Comparison of Epidural Bupivacaine and Bupivacaine-Magnesium Sulphate Combination in Lower Abdominal Surgeries

Abstract

BACKGROUNDThe epidural technique became popular as it has some specific advantages over spinal anaesthesia. The feasibility of extended duration and differential blockade extended its application into other fields like post-operative analgesia, chronic pain relief and obstetric pain relief. But some inherent negative points of epidural technique like delayed onset and patchy analgesia persist. Various attempts have been made to rectify these negative points. Analgesic effects of magnesium sulphate on peripheral nerves may be due to the antagonism of NMDA receptors, thus preventing central sensitisation from peripheral nociceptive stimulation. Also, magnesium competitively blocks calcium influx into presynaptic endings leading to reduced acetylcholine release. The aim of the study is to add magnesium sulphate as an adjunct to epidural Bupivacaine and evaluate the impact of magnesium sulphate on the quality of the block using the following parameters; Onset of sensory blockade, Motor blockade quality, two segment regression time, Post-operative analgesia and Impact of magnesium sulphate on haemodynamic changes.

The effects of magnesium sulfate added to epidurally administered local anesthetic on postoperative pain: a systematic review

“…The seventeen studies 29 , 30 , 31 , 32 , 33 , 34 , 35 , 36 , 37 , 38 , 39 , 40 , 41 , 42 , 43 (1150 patients) used only magnesium as an adjuvant to local anesthetic in the intervention group. Only data applicable to the meta-analyses of the current study were extracted from these studies.…”

“…Time to the first analgesic request was reported in 12 studies (790 patients). 29 , 31 , 33 , 34 , 36 , 37 , 38 , 39 , 40 , 41 , 42 Analgesic consumption during the first 24 postoperative hours was reported in six studies (416 patients). 30 , 31 , 32 , 34 , 37 , 44 Postoperative pain intensity was reported as visual analog pain scores during the first six postoperative hours in eight studies 31 , 32 , 33 , 34 , 37 , 39 , 41 , 43 (540 patients), and during the first 24 postoperative hours in five studies 30 , 31 , 32 , 34 , 37 (356 patients).…”

“…Included studies were performed on patients undergoing the following surgical procedures: cesarean section (n = 2), 31 , 45 lower limb surgery (n = 6), 29 , 30 , 35 , 40 , 42 , 44 lower abdominal and pelvic surgeries (n = 5), 32 , 34 , 36 , 39 , 41 mixed lower limb and low abdominal surgery (n = 2), 33 , 38 spine surgery (n = 1), 43 and thoracotomy (n = 1). 37 …”

“… 39 , 37 Epidural anesthesia alone was used in 14 studies. 29 , 30 , 31 , 33 , 34 , 35 , 36 , 38 , 40 , 41 , 42 , 44 …”

“…All studies used epidural magnesium as a single bolus dose. The initial bolus dose of magnesium sulfate was 50 mg in 15 studies, 29 , 30 , 32 , 33 , 34 , 35 , 36 , 37 , 38 , 39 , 40 , 41 , 42 , 43 , 44 and 500 mg in two studies. 31 , 45 After the initial bolus, continuous epidural infusion of magnesium sulfate was used in five studies 30 , 32 , 39 , 43 , 44 at rates varying from 10–15 mg.h −1 , limited to the intraoperative period in four studies, and continued for 48 hours postoperatively in one study.…”