Effect of ultrasound-guided quadratus lumborum block on neuroendocrine stress response and postoperative analgesia in paediatric patients undergoing elective open pyeloplasty – A randomised clinical trial

Quadratus lumborum block (QLB) is a compartmental block of the anterior abdominal wall. Surgical trauma produces neuroendocrine surgical stress responses, which are modified by anaesthetic blocks. The aim of this study was to evaluate the effect of ultrasound (US)-guided QLB on analgesia and surgical neuroendocrine stress response in paediatric patients undergoing pyeloplasty. A randomised trial was conducted in 60 children aged 1–7 years undergoing elective open pyeloplasty. Patients were randomised into Group QLB [US-guided QLB with 0.5 ml/kg of 0.25% ropivacaine after induction of general anaesthesia (GA)], and Group GA, which received only GA. Perioperative haemodynamic parameters, serum cortisol, blood glucose, analgesic consumption and postoperative FLACC scores were recorded. Unpaired t-test, Wilcoxon rank-sum test or Mann–Whitney U test was used to compare variables between the two groups. Two-way analysis of variance or the Friedmann test was used to compare quantitative variables at various points within a group. A decrease in serum cortisol and blood glucose values was observed in Group QLB at 30 min after surgical incision and 24 h after surgery compared to the preoperative value and compared to Group GA (P < 0.05). The quality of analgesia assessed by the FLACC scale was significantly better in group QLB. Dose of fentanyl consumption (µg/kg) was higher in Group GA compared to Group QLB in the intraoperative and postoperative period (P < 0.05). QLB is effective as part of multimodal analgesia and attenuates the neuroendocrine stress in paediatric patients undergoing open pyeloplasty.