Cutaneous Sensory BlockadeRSB-SENSENCT07876297
Effects of Injection Volume and Site on Sensory Distribution After Rectus Sheath Block
A study testing Ultrasound-Guided Upper Rectus Sheath Block (20 mL), Ultrasound-Guided Upper Rectus Sheath Block (30 mL) and Ultrasound-Guided Middle Rectus Sheath Block (20 mL) in people with Cutaneous Sensory Blockade, run by Chiang Mai University at 1 site in Thailand.
Trial summary
This randomized controlled study aims to evaluate the effects of local anesthetic injection volume and injection site on cutaneous sensory distribution following ultrasound-guided rectus sheath block (RSB). Read more about this study
- Who is it for?
- Ages 20 years and older
- Conditions the study is for
- Cutaneous Sensory Blockade
- What is being tested?
- Ultrasound-Guided Upper Rectus Sheath Block (20 mL), Ultrasound-Guided Upper Rectus Sheath Block (30 mL) and Ultrasound-Guided Middle Rectus Sheath Block (20 mL)
- Type of treatment
- Injection or infusion, Surgery or procedure
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 120 participants
- Where
- 1 siteThailand
- Study dates
- 12 Oct 2026to 31 Dec 2027
- Phase
- Interventional
- 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 20 years and older
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Patients scheduled for laparoscopic upper abdominal surgery and laparoscopic lower abdominal surgery, including urological procedures
- American Society of Anesthesia (ASA) physical status I-III
- Have ability to communicate and understand the study and accept to participate in the study
Who cannot join
- Aged < 20 years
- Patients who have following underlying disease: severe hepatic impairment [diagnosed of cirrhosis (Child-Pugh C)], coagulopathy (diagnosed of disease associated with abnormal coagulation), pre-existing neurological deficits, end-stage renal disease (ESRD), chronic pain (diagnosed of chronic pain disease or current use regular analgesic drugs), or any drug addiction.
- Known allergy to bupivacaine or weighing less than 50 kg
- Patient with previous abdominal surgery
- Patient with Morbid obesity (BMI > 40 kg/m2)
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
Thailand1 site
Maharaj Nakorn Chiang Mai Hospital, Faculty of Medicine, Chiang Mai University
Chiang Mai, Chiang Mai, 50200
Kittitorn Supphapipat, MD, +6653935522, kittitorn.pans@gmail.com
About this study
Official title: Effects of Local Anesthetic Volume and Injection Site on Cutaneous Sensory Distribution After Rectus Sheath Block: A Randomized Study
This randomized controlled study aims to evaluate the effects of local anesthetic injection volume and injection site on cutaneous sensory distribution following ultrasound-guided rectus sheath block (RSB). Participants undergoing laparoscopic abdominal surgery will be randomized to receive RSB using different injection sites and volumes (20 mL or 30 mL per side). Injection sites will be selected according to the surgical location, including upper, middle, or lower rectus sheath approaches. Cutaneous sensory distribution will be assessed to determine the extent and pattern of sensory blockade associated with each technique.
The findings may help optimize injection techniques and local anesthetic volumes to achieve adequate sensory coverage for abdominal surgery.
Read the detailed description
Rectus sheath block (RSB) is an ultrasound-guided regional anesthesia technique used to provide analgesia for laparoscopic abdominal surgery. Local anesthetic is injected between the rectus abdominis muscle and the posterior rectus sheath to block the anterior cutaneous branches of the thoracoabdominal nerves. Although RSB is commonly used for perioperative analgesia, the optimal injection site and local anesthetic volume required to achieve adequate cutaneous sensory distribution remain uncertain.
This prospective, randomized study aims to investigate the effects of local anesthetic injection volume and injection site on the extent and pattern of cutaneous sensory blockade following ultrasound-guided RSB in patients undergoing laparoscopic abdominal surgery.
