Analgesic Efficacy of Dexamethasone and Dexmedetomidine as an Adjuvant to 2% Lignocaine Adrenaline and 0.5% Bupivacaine in Transversus Abdominis Plane Block after Caesarean Delivery

Abstract

Introduction: The ultrasound-guided Transversus Abdominis Plane (TAP) block is an analgesic technique which involves injection of a local anaesthetic between the internal oblique abdominal and the transversus abdominis muscle planes. It provides analgesia to the cranial branches of T10-L1 nerve roots. It has been a practice to provide analgesia in patients following various surgical procedures including the gynaecological procedures like hysterectomy and caesarean section. Aim: To assess the analgesic efficacy of dexamethasone and dexmedetomidine as an adjuvant to 2% lignocaine adrenaline and 0.5% bupivacaine in TAP block following caesarean delivery. Materials and Methods: This was a cross-sectional study conducted at Konaseema Institute of Medical Sciences and Research Foundation (KIMS&RF), Amalapuram, Andhra Pradesh, India for a period of one year from January 2021 to December 2021. One hundred patients with an American Society of Anaesthesiologists (ASA) physical scores of I-II, who underwent caesarean section under the Pfannenstiel incision method under subarachnoid anaesthesia with 0.5% heavy bupivacaine, were enrolled in the study. Group I consisted of patients that received an ultrasound-guided bilateral TAP block immediately following surgery with 10 mL of 0.5% bupivacaine, 10 mL of 2% lignocaine with adrenaline, and 20 mcg dexmedetomidine. Group II included patients who received ultrasound-guided bilateral TAP block immediately following surgery with 10 mL of 0.5% bupivacaine, 10 mL of 2% lignocaine adrenaline, and 8 mg dexamethasone. The Electrocardiogram (ECG) recordings and blood pressure were recorded during the block in each patient. This approach enabled a more precise analgesic approach for each individual patient. The patients were assessed for pain up to 12 hours of surgery based on a Visual Analog Scale (VAS), where 0 represented no pain and 10 represented ‘the worst pain ever possible. Results: The mean age in the dexamethasone group was 26.48±3.93 and in the dexmedetomidine group was 25.92±4.13 years. The patients who received ultrasound-guided TAP block with dexmedetomidine were significantly less on-demand of tramadol (p-value=0.005). The patients who received ultrasound-guided TAP block with dexmedetomidine were had significantly lower VAS scores at 4 hours (p-value=0.002), 6 hours (p=0.001), and 12 hours (p=0.3), postoperatively. Conclusion: This study proved that dexmedetomidine was more effective when compared to dexamethasone, when added as an adjuvant to 2% lignocaine adrenaline and 0.5% bupivacaine. Ultrasound guided TAP block was a safe and effective postoperative analgesia in caesarean section.

Keywords

• analgesia
• gynaecological procedures
• local anaesthetic
• postoperative analgesia
• visual analog scale