Breast cancer has continued to be the most common cancer afflicting women, accounting for 31% of all new cancer cases in the female population. Every year, thousands of patients undergo surgery in the region of the breast and axilla. Surgery is one of the mainstays of treatment, and a procedure called modified radical mastectomy (MRM) is now a standard surgical treatment for early-stage breast cancers.

To evaluate the Efficacy of combined ultrasound guided Pectoral Nerve Block (PECS I block and PECS II block) using Bupivacaine with or without Magnesium Sulfate in modified radical mastectomy under general anathesia.

After obtaining approval from the medical ethical committee in Ain Shams University This study was conducted in the operating theatres of Ain Shams University Hospitals. It included Thirty Female patients undergoing Modified Radical Mastectomy were divided randomly into two groups, each group consisted of 25 patients group I in which patients received general anesthesia followed by PECS BLOCK using only bupivacaine 0.25 % and group II in which patients received general anesthesia followed by PECS BLOCK using bupivacaine 0.25 % plus magnesium sulfate 50% (200mg).

The two groups were adequately monitored and assessed post-operatively and they were compared regarding analgesic outcome by using the visual analogue scaling system, besides, recording time for first for analgesic need and total consumption of opioid and analgesic in the 1st 24 postoperative hours. Demographic data and post operative hemodynamics were also assessed.

The addition of 200 mg of magnesium sulfate to bupivacaine in an ultrasound-guided Pectoral Nerve Block significantly reduce postoperative opioid consumption, prolong the duration of the analgesia, and reduce the VAS score without significant side effects after Modified Radical Mastectomy under general anesthesia.