Effect of combined dexmedetomidine with ropivacaine in transversus thoracis plane block on surgical stress response during cardiopulmonary bypass surgery: a randomized controlled trial.

Objective: To examine how patients having open heart surgery under cardiopulmonary bypass (CPB) react to surgical stress following bilateral transversus thoracis plane (TTP) block with ropivacaine improved by dexmedetomidine (DEX). Methods: Three groups of sixty patients (26M/34F, ASA II-III, 18-65 years old) slated for elective CPB heart surgery were randomly assigned: general anesthesia alone (Group C), TTP (ropivacaine) combined with general anesthesia group (Group R), or TTP (ropivacaine + DEX) combined with general anesthesia group (Group RD). Primary outcomes measured serum cortisol levels at five perioperative phases, while the secondary outcomes included glucose/C-reactive protein (CRP) levels, Numeric Rating Scale (NRS) pain scores postextubation, 48-hr sufentanil consumption, patient-controlled analgesia (PCA) demand frequency, rescue analgesia rates, mechanical ventilation duration, ICU stay, and complications. Results: At 24 h postoperatively, RD and R groups exhibited statistical lower serum cortisol levels compared to controls (p < 0.05), with parallel glucose reductions. However, the CRP level increased significantly. NRS scores in RD/R groups were significantly lower than controls at 0 h, 6 h, and 12 h postextubation (p < 0.05), and the RD group maintained superior analgesia vs. both groups at 24 h. RD and R groups demonstrated significant reductions for 48-h sufentanil consumption vs. controls, and RD group showed less total sufentanil consumption vs. R group. Besides, both mechanical ventilation duration and ICU stay were shortened by serval hours compared to control. Significant reductions in the count of effective analgesic pump compressions were observed in groups R and RD compared to the control group. Moreover, rescue analgesia rates were 55%, and 15% lower in RD vs. R and Control groups, respectively (p = 0.031). However, no intergroup differences occurred pulmonary complications. Conclusion: DEX-enhanced TTP blockade may contribute to attenuating the stress response, optimizing analgesia, and improving early postoperative recovery parameters in CPB cardiac surgery through opioid-sparing mechanisms and sympatholytic effects, demonstrating clinical viability within Enhanced Recovery After Surgery (ERAS) protocols. Clinical Trial Registration: https://www.chictr.org.cn/index.html, identifier ChiCTR2400085899.