Acute PainPhase 4SQUARENCT07566312
Study of QL Analgesic Response and Extent
A Phase 4 study testing Quadratus Lumborum with 1.5% Lidocaine in people with Acute Pain and Postoperative Pain, run by Duke University.
Trial summary
A total of 14-18 healthy volunteers will be included. There will be three different procedure days, separated by at least one week. On each visit, the subjects will receive a QL block, according to the randomization process. Each volunteer will undergo pre-procedure screening on the first visit. Read more about this study
- Who is it for?
- Ages 18 years and olderHealthy volunteers can take part
- Conditions the study is for
- Acute Pain, Postoperative Pain, Regional Anesthesia Block
- What is being tested?
- Quadratus Lumborum with 1.5% Lidocaine
- Type of treatment
- Injection or infusion
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 25 participants
- Where
- No sites listed yet
- Study dates
- Jan 2027to Apr 2027
- Phase
- Phase 4
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 years and older
- All sexes
- Healthy volunteers accepted
- Adult, Older adult
Who may be able to join
- Ability to provide written informed consent
- Ability and willingness to comply with the study procedures and duration requirements
- ASA physical status 1 or 2
- Age ≥ 18 years
- Weight > 70kg
Who cannot join
- BMI > 35kg.m2
- Use of analgesics within 24 hours before the procedure
- History of thoracic trauma or surgery
- Abdominal deformities or abnormalities that may prevent proper block performance
- Abdominal tattoos in the area of block performance
- Systemic neuromuscular disease
Show all 10Show fewer
- Contraindications to regional anesthesia (e.g., infection, allergy, challenging sonoanatomy)
- Structures are unable to be visualized by ultrasound
- Pregnancy
- Other known health conditions that would affect the participant's ability to successfully complete the study
Trial locations and contacts
No sites are listed yet. Contact the study team or a site near you to ask about taking part.
About this study
Official title: Anterior Versus Posterior Versus Lateral Quadratus Lumborum Block: a Randomized Control Trial in Healthy Volunteers
A total of 14-18 healthy volunteers will be included. There will be three different procedure days, separated by at least one week. On each visit, the subjects will receive a QL block, according to the randomization process. Each volunteer will undergo pre-procedure screening on the first visit. The blocks will be performed on the same side, by the same anesthesiologist, with at least one week between each block. An anterior QL block will be administered on one day, a posterior QL block on another, and a lateral QL block on the third. The order will be randomized, and both the subject and the research team member assessing the block will be blinded. To compare the dermatomal sensory block distribution, the investigators will use detailed mapping with pinprick, cold, and heat stimuli. A handheld dynamometric assessment of lower extremity strength. The testing will be performed 60 to 90 minutes after performance of the blocks.
Read the detailed description
Regional anesthesia techniques are widely employed to achieve sensory blockade of the abdominal wall. Among these, the epidural remains the most well-established approach, offering bilateral spread. However, its association with neuraxial complications has led to a decline in its clinical use. In contrast, fascial plane blocks, avoid neuraxial-related risks. The advent of ultrasound-guided blocks has sparked growing interest in novel fascial plane blocks, that can deliver multi-dermatomal with a lower rate of complications.
Three Quadratus Lumborum (QL) blocks are an example of these fascial plane blocks, commonly performed for abdominal and pelvic surgery. Despite their widespread clinical use, no prior studies have directly compared the three techniques in terms of their cutaneous distribution. Additionally, case reports note that lower extremity weakness can sometimes temporarily occur as a result of accidental spread to the lumbar plexus. Thus, this randomized, double-blinded trial aims to investigate the cutaneous distribution of these three blocks in healthy adult volunteers. Lastly, this study will assess the incidence and severity of lower extremity weakness that may occur with each technique. In addition, this study also seeks to investigate the pharmacokinetics (PK) of lidocaine in each technique. The rationale for this lies in the anatomical differences between the blocks. Theoretically, there may be a difference in the anatomical target for these blocks, but the investigators hypothesize that there is no difference in the local anesthetic absorption. Therefore, as the investigators expect similar systemic absorption, the chances of local anesthetic systemic toxicity (LAST) should be equally low, and all blocks should be similarly safe.