A total of 120 participants will be enrolled and stratified according to the surgical location into two strata: upper abdominal surgery (US) and lower abdominal surgery (LS). Within each stratum, participants will be randomly allocated to one of four groups using a computer-generated randomization sequence with variable block sizes and a 2:2:1:1 allocation ratio.
In the upper abdominal surgery stratum, participants will receive one of the following interventions:
- Group U-20: Upper RSB with 20 mL of local anesthetic per side.
- Group U-30: Upper RSB with 30 mL of local anesthetic per side.
- Group M-20: Middle RSB with 20 mL of local anesthetic per side.
- Group M-30: Middle RSB with 30 mL of local anesthetic per side.
In the lower abdominal surgery stratum, participants will receive one of the following interventions:
- Group L-20: Lower RSB with 20 mL of local anesthetic per side.
- Group L-30: Lower RSB with 30 mL of local anesthetic per side.
- Group M-20: Middle RSB with 20 mL of local anesthetic per side.
- Group M-30: Middle RSB with 30 mL of local anesthetic per side.
All blocks will be performed under ultrasound guidance using 0.25% bupivacaine with epinephrine, according to the assigned injection site and volume.
Following block administration, cutaneous sensory distribution will be systematically assessed to determine the extent and pattern of sensory blockade. The sensory distribution achieved with different injection volumes and injection sites will be compared within each surgical stratum.
The findings of this study may provide evidence to guide the selection of injection sites and local anesthetic volumes for ultrasound-guided RSB and help optimize sensory coverage in patients undergoing abdominal surgery.
- Conditions
- Cutaneous Sensory Blockade
- Being tested
- Ultrasound-Guided Upper Rectus Sheath Block (20 mL), Ultrasound-Guided Upper Rectus Sheath Block (30 mL), Ultrasound-Guided Middle Rectus Sheath Block (20 mL), Ultrasound-Guided Middle Rectus Sheath Block (30 mL), Ultrasound-Guided Lower Rectus Sheath Block (20 mL)
- Keywords
- rectus sheath block, regional anesthesia, cutaneous sensory distribution, abdominal surgery, analgesia
- Medical subject headings
- Agnosia
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Ultrasound-Guided Upper Rectus Sheath Block (20 mL)Procedure or surgery
Bilateral ultrasound-guided upper rectus sheath block will be performed using 20 mL of 0.25% bupivacaine with epinephrine per side. The local anesthetic will be injected into the plane between the rectus abdominis muscle and the posterior rectus sheath at the upper abdominal injection site.
Ultrasound-Guided Upper Rectus Sheath Block (30 mL)Procedure or surgery
Bilateral ultrasound-guided upper rectus sheath block will be performed using 30 mL of 0.25% bupivacaine with epinephrine per side. The local anesthetic will be injected into the plane between the rectus abdominis muscle and the posterior rectus sheath at the upper abdominal injection site.
Ultrasound-Guided Middle Rectus Sheath Block (20 mL)Procedure or surgery
Bilateral ultrasound-guided middle rectus sheath block will be performed using 20 mL of 0.25% bupivacaine with epinephrine per side. The local anesthetic will be injected into the plane between the rectus abdominis muscle and the posterior rectus sheath at the middle abdominal injection site.
Ultrasound-Guided Middle Rectus Sheath Block (30 mL)Procedure or surgery
Bilateral ultrasound-guided middle rectus sheath block will be performed using 30 mL of 0.25% bupivacaine with epinephrine per side. The local anesthetic will be injected into the plane between the rectus abdominis muscle and the posterior rectus sheath at the middle abdominal injection site.
Ultrasound-Guided Lower Rectus Sheath Block (20 mL)Procedure or surgery
Bilateral ultrasound-guided lower rectus sheath block will be performed using 20 mL of 0.25% bupivacaine with epinephrine per side. The local anesthetic will be injected into the plane between the rectus abdominis muscle and the posterior rectus sheath at the lower abdominal injection site.
