title: A dose-finding randomised controlled trial of magnesium sulphate as an adjuvant in ultrasound-guided supraclavicular brachial plexus block.
abstract: OBJECTIVE
  Magnesium sulphate (MgSO4) has been used as an adjuvant in brachial plexus block with encouraging results; however, there is no consensus regarding its optimal dose. Thereby, we compared the efficacy of two doses of MgSO4as an adjuvant in ultrasound (USG) guided supraclavicular brachial plexus block.
  
  
  METHODS
  Ninety patients, aged 20-60 years, belonging to American Society of Anesthesiologists physical status 1 or 2, were given USG-guided supraclavicular block. Group B (n= 30) received 20 ml of 0.5%bupivacaine + 5 ml normal saline (NS), Group BM0.5(n= 30) received 20 ml of 0.5%bupivacaine + 3.75 ml NS and 125 mg MgSO4(1.25 ml) and Group BM1(n= 30) received 20 ml of 0.5%bupivacaine + 2.5 ml NS and 250 mg MgSO4(2.5 ml). The primary outcome of study was the duration of post-operative analgesia. The normally distributed data were analysed using analysis of variance and categorical data analysed using Chi-square test.
  
  
  RESULTS
  Duration of post-operative analgesia was prolonged in Groups BM1and BM0.5(665.13 ± 97.874, 475.10 ± 53.294) min respectively as compared to Group B (272.03 ± 40.404 min:P= 0.00). The onset times of sensory and motor block were shorter in Group BM1(5.17 ± 2.2 min) as compared to Groups BM0.5and B (8.9 ± 2.3 and 17.7 ± 5.1 min:P= 0.00) respectively. Sensory and motor block durations were prolonged in Group BM1as compared to BM0.5and B (P= 0.00).
  
  
  CONCLUSIONS
  MgSO4as adjuvant in brachial plexus block increases the duration of post-operative analgesia. MgSO4in the dose of 250mg has greater efficacy as compared to 125 mg.
authors.affiliation: Department of Anaesthesia, DRPGMC, Tanda, Himachal Pradesh, India.
authors.forename: Versha
authors.initials: V
authors.lastname: Verma
authors.affiliation: Department of Anaesthesia, DRPGMC, Tanda, Himachal Pradesh, India.
authors.forename: Shelly
authors.initials: S
authors.lastname: Rana
authors.affiliation: Department of Anaesthesia, DRPGMC, Tanda, Himachal Pradesh, India.
authors.forename: Sudarshan Kumar
authors.initials: SK
authors.lastname: Chaudhary
authors.affiliation: Department of Anaesthesia, DRPGMC, Tanda, Himachal Pradesh, India.
authors.forename: Jai
authors.initials: J
authors.lastname: Singh
authors.affiliation: Department of Anaesthesia, DRPGMC, Tanda, Himachal Pradesh, India.
authors.forename: Ravinder Kumar
authors.initials: RK
authors.lastname: Verma
authors.affiliation: Department of Anaesthesia, DRPGMC, Tanda, Himachal Pradesh, India.
authors.forename: Saloni
authors.initials: S
authors.lastname: Sood
keywords: Anaesthetic adjuvants; brachial plexus; magnesium sulphate; pain; post-operative