- Conditions
- Acute Pain, Postoperative Pain, Regional Anesthesia Block
- Being tested
- Quadratus Lumborum with 1.5% Lidocaine
- Keywords
- Quadratus lumborum block, QL block, QL, Quadratus lumborum, Fascial plane block, Regional anesthesia, Abdominal blocks
- Medical subject headings
- Acute Pain, Pain, Postoperative
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Quadratus Lumborum with 1.5% LidocaineCombination product
For the anterior QL block, a curvilinear probe and nerve stimulator will be used. Local anesthetic will be deposited anterior to the QL muscle but posterior to the psoas muscle. A nerve stimulator at 2 Hz frequency, 1.5 mA will be used to aid in identification of intramuscular placement of the needle. Local anesthetic will only be deposited if no twitch is seen in either the QL or psoas muscle with an appropriate circuit formed. For the posterior QL block, a linear or curvilinear probe will be used, at the discretion of the anesthesiologist. Local anesthetic will be deposited posterior to the QL muscle such that anterior depression of the muscle is seen. For the lateral QL block, local anesthetic will be deposited lateral to the QL muscle.
| Study group | Role | What they receive |
|---|---|---|
| Lateral Quadratus Lumborum block | Active comparator | Participants receive quadratus lumborum block under ultrasound guidance, with 30mL of 1.5% lidocaine on one visit. Receives: Combination Product: Quadratus Lumborum with 1.5% Lidocaine |
| Anterior Quadratus Lumborum Block | Experimental | Participants receive anterior quadratus lumborum block under ultrasound guidance, with 30mL of 1.5% lidocaine on one visit. Receives: Combination Product: Quadratus Lumborum with 1.5% Lidocaine |
| Posterior Quadratus Lumborum Block | Experimental | Participants receive posterior quadratus lumborum block under ultrasound guidance, with 30mL of 1.5% lidocaine on one visit. Receives: Combination Product: Quadratus Lumborum with 1.5% Lidocaine |
What is being measured
The primary outcome is the main question the study is designed to answer.
Number of participants with blocked areas as measured by skin temperature discrimination
Skin temperature assessment using gloved ice on the chest wall, to discriminate blocked vs unblock areas.
Measured: 60 to 90 minutes post-block
Number of participants with blocked areas as measured by mechanical discrimination
Mechanical assessment using a neuropin (pinprick) on the chest wall, to discriminate blocked vs unblock areas.
Measured: 60 to 90 minutes post-block
Blocked area as measured by cutaneous distribution mapping
Mapping the blocked area (using the previous temperature and mechanical assessments, demarcating lines on the skin) to calculate the area blocked.
Measured: 60 to 90 minutes post-block
Secondary outcomes (3)
Skin temperature of the chest wall
Infrared camera will assess skin temperature of the chest wall.
Measured: 60 to 90 minutes post-block
Blocked area as measured by nociceptive discrimination
Nociceptive stimuli will be delivered using controlled heat to discriminate blocked versus unblocked areas on the chest wall.
Measured: 60 to 90 minutes post-block
Lidocaine systemic absorption
Calculate lidocaine systemic absorption (Cmax).
Measured: 0, 30, 60, 120, and 240 minutes after lidocaine administration
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted5 May 2026
- Study startJan 2027 (estimated)
- Primary completionApr 2027 (estimated)
- Study completionApr 2027 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Acute PainStudies of the same condition, open and under way.
