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Background and Aims To compare the effect of ultrasound-guided PENG block vs ESPB on pain scores, opioid requirements, and stress response to surgery expressed by the neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio (PLR) in children scheduled for hip surgery.

Methods 90 patients aged 2-7 years, ASA PS I-III were randomised into 3 equal groups, each receiving a PENG block, ESPB, or control group (CG). In all groups, sedation was performed with continuous propofol infusion at 5mg/kg/h. Spontaneous ventilation was maintained with an oxygen mask at 2 L/min. Spinal anaesthesia was performed with 0.1ml/kg of 0.5% ropivacaine. After the spinal anaesthesia, the block was performed with 0.5/kg mL of 0.2% ropivacaine. The primary outcome was the pain scores (FLACC). The secondary outcomes included postoperative NLR, PLR, and cumulative opioid consumption.

Results The FLACC score was significantly lower in the ESPB and PENG groups compared to the CG (p<0.0001), as seen in table 2. The NLR and PLR levels were significantly lower in the PENG and ESPB groups (p<0.0001) compared to the CG. There was no difference in NLR and PLR levels between the PENG and ESPB groups. The cumulative opioid consumption was significantly lower in the PENG and ESPB groups compared to the CG (p<0.0001). Also, 43% of children in the PENG group and 50% of children in the ESPB group did not require opioids postoperatively, as seen in table 3.

Conclusions PENG block and ESPB provide better analgesia, lower opioid consumption and lower NRL and PLR levels after hip surgery.