Magnesium Sulfate in Pediatric Abdominal Cancer Surgery: Safety and Efficacy in Ultrasound-Guided Transversus Abdominis Plane (US-TAP) Block in Conjugation with Levobupivacaine.

Purpose: Magnesium sulfate (MgSO4) may enhance the effects of local anesthetics when used as an adjuvant in peripheral nerve blocks. Our objective was to evaluate efficiency and safety of utilizing MgSO4 alongside levobupivacaine in bilateral ultrasound-guided transversus abdominis plane (US-TAP) block for postoperative pain in pediatric cancer patients who underwent abdominal surgery.

Methodology: A randomized double-blinded controlled trial at South Egypt Cancer Institute, Assiut University, Assiut, Egypt, included that 40 pediatric patients with Wilms' tumor or neuroblastoma were randomly allocated to get bilateral (US-TAP) block and divided into two groups; M group: received US-TAP with 0.6 mL/kg levobupivacaine 0.25% + 2 mg/kg MgSO4 and C group: received with 0.6 mL/kg levobupivacaine 0.25% only. FLACC scores (Face, Leg, Activity, Cry, Consolability) were used to evaluate post-operative pain, first analgesic request, total analgesic consumption, adverse effects, as well as hemodynamics were monitored for 24 h and recorded at time points (2, 4, 6, 8, 12, 18, and 24h). Parent's satisfaction at discharge, also, was evaluated.

Results: FLACC score in M group was significantly lower than in C group from 4 h to 24 h with the first analgesic request being longer (15.95 ± 1.99 vs 7.70 ± 0.80 (h); p < 0.001) and lower total analgesic consumption (231.75 ± 36.57 vs 576.00 ± 170.71 (mg); p < 0.001) when comparing M group to C group, respectively. Both groups had insignificant differences regarding hemodynamics, parent satisfaction, postoperative agitation, and side effects except vomiting occurred in two patients in the C group and one patient in the M group.

Conclusion: We conclude that adding magnesium sulphate as an adjuvant to local anaesthetic in US-TAP block for pain management in pediatric abdominal cancer surgeries resulted in better and longer analgesia, with less consumption of rescue analgesics with no serious side effects.