Comparison of Adding Magnesium Sulphate to Bupivacaine with Plain Bupivacaine in Ultrasoun Guided Pectoral Nerve Block for Postoperative Analgesia in Modified Radical Mastectomy

Abstract

reast cancer is the most common malignancy in women, and its incidence continues to increase. Surgery is one of the mainstays of treatment of breast cancer, and modified radical mastectomy (MRM) is one of the standard treatments for multi-centric disease or tumors with extensive coexistent ductal carcinoma in situ, where achieving a clear surgical margin becomes difficult with a segmental mastectomy (Arsalani-Zadeh et al., 2011). In breast surgery, acute postoperative pain from injured muscles and nerves is a consistent risk factor for chronic pain in association with its severity. Postoperative pain can seriously reduce the life quality (Andersen and Kehlet, 2011). However, Traditional opioid-based analgesia remains the mainstay, different techniques including regional local anaesthetic infiltrations, paravertebral and neuraxial analgesia, anti-neuropathic analgesics and NMDA antagonists have all been used either in isolation or in combination. After the application of ultrasound in anesthetic practice, several interfascial plane blocks have been described recently. Pec 1 block involves a hydro dissection of the plane between the pectoral muscles with local anaesthetic to block the lateral and medial pectoral nerves. Serratus anterior plane blocks performed at the axillary fossa, the intercostobrachialis nerve, lateral cutaneous branches of the intercostal nerves (T3–T9), long thoracic nerve, and thoracodorsal nerve are located in a compartment between the serratus anterior and the latissimus dorsi muscles, between the posterior and midaxillary lines. Those are newer US-guided blocks for analgesia after breast and lateral thoracic wall surgery. The key sonographic landmarks are the pectoralis major, pectoralis minor, and serratus anterior muscles and the pectoral branch of the acromiothoracic artery.