Overview
This randomized controlled trial evaluates the effect of ultrasound-guided iPACK block with Adductor Canal Block (ACB) 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 iPACK block with ACB attenuates the systemic inflammatory reaction to surgical trauma compared to sham block.
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 activation of the inflammatory cascade. While previous studies have evaluated the impact of regional anesthesia on NLR and PLR, the influence of iPACK block with Adducto Canal Block on SII in hip arthroplasty has not been previously investigated.
The primary objective of this study is to determine whether the PENG block reduces postoperative SII levels compared with the 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.
Eligibility
Inclusion Criteria:
- Patients with ASA classification I-III
- Aged 65-100 years
- Who will be scheduled for hip arthroplasty under spinal anesthesia
Exclusion Criteria:
- Patients who have a history of bleeding diathesis
- Take anticoagulant therapy
- History of chronic pain before surgery
- Multiple trauma
- patients unable to assess their pain (dementia)
- patients operated under general anesthesia
- patients having an infection in the region of the procedure
- the patient who does not accept the procedure
