Analgesic efficacy and spread of local anesthetic in ultrasound-guided paravertebral, pectoralis II, and serratus anterior plane block for breast surgeries: A randomized controlled trial.

Background: Thoracic paravertebral block (TPVB) has become the gold standard to provide postoperative analgesia in breast surgery. Recently, ultrasound-guided (USG) pectoralis (PECS) block and serratus anterior plane (SAP) block have been described as an alternative to TPVB. The objectives were to compare TPVB, PECS, and SAP block in terms of analgesic efficacy and the spread of local anesthetic by ultrasound imaging, correlating it with the sensory blockade.

Materials And Methods: Prospective randomized interventional study conducted in 45 ASA grades I-II patients scheduled for the elective breast surgery. Patients were randomly allocated into three groups, i.e., Gr.1 (USG -TPVB) (ropivacaine 0.375% 20 ml), Gr.2 (USG-PECS II) block (ropivacaine 0.375% 30 ml), and Gr.3 (USG-SAP) (ropivacaine 0.375% 30 ml). Spread of the local anesthetics was seen with ultrasound imaging. Onset of sensory blockade, postoperative fentanyl consumption, and pain scores was measured.

Results: TPVB and SAP group had comparatively higher spread and sensory block compared to PECS group. Postoperative fentanyl requirement (mean ± SD) was 428.33 ± 243.1 μg, 644.67 ± 260.15 μg, and 415 ± 182.44 μg in the TPVB group, PECS II group, and SAP group, respectively. SAP group had significantly lesser requirement than PECS II group ( = 0.028) but similar requirement as in TPVB group ( = 1.0). Pain scores were not significantly different among the group in the postoperative period.

Conclusion: TPVB and SAP group result in a greater spread of the drug and provide equivalent analgesia and are superior to the PECS II block in providing analgesia for breast surgeries. SAP block is easier to perform than TPVB with lesser chances of complications and results in faster onset.