Continuous Pectoral Nerve Block Compared With Continuous Thoracic Paravertebral Block and Intravenous Opioid Analgesia for the Postoperative Analgesic Efficacy in Patients Undergoing Modified Radical Mastectomy: A Prospective Randomized Trial.

Objectives: Postoperative pain following mastectomy is often severe and pain management is necessary. We evaluated the analgesic efficacy of continuous pectoral nerve block (PEC) in comparison with that of the continuous thoracic paravertebral block (TPVB) and the intravenous opioid analgesia in patients scheduled for modified radical mastectomy (MRM).

Materials And Methods: A total of 90 female patients aged 20 to 70 years, American Society of Anesthesiologists (ASA) I to III, undergoing unilateral MRM were randomly allocated into 3 groups. All patients received postoperative morphine patient-controlled analgesia (PCA). Continuous TPVB and continuous PECs were added in group II and group III, respectively. Postoperative morphine consumption during the first 48 hours and postoperative visual analog scale were recorded.

Results: The cumulative morphine consumption in the first 24 hours postoperative was higher in the PCA-M group (27.47±4.95 mg) than that of the TPVB group (8.43±2.67 mg) and PEC group (13.47±3.89 mg) (P<0.001, confidence interval: 16.6-21.5 and 11.6-16.4, respectively). It was significantly higher in the PEC group as compared with the TPVB group (P<0.001, confidence interval: 2.6-7.5). On admission to postanesthesia care unit till 2 hours postoperative, the median visual analog scale score at rest was higher in the PCA-M group than that of the TPVB group (P<0.05) and PEC group (P<0.05) without statistical difference between the TPVB group and PEC group.

Discussion: Continuous PEC and continuous TPVB reduced the postoperative morphine consumptions as compared with the intravenous opioid analgesia in patients undergoing MRM with greater reduction in TPVB and without increased adverse effects.