The Effect of Bilateral Lumbar Erector Spinae Plane Block on Postoperative Analgesia in Lumbar Spinal Surgery
Phase: NA
Conditions: Nerve Block, Postoperative Pain, Randomised Clinical Trial
Sponsor: Kutahya City Hospital

 
 
 
 
 
STUDY PROTOCOL AND STATISTICAL ANALYSIS PLAN          
Official Title of the StudyEffect of Bilateral Lumbar Erector Spinae Plane 
Block on Postoperative Analgesia in LumbarSpinal Surgery 
 
ClinicalTrials.gov Identifier (NCT Number) 
Not yet assigned (Retrospective registration) 
 
Document Information 
 Document Type: Study Protocol and Statistical Analysis Plan 
 Document Date: 24 August 2021 
 Protocol Version: Version 1.0 
 
Study Sponsor / Institution 
Afyonkarahisar Health Sciences University 
 
Principal Investigator 
Prof. Dr. Remziye Sivacı 
Department of Anesthesiology and Reanimation 
Afyonkarahisar Health Sciences University 
 
Study Site 
Afyonkarahisar Health Sciences University Hospital 
Statement for Retrospective Registration                                                                
This protocol and statistical analysis plan were finalized prior to participant enrollment. 
The study was completed before registration on ClinicalTrials.gov. 
This document is submitted to support retrospective registration and verification of the 
study design. 
 
 
 
 
 

Evaluation of the Effect of Bilateral Lumbar Erector Spinae Plane Block on 
Postoperative Analgesia in Lumbar Spinal Surgery 
 
1. Introduction 
Lumbar spinal surgery is frequently associated with significant postoperative pain due to 
extensive tissue manipulation and muscular dissection. Effective postoperative analgesia is 
essential to ensure early mobilization, reduce opioid consumption, and improve overall 
patient satisfaction. 
The Erector Spinae Plane (ESP) block is an ultrasound-guided interfascial block increasingly 
utilized for postoperative analgesia in thoracic and lumbar procedures. Bilateral lumbar ESP 
block has been shown to provide extensive somatic and visceral analgesia with a favorable 
safety profile. However, evidence regarding its efficacy in lumbar spinal surgery remains 
limited. 
This study aims to evaluate the effect of bilateral lumbar ESP block on postoperative pain 
management, opioid consumption, and recovery parameters following lumbar spinal 
surgery. 
2. Aim 
The primary aim of this randomized controlled study is to determine whether bilateral 
lumbar ESP block improves postoperative analgesia compared with standard analgesic 
practices in patients undergoing lumbar spinal surgery. 
Secondary aims: 
 To compare postoperative opioid consumption 
 To evaluate mobilization time and length of hospital stay 
 To assess patient satisfaction and block-related complications 
3. Hypothesis 
 H0 (Null Hypothesis): Bilateral lumbar ESP block does not significantly reduce 
postoperative pain scores or opioid consumption compared with standard analgesia. 
 H1 (Alternative Hypothesis): Bilateral lumbar ESP block significantly reduces 
postoperative pain scores and opioid consumption compared with standard 
analgesia. 
4. Study Type 
This study is a prospective, randomized, controlled, and single-blind clinical interventional 
trial. The study is designed as a clinical efficacy comparison evaluating the effectiveness of a 
regional anesthesia technique added to routine clinical practice 
5. Study Population 
Patients aged 18–80 years undergoing elective lumbar spinal surgery (e.g., discectomy, 
laminectomy) at Afyonkarahisar Health Sciences University Hospital. 
6. Inclusion Criteria 
Patients aged 18 and over, 80 and under 
American Society of Anesthesiologists Patient Classification Score (ASA) between I and Ⅲ 
Patients who can cooperate and give consent 
No chronic analgesic or opioid use 
No mental or psychiatric disorders 
No alcohol or illicit drug use 
Patients scheduled for elective spinal surgery 
7. Exclusion Criteria 

Patients who withdrew from participation at any time during the study 
Foreign nationals who could not be contacted 
Patients with an ASA score of Ⅳ or higher 
Patients scheduled for emergency surgery 
Pregnant women and breastfeeding mothers 
Bleeding diathesis 
Drug allergy 
Anticoagulant use 
Local/systemic infection 
Serious arrhythmia 
8. Withdrawal Criteria 
 Patient request for withdrawal 
 Noncompliance with study procedures 
 Incomplete postoperative data 
9. Study Location 
Afyonkarahisar Health Sciences University Department of Anesthesiology and Reanimation 
10. Study Duration 
8 months 
11. Materials and Methods 
This study is a prospective, randomized, controlled trial comparing bilateral ESP block with 
standard analgesia in lumbar spinal surgery. 
       a. Standard Anesthesia 
 Induction: Propofol (1–2 mg/kg), fentanyl (1–2 mcg/kg), rocuronium (0.6 mg/kg) 
 Maintenance: Sevoflurane in oxygen–air mixture 
 Standard IV fluid replacement 
 Hemodynamic monitoring per ASA guidelines 
       b. Block Technique (Group 1 – ESP Block) 
 Timing: Preoperative, after induction of anesthesia 
 Position: Prone  
 Level: Bilateral ESP block at L2–L4 
 Technique: Ultrasound-guided, in-plane 
 Injectate: 20 mL of 0.25% bupivacaine per side 
 Negative aspiration performed before injection 
 Spread of local anesthetic visualized under ultrasound 
      c. Study Groups 
Group 1 (ESP Group): 
Bilateral lumbar ESP block + standard multimodal analgesia 
Group 2 (Control Group): 
Only standard multimodal analgesia (no block) 
      d. Postoperative Analgesia Protocol 
Both groups will receive: 
 IV paracetamol (1 g every 8 hours) 
 IV tenoksikam (20 mg every 12 hours) 
Rescue analgesia: 
 When the VAS score exceeds 4, an additional 40 mg of tramadol will be administered. 
      e. Pain Assessment 

Pain will be assessed using VAS (0–10): 
 At PACU admission 
 Postoperative 2nd, 4th, 8th, 12th, and 24th hours 
VAS scores between 0–3 represent mild pain. 
Additional recorded outcomes: 
 Total opioid consumption 
 Time to first mobilization 
 Length of hospital stay 
 Nausea, vomiting, hypotension, motor block 
 Block-related adverse events 
12. Study Budget 
No external funding is used. 
All interventions and medications are standard clinical practice. 
13. Ethics Approval 
The study will begin after receiving approval from: 
Afyonkarahisar Health Sciences University Clinical Research Ethics Committee 
(Decision number: AFSU 2021/10-448 Ethics Committee Code 2011-KAEK-2 ) 
Written informed consent will be obtained from all participants. 
14. Statistical Analysis 
Sample size estimation was performed using the G*Power 3.1.9.2 software. 
Using an effect size of 0.5, a significance level of α = 0.05, and a power of 80%, the required 
total sample size was calculated as 102 participants. 
Study data were analyzed using IBM SPSS Statistics version 22. 
Data were expressed as proportions, median (min–max), or mean ± SD. 
The normality of distribution was evaluated using: 
Visual methods (histograms) 
Analytical tests (Kolmogorov–Smirnov test) 
For comparison of continuous variables: 
Student’s t-test was used for normally distributed data 
Mann–Whitney U test was used for non-normally distributed data 
For categorical variables, the chi-square test was applied. 
A p-value < 0.05 was considered statistically significant. 
Primary outcomes: 
Postoperative VAS scores 
Opioid consumption at 24 hours 
Secondary outcomes: 
Mobilization time 
Length of hospital stay 
Adverse events