Comparison of Paravertebral Block with Conventional Spinal Anesthesia in Patients Undergoing Unilateral Inguinal Hernia Repair

Although spinal anesthesia (also known as subarachnoid block [SAB]) is used widely for inguinal hernia repair, the paravertebral block (PVB) that produces unilateral, segmental analgesia is used with a high success rate in inguinal hernia repair. The aim of the study was to compare SAB and PVB in inguinal hernia repair, in terms of the duration of postoperative analgesia and adverse events. This was a prospective, randomized, controlled double-blind study. This study was done on 60 male patients of American Society of Anesthesiology (ASA) I and II. Patients were categorized into 30 in each group, either to receive PVB block at two levels T10 and L1 using 15 mL and 5 mL of 0.5% bupivacaine and 1 μg.kg of buprenorphine or SAB with 12.5 mg of 0.5% hyperbaric bupivacaine injected intrathecally. SPSS 18.0 and R version 3.2.2 were used for analyzing the data. Categorical measurements were presented in number (%) and analyzed using Chi-square/Fischer's exact test. Continuous measurements were analyzed using Student's -test. Age, weight, height, and ASA status were comparable in both the groups. In the PVB group, eight patients had failure of block. Hemodynamic responses, time to first analgesia and ambulation, time required to perform the block, Bromage score, satisfaction score, failure rate, and intra- and postoperative drugs used showed a statistically significant difference between the groups ( < 0.001). PVB is not a sole anesthetic technique due to a higher failure rate and increased intraoperative fentanyl requirement but has advantages such as prolonged analgesia, stable hemodynamics, and early ambulation.