Ultrasound-Guided Lower Rectus Sheath Block (30 mL)Procedure or surgery
Bilateral ultrasound-guided lower rectus sheath block will be performed using 30 mL of 0.25% bupivacaine with epinephrine per side. The local anesthetic will be injected into the plane between the rectus abdominis muscle and the posterior rectus sheath at the lower abdominal injection site.
| Study group | Role | What they receive |
|---|---|---|
| Upper RSB 20 mL (U-20) | Experimental | Participants undergoing laparoscopic upper abdominal surgery will receive bilateral ultrasound-guided upper rectus sheath block using 20 mL of local anesthetic per side. Receives: Procedure: Ultrasound-Guided Upper Rectus Sheath Block (20 mL) |
| Upper RSB 30 mL (U-30) | Experimental | Participants undergoing laparoscopic upper abdominal surgery will receive bilateral ultrasound-guided upper rectus sheath block using 30 mL of local anesthetic per side. Receives: Procedure: Ultrasound-Guided Upper Rectus Sheath Block (30 mL) |
| Middle RSB 20 mL (M-20) | Experimental | Participants undergoing either laparoscopic upper or lower abdominal surgery will receive bilateral ultrasound-guided middle rectus sheath block using 20 mL of local anesthetic per side. Receives: Procedure: Ultrasound-Guided Middle Rectus Sheath Block (20 mL) |
| Middle RSB 30 mL (M-30) | Experimental | Participants undergoing either laparoscopic upper or lower abdominal surgery will receive bilateral ultrasound-guided middle rectus sheath block using 30 mL of local anesthetic per side. Receives: Procedure: Ultrasound-Guided Middle Rectus Sheath Block (30 mL) |
| Lower RSB 20 mL (L-20) Copy | Experimental | Participants undergoing laparoscopic lower abdominal surgery will receive bilateral ultrasound-guided lower rectus sheath block using 20 mL of local anesthetic per side. Receives: Procedure: Ultrasound-Guided Lower Rectus Sheath Block (20 mL) |
| Lower RSB 30 mL (L-30) | Experimental | Participants undergoing laparoscopic lower abdominal surgery will receive bilateral ultrasound-guided lower rectus sheath block using 30 mL of local anesthetic per side. Receives: Procedure: Ultrasound-Guided Lower Rectus Sheath Block (30 mL) |
What is being measured
The primary outcome is the main question the study is designed to answer.
Cutaneous Sensory Blockade Area Assessed by Pinprick Testing
The extent of cutaneous sensory blockade following ultrasound-guided rectus sheath block will be assessed using pinprick testing. Areas with reduced or absent pinprick sensation will be identified and mapped to determine the total cutaneous sensory blockade area (CSBA).
Measured: 30 minutes after surgery
Secondary outcomes (9)
Cutaneous Sensory Blockade Area Assessed by Pinprick Testing
The extent of cutaneous sensory blockade following ultrasound-guided rectus sheath block will be assessed using pinprick testing. Areas with reduced or absent pinprick sensation will be identified and mapped to determine the total cutaneous sensory blockade area (CSBA).
Measured: 24 hours after block completion
Cutaneous Sensory Blockade Area Assessed by Cold Testing
The extent of cutaneous sensory blockade will be assessed using cold sensation testing. Areas with reduced or absent cold sensation will be identified and mapped to determine the total cutaneous sensory blockade area (CSBA).
Measured: 30 minutes after surgery and 24 hours after block completion
Number of Dermatomes With Sensory Blockade
The number of dermatomes demonstrating reduced or absent cutaneous sensation following rectus sheath block will be recorded using standardized sensory testing. The total number of dermatomes with sensory blockade will be compared between groups.
Measured: 30 minutes after surgery and 24 hours after block completion
Dermatomal Distribution of Sensory Blockade
The anatomical distribution of sensory blockade will be evaluated by identifying the dermatomal levels demonstrating reduced or absent sensation following rectus sheath block.
