Ultrasound-guided popliteal sciatic nerve block using bupivacaine alone or combined with magnesium sulfate for diabetic foot surgeries

Background This prospective study examined the influence of adding magnesium sulfate to bupivacaine in popliteal sciatic nerve block in diabetic foot surgeries. Patients and methods Patients were divided into two equal groups: patients in B group received 28 ml of 0.25% bupivacaine plus 2-ml normal saline, and patients in BM group received 28 ml of 0.25% bupivacaine plus 2-ml magnesium sulfate 10%. The primary end point was postoperative analgesic duration assessment. Secondary aims were to assess the sensory and motor block regarding the onset and the duration and assessment of analgesic requirements postoperatively. Results In B group, the range of analgesic duration was between 450 and 690 min, with a mean of 585.90±78.96 min, whereas in BM group, it ranged from 720 to 1080 min, with a mean of 870.0±100.6 min. A statistically significant higher prolongation in the duration of analgesia was found in the BM group than the B group. Conclusions Magnesium sulfate when added to bupivacaine produced prolongation of analgesic duration postoperatively with decreased analgesic requirements without significant complications.