Analgesic Efficacy of Bilateral Ultrasound-Guided Transversus Thoracic Muscle Plane Block Versus Erector Spinae Plane Block in Pediatric Patients Undergoing Corrective Cardiac Surgeries: A Randomized Controlled Study

Abstract

Objectives: Transversus thoracic plane block (TTPB) and erector spinae plane block (ESPB) are gaining popularity in cardiac surgeries to avoid excessive narcotic use and achieve fast-track extubation This study was performed to compare the analgesic efficacy of TTPB to that of ESPB in pediatric patients undergoing cardiac surgeries. The study was conducted in a university pediatric hospital (ClinicalTrials.gov NCT05559684).

Design: Single-center prospective randomized controlled study.

Setting: Tertiary referring pediatric university hospital.

Participants: Sixty pediatric patients undergoing corrective cardiac surgeries during the period from November 2022 to August 2023.

Interventions: Randomization was done using a sealed envelope technique that contained 20 labels of (control), 20 labels of (ESPB), and another 20 labels of (TTPB). Patients in the control group (n = 20) were given fentanyl infusion at a dosage of 0.5 µg/kg/h throughout the whole operation, in addition to 1 µg/kg during skin incision, sternotomy, and aortic cannulation. Patients in the ESPB group (n = 20) were given fentanyl infusion at a dose of 0.5 µg/kg/h all through the whole operation plus ultrasound-guided ESPB done bilaterally by injecting 0.4 mL/kg (1:1 solution of Bupivacaine25 % and lidocaine 1%) on each side. Patients in the TTPB group were given fentanyl infusion at a dose of 0.5 µg/kg/h throughout the operation plus ultrasound-guided TTPB done bilaterally by injecting 0.4 mL/kg on each side (1:1 solution of bupivacaine 0.25 % and lidocaine 1%).

Measurements and main results: Primary outcome was the total intraoperative fentanyl consumption; secondary outcomes included hemodynamics and time to first analgesic request (which is the elapsed time between giving the block and the patient's FLACC score ≥4), postoperative fentanyl consumption, extubation time, and adverse events. Intraoperative fentanyl consumption was significantly decreased in the TTPB group (3.4 ± 2.9) compared with the control group (6.7 ± 4.2), mean difference = 3.35, 95% CI (0.84, 5.86), p = 0.006. It was comparable between the ESPB group and the control group. Also, the TTPB and ESPB groups were comparable regarding the primary outcome, mean difference 1.2, 95% CI (-1.31, 3.71), p = 0.486. Total fentanyl consumption in the intensive care unit was significantly decreased in the TTPB group (1.1 ± 1.54) than in the control group (4.6 ± 4.25), mean difference 3.55, 95% CI (1.5, 5.6) with p = 0.001. Other pairwise comparisons were comparable between the groups. The time to first rescue analgesia was significantly longer in TTPB group (5.15 ± 4.21) compared to the control group (1.95 ± 3.5), mean difference -3.2, 95% CI (-5.68, -0.72), p = 0.04. Patients in ESPB needed first rescue analgesia slightly earlier (4.9 ± 4.4) than patients in TTPB group, mean difference -0.25, 95% CI (-3.01, 2.51), p = 0.979 and non-significantly longer than control group, mean difference -2.95, 95% CI (-5.5, -0.4), p = 0.064. Fast-track extubation was significantly increased in patients who received TTPB (85%) than in those who received ESPB (50%), relative risk = 0.58, 95% CI (0.36, 0.94), p = 0.018 and those in the control group (30%), relative risk = 0.35, 95% CI (0.17, 0.706), p < 0.001). Also, ultrafast-track extubation was significantly increased in patients who received TTPB (60%) than those in the control group 15%), relative risk = 0.25, 95% CI (0.08, 0.75), p = 0.007.

Conclusion: Both TTPB and ESPB reduced nociception and appeared comparable in providing perioperative analgesia as they reduced pain scores and intraoperative and postoperative narcotic dosage, which facilitated early extubation. TTPB was superior to ESPB regarding fast-track extubation and provided a double incidence for the ultrafast-track extubation, but this was related to the hyper incidence of adverse events not thought related to analgesia.

Keywords: FLACC score; erector spinae plane block; fast-track protocol; pain management; regional anesthesia; transversus thoracic muscle plane block.