Measured: 30 minutes after surgery and 24 hours after block completion
Regression of Cutaneous Sensory Blockade Over Time
Changes in cutaneous sensory blockade area over time will be assessed through repeated sensory testing following rectus sheath block.
Measured: 30 minutes after surgery and 24 hours after block completion
Cumulative Opioid Consumption During the First 24 Postoperative Hours
Total opioid consumption during the first 24 hours after surgery will be recorded and converted to intravenous morphine milligram equivalents (MME).
Measured: From completion of surgery to 24 hours postoperatively
Postoperative Pain Intensity
Postoperative pain intensity will be assessed using the Numerical Rating Scale (NRS), ranging from 0 (no pain) to 10 (worst imaginable pain).
Measured: At 2, 6, 12, and 24 hours postoperatively
Time to First Rescue Analgesic Administration
The time from completion of surgery to the first administration of rescue analgesic medication will be recorded in minutes. Participants who do not require rescue analgesia during the observation period will be documented accordingly.
Measured: From completion of surgery to 24 hours postoperatively.
Incidence of Block-Related Adverse Events
The number and proportion of participants experiencing block-related adverse events will be recorded.
Measured: From block administration to 24 hours postoperatively
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted15 Oct 2026
- Study start12 Oct 2026 (estimated)
- Primary completion20 Dec 2027 (estimated)
- Study completion31 Dec 2027 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (2)Papers the sponsor has linked to this study.
- Other trials for Cutaneous Sensory BlockadeStudies of the same condition, open and under way.
- 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 N/A
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Model description
- This prospective, randomized, parallel-group study will stratify participants according to surgical location (upper or lower abdominal surgery). Within each stratum, participants will be randomly assigned to one of four groups in a 2:2:1:1 ratio based on the injection site and local anesthetic volume (20 or 30 mL per side). Each participant will receive only the assigned rectus sheath block technique.
- Masking
- Quadruple blind
- Who is masked
- Participant, Care provider, Investigator, Outcomes assessor
- Enrolment
- 120 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Chiang Mai University
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Kittitorn Supphapipat, MD, Chiang Mai University
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07876297
- Sponsor's protocol ID
- ANE-2569-0340
- Acronym
- RSB-SENSE
- Status last verified
- Oct 2026
- First submitted
- 9 Oct 2026
- Last updated
- 15 Oct 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Publications
Fernandes HDS, Azevedo AS, Ferreira TC, Santos SA, Rocha-Filho JA, Vieira JE. Ultrasound-guided peripheral abdominal wall blocks. Clinics (Sao Paulo). 2021 Jan 20;76:e2170. doi: 10.6061/clinics/2021/e2170. eCollection 2021.
PubMed 33503184Rojas A, McMillan DT, Allan JD, Nanda M, Anumudu C, Armbruster J, Jolly M, Magin J, Maquoit G, Grant SA. Evaluating Patterns of Injectate Spread After Rectus Sheath Block: A Cadaveric Dissection Study. Cureus. 2023 Jan 24;15(1):e34142. doi: 10.7759/cureus.34142. eCollection 2023 Jan.
PubMed 36843817
Study at a glance
From the registry record, last updated by the sponsor on 15 Oct 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Effects of Local Anesthetic Volume and Injection Site on Cutaneous Sensory Distribution After Rectus Sheath Block: A Randomized Study
- ClinicalTrials.gov ID
- NCT07876297
- Acronym / sponsor ID
- RSB-SENSE / ANE-2569-0340
- Conditions
- Cutaneous Sensory Blockade
- Keywords
- rectus sheath block, regional anesthesia, cutaneous sensory distribution, abdominal surgery, analgesia
- Study type
- Interventional
- Recruitment status
- Not yet recruiting
- Enrolment
- 120 participants (estimated)
- Lead sponsor
- Chiang Mai UniversityUniversity, hospital or other
- Study start
- 12 Oct 2026 (estimated)
- Primary completion
- 20 Dec 2027 (estimated)
- Study completion
- 31 Dec 2027 (estimated)
- First posted
- 15 Oct 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.
