Efficacy and Safety of Ketamine Added to Local Anesthetic in Modified Pectoral Block for Management of Postoperative Pain in Patients Undergoing Modified Radical Mastectomy.

BACKGROUND Breast surgery is an exceedingly common procedure with an increased incidence of acute and chronic pain. Pectoral nerve block is a novel peripheral nerve block alternative to neuro-axial and paravertebral blocks for ambulatory breast surgeries. OBJECTIVES This study aims to compare the analgesic efficacy and safety of modified Pecs block with ketamine plus bupivacaine versus bupivacaine in patients undergoing breast cancer surgery. STUDY DESIGN A randomized, double-blind, prospective study. SETTING Academic medical center. METHODS This study is registered at www.clinicaltrials.gov under number: (NCT02620371) after approval by the ethics committee of South Egypt Cancer Institute, Assuit University, Assuit, Egypt. Sixty patients aged 18 - 60 years scheduled for modified radical mastectomy were enrolled and randomly assigned into 2 groups (30 patients each): Control group patients were given ultrasound-guided, Pecs block with 30 mL of 0.25% bupivacaine only. Ketamine group patients were given ultrasound-guided, Pecs block with 30 mL of 0.25% bupivacaine plus ketamine hydrochloride (1 mg/kg). Patients were followed up for 48 hours postoperatively for vital signs, VAS score, first request of rescue analgesia and total morphine consumption, sedation score, and side effects. RESULTS Ketamine plus bupivacaine in Pecs block compared to bupivacaine alone prolonged the mean time of first request of analgesia (18.25 ± 1.98), (12.56 ± 2.64), respectively (P < 0.001), reduced total morphine consumption (12.50 ± 4.63), (18.86 ± 6.28), respectively (P = 0.016). With no significant difference in hemodynamics, respiratory rate, oxygen saturation, VAS and sedation scores, and side effects observed between the 2 groups (P > 0.05). LIMITATIONS This study is limited by its sample size. CONCLUSION The addition of ketamine to modified Pecs block prolonged the time to first request of analgesia and reduced total opioid consumption without serious side effects in patients who underwent a modified radical mastectomy. KEY WORDS Ketamine, bupivacaine, pecs block, postoperative, pain, breast cancer.