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.
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.
Study Type
INTERVENTIONAL
Allocation
After spinal anesthesia, the ultrasound-guided PENG block will be performed with 20ml of 0.9% sodium chloride
After spinal anesthesia, the ultrasound-guided PENG block will be performed with 20 ml of 0.2% ropivacaine
Poznan University of Medical Sciences
Poznan, Poland
RECRUITINGSystemic Inflammation Response Index (SIRI)
Systemic Inflammation Response Index (SIRI) is used as a composite marker of systemic inflammatory activation. It is calculated from peripheral venous blood samples using the formula: SIRI = (Neutrophil count × Monocyte count) / Lymphocyte count All parameters are obtained from routine complete blood count (CBC) analysis and expressed in ×10⁹/L. SIRI reflects the interaction between innate immune activation (neutrophils and monocytes) and adaptive immune suppression (lymphocytes). Higher SIRI values indicate greater systemic inflammatory response.
Time frame: 12 hours after surgery
Systemic Inflammation Response Index (SIRI)
Systemic Inflammation Response Index (SIRI) is used as a composite marker of systemic inflammatory activation. It is calculated from peripheral venous blood samples using the formula: SIRI = (Neutrophil count × Monocyte count) / Lymphocyte count All parameters are obtained from routine complete blood count (CBC) analysis and expressed in ×10⁹/L. SIRI reflects the interaction between innate immune activation (neutrophils and monocytes) and adaptive immune suppression (lymphocytes). Higher SIRI values indicate greater systemic inflammatory response.
Time frame: 24 hours after surgery
Systemic Inflammation Response Index (SIRI)
Systemic Inflammation Response Index (SIRI) is used as a composite marker of systemic inflammatory activation. It is calculated from peripheral venous blood samples using the formula: SIRI = (Neutrophil count × Monocyte count) / Lymphocyte count All parameters are obtained from routine complete blood count (CBC) analysis and expressed in ×10⁹/L. SIRI reflects the interaction between innate immune activation (neutrophils and monocytes) and adaptive immune suppression (lymphocytes). Higher SIRI values indicate greater systemic inflammatory response.
Time frame: 48 hours after surgery
Aggregate Index of Systemic Inflammation (AISI)
Aggregate Index of Systemic Inflammation (AISI) is calculated as: AISI = (Neutrophil count × Monocyte count × Platelet count) / Lymphocyte count All values are obtained from routine CBC and expressed in ×10⁹/L. AISI integrates neutrophils, monocytes, platelets, and lymphocytes, providing a broader assessment of systemic inflammatory and immune response compared to single ratios.
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RANDOMIZED
Purpose
TREATMENT
Masking
QUADRUPLE
Enrollment
60
Time frame: 12 hours after surgery
Aggregate Index of Systemic Inflammation (AISI)
Aggregate Index of Systemic Inflammation (AISI) is calculated as: AISI = (Neutrophil count × Monocyte count × Platelet count) / Lymphocyte count All values are obtained from routine CBC and expressed in ×10⁹/L. AISI integrates neutrophils, monocytes, platelets, and lymphocytes, providing a broader assessment of systemic inflammatory and immune response compared to single ratios.
Time frame: 24 hours after surgery
Aggregate Index of Systemic Inflammation (AISI)
Aggregate Index of Systemic Inflammation (AISI) is calculated as: AISI = (Neutrophil count × Monocyte count × Platelet count) / Lymphocyte count All values are obtained from routine CBC and expressed in ×10⁹/L. AISI integrates neutrophils, monocytes, platelets, and lymphocytes, providing a broader assessment of systemic inflammatory and immune response compared to single ratios.
Time frame: 48 hours after surgery
Platelet Mass Index (PMI)
Platelet Mass Index (PMI) reflects total circulating platelet mass and is calculated as: PMI = Platelet count × Mean Platelet Volume (MPV) Platelet count is expressed in ×10⁹/L and MPV in femtoliters (fL). PMI reflects platelet activation and thrombo-inflammatory potential, which may increase in response to surgical stress.