This randomized controlled study aims to evaluate the effects of local anesthetic injection volume and injection site on cutaneous sensory distribution following ultrasound-guided rectus sheath block (RSB). Participants undergoing laparoscopic abdominal surgery will be randomized to receive RSB using different injection sites and volumes (20 mL or 30 mL per side). Injection sites will be selected according to the surgical location, including upper, middle, or lower rectus sheath approaches. Cutaneous sensory distribution will be assessed to determine the extent and pattern of sensory blockade associated with each technique.
The findings may help optimize injection techniques and local anesthetic volumes to achieve adequate sensory coverage for abdominal surgery.
Detailed description
Rectus sheath block (RSB) is an ultrasound-guided regional anesthesia technique used to provide analgesia for laparoscopic abdominal surgery. Local anesthetic is injected between the rectus abdominis muscle and the posterior rectus sheath to block the anterior cutaneous branches of the thoracoabdominal nerves. Although RSB is commonly used for perioperative analgesia, the optimal injection site and local anesthetic volume required to achieve adequate cutaneous sensory distribution remain uncertain.
This prospective, randomized study aims to investigate the effects of local anesthetic injection volume and injection site on the extent and pattern of cutaneous sensory blockade following ultrasound-guided RSB in patients undergoing laparoscopic abdominal surgery.
A total of 120 participants will be enrolled and stratified according to the surgical location into two strata: upper abdominal surgery (US) and lower abdominal surgery (LS). Within each stratum, participants will be randomly allocated to one of four groups using a computer-generated randomization sequence with variable block sizes and a 2:2:1:1 allocation ratio.
In the upper abdominal surgery stratum, participants will receive one of the following interventions:
- Group U-20: Upper RSB with 20 mL of local anesthetic per side.
- Group U-30: Upper RSB with 30 mL of local anesthetic per side.
- Group M-20: Middle RSB with 20 mL of local anesthetic per side.
- Group M-30: Middle RSB with 30 mL of local anesthetic per side.
In the lower abdominal surgery stratum, participants will receive one of the following interventions:
- Group L-20: Lower RSB with 20 mL of local anesthetic per side.
- Group L-30: Lower RSB with 30 mL of local anesthetic per side.
- Group M-20: Middle RSB with 20 mL of local anesthetic per side.
- Group M-30: Middle RSB with 30 mL of local anesthetic per side.
All blocks will be performed under ultrasound guidance using 0.25% bupivacaine with epinephrine, according to the assigned injection site and volume.
Following block administration, cutaneous sensory distribution will be systematically assessed to determine the extent and pattern of sensory blockade. The sensory distribution achieved with different injection volumes and injection sites will be compared within each surgical stratum.
The findings of this study may provide evidence to guide the selection of injection sites and local anesthetic volumes for ultrasound-guided RSB and help optimize sensory coverage in patients undergoing abdominal surgery.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Quadruple blind (participant, care provider, investigator, outcomes assessor)
- Number of arms
- 6
- Model description
- This prospective, randomized, parallel-group study will stratify participants according to surgical location (upper or lower abdominal surgery). Within each stratum, participants will be randomly assigned to one of four groups in a 2:2:1:1 ratio based on the injection site and local anesthetic volume (20 or 30 mL per side). Each participant will receive only the assigned rectus sheath block technique.
