Comparing Bi-level and Single-level ESP Block for Open Inguinal Hernia Repair

May 9, 2026 updated by: Patricia Ip, Hospital Authority, Hong Kong

Comparing Analgesic Efficacy and Quality of Recovery of Bi-level and Single-level Erector Spinae Plane Block for Open Inguinal Hernia Repair Surgery - a Randomised, Observed-blinded Active-controlled Trial

The goal of this clinical trial is to compare the effects of single-level and bi-level erector spinae plane block in open inguinal hernia repair surgery. The main question it aims to answer are:

  • Whether bi-level ESP block will improve pain control after open inguinal hernia repair surgery
  • Whether bi-level ESP block will improve quality of recovery after open inguinal hernia repair surgery

Participants will receive erector spinae plane block, and will be randomised into 2 groups, single-level ESP block and bi-level ESP block, before open hernia repair surgery. They will be followed up after operation for assessment of pain control and quality of recovery.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Completed

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Detailed Description

Open inguinal hernia repair is increasingly performed as a day case surgery. As a result, satisfactory acute pain control is very important to reduce discomfort, as well as to facilitate early mobilisation and recovery. Regional anaesthesia, eg. erector spinae plane block (injection below para-spinal muscles) is increasingly implemented as part of multi-modal analgesia to establish better post-operative pain control and spare the use of opioids which can lead to unwanted side effects eg. sedation, nausea and vomiting. Acute post-surgical pain from open inguinal hernia repair consists of subcutaneous, deep somatic and visceral components. The erector spinae plane (ESP) block acts by local anaesthetic (LA) spread to ventral and dorsal rami of spinal nerves, producing somatic and visceral pain relief. Therefore, it can effectively relieve acute post-surgical pain resulted from open hernia repair. Bi-level ESP block has been utilised clinically to provide multi-dermatomal analgesia in pain management eg. flail chest; or anaesthetic management eg. open inguinal hernia repair, scoliosis surgery, mastectomy. However, to date, there have been no studies comparing the analgesic efficacy of bi-level and single-level erector spinae plane blocks. The investigators postulate that comparing with single-level ESP block, bi-level ESP block can facilitate LA spread into paraspinal areas more effectively, producing more reliable analgesia; and therefore would reduce post-operative pain scores and improve quality of recovery in patients undergoing open inguinal hernia repair.

To investigate the above clinical question, a parallel-group observer-blinded randomised clinical trial was designed. Patients will be randomised into 2 groups. One group of patients (2ESP) will receive ESP block at ipsilateral T12 and L1; while the other group of patients (1ESP) will receive ESP block at ipsilateral L1. L1 was chosen as an injection level, since it is at the midpoint of corresponding spinal nerve roots innervating the groin (T12-L3). For bi-level injection group, thoracic instead of another lower lumbar level was chosen to avoid motor blockade caused by excessive local anaesthetic spread into lumbar plexus, leading to delayed mobilisation which is undesirable for patients undergoing ambulatory surgery.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Actual)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
90

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact

The name and contact information for the person who can answer enrollment questions for a clinical study. Each location where the study is being conducted may also have a specific contact, who may be better able to answer those questions.

Study Locations

  • Hong Kong
      • Hong Kong, Hong Kong
        • Tin Shui Wai Hospital

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

Yes

Description

Inclusion Criteria:

  • Patients above 18 years old
  • ASA (American Society of Anesthesiologists) class I to III
  • Unilateral open inguinal hernia repair

Exclusion Criteria:

  • Patient refusal or unable to consent to study
  • Contraindication of ESP block including patient refusal, injection site infection, coagulopathy, hypersensitivity to local anaesthetic
  • Pre-existing chronic pain
  • Alcohol and substance dependence
  • Pre-existing psychiatric diseases

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Double

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Active Comparator: Single-level ESP group (1ESP)
Subjects in 1ESP group will receive a single-shot single-level erector spinae plane block at L1 level under ultrasound guidance immediately before surgery.
Procedure: Erector spinae plane block

ESP block is a paraspinal fascial plane block that involves injection of local anesthetic underneath the anterior fascia of the erector spinae muscles.

Local anaesthetic mixture (lignocaine 2% with adrenaline, bupivacaine 0.25%) will be delivered with insulated needle in bolus(es) to above-mentioned levels (L1 in 1ESP group, T12 & L1 in 2ESP group)
Active Comparator: Bi-level ESP group (2ESP)
Subjects in this group will receive a single-shot single-level erector spinae plane block at T12 and L1 levels under ultrasound guidance immediately before surgery.
Procedure: Erector spinae plane block

ESP block is a paraspinal fascial plane block that involves injection of local anesthetic underneath the anterior fascia of the erector spinae muscles.

Local anaesthetic mixture (lignocaine 2% with adrenaline, bupivacaine 0.25%) will be delivered with insulated needle in bolus(es) to above-mentioned levels (L1 in 1ESP group, T12 & L1 in 2ESP group)

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Post-operative pain score
Time Frame: 1 day
Numeric rating score (11-point scale) will be used to assess pain. (0 = no pain, 10 = worst pain)
1 day
Quality of recovery score (QoR-15)
Time Frame: 1 day
This is a validated questionnaire to evaluate the physical, emotional and functional aspects of patients and their abilities to resume usual activities of daily living after surgery and anaesthesia. It ranges from 0-150. Higher score indicates better recovery.
1 day

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Peri-operative fentanyl dosage
Time Frame: 1 day
Dosage of fentanyl in micrograms used in the peri-operative period will be compared between both groups.
1 day
Time to first rescue analgesic
Time Frame: 1 day
Time from completion of ESP block to first rescue analgesic will be recorded and compared.
1 day
Rate of motor deficit
Time Frame: 1 day
Rate of lower limb weakness in both groups of subjects affecting ambulation / weight bearing will be compared.
1 day
Rate of post-operative urinary retention
Time Frame: 2 days
Rate of post-operative urinary retention in both groups of subjects affecting gait / weight bearing will be compared.
2 days
Rate of post-operative nausea and vomiting
Time Frame: 2 days
Rate of post-operative nausea and vomiting in both groups of subjects will be compared.
2 days

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
Hospital Authority, Hong Kong

Investigators

Investigators

A researcher involved in a clinical study. Related terms include site principal investigator, site sub-investigator, study chair, study director, and study principal investigator.
  • Principal Investigator: Patricia Ip, HA

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
January 15, 2024

Primary Completion (Actual)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
October 23, 2025

Study Completion (Actual)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
May 9, 2026

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
October 19, 2023

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
November 30, 2023

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
December 4, 2023

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
May 13, 2026

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
May 9, 2026

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
May 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • CIRB-2023-091-2

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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