Comparison of Outcomes of Management of Bowel Obstruction Pilot Study (COMBO Pilot)