Dexmedetomidine vs Dexamethasone as an Adjuvant to Levobupivacaine in Ultrasound-Guided Transversus Abdominis Plane Block for Postoperative Analgesia in Patients Undergoing Total Abdominal Hysterectomies.

Background: In the postoperative period, open total abdominal hysterectomy (TAH) surgeries induce considerable pain. Multimodal strategies are being used to alleviate pain.

Objectives: This study aimed to examine the efficacy and safety of dexamethasone and dexmedetomidine as an adjuvant to levobupivacaine in ultrasound-guided transversus abdominis plane (TAP) blocks for postoperative pain in TAH patients.

Methods: A total of 72 patients with ASA grade I and grade II were randomly and equally assigned to two groups. After the completion of surgery with a subarachnoid block (SAB), patients in group 1 received a mixture of 20 mL of 0.25% levobupivacaine and 4 mg of dexamethasone on each side of the TAP block. Patients in group 2 received a mixture of 20 mL of 0.25% levobupivacaine and dexmedetomidine, with a total dose of 1 µg/kg body weight evenly distributed bilaterally in the TAP block. Patients were evaluated for pain using the Visual Analog Scale (VAS), total tramadol consumption as rescue analgesia, time to first rescue analgesia, any adverse effects, and patient satisfaction.

Results: When comparing VAS scores for pain assessment, we observed that the mean VAS score was initially comparable between the two groups for the first hour. However, at 6, 9, and 12 h, VAS scores were significantly lower in group 2. The mean total tramadol consumption was higher in group 1 than in group 2 (213.33 ± 44.08 vs 161.11 ± 37.93 mg, P-value 0.027). The time to the first rescue analgesia after the TAP block in the postoperative period was significantly longer in group 2 (47.5 ± 62.76 vs 77.22 ± 56.14 min, P-value 0.002). No significant side effects were noted, and a greater proportion of patients in group 2 expressed satisfaction with their overall pain treatment.

Conclusions: The addition of dexmedetomidine to levobupivacaine is superior to the addition of dexamethasone, as it prolongs the duration of the block in the dexmedetomidine group. However, the use of dexamethasone as an adjuvant is a good alternative option, particularly due to its lower cost and reduced incidence of adverse effects such as postoperative nausea and vomiting.