- More trials run by Duke UniversityThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase 4
- Primary purpose
- Other
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Double blind
- Who is masked
- Participant, Outcomes assessor
- Enrolment
- 25 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Duke University
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
- Investigators
- Brian Mendelson, MD, Principal investigator, Duke University
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07566312
- Sponsor's protocol ID
- Pro00118381
- Acronym
- SQUARE
- Status last verified
- Apr 2026
- First submitted
- 29 Apr 2026
- Last updated
- 8 Jul 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- Yes
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 8 Jul 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Anterior Versus Posterior Versus Lateral Quadratus Lumborum Block: a Randomized Control Trial in Healthy Volunteers
- ClinicalTrials.gov ID
- NCT07566312
- Acronym / sponsor ID
- SQUARE / Pro00118381
- Conditions
- Acute Pain, Postoperative Pain, Regional Anesthesia Block
- Keywords
- Quadratus lumborum block, QL block, QL, Quadratus lumborum, Fascial plane block, Regional anesthesia, Abdominal blocks
- Phase
- Phase 4
- Study type
- Interventional
- Recruitment status
- Not yet recruiting
- Enrolment
- 25 participants (estimated)
- Lead sponsor
- Duke UniversityUniversity, hospital or other
- Study start
- Jan 2027 (estimated)
- Primary completion
- Apr 2027 (estimated)
- Study completion
- Apr 2027 (estimated)
- First posted
- 5 May 2026 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
A total of 14-18 healthy volunteers will be included. There will be three different procedure days, separated by at least one week. On each visit, the subjects will receive a QL block, according to the randomization process. Each volunteer will undergo pre-procedure screening on the first visit. The blocks will be performed on the same side, by the same anesthesiologist, with at least one week between each block. An anterior QL block will be administered on one day, a posterior QL block on another, and a lateral QL block on the third. The order will be randomized, and both the subject and the research team member assessing the block will be blinded. To compare the dermatomal sensory block distribution, the investigators will use detailed mapping with pinprick, cold, and heat stimuli. A handheld dynamometric assessment of lower extremity strength. The testing will be performed 60 to 90 minutes after performance of the blocks.
Detailed description
Regional anesthesia techniques are widely employed to achieve sensory blockade of the abdominal wall. Among these, the epidural remains the most well-established approach, offering bilateral spread. However, its association with neuraxial complications has led to a decline in its clinical use. In contrast, fascial plane blocks, avoid neuraxial-related risks. The advent of ultrasound-guided blocks has sparked growing interest in novel fascial plane blocks, that can deliver multi-dermatomal with a lower rate of complications.
Three Quadratus Lumborum (QL) blocks are an example of these fascial plane blocks, commonly performed for abdominal and pelvic surgery. Despite their widespread clinical use, no prior studies have directly compared the three techniques in terms of their cutaneous distribution. Additionally, case reports note that lower extremity weakness can sometimes temporarily occur as a result of accidental spread to the lumbar plexus. Thus, this randomized, double-blinded trial aims to investigate the cutaneous distribution of these three blocks in healthy adult volunteers. Lastly, this study will assess the incidence and severity of lower extremity weakness that may occur with each technique. In addition, this study also seeks to investigate the pharmacokinetics (PK) of lidocaine in each technique. The rationale for this lies in the anatomical differences between the blocks. Theoretically, there may be a difference in the anatomical target for these blocks, but the investigators hypothesize that there is no difference in the local anesthetic absorption. Therefore, as the investigators expect similar systemic absorption, the chances of local anesthetic systemic toxicity (LAST) should be equally low, and all blocks should be similarly safe.
