Study of Intrathecal Magnesium Sulphate as an Adjunct to Bupivacaine for Subarachnoid Block in Infraumbilical Surgeries - A Randomised Double-Blind Study

BACKGROUND improve the quality and duration of subarachnoid block various adjuncts have used. But they exhibit side effects like nausea, vomiting, pruritis, respiratory , urinary retention and haemodynamic instability. Magnesium does not adverse effects when used as an adjuvant in therapeutic doses. was a prospective, randomized, double blind, controlled study. 50 patients to ASA physical status I and II posted for infraumbilical surgery were into two groups. Group I patients received Inj. bupivacaine 0.5% 2.5 mL (12.5 mg) with Inj. normal saline 0.2 mL intrathecally. Group II received Inj. bupivacaine 0.5% heavy 2.5 mL (12.5 mg) with Inj. sulphate 25% 0.2 mL (50 mg) intrathecally. The onset and duration sensory blockade, the onset and duration of motor blockade, haemodynamic , Ramsay sedation score and Visual Analogue Scale were assessed. analgesia was given when VAS score was >3. Statistical analysis was by student’s t-test for nominal data, Chi-square test or Fisher’s exact test for categorical data. 50 mg of magnesium sulphate was added intrathecally, the duration of blockade was prolonged (p value of <0.001); the onset of motor blockade significantly slower, and the duration of analgesia was prolonged (p value <0.001). The prolonged analgesia in magnesium sulphate group was accompanied an average 24-hour postoperative visual analogue scale of 1 to 2 when to 3 to 4 in saline group (p ≤ 0.001). magnesium sulphate as an adjunct to bupivacaine in spinal anaesthesia the duration of spinal anaesthesia and postoperative analgesia, without effects.