Comparison of levobupivacaine with dexamethasone versus levobupivacaine for ultrasound-guided transversus abdominis plane block in lower abdominal surgeries in a tertiary care hospital in Chengalpattu district – A randomized control trial

Abstract

Introduction: Transversus abdominis plane (TAP) block is a regional technique for analgesia of the anterolateral abdominal wall. Ultrasound guidance is now considered the gold standard in TAP blocks. It involves the injection of a local anesthetic solution into a plane between the internal oblique muscle and transversus abdominis muscle. Since the thoracolumbar nerves originating from the T6 to L1 spinal roots run into this plane and supply sensory nerves to the anterolateral abdominal wall, the local anesthetic spread in this plane can block the neural afferents and provide analgesia to the anterolateral abdominal wall. Levobupivacaine is a local anesthetic from the amino amide class of medications. Adjuvants are drugs when added along with local anesthetics have a synergistic action to improve the duration and quality of analgesia. Objectives: The objective of this study was to study the effectiveness of ultrasound-guided transversus abdominis plane block using levobupivacaine with dexamethasone in terms of hemodynamic stability and duration of postoperative analgesia and pain scores (visual analog scale [VAS]), time of requirement of rescue analgesics among patients who have undergone lower abdominal surgeries. Methods: This is a double-blinded randomized control trial. This study was conducted among 60 patients who have undergone lower abdominal surgeries in a tertiary care hospital. Postsurgery, intraoperatively prior shifting out the patient, two groups received transversus abdominis plane block, one received 28 ml of 0.25% levobupivacaine with 2 ml of normal saline and another group received 28 ml of 0.25% levobupivacaine with 2 ml (8 mg) dexamethasone. Duration of postoperative analgesia and the efficacy between the two groups were compared with hemodynamic parameters and VAS score. Results: The study groups were not significantly different in terms of demographic data or the American Society of Anesthesiologists Grading. The mean onset of breakthrough pain was significantly higher in the L group. The time of requirement of rescue analgesics was also significantly shorter in the L group compared to the LD group. The VAS pain score was significantly lower in the Group LD as compared to the L group. Conclusion: Hence, it was noticed that dexamethasone when added to levobupivacaine had better hemodynamic stability in terms of blood pressure, heart rate, saturation, respiratory rate, and mean arterial pressure. The requirement of rescue analgesics was also reduced in this group and the time of breakthrough pain was also prolonged. This group had significantly lower pain scores.