Effect of pre-emptive epidural low-dose magnesium sulfate on postoperative analgesic requirement after open abdominal hysterectomy Ramadan Shabana

Abstract

Objectives The aim of the study was to evaluate the efficacy of single-shot epidural injection of combined low-dose magnesium sulfate with levobupivacaine as a pre-emptive analgesic to decrease the postoperative analgesic requirement in female patients undergoing abdominal hysterectomy. Patients and Methods The study included 90 ASA I-II adult female patients assigned for open abdominal hysterectomy. Patients were randomly allocated into two equal groups: group L received single-shot epidural plain levobupivacaine 0.25% and group M received single-shot epidural levobupivacaine 0.25% mixed with 50 mg MgSO 4 . The intensity of postoperative pain was measured with 0-100 point visual analog scale (VAS). Rescue analgesia was given if patients had VAS scores of 40 or more and the duration of analgesia was determined. The degree of sedation was assessed 30 and 120 min after admission to the recovery room using the four-point Brussels Sedation Scale. Results Cumulative pain VAS until the end of first postoperative 24 h was significantly lower in patients who received combined epidural therapy compared with those who received local anesthetic alone. Moreover, pain-free duration was significantly longer in group M compared with group L. Throughout 24 h after surgery, 31 patients requested rescue analgesia only once, 37 patients requested it twice, 16 patients requested it three times, and only six patients required rescue analgesia for more than three times. Patients who received combined therapy requested rescue analgesia at significantly lower frequency compared with those who received local anesthetic alone. Patients enrolled in group M showed a significantly lower mean sedation score at 30 min; however, at 120 min postoperatively, the score was nonsignificantly lower in comparison with group L. Conclusion Pre-emptive epidural bolus of magnesium sulfate and levobupivacaine provides postoperative analgesia superior to epidural levobupivacaine alone for patients undergoing open abdominal hysterectomy.