A prospective randomised comparative study of unilateral paravertebral block with conventional spinal anesthesia for inguinal hernia repair

Abstract

Background: Inguinal hernia repair can be performed under satisfactory anaesthetic conditions using general, regional and peripheral nerve block anaesthesia. Unilateral spinal anaesthesia provides optimal anaesthesia, with stable haemodynamics and minimal adverse events .The paravertebral block being segmental in nature can be expected to produce some advantages and may be a viable technique. Objective: Primary objective of the study was to compare the block characteristics-time required for performing the block, time to surgical anesthesia, time to ambulation, time to first analgesic, adverse events between the two groups. Secondary objective is to compare the post operative analgesia between the two groups. Methodology: About 60 consenting male patients posted for inguinal hernia repair were randomized into two groups to receive either paravertebral block (Group P, n=30) at T10 with 15 ml of 0.5% bupivacaine and at L1 with 5ml of 0.5% bupivacaine or spinal anesthesia (Group S) with 12.5 mg of 0.5% hyperbaric bupivacaine and primary outcome secondary outcome were noted. Results: Time to perform the block and time to reach surgical anesthesia were significantly higher in the patients of group P as compared to group S (p<0.001). Time to ambulation was significantly shorter in group P than compared to group S (p<0.001). Haemodynamic parameters mean arterial pressure and heart rate were found to be more stable in group P than group S (p<0.05). Minimal adverse events were noted in both the group and it was statistically not significant. Conclusion: It can be concluded that both spinal anesthesia and paravertebral block can be used for patients undergoing inguinal hernia repair. Spinal anesthesia provides adequate analgesia and motor blockade and also less time to perform block and to reach surgical anesthesia. On the other hand paravertebral block provides good haemodynamic stability as well as less time to ambulation, minimal adverse events, however the expertise related to perform, procedure related time and prolonged onset of effect are the main concerns.