Comparative randomized double-blinded study of a continuous subcutaneous infusion of bupivacaine 0.25% for right anterolateral thoracotomy incision in pediatric cardiac patients

Background The aim of this study was to test whether a continuous subcutaneous infusion of bupivacaine solution 0.25% at the surgical incision site would provide effective postoperative analgesia and reduce the postoperative requirement of opioid analgesics in pediatric patients undergoing cardiac surgery repair with right anterolateral thoracotomy incision. Patients and methods Thirty-three consenting patients undergoing cardiac surgery repair for congenital lesions by right-sided anterolateral thoracotomy incision were enrolled in this prospective, randomized, double-blind clinical trial. An indwelling infusion catheter was placed subcutaneously parallel to the incision at the end of the surgery. The patients were randomly assigned to receive normal saline (group C) or bupivacaine 0.25% (0.4 mg/kg/h) through the indwelling catheter for 48 h postoperatively (group B).Pain scores and postoperative analgesics were recorded for 48 h; stress response to surgery was assessed by preoperative and postoperative plasma cortisol and prolactin levels. The times to first oral intake, first bowel movement, urinary catheter removal, and length of ICU and hospital stay were recorded. Finally, the plasma level of bupivacaine was measured postoperatively in the treated group. Results Compared with the control group, there was a significant reduction in the pain scores at 4, 8, 12, 24, 36, and 48 h after surgery and total morphine requirement over the first 48 h in the bupivacaine group (0.4±0.08 vs. 0.9±0.1, P=0.04). Times to urinary catheter removal were shorter in the treated group compared with the control group (28.5±6.4 vs. 39.8±4.2 h, P 0.001); time to first bowel movement and time to first oral intake were earlier in the bupivacaine group (23.4±3.1 vs. 36.6±7.3 h, P 0.001 and 25. 7±2.1 vs. 39 ±7.7 h, P 0.001, respectively). The duration of ICU stay and hospital (LOS) were significantly lower in the bupivacaine group (22.5±5.1 vs. 46.4±0.7 h, P 0.001 and 114.2±14.1 vs. 168.9±23.5, P 0.001, respectively). The ondansetron used was less in the bupivacaine group (0.4±0.2 vs. 0.8±0.2 mg/kg, P 0.001). In terms of the stress hormone, postoperative plasma cortisol and prolactin levels were significantly lower in the bupivacaine group than the control group (26±9.5 and 33.2±14.0 vs. 42.7±10.5 and 52.2±24.2), Finally, the serum level of bupivacaine was 0.5±0.1, 0.7±0.3, 0.8±0.7, and 1.2±0.8 at the 4, 12, 24, and 48 h postoperatively, respectively, which were less than the toxic threshold (4 mg/ml). Conclusion The use of a continuous subcutaneous incisional infusion of bupivacaine 0.25% in children undergoing cardiac surgery through a thoracotomy incision is a safe and efficacious analgesic modality for up to 48 h postoperatively.