Effect of Varying Doses of Dexmedetomidine Added to Dexamethasone-Enhanced TAPB for Post-Cesarean Pain Management

Yang Gu^1,2Fan Yang³Jiamin Bao²Fa Wang¹Biyun Tian²Hui Sun²Ningkang Li^2*Qingshan Ye^2*

• ¹Department of Anesthesiology, Ningxia Medical University,, Yinchuan, China
• ²Department of Anesthesiology, People’s Hospital of Ningxia Hui Autonomous Region, Yinchuan, China
• ³Department of Anesthesiology, General Hospital of Ningxia Medical University, Yinchuan, Henan Province, China

Background: The management of post-cesarean pain exhibits considerable variation across different regions and hospitals, with a prevalent tendency to utilize opioid medications as the primary analgesic approach. This study investigates the impact of different doses of dexmedetomidine combined with dexamethasone as an adjunct to transversus abdominis plane block (TAPB) on the analgesic efficacy and quality of recovery following cesarean section. Methods: In this prospective randomized clinical trial, 90 patients scheduled for cesarean section were randomly assigned in a 1:1:1 ratio to receive postoperative TAPB with one of three solutions: 8 mg dexamethasone with 0.375% ropivacaine (Group C), 0.5 µg/kg dexmedetomidine with 8 mg dexamethasone and 0.375% ropivacaine (Group D1), or 1 µg/kg dexmedetomidine with 8 mg dexamethasone and 0.375% ropivacaine (Group D2). The primary outcome measures were the VAS scores for rest and movement at 6, 12, 24, and 48 hours post TAPB, as well as the incidence of moderate to severe pain. Results: Postoperative VAS scores demonstrated distinct patterns between rest and dynamic pain. At rest, no significant differences were observed among groups C, D1, and D2 at any time point (6-48 hours; all P>0.05). For dynamic pain, group C exhibited higher median scores than D1 and D2 at 12 hours (3.00 [IQR 2.00-4.00] vs 1.00 [1.00-3.00], median difference 1.00 [95% CI 1.00-2.00]; P=0.001; vs 2.00 [1.00-3.00], difference 1.00 [0.00-2.00]; P=0.003) and 24 hours (4.00 [3.00-4.00] vs D1: 3.00 [2.00-3.00], difference 1.00 [0.00-1.00]; P<0.001; vs D2: 2.00 [2.00-3.00], difference 1.00 [1.00-2.00]; P=0.009). By 48 hours, D2 showed the lowest dynamic pain scores (1.00 [1.00-2.00] vs C: 3.00 [2.00-3.00]; difference 1.00 [1.00-1.00]; P=0.001). Moderate-to-severe dynamic pain incidence differed significantly at 12 hours (C: 26.7%; D1: 13.3%; D2: 3.3%; P=0.04) and peaked in group C at 24 hours (53.3% vs D1: 13.3% [risk ratio 7.43, 95% CI 2.08-26.55; P=0.002] and D2: 10.0% [risk ratio 10.29, 2.56-41.37; P=0.001]). No intergroup differences were observed for resting pain or dynamic pain at 48 hours. Groups D1 and D2 showed no significant differences in outcomes at any time point. Conclusions: Adding dexmedetomidine and dexamethasone to ropivacaine for TAPB can improve post-cesarean section pain conditions.