Efficacy and safety of Pericapsular Nerve Group Block (PENG) in hip surgery under general anaesthesia: a systematic literature review and meta-analysis

Introduction: The pericapsular nerve group (PENG) block is a novel ultrasound-guided regional technique that may provide analgesia to patients undergoing hip surgery. It has been extensively studied in recent years, but the evidence of superiority over other regional anesthetic techniques is inconclusive. This review aimed to compare outcomes of the PENG block in patients undergoing hip surgery with standard techniques under general anaesthesia. Methods: PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines were followed throughout the preparation of this review. Randomized trials from electronic databases such as MEDLINE, Embase, PubMed, CINAHL, Cochrane Database of Systematic Reviews, Cochrane Central Register of Controlled Trials databases and clinicaltrials.gov were included. We investigated postoperative pain scores, required analgesia, and adverse events associated with the block. Results: Ten studies satisfied the criteria to be included in the meta-analysis. Data from 646 patients were analysed, in which 321 patients received PENG block and 325 were included in the comparative groups. Pain scores at rest, at 24 hours (p=0.04) and 48 hours (p=0.02) were lower in patients that had received the PENG block. This group also required smaller amount of opioid at 24 hours after the proce-dure; but this difference was not statistically significant (p=0.53); while a similar non-significant reduction in opioid consumption was observed also at 48 hours. Although PENG seems to delay the time to first analgesic request we failed to prove a statistically significant difference. (p=0.83) Patient satisfaction also seems to be better in the PENG group but not in a statistically significant way. No important side effects related to the block were described. Conclusions: PENG block for major hip surgery offers better postoperative analgesia, with possibly less opioid consumption. It seems to prolong time to first analgesic but does not affect significantly common side effects of anaesthesia/analgesia such as PONV, or duration of hospital stay. Systematic Review Registration PROSPERO - CRD42022335593