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NCT Number: NCT07455565

Postoperative Pain Monitoring With ANI in Lumbar Spine Surgery

This study aims to compare two different pain management methods in patients undergoing elective lumbar spine surgery. Patients are randomly assigned to receive either an ultrasound-guided erector spinae plane block (ESPB) or intravenous multimodal analgesia.

Postoperative pain will be assessed using both clinical pain scores and the Analgesia Nociception Index (ANI), a non-invasive monitoring system that evaluates pain-related responses based on heart rate variability. The goal of this study is to determine which method provides better postoperative pain control.

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Key information

Conditions

Postoperative Pain Lumbar Spine Surgery Neurologic Manifestations Pain Pain, Postoperative Pathologic Processes Pathological Conditions, Signs and Symptoms Postoperative Complications Signs and Symptoms

Age range

18 year–65 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

Akdeniz University Faculty of Medicine Hospital

Antalya, 0707, Turkey (Türkiye)

Location status: Recruiting

Location contact

Ayşe Tekin, MD

CONTACT

[email protected]

+905376180290

About this study

Effective postoperative pain management is essential in lumbar spine surgery to improve patient comfort and recovery. Traditional pain assessment methods rely on subjective scales, such as the Visual Analog Scale (VAS). The Analgesia Nociception Index (ANI) is a non-invasive monitoring tool based on heart rate variability analysis that provides an objective assessment of the balance between nociception and analgesia.

This randomized parallel-group clinical study compares two analgesic strategies in adult patients undergoing elective lumbar spine surgery. Participants are randomly assigned using a simple lottery method to receive either ultrasound-guided bilateral erector spinae plane block (ESPB) or intravenous multimodal analgesia.

ANI values are recorded at postoperative 0, 15, 30, 45, 60, 90, 120, and 180. minutes, and at 6, 12, and 24. hours. These measurements are evaluated together with clinical pain scores, total opioid consumption within 24 hours, hemodynamic parameters, and adverse events.

The primary objective is to compare ANI values between the two groups during the early postoperative period. Secondary objectives include comparison of VAS scores, opioid requirements, and incidence of analgesia-related adverse effects.

Who can participate

Healthy volunteers accepted: No

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

Inclusion criteria

  • Age between 18 and 65 years
  • ASA physical status I-II
  • Scheduled for elective lumbar spine surgery
  • Ability to provide informed consent

Exclusion criteria

  • Known allergy to study medications
  • Coagulation disorders
  • Infection at the block site
  • Severe cardiovascular disease
  • Pregnancy
  • Inability to understand the study protocol

Treatment and study plan

Erector Spinae Plane Block

Procedure

Ultrasound-guided bilateral erector spinae plane block performed at the thoracolumbar level using a total of 200 mg bupivacaine for postoperative analgesia.

Intravenous Multimodal Analgesia

Drug

Intravenous administration of paracetamol 1 g, morphine 0.1 mg/kg, dexamethasone 8 mg, and ketamine 0.5 mg/kg bolus followed by 0.3 mg/kg/h infusion for postoperative pain management.

Other names: IV Multimodal Analgesia

Primary outcomes

  1. Analgesia Nociception Index (ANI)

    Time frame: From 0 minutes to 24 hours postoperatively

    Analgesia Nociception Index (ANI) measured using the ANI monitor. The ANI ranges from 0 to 100. Higher values indicate greater parasympathetic tone and lower nociceptive stimulation, whereas lower values indicate higher nociceptive stimulation.

Secondary outcomes

  1. Visual Analog Scale (VAS) Pain Score

    Time frame: From 0 minutes to 24 hours postoperatively

    Pain intensity assessed using the Visual Analog Scale (VAS), ranging from 0 (no pain) to 10 (worst imaginable pain). Higher scores indicate worse pain.

  2. Postoperative Nausea

    Time frame: Within 24 hours postoperatively.

    Incidence of postoperative nausea within 24 hours after surgery.

Study contacts

Contact information is provided by the study sponsor or research team.

Ayşe Tekin, MD

CONTACT

[email protected]

+905376180290

Neval Boztuğ, MD

CONTACT

nboztuğ@akdeniz.edu.tr

+905327995810

Sponsors and collaborators

Lead sponsor

Akdeniz University Hospital

Other

Registry information

Official study title

Comparison Of Postoperative Analgesic Efficacy Using Analgesia Nociception Index Monitoring In Patients Undergoing Elective Lumbar Spine Surgery: A Randomized Parallel-Group Study

Acronym: SPINE-ANI

Important dates

Study start
2025
Primary completion
2026
Study completion
2026
First posted
Mar 6, 2026
Registry last updated
Mar 6, 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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