| Arm | Type | Receives |
|---|---|---|
| Upper RSB 20 mL (U-20) | Experimental | Procedure: Ultrasound-Guided Upper Rectus Sheath Block (20 mL)Participants undergoing laparoscopic upper abdominal surgery will receive bilateral ultrasound-guided upper rectus sheath block using 20 mL of local anesthetic per side. |
| Upper RSB 30 mL (U-30) | Experimental | Procedure: Ultrasound-Guided Upper Rectus Sheath Block (30 mL)Participants undergoing laparoscopic upper abdominal surgery will receive bilateral ultrasound-guided upper rectus sheath block using 30 mL of local anesthetic per side. |
| Middle RSB 20 mL (M-20) | Experimental | Procedure: Ultrasound-Guided Middle Rectus Sheath Block (20 mL)Participants undergoing either laparoscopic upper or lower abdominal surgery will receive bilateral ultrasound-guided middle rectus sheath block using 20 mL of local anesthetic per side. |
| Middle RSB 30 mL (M-30) | Experimental | Procedure: Ultrasound-Guided Middle Rectus Sheath Block (30 mL)Participants undergoing either laparoscopic upper or lower abdominal surgery will receive bilateral ultrasound-guided middle rectus sheath block using 30 mL of local anesthetic per side. |
| Lower RSB 20 mL (L-20) Copy | Experimental | Procedure: Ultrasound-Guided Lower Rectus Sheath Block (20 mL)Participants undergoing laparoscopic lower abdominal surgery will receive bilateral ultrasound-guided lower rectus sheath block using 20 mL of local anesthetic per side. |
| Lower RSB 30 mL (L-30) | Experimental | Procedure: Ultrasound-Guided Lower Rectus Sheath Block (30 mL)Participants undergoing laparoscopic lower abdominal surgery will receive bilateral ultrasound-guided lower rectus sheath block using 30 mL of local anesthetic per side. |
Who may qualify
- Ages
- 20 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (3 listed)
- Patients scheduled for laparoscopic upper abdominal surgery and laparoscopic lower abdominal surgery, including urological procedures
- American Society of Anesthesia (ASA) physical status I-III
- Have ability to communicate and understand the study and accept to participate in the study
Key exclusion criteria (5 listed)
- Aged < 20 years
- Patients who have following underlying disease: severe hepatic impairment [diagnosed of cirrhosis (Child-Pugh C)], coagulopathy (diagnosed of disease associated with abnormal coagulation), pre-existing neurological deficits, end-stage renal disease (ESRD), chronic pain (diagnosed of chronic pain disease or current use regular analgesic drugs), or any drug addiction.
- Known allergy to bupivacaine or weighing less than 50 kg
- Patient with previous abdominal surgery
- Patient with Morbid obesity (BMI > 40 kg/m2)
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 |
|---|---|---|
| Ultrasound-Guided Upper Rectus Sheath Block (20 mL)Bilateral ultrasound-guided upper rectus sheath block will be performed using 20 mL of 0.25% bupivacaine with epinephrine per side. The local anesthetic will be injected into the plane between the rectus abdominis muscle and the posterior rectus sheath at the upper abdominal injection site. | Procedure or surgery | Upper RSB 20 mL (U-20) |
| Ultrasound-Guided Upper Rectus Sheath Block (30 mL)Bilateral ultrasound-guided upper rectus sheath block will be performed using 30 mL of 0.25% bupivacaine with epinephrine per side. The local anesthetic will be injected into the plane between the rectus abdominis muscle and the posterior rectus sheath at the upper abdominal injection site. | Procedure or surgery | Upper RSB 30 mL (U-30) |
| Ultrasound-Guided Middle Rectus Sheath Block (20 mL)Bilateral ultrasound-guided middle rectus sheath block will be performed using 20 mL of 0.25% bupivacaine with epinephrine per side. The local anesthetic will be injected into the plane between the rectus abdominis muscle and the posterior rectus sheath at the middle abdominal injection site. | Procedure or surgery | Middle RSB 20 mL (M-20) |
| Ultrasound-Guided Middle Rectus Sheath Block (30 mL)Bilateral ultrasound-guided middle rectus sheath block will be performed using 30 mL of 0.25% bupivacaine with epinephrine per side. The local anesthetic will be injected into the plane between the rectus abdominis muscle and the posterior rectus sheath at the middle abdominal injection site. | Procedure or surgery | Middle RSB 30 mL (M-30) |