Study design
- Primary purpose
- Other
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Double blind (participant, outcomes assessor)
- Number of arms
- 3
| Arm | Type | Receives |
|---|---|---|
| Lateral Quadratus Lumborum block | Active comparator | Combination Product: Quadratus Lumborum with 1.5% LidocaineParticipants receive quadratus lumborum block under ultrasound guidance, with 30mL of 1.5% lidocaine on one visit. |
| Anterior Quadratus Lumborum Block | Experimental | Combination Product: Quadratus Lumborum with 1.5% LidocaineParticipants receive anterior quadratus lumborum block under ultrasound guidance, with 30mL of 1.5% lidocaine on one visit. |
| Posterior Quadratus Lumborum Block | Experimental | Combination Product: Quadratus Lumborum with 1.5% LidocaineParticipants receive posterior quadratus lumborum block under ultrasound guidance, with 30mL of 1.5% lidocaine on one visit. |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (5 listed)
- Ability to provide written informed consent
- Ability and willingness to comply with the study procedures and duration requirements
- ASA physical status 1 or 2
- Age ≥ 18 years
- Weight > 70kg
Key exclusion criteria (10 listed)
- BMI > 35kg.m2
- Use of analgesics within 24 hours before the procedure
- History of thoracic trauma or surgery
- Abdominal deformities or abnormalities that may prevent proper block performance
- Abdominal tattoos in the area of block performance
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Quadratus Lumborum with 1.5% LidocaineFor the anterior QL block, a curvilinear probe and nerve stimulator will be used. Local anesthetic will be deposited anterior to the QL muscle but posterior to the psoas muscle. A nerve stimulator at 2 Hz frequency, 1.5 mA will be used to aid in identification of intramuscular placement of the needle. Local anesthetic will only be deposited if no twitch is seen in either the QL or psoas muscle with an appropriate circuit formed. For the posterior QL block, a linear or curvilinear probe will be used, at the discretion of the anesthesiologist. Local anesthetic will be deposited posterior to the QL muscle such that anterior depression of the muscle is seen. For the lateral QL block, local anesthetic will be deposited lateral to the QL muscle. | Combination product | Anterior Quadratus Lumborum Block, Lateral Quadratus Lumborum block, Posterior Quadratus Lumborum Block |
Primary outcome
Number of participants with blocked areas as measured by skin temperature discrimination
Time frame: 60 to 90 minutes post-block
Skin temperature assessment using gloved ice on the chest wall, to discriminate blocked vs unblock areas.
Number of participants with blocked areas as measured by mechanical discrimination
Time frame: 60 to 90 minutes post-block
Mechanical assessment using a neuropin (pinprick) on the chest wall, to discriminate blocked vs unblock areas.
Blocked area as measured by cutaneous distribution mapping
Time frame: 60 to 90 minutes post-block
Mapping the blocked area (using the previous temperature and mechanical assessments, demarcating lines on the skin) to calculate the area blocked.
3 secondary outcomes
Skin temperature of the chest wall
Time frame: 60 to 90 minutes post-block
Blocked area as measured by nociceptive discrimination
Time frame: 60 to 90 minutes post-block
Lidocaine systemic absorption
Time frame: 0, 30, 60, 120, and 240 minutes after lidocaine administration
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 8 Jul 2026.
- Individual participant dataSharing planned: No
Related trials for Acute Pain
Not yet recruiting
Human Experimental Models of Pain (HEMP)
Acute Pain
Not yet recruitingPhase 2
Investigating the Analgesic Potential of (2R,6R)-HNK in Acute Pain in Healthy Volunteers
Healthy Volunteers
Not yet recruiting
Post-operative Pain and Apical Healing After Root Canal (re)Treatment With Laser-activated Irrigation Versus Sonic or no Activation
Apical Periodontitis, Post Operative Pain, Acute
RecruitingPhase 1/2
A Study of CYT-1010 in Healthy Volunteers and Participants With Acute Pain After Third Molar Extraction
Acute Postoperative Pain, Dental Pain
Not yet recruiting
Two Bupivacaine Concentrations for Recto-Intercostal Fascial Plane Block After Laparoscopic Cholecystectomy
Postoperative Pain, Acute Pain
Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
Brian Mendelson, MD principal investigator
Duke University
Questions about this trial
What is this clinical trial studying?
A Phase 4 study testing Quadratus Lumborum with 1.5% Lidocaine in people with Acute Pain and Postoperative Pain, run by Duke University.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 5 inclusion and 10 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: opening soon, as of the sponsor's last update on 8 Jul 2026. Status can change between updates, so confirm with the study contact before making plans.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
What does this phase mean?
Phase 4 studies take place after a treatment is approved, to learn more about its long-term benefits and risks in everyday use.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Brian Mendelson, MD (818-456-7040, brian.mendelson@duke.edu), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Number of participants with blocked areas as measured by skin temperature discrimination (time frame: 60 to 90 minutes post-block). The study lists 3 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 8 Jul 2026.