Time frame: 12 hours after surgery
Platelet Mass Index (PMI)
Platelet Mass Index (PMI) reflects total circulating platelet mass and is calculated as: PMI = Platelet count × Mean Platelet Volume (MPV) Platelet count is expressed in ×10⁹/L and MPV in femtoliters (fL). PMI reflects platelet activation and thrombo-inflammatory potential, which may increase in response to surgical stress.
Time frame: 24 hours after surgery
Platelet Mass Index (PMI)
Platelet Mass Index (PMI) reflects total circulating platelet mass and is calculated as: PMI = Platelet count × Mean Platelet Volume (MPV) Platelet count is expressed in ×10⁹/L and MPV in femtoliters (fL). PMI reflects platelet activation and thrombo-inflammatory potential, which may increase in response to surgical stress.
Time frame: 48 hours after surgery
C-reactive Protein (CRP) Concentration
C-reactive protein (CRP) is a laboratory marker of acute systemic inflammation measured in peripheral venous blood samples. CRP concentration is expressed in mg/L and determined using standard hospital laboratory methods. Higher CRP values indicate greater postoperative inflammatory response.
Time frame: 12 hours after surgery
C-reactive Protein (CRP) Concentration
C-reactive protein (CRP) is a laboratory marker of acute systemic inflammation measured in peripheral venous blood samples. CRP concentration is expressed in mg/L and determined using standard hospital laboratory methods. Higher CRP values indicate greater postoperative inflammatory response.
Time frame: 24 hours after surgery
C-reactive Protein (CRP) Concentration
C-reactive protein (CRP) is a laboratory marker of acute systemic inflammation measured in peripheral venous blood samples. CRP concentration is expressed in mg/L and determined using standard hospital laboratory methods. Higher CRP values indicate greater postoperative inflammatory response.
Time frame: 48 hours after surgery
Postoperative Pain Intensity (NRS)
Postoperative pain intensity will be assessed using the Numerical Rating Scale (NRS), ranging from 0 to 10, where: 0 = no pain 10 = worst pain imaginable Pain scores will be recorded at rest.
Time frame: 4 hours after surgery
Postoperative Pain Intensity (NRS)
Postoperative pain intensity will be assessed using the Numerical Rating Scale (NRS), ranging from 0 to 10, where: 0 = no pain 10 = worst pain imaginable Pain scores will be recorded at rest.
Time frame: 8 hours after surgery
Postoperative Pain Intensity (NRS)
Postoperative pain intensity will be assessed using the Numerical Rating Scale (NRS), ranging from 0 to 10, where: 0 = no pain 10 = worst pain imaginable Pain scores will be recorded at rest.
Time frame: 12 hours after surgery
Postoperative Pain Intensity (NRS)
Postoperative pain intensity will be assessed using the Numerical Rating Scale (NRS), ranging from 0 to 10, where: 0 = no pain 10 = worst pain imaginable Pain scores will be recorded at rest.
Time frame: 24 hours after surgery
Postoperative Pain Intensity (NRS)
Postoperative pain intensity will be assessed using the Numerical Rating Scale (NRS), ranging from 0 to 10, where: 0 = no pain 10 = worst pain imaginable Pain scores will be recorded at rest.
Time frame: 48 hours after surgery
Opioid Consumption
Total opioid consumption within the first 48 hours after surgery will be recorded. All administered opioids will be converted to intravenous morphine milligram equivalents (MME) for standardization. Higher cumulative MME indicates greater analgesic requirement.
Time frame: 48 hours after surgery
Time to First Rescue Analgesia
Time from completion of surgery to first administration of rescue opioid analgesia. Measured in minutes. Shorter time indicates earlier breakthrough pain.
Time frame: 48 hours after surgery