title: Efficacy of magnesium as an adjuvant to bupivacaine in 3-in-1 nerve block for arthroscopic anterior cruciate ligament repair.
abstract: OBJECTIVE
  Three-in-one and femoral nerve blocks are proven modalities for postoperative analgesia following anterior cruciate ligament (ACL) reconstruction. The aim of this study was to evaluate the efficacy of magnesium (Mg) as an adjuvant to bupivacaine in 3-in-1 block for ACL reconstruction.
  
  
  METHODS
  Sixty patients undergoing arthroscopic ACL reconstruction were randomly allocated to Group I (3-in-1 block with 30 ml of 0.25% bupivacaine preceded by 1.5 ml of intravenous [IV] saline), Group II (3-in-1 block with 30 ml of 0.25% bupivacaine preceded by 1.5 ml of solution containing 150 mg Mg IV) or Group III (3-in-1 block with 30 ml containing 0.25% bupivacaine and 150 mg of Mg as adjuvant preceded by 1.5 ml of IV saline). Post-operatively, patients received morphine when visual analogue scale (VAS) score was ≥4. Quantitative parameters were compared using one-way ANOVA and Kruskal-Wallis test and qualitative data were analysed using Chi-square test.
  
  
  RESULTS
  Demographics, haemodynamic parameters, intra-operative fentanyl requirement, post-operative VAS scores and total morphine requirement were comparable between groups. Time to first analgesic requirement was significantly prolonged in Group III (789 ± 436) min compared to Group I (466 ± 290 min) and Group II (519 ± 274 min), (P = 0.02 and 0.05). Significantly less number of patients in Group III (1/20) received morphine in the first 6 h post-operatively, compared to Group I (8/20) and Group II (6/20) (P = 0.008 and 0.03). No side effects were observed.
  
  
  CONCLUSIONS
  Mg as an adjuvant to bupivacaine in 3-in-1 block for ACL reconstruction significantly prolongs the time to first analgesic requirement and reduces the number of patients requiring morphine in the immediate post-operative period.
authors: Department of Anaesthesiology and Critical Care, Chettinad Hospital and Research Institute, Kanchipuram, Tamil Nadu, India.
authors: Thilaka
authors: T
authors: Muthiah
authors: Department of Anaesthesiology, Pain Medicine and Critical Care, All India Institute of Medical Sciences, New Delhi, India.
authors: Mahesh K
authors: MK
authors: Arora
authors: Department of Anaesthesiology, Pain Medicine and Critical Care, All India Institute of Medical Sciences, New Delhi, India.
authors: Anjan
authors: A
authors: Trikha
authors: Department of Anaesthesiology, Seattle Children's Hospital, Seattle, Washington, USA.
authors: Rani A
authors: RA
authors: Sunder
authors: Department of Anaesthesiology, Pain Medicine and Critical Care, All India Institute of Medical Sciences, New Delhi, India.
authors: Ganga
authors: G
authors: Prasad
authors: Department of Anaesthesiology, Pain Medicine and Critical Care, All India Institute of Medical Sciences, New Delhi, India.
authors: Preet M
authors: PM
authors: Singh
keywords: Adjuvants; bupivacaine; magnesium; three in one block