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NCT Number: NCT07449403

SII Levels Following PENG Block in Hip Arthroplasty

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.

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Key information

Conditions

Hip Osteoarthritis Arthritis Joint Diseases Musculoskeletal Diseases Osteoarthritis Osteoarthritis, Hip Rheumatic Diseases

Age range

65 year–100 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

Poznan University of Medical Sciences

Poznan, 62-701, Poland

Location status: Recruiting

Location contact

Malgorzata Reysner, M.D. Ph.D.

CONTACT

[email protected]

+48 61 873 83 03

About this study

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.

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

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

Treatment and study plan

Sodium Chloride

Drug

After spinal anesthesia, the ultrasound-guided PENG block will be performed with 20ml of 0.9% sodium chloride

Other names: 0.9% Sodium Chloride Injection

Ropivacaine 0.2% Injectable Solution

Drug

After spinal anesthesia, the ultrasound-guided PENG block will be performed with 20 ml of 0.2% ropivacaine

Other names: 0.2% ropivacaine

Primary outcomes

  1. Systemic Inflammation Response Index (SIRI)

    Time frame: 12 hours after surgery

    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.

Secondary outcomes

  1. Systemic Inflammation Response Index (SIRI)

    Time frame: 24 hours after surgery

    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.

  2. Systemic Inflammation Response Index (SIRI)

    Time frame: 48 hours after surgery

    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.

  3. Aggregate Index of Systemic Inflammation (AISI)

    Time frame: 12 hours after surgery

    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.

  4. Aggregate Index of Systemic Inflammation (AISI)

    Time frame: 24 hours after surgery

    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.

  5. Aggregate Index of Systemic Inflammation (AISI)

    Time frame: 48 hours after surgery

    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.

  6. Platelet Mass Index (PMI)

    Time frame: 12 hours after surgery

    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.

  7. Platelet Mass Index (PMI)

    Time frame: 24 hours after surgery

    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.

  8. Platelet Mass Index (PMI)

    Time frame: 48 hours after surgery

    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.

  9. C-reactive Protein (CRP) Concentration

    Time frame: 12 hours after surgery

    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.

  10. C-reactive Protein (CRP) Concentration

    Time frame: 24 hours after surgery

    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.

  11. C-reactive Protein (CRP) Concentration

    Time frame: 48 hours after surgery

    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.

  12. Postoperative Pain Intensity (NRS)

    Time frame: 4 hours after surgery

    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.

  13. Postoperative Pain Intensity (NRS)

    Time frame: 8 hours after surgery

    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.

  14. Postoperative Pain Intensity (NRS)

    Time frame: 12 hours after surgery

    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.

  15. Postoperative Pain Intensity (NRS)

    Time frame: 24 hours after surgery

    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.

  16. Postoperative Pain Intensity (NRS)

    Time frame: 48 hours after surgery

    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.

  17. Opioid Consumption

    Time frame: 48 hours after surgery

    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.

  18. Time to First Rescue Analgesia

    Time frame: 48 hours after surgery

    Time from completion of surgery to first administration of rescue opioid analgesia.

    Measured in minutes. Shorter time indicates earlier breakthrough pain.

Sponsors and collaborators

Lead sponsor

Poznan University of Medical Sciences

Other

Registry information

Official study title

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

Important dates

Study start
2026
Primary completion
2026
Study completion
2026
First posted
Mar 4, 2026
Registry last updated
Jul 1, 2026

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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