title: Comparative induction of controlled circulation by magnesium and remifentanil in spine surgery.
abstract: OBJECTIVE
  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).
  
  
  CONCLUSIONS
  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.
authors.affiliation: Mohammad R Ghodraty, Mohammad M Homaee, Kourosh Farazmehr, Ali R Nikzad-Jamnani, Ali R Pournajafian, Department of Anesthesiology, Tehran University of Medical Sciences, Tehran 1336616357, Iran.
authors.forename: Mohammad R
authors.initials: MR
authors.lastname: Ghodraty
authors.affiliation: Mohammad R Ghodraty, Mohammad M Homaee, Kourosh Farazmehr, Ali R Nikzad-Jamnani, Ali R Pournajafian, Department of Anesthesiology, Tehran University of Medical Sciences, Tehran 1336616357, Iran.
authors.forename: Mohammad M
authors.initials: MM
authors.lastname: Homaee
authors.affiliation: Mohammad R Ghodraty, Mohammad M Homaee, Kourosh Farazmehr, Ali R Nikzad-Jamnani, Ali R Pournajafian, Department of Anesthesiology, Tehran University of Medical Sciences, Tehran 1336616357, Iran.
authors.forename: Kourosh
authors.initials: K
authors.lastname: Farazmehr
authors.affiliation: Mohammad R Ghodraty, Mohammad M Homaee, Kourosh Farazmehr, Ali R Nikzad-Jamnani, Ali R Pournajafian, Department of Anesthesiology, Tehran University of Medical Sciences, Tehran 1336616357, Iran.
authors.forename: Ali R
authors.initials: AR
authors.lastname: Nikzad-Jamnani
authors.affiliation: Mohammad R Ghodraty, Mohammad M Homaee, Kourosh Farazmehr, Ali R Nikzad-Jamnani, Ali R Pournajafian, Department of Anesthesiology, Tehran University of Medical Sciences, Tehran 1336616357, Iran.
authors.forename: Masoud
authors.initials: M
authors.lastname: Soleymani-Dodaran
authors.affiliation: Mohammad R Ghodraty, Mohammad M Homaee, Kourosh Farazmehr, Ali R Nikzad-Jamnani, Ali R Pournajafian, Department of Anesthesiology, Tehran University of Medical Sciences, Tehran 1336616357, Iran.
authors.forename: Ali R
authors.initials: AR
authors.lastname: Pournajafian
authors.affiliation: Mohammad R Ghodraty, Mohammad M Homaee, Kourosh Farazmehr, Ali R Nikzad-Jamnani, Ali R Pournajafian, Department of Anesthesiology, Tehran University of Medical Sciences, Tehran 1336616357, Iran.
authors.forename: Nader D
authors.initials: ND
authors.lastname: Nader
keywords: Blood loss; Controlled hypotension; Magnesium sulfate; Remifentanil; Spine surgery