Direct Pectoral Nerve Block versus Ultrasound-Guided Paravertebral Block for Analgesia and Improved Recovery after Modified Radical Mastectomy: A Randomized Clinical Trial

Background: Ultrasound-guided paravertebral (USG-TPVB) has already been proven to provide excellent perioperative analgesia in breast surgeries. However, this is time-consuming and requires expertise in ultrasound-guided analgesic techniques. Whereas the intraoperative pectoral nerve (direct-PECS) block performed after the resection of the breast tumor is a quicker and more precise method by injecting the drug directly into the intended interfacial planes under directvision. This study was undertaken to compare USG-TPVB and direct-PECS blocks in terms of the efficacy  of postoperative analgesia and the quality of recovery after modified radical mastectomy (MRM).
Methods: After obtaining written informed consent, this randomized prospective trial was conducted on sixty female patients (18-60 years), scheduled for MRM under general anesthesia. Patients were randomly divided into group PV (preoperative USG-TPVB with 20 ml of study drug) and group DP (intraoperative direct-PECS block, 10 ml of study drug each in PECS I and PECS II block). The study drug used was 20 ml of 0.25% levobupivacaine with dexmedetomidine (0.5 µg/kg). The main outcome parameters compared were time of first rescue analgesia, total morphine consumption, and quality of recovery-15 score (QoR-15). 
Results: The mean (standard deviation) of the time of first analgesic requirement was 18.85 (± 5.34) hrs in group DP and 7.54 (±3.63) hrs in group PV (p <0.001). The mean (SD) total opioid consumption of group DP was 8.04 (±4.59) mg in the first 24 h, while 19.12 (±3.65) mg in group PV (p <0.001). Mean (SD) QoR-15 score at 24 h was 133.81 (±7.25) in group DP and 111.62 (±8.53) in group PV.
Conclusion: Direct-PECS provided prolonged postoperative analgesia with lesser total opioid consumption and a better recovery profile than USG-TPVB after breast surgery. Hence, direct-PECS is a preferable technique with reduced dependence on USG skills in low-resource settings.