| Ultrasound-Guided Lower Rectus Sheath Block (20 mL)Bilateral ultrasound-guided lower rectus sheath block will be performed using 20 mL of 0.25% bupivacaine with epinephrine per side. The local anesthetic will be injected into the plane between the rectus abdominis muscle and the posterior rectus sheath at the lower abdominal injection site. | Procedure or surgery | Lower RSB 20 mL (L-20) Copy |
| Ultrasound-Guided Lower Rectus Sheath Block (30 mL)Bilateral ultrasound-guided lower rectus sheath block will be performed using 30 mL of 0.25% bupivacaine with epinephrine per side. The local anesthetic will be injected into the plane between the rectus abdominis muscle and the posterior rectus sheath at the lower abdominal injection site. | Procedure or surgery | Lower RSB 30 mL (L-30) |
Primary outcome
Cutaneous Sensory Blockade Area Assessed by Pinprick Testing
Time frame: 30 minutes after surgery
The extent of cutaneous sensory blockade following ultrasound-guided rectus sheath block will be assessed using pinprick testing. Areas with reduced or absent pinprick sensation will be identified and mapped to determine the total cutaneous sensory blockade area (CSBA).
9 secondary outcomes
Cutaneous Sensory Blockade Area Assessed by Pinprick Testing
Time frame: 24 hours after block completion
Cutaneous Sensory Blockade Area Assessed by Cold Testing
Time frame: 30 minutes after surgery and 24 hours after block completion
Number of Dermatomes With Sensory Blockade
Time frame: 30 minutes after surgery and 24 hours after block completion
Dermatomal Distribution of Sensory Blockade
Time frame: 30 minutes after surgery and 24 hours after block completion
Regression of Cutaneous Sensory Blockade Over Time
Time frame: 30 minutes after surgery and 24 hours after block completion
Cumulative Opioid Consumption During the First 24 Postoperative Hours
Time frame: From completion of surgery to 24 hours postoperatively
Postoperative Pain Intensity
Time frame: At 2, 6, 12, and 24 hours postoperatively
Time to First Rescue Analgesic Administration
Time frame: From completion of surgery to 24 hours postoperatively.
Incidence of Block-Related Adverse Events
Time frame: From block administration to 24 hours postoperatively
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 15 Oct 2026.
- Results publication: PubMed 33503184Fernandes HDS, Azevedo AS, Ferreira TC, Santos SA, Rocha-Filho JA, Vieira JE. Ultrasound-guided peripheral abdominal wall blocks. Clinics (Sao Paulo). 2021 Jan 20;76:e2170. doi: 10.6061/clinics/2021/e2170. eCollection 2021.
- Results publication: PubMed 36843817Rojas A, McMillan DT, Allan JD, Nanda M, Anumudu C, Armbruster J, Jolly M, Magin J, Maquoit G, Grant SA. Evaluating Patterns of Injectate Spread After Rectus Sheath Block: A Cadaveric Dissection Study. Cureus. 2023 Jan 24;15(1):e34142. doi: 10.7759/cureus.34142. eCollection 2023 Jan.
- Individual participant dataSharing planned: No
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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.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Ultrasound-Guided Upper Rectus Sheath Block (20 mL), Ultrasound-Guided Upper Rectus Sheath Block (30 mL) and Ultrasound-Guided Middle Rectus Sheath Block (20 mL) in people with Cutaneous Sensory Blockade, run by Chiang Mai University at 1 site in Thailand.
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 3 inclusion and 5 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 15 Oct 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Thailand. Whether a site is taking part right now should be confirmed with that site. See every site.
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.
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 Kittitorn Supphapipat, MD (+6653935522, kittitorn.pans@gmail.com), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Cutaneous Sensory Blockade Area Assessed by Pinprick Testing (time frame: 30 minutes after surgery). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT07876297, which also lists 2 linked publications.
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 15 Oct 2026.