Revised: December 10, 2013
Accepted: December 17, 2013
Published online: January 18, 2014
AIM: To evaluate the efficacy of magnesium sulfate (MGS) in comparison with remifentanil for induction of relative hypotension in posterior fusion of spine (PSF).
METHODS: In this randomized clinical trial, 40 patients with the American Society of Anesthesiologists I and II physical status undergoing lumbar PSF were randomized to receive remifentanil (REM) 0.15 μg/kg or MGS 50 mg/kg for controlled hypotension. The administering anesthesiologist was blinded to the medication. Continuous infusion was maintained at a fixed volume rate to deliver precalculated doses of either study drugs. All other aspects of anesthesia and surgery were similar in the two groups. The target mean arterial pressure (MAP) range used in this study was 60-70 mmHg. In the course of surgery, the hemodynamic variables, volume of blood loss, urine output, fluid intake and surgeon’s satisfaction were recorded. Data was analyzed with SPSS version 13.0 and P values less than 0.05 were considered significant.
RESULTS: Twenty patients in the MGS group and 19 patients in the REM group were studied. There was no difference between the two groups in the hemodynamic variables, blood loss, urine output, fluid requirement and surgeon’s satisfaction for exposure. The target MAP was achieved in 75% of Mg and 58% of remifentanil groups. Although a higher number of patients in the REM group required nitroglycerin (42.1%) to reach the target MAP than those in the MGS group (25%), this difference was not statistically significant (P = 0.32).
CONCLUSION: Our findings showed that in patients undergoing lumbar PSF surgery, remifentanil and MGS have a similar hypotensive effect and comparable amount of blood loss without any significant adverse effects.
Core tip: We conducted a relatively small sized prospective randomized clinical trial comparing intravenous infusion of remifentanil with magnesium in controlling blood pressure during posterior spine fusion in order to decrease the intraoperative blood loss. Our experiments showed no difference between the two administered regimens in reducing mean arterial blood pressure and intraoperative blood loss, and satisfaction of the operating surgeons.