Efficacy of Adding Magnesium Sulfate to Ropivacaine in Ultrasound-guided Transversus Abdominis Plane Block on Analgesia After Open Appendectomy

Proper management of postoperative pain relieves the patient’s discomfort, reduces the length of hospitalization, reduces hospital costs, and increases patient satisfaction. This study was aimed to determine the efficacy of adding magnesium sulfate to ropivacaine 0.25% in transverse abdominis plane (TAP) block under ultrasound guidance on analgesia after open appendectomy.

This double-blind randomized clinical trial was performed on 50 patients undergoing an open appendectomy. Transverse abdominis plane block under ultrasound guidance was performed immediately after surgery and before extubation in all patients. Magnesium sulfate (250 mg) and normal saline (0.5 ml) were added to the anesthetic drug ropivacaine 0.25% in the intervention group (RM) and control group (RN) respectively. Data collection tools included a demographic information questionnaire and a Visual Analog Scale (VAS). Patients were assessed in terms of pain intensity and their need for opioids at PACU (post-anesthesia care unit) in the hours of 6, 12 and 24 after surgery. Data analysis was performed using SPSS software version 16.

There were no significant differences in the mean pain score in none of the time periods after surgery as well as the need for opioids in the two groups (P-value> 0.05).

The addition of magnesium sulfate resulted in lower pain scores and less need for opioids. However, it could not have a significant effect on increasing the duration of analgesia. Therefore, more extensive studies are recommended with higher doses or in combination with other drugs.