A Comparative Study of Remifentanil/Propofol versus Alfentanil/Propofol for Wake-up Test in Major Spinal Surgery

Background: Early warning of potential damage to spinal cord during major spinal surgery is highly desirable to prevent postoperative neurological deficits. Wake-up test is a simple, safe and reliable method of recognition of such a complication, and has been extensively used in many spinal surgical units. The present study is evaluating the remifentanil, propofol versus alfentanil, propofol as a part of balanced anesthesia for rapid performance of wake-up test during major spinal surgery. Methods: Fifty patients undergoing elective spinal surgery were randomized to receive either remifentanillpropofol (group A) or alfentanillpropofol (group B). Premedicated patients received remifentanil (a loading dose of 2 (MU)g/kg and a continuous infusion of I (MU)g/kg/rnin), or alfentanil (a loading dose of 25 (MU)g/kg and a continuous infusion of 1 (MU)g/kg/min). Propofol was given as a loading dose of 1.5 mg/kg and a continuous infusion of 100 (MU)g/kg/min. The awakening was accomplished by withdrawing propofol and N20 at 20 and 5 minutes before the test, respectively, whereas remifentanil or alfentanil infusion continued through the wake-up period at a rate of 0.02 ug/kg/min. Results: The onset of intra-operative neurological examination in remifentanillpropofol receiving group (4.6(PLUS-MINUS) 1.4 minutes) was significantly faster than that for alfentanil/propofol receiving group (7.5(PLUS-MINUS)1.8 minutes). Conclusion: Combination of remifentanil and propofol induced a balanced anesthesia for intra-operative awakening and provided a faster opportunity for detecting any potential damage that may occur during spinal instrumentation.