COMFORT Trial: Complex Obstetric Management With Focused Regional Transversus Abdominis Plane Block (COMFORT)

March 8, 2026 updated by: Michael B VanDillen MD, University of Tennessee
To assess the effect of intraoperative transversus abdominis plane (TAP) blocks on the amount of opioid pain medications expressed as morphine milliequivalents (MME) used postoperatively in patients who have undergone cesarean delivery (CD) in the setting of complex obstetric surgery (COS).

Study Overview

Status

Status

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

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

The Transversus Abdominis Plane (TAP) block is a regional anesthesia technique that targets the nerves innervating the abdominal wall, providing effective postoperative analgesia for patients undergoing various abdominal surgeries, including cesarean deliveries. The standard clinical practice for TAP blocks typically involves local anesthetics like bupivacaine, which, when administered in the appropriate plane, has been shown to reduce opioid consumption and improve pain management in the postoperative period.

Transversus abdominal plane (TAP) blocks, when administered intraoperatively, have demonstrated significant benefits in managing postoperative pain, especially in abdominal surgeries. Placing the TAP block during surgery provides early and prolonged analgesia, potentially reducing the need for postoperative opioids and improving recovery outcomes. A study completed in 2007 was one of the first to highlight the effectiveness of intraoperative TAP block placement in patients undergoing lower abdominal surgeries, showing a significant reduction in opioid consumption and better pain control. In the context of cesarean section, an intraoperative TAP block was shown to provide effective analgesia with a reduction in postoperative narcotic use. Similarly, a randomized trial in 2017 demonstrated that intraoperative TAP blocks significantly improved pain scores and reduced opioid consumption in patients undergoing colorectal surgeries. Furthermore, a study completed in 2014 found that performing TAP blocks intraoperatively for laparoscopic cholecystectomy patients resulted in lower visual analog scale (VAS) pain scores in the recovery room and reduced the incidence of postoperative nausea and vomiting. These findings underscore the advantages of intraoperative TAP block placement in enhancing postoperative analgesia across a variety of abdominal procedures.

Despite the widespread use of TAP blocks, there remains a gap in the literature regarding the effectiveness of bupivacaine TAP block use placed intraoperatively during more complex obstetric surgeries. Most existing studies focus on the use of TAP blocks for pain management after routine Pfannenstiel cesarean deliveries, with limited attention given to their role in cases involving higher-risk or more complicated obstetric situations, such as cesareans with significant intra-abdominal adhesions or other complications.

Although bupivacaine is commonly used in TAP blocks, its specific efficacy, optimal dosing, and potential benefits when placed intraoperatively in complex obstetric cases remain underexplored. The limited data in this area presents a critical gap in our understanding of how best to optimize pain management and improve surgical outcomes for women undergoing cesarean delivery, particularly in high-risk obstetric cases.

This blinded randomized controlled trial (RCT) seeks to address this gap by evaluating the effectiveness of intraoperative TAP blocks with bupivacaine during complex cesarean sections, focusing on the impact on postoperative analgesia and pain scores. By clarifying the role of bupivacaine in TAP blocks during complex obstetric surgery, this study aims to contribute valuable insights to the field of obstetric anesthesia and improve the perioperative experience for patients undergoing cesarean delivery.

Primary Objective: To assess the effect of intraoperative transversus abdominis plane (TAP) blocks on the amount of opioid pain medications expressed as morphine milliequivalents (MME) used postoperatively in patients who have undergone cesarean delivery (CD) in the setting of complex obstetric surgery (COS).

Primary Endpoint/Outcome: Pain medication requested, expressed as MMEs, between 24 and 48 hours after surgery.

Secondary Endpoint(s)/Outcome(s):

Total MME requested within first 24-hours post operatively Total MME requested within 48-hours post operatively Total MME at 1-week after surgery Functional assessment of activities of daily life (ADL) at 1-week post operatively Number of unplanned postoperative visits within 6-months of surgery Geographic region of patients needing complex obstetric surgery. Heat maps: diversity equity and inclusion (DEI) zip codes

Hypothesis: The investigators hypothesize that utilization of the TAP block will reduce MME requirements by 20% for patients who have undergone CD in the setting of COS.

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 (Estimated)

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.
120

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.
  • Phase 4

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.
  • Name: Michael VanDillen Fellow physician, PI of study, MD
  • Phone Number: 314-619-1046
  • Email: mvandill@uthsc.edu

Study Locations

  • United States
    • Tennessee
      • Memphis, Tennessee, United States, 38103
        • Recruiting
        • Regional One Health
        • Contact:

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

Accepts Healthy Volunteers

No

Description

Inclusion criteria:

Patient has a history of a least one of the following:

  • Prior exploratory laparotomy
  • History of non-obstetric open intra-abdominal surgery
  • History of three or more prior cesarean deliveries
  • History of intra-abdominal or pelvic adhesive disease
  • History of abdominoplasty
  • History of abdominal re-exploration surgery

Exclusion Criteria:

  • Received general anesthesia
  • History of less than 3 cesarean deliveries if do not meet other inclusion criteria
  • History of chronic opioid use
  • History of substance abuse (i.e. alcohol, methamphetamine/amphetamine, abuse of prescription opioid medication, or heroin use)
  • History of chronic kidney disease
  • Allergies to bupivacaine or oral analgesics
  • Patient preference
  • Cesarean hysterectomy
  • Administration of ≥4mg morphine to epidural
  • Loss to follow-up

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: Quadruple

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.
Placebo Comparator: Placebo group
Placebo group TAP (Transversus Abdominis Plane) block syringe will include 30mL normal saline.
Drug: Placebo arm
Placebo group TAP block syringe will include 30mL normal saline
Active Comparator: Intervention group
TAP (Transversus Abdominis Plane) blocks will include 0.5% bupivacaine in 30mL solution of 15mL normal saline and 15mL bupivacaine.
Drug: Bupivicaine intervention arm
TAP blocks in intervention group will include 0.5% bupivacaine in 30mL solution of 15mL normal saline and 15mL bupivacaine

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
Pain medication requested
Time Frame: Between 24 and 48 hours after surgery
Total pain medication requested expressed in morphine milligram equivalents.
Between 24 and 48 hours after surgery

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
Total MME requested within first 24 hours postoperatively
Time Frame: 24 hours postoperatively
24 hours postoperatively
Total MME requested within 48 hours postoperatively
Time Frame: 48 hours postoperatively
48 hours postoperatively
Total MME at one week after surgery
Time Frame: One week postoperatively
One week postoperatively
Functional assessment of activities of daily life (ADL) at one week postoperatively
Time Frame: One week postoperatively
One week postoperatively
Number of unplanned postoperative visits within six months of surgery
Time Frame: Six months postoperatively
Six months postoperatively
Geographic region of patients needing complex obstetric surgery
Time Frame: 24 months - through the duration of the study
Heat maps to evaluate the distribution of patients across different demographic categories based on race and age within certain zip codes
24 months - through the duration of the study

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.
University of Tennessee

Collaborators

Collaborators

An organization other than the sponsor that provides support for a clinical study. This support may include activities related to funding, design, implementation, data analysis, or reporting.
Regional One Health

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

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.
July 15, 2025

Primary Completion (Estimated)

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.
May 1, 2028

Study Completion (Estimated)

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 1, 2028

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).
March 19, 2025

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.
April 5, 2025

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.
April 13, 2025

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.
March 11, 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.
March 8, 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.
March 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.
  • COMFORT2025

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

Yes

Studies a U.S. FDA-regulated device product

No

product manufactured in and exported from the U.S.

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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Conditions

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Dietary Supplements

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