NCT07449403

SII Levels Following PENG Block in Hip Arthroplasty

Pericapsular Nerve Group Block Mitigates Surgical Stress and Enhances Analgesia in Total Hip Arthroplasty: A Randomized Controlled Trial

• Status: Not Yet Recruiting
• Phase: N/A
• Study type: Interventional
• Enrollment: 60 (estimated)
• Sponsor: Poznan University of Medical Sciences · Academic / Other
• Sex: All
• Age: 65 Years – 100 Years
• Healthy volunteers: Not accepted

Summary

This randomized controlled trial evaluates the effect of ultrasound-guided Pericapsular Nerve Group (PENG) block on the Systemic Immune-Inflammation Index (SII) in elderly patients undergoing total hip arthroplasty under spinal anesthesia. SII, calculated as platelet × neutrophil / lymphocyte count, is used as a composite marker of perioperative inflammatory and immune response. The study investigates whether PENG block attenuates the systemic inflammatory reaction to surgical trauma compared to sham block.

Detailed description

Surgical trauma induces a systemic inflammatory response characterized by neutrophilia, lymphopenia, and platelet activation. These hematologic alterations reflect the interaction between innate immune activation, stress-induced immunosuppression, and pro-thrombotic mechanisms. The modulation of this response may influence postoperative recovery and complication risk. The Systemic Immune-Inflammation Index (SII) is calculated using the formula: SII = (Platelet count × Neutrophil count) / Lymphocyte count SII integrates three components of systemic inflammation and immune regulation and is considered a more comprehensive marker than isolated ratios such as neutrophil-to-lymphocyte ratio (NLR) or platelet-to-lymphocyte ratio (PLR). Compared with NLR and PLR, SII may better reflect the balance between inflammatory activation and adaptive immune suppression in the perioperative period. Regional anesthesia techniques, including the Pericapsular Nerve Group (PENG) block, may attenuate surgical stress by reducing afferent nociceptive signaling, sympathetic activation, and subsequent inflammatory cascade activation. While previous studies have evaluated the impact of regional anesthesia on NLR and PLR, the influence of PENG block on SII in hip arthroplasty has not been previously investigated. The primary objective of this study is to determine whether PENG block reduces postoperative SII levels compared with sham block in elderly patients undergoing total hip arthroplasty under spinal anesthesia. Peripheral venous blood samples will be collected preoperatively and at predefined postoperative time points (e.g., 12, 24, and 48 hours). The primary endpoint will be postoperative SII at 24 hours or the change from baseline (ΔSII), depending on statistical analysis plan. This study aims to determine whether motor-sparing regional anesthesia may modulate systemic inflammatory response beyond analgesic effects, potentially contributing to improved perioperative outcomes.

Conditions

• Hip Osteoarthritis

Interventions

Type	Name	Description
DRUG	sodium Chloride	After spinal anesthesia, the ultrasound-guided PENG block will be performed with 20ml of 0.9% sodium chloride
DRUG	Ropivacaine 0.2% Injectable Solution	After spinal anesthesia, the ultrasound-guided PENG block will be performed with 20 ml of 0.2% ropivacaine

Timeline

• Start date: 2026-04-01
• Primary completion: 2026-05-01
• Completion: 2026-06-30
• First posted: 2026-03-04
• Last updated: 2026-03-04