Effect of adding magnesium sulphate to bupivacaine on the clinical profile of ultrasound-guided thoracic paravertebral block in patients undergoing modified radical mastectomy

Abstract

Background: Paravertebral block is an effective perioperative analgesic modality in patients undergoing breast or thoracic surgery. Several adjuvants have been reported to improve the clinical profile of local anaesthetic-induced paravertebral block. In the present study, we hypothesized that the addition of magnesium sulphate could potentiate the analgesic effects of paravertebral bupivacaine in female patients undergoing modified radical mastectomy. Methods: Ninety female patients ASA physical status 1 and 2 patients scheduled for modified radical mastectomy were allocated into 2 groups (45 patients each). Group (B) received bupivacaine 0.25% 0.3 ml/kg in the paravertebral space while group (BM) received 100 mg magnesium sulphate + bupivacaine 0.25% 0.3 ml/kg in the paravertebral space. Both blocks were done guided by ultrasound before induction of standard general anaesthetic technique which was the same in both groups. The two groups were assessed in the first post-operative 24 h for post-operative visual analogue scale (VAS) scores, time to first analgesic request, total 24 h morphine consumption, number of attacks of PONV and any complications from paravertebral block or from the drugs used in the study. Results: Patients in group (BM) were found to have reduced VAS scores at 30 min, 2, 4, 6, 12, 24 h intervals post-operative. The time to first analgesic request was longer in patients of group (BM) with less amount of post-operative opioid consumption and consequently less number of attacks of PONV in first post-operative 24 h. These results were significant with a P value < 0.001. Conclusion:Adding magnesium sulphate to bupivacaine in ultrasound-guided paravertebral block resulted in more efficient analgesia and opioid-sparing in female patients undergoing modified radical mastectomy.

Magnesium Sulfate as Adjuvant in Prehospital Femoral Nerve Block for a Patient with Diaphysial Femoral Fracture: A Randomized Controlled Trial

“…Hassan and Mahran [18] conducted a study enrolling 90 female patients scheduled for radical mastectomy. Patients were randomized into two groups: group 1 received paravertebral block analgesia with bupivacaine alone and group 2 received paravertebral block analgesia with bupivacaine and MgS.…”

Magnesium: Emerging Potentials in Anesthesia Practice

“…Magnesium affects peripheral nerves as it interferes with release of neurotransmitters at the synaptic cleft or potentiates local anaesthetic action [2]. Hassan et al evaluated the effect of magnesium sulphate as an adjuvant in potentiating the analgesic effect of bupivacaine in paravertebral block in modified radical mastectomy and concluded that adding magnesium sulphate to bupivacaine resulted in more efficient analgesia with opioid-sparing and decreased postoperative nausea and vomiting in first postoperative 24 hours [33]. Goyal et al concluded that administration of a small dose of magnesium only in the axillary sheath during brachial plexus analgesia resulted in prolonged time of postopearive pain relief with reduction of postoperative analgesia requirement without any major side effects [34].…”

Effect of Adding Magnesium Sulphate as An Adjuvant to Bupivacaine in Ultrasound Guided Transversus Abdominis Plane (TAP) Block for

“…Magnesium increase the amplitude of compound nerve action potentials from 15.10% to 35.43%. Patients who had TPVB by 0.5% plain bupivacaine with 150 mg magnesium sulphate had considerably longer sensory block periods (16) , lower VAS over the postoperative 48 h, and reduced need for postoperative morphine, according to Ammar et al (17) . Patients that administered 0.5% pure bupivacaine experienced sensory block durations that were considerably shorter.…”

“…Patients that administered 0.5% pure bupivacaine experienced sensory block durations that were considerably shorter. 90 female patients who were scheduled for modified radical mastectomy were split into two groups for the study by Hassan et al (17) . Group (BM) received 150 mg of magnesium sulphate along with plain bupivacaine 0.25% (0.3 ml/kg) in the paravertebral space prior to the induction of general anaesthesia.…”