Pericapsular nerve group block (peng-b) versus intrathecal morphine (it-m) for the postoperative pain management in surgical repair of hip fractures: Preliminary data of a single-center prospective observational study

Introduction. Pain management in hip fractures surgery is crucial in preventing postoperative complications and delayed mobilization. Intrathecal morphine (IT-M) is effective in pain control, but it is associated with several adverse effects and longer length of hospital stay. The Pericapsular Nerve Group block (PENG-b) is an echo-guided analgesic motor-sparing regional technique first described by Giròn et al. The PROSPECT ESRA guidelines classify it as having “lack of evidence” for hip surgery analgesia and to date, only one randomized trial comparing PENG block to intrathecal morphine in hip fractures has been published (1,2). Aim of this study is to compare the analgesic effectiveness of these techniques by NRS (Numerical Rating Scale) evaluation.Methods. The STROBE Statement was followed and informed consent was obtained for this publication. Seventy-six patients were enrolled: 38 - group A - received PENG-b (ropivacaine 0.5% 20 ml); 38 - group B - received IT-M (100 mcg). Both groups received spinal anesthesia with L-bupivacaine 0,5% 10 mg at L2-L3 level before surgery. Statistical analysis was made by Mann-Whitney U test.Results. Graphs show the NRS values at 6, 12 and 24 hours after surgery, at rest and during 20-degree passive hip flexion. At 6 and 12 hours no statistically significant differences in NRS scores at rest were observed between groups. At 24 hours group A demonstrated significantly lower NRS scores at rest (p = 0,003). No significant differences in dynamic NRS scores were shown at 6 and 12 hours. At 24 hours a trend towards lower pain scores during movement was observed in the group A, although this did not reach statistical significance (p = 0,051). The proportion of patients requiring first step rescue analgesia was higher in the group B, but with no statistically significant difference. Neither group required rescue opioid therapy.Conclusion. The main finding is that PENG-b was associated with significantly lower pain scores at rest at 24 hours, whereas no clinically meaningful differences were observed during the early postoperative period or in dynamic pain scores. The absence of differences in NRS scores at 6 and 12 hours suggests that both techniques provide comparable early analgesia. The improved pain control observed with PENG-b at 24 hours may reflect a more sustained peripheral analgesic effect. No significant differences were observed in the consumption of rescue analgesia. This study has several limitations: the non-randomised design introduces the potential for selection bias and residual confounding; the relatively small sample size may limit the power to detect differences in secondary outcomes.In conclusion, PENG-b provided superior analgesia at rest at 24 hours compared with IT-M, and it has a more favorable trend in dynamic NRS evaluation, although not statistically significant, without differences in rescue analgesia consumption. Both techniques remain valid options, with PENG-b offering a potential advantage in late postoperative pain control. To better assess, more data are necessary and further randomized studies are needed.