The Effects of Body Mass Index on Erector Spinae Plane Block Analgesia

The Effects of Body Mass Index on Erector Spina Plane Block Analgesia Treatment in Lumbar Disc Herniation Surgery

In recent years, obesity has become one of the leading health problems worldwide. It is known that obesity can cause various diseases and negatively impact the quality of life. Therefore, many conditions believed to be affected by obesity and relevant to patients' quality of life have been scientifically investigated and continue to be researched. One of these conditions is postoperative pain, with studies in the literature indicating that postoperative pain levels increase in parallel with each unit increase in BMI.

The incidence of lumbar disc herniation (LDH) is on the rise and adversely affecting the quality of life. The primary surgical intervention for LDH is discectomy. In recent years, various less invasive techniques, such as microdiscectomy, have been described to improve both surgical and analgesic outcomes. However, even with microdiscectomy surgery, postoperative pain may occur, and its control should be well-managed. Inadequate pain control can lead to unwanted effects of postoperative pain. Regional analgesia techniques may be preferred for effective analgesic treatment after spinal surgery. Methods such as paravertebral block, erector spinae plane block (ESPB), thoracolumbar interfascial plane block are widely used for analgesia in spinal surgery. The effectiveness of these regional techniques may vary depending on various factors, one of which is BMI.

The hypothesis in this study is that as BMI increases, the level of pain in patients may also increase. As a result, this study aims to investigate the relationship between BMI and postoperative pain levels in patients undergoing standard LDH surgery, anesthesia, and analgesia.

Study Overview

• Status: Completed
• Conditions: Pain; Lumbar Disc Herniation; Erector Spinae Plane Block; Body Mass Index; Pain Acute; Pain Postoperative
• Intervention / Treatment: Procedure: Erector spinae plane block

• Study Type: Observational
• Enrollment (Actual): 75
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Turkey (Türkiye)
  • Ankara
    • Yenimahalle, Ankara, Turkey (Türkiye), 06170
      • Ankara Etlik City Hospital

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

• Sampling Method: Non-Probability Sample

Study Population

This prospective study includes adult patients aged 18 to 65 years with ASA physical status I-III who are scheduled to undergo elective LDH surgery under standardized general anesthesia and bilateral ESPB for postoperative analgesia at Ankara Etlik City Hospital.

All participants meet predefined inclusion and exclusion criteria. Patients are categorized into three groups according to their preoperative BMI: 18-24.9 kg/m², 25-29.9 kg/m², and 30-40 kg/m².

The study population represents consecutive eligible surgical patients during the study period. No experimental intervention beyond routine anesthetic and analgesic management is introduced; BMI serves as the exposure variable for comparative analysis of analgesic outcomes.

Description

Inclusion Criteria:

• 18 to 65 years old
• ASA physical status I-II-III
• BMI 18 to 40 kg/m²
• Elective LDH surgery

Exclusion Criteria:

• Patient refusing the procedure
• Patients who have previously undergone spinal surgery
• Chronic opioid or analgesic use
• Patients who will operate under emergency conditions
• Patients who will not undergo LDH surgery

Study Plan

How is the study designed?

Number of groups / cohorts

3

Cohorts and Interventions

Group / Cohort	Intervention / Treatment
Patients with a BMI of 18-24.9 kg/m2; Following the visualization of the anatomical structures, the nerve block needle was advanced via the in-plane technique beneath the erector spinae muscles until the interfascial space was reached. After hydrodissection with 2 ml normal saline, 15 ml of 0.25% bupivacaine was injected into the area. Then the block process will be applied to the other side in the same way. A total of 30 ml of 15 ml 0.25% bupivacaine will be injected.	Procedure: Erector spinae plane block; Erector spinae plane block will be applied to the patients under real-time ultrasound guidance.
Patients with a BMI of 25-29.9 kg/m2; Following the visualization of the anatomical structures, the nerve block needle was advanced via the in-plane technique beneath the erector spinae muscles until the interfascial space was reached. After hydrodissection with 2 ml normal saline, 15 ml of 0.25% bupivacaine was injected into the area. Then the block process will be applied to the other side in the same way. A total of 30 ml of 15 ml 0.25% bupivacaine will be injected.	Procedure: Erector spinae plane block; Erector spinae plane block will be applied to the patients under real-time ultrasound guidance.
Patients with a BMI of 30-40 kg/m2; Following the visualization of the anatomical structures, the nerve block needle was advanced via the in-plane technique beneath the erector spinae muscles until the interfascial space was reached. After hydrodissection with 2 ml normal saline, 15 ml of 0.25% bupivacaine was injected into the area. Then the block process will be applied to the other side in the same way. A total of 30 ml of 15 ml 0.25% bupivacaine will be injected.	Procedure: Erector spinae plane block; Erector spinae plane block will be applied to the patients under real-time ultrasound guidance.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Pain Scores	Pain will be assessed at the first-hour rest and while coughing using the visual analog scale on a scale from 0 (no pain) to 10 (worst pain). Pain assessment will be done at the 1st hour after surgery.	1st hour after surgery.

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Intraoperative remifentanil consumption	The amount of remifentanil that patients need to maintain anesthesia during the intraoperative period will be recorded.	During the intraoperative period
Pain Scores	Pain will be assessed at the 2nd-hour rest and while coughing using the visual analog scale on a scale from 0 (no pain) to 10 (worst pain).	2nd hour after surgery.
Pain Scores	Pain will be assessed at the 6th-hour rest and while coughing using the visual analog scale on a scale from 0 (no pain) to 10 (worst pain).	6th hour after surgery.
Pain Scores	Pain will be assessed at the 12th-hour rest and while coughing using the visual analog scale on a scale from 0 (no pain) to 10 (worst pain).	12th hour after surgery.
Pain Scores	Pain will be assessed at the 24th-hour rest and while coughing using the visual analog scale on a scale from 0 (no pain) to 10 (worst pain).	24th hour after surgery.

Collaborators and Investigators

• Sponsor: Atatürk Chest Diseases and Chest Surgery Training and Research Hospital

Study record dates

Study Major Dates

• Study Start (Actual): January 10, 2024
• Primary Completion (Actual): June 10, 2024
• Study Completion (Actual): June 26, 2024

Study Registration Dates

• First Submitted: February 6, 2024
• First Submitted That Met QC Criteria: February 6, 2024
• First Posted (Actual): February 14, 2024

Study Record Updates

• Last Update Posted (Actual): February 27, 2026
• Last Update Submitted That Met QC Criteria: February 25, 2026
• Last Verified: February 1, 2026

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Neurologic Manifestations; Bone Diseases; Musculoskeletal Diseases; Postoperative Complications; Pathologic Processes; Pathological Conditions, Anatomical; Spinal Diseases; Hernia; Pathological Conditions, Signs and Symptoms; Signs and Symptoms; Pain; Pain, Postoperative; Intervertebral Disc Displacement; Acute Pain
• Other Study ID Numbers: AEŞH-BADEK-2024-035

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No