(3.0) μg·L^-1,3.5 μg·L^-1,3.6 μg·L^-1 and 3.4 μg·L^-1 before skin incision,during skull opening,intracranial procedure and skull closing,respectively.

Key words: remifentanil, target-controlled infusion, total intravenous anesthesia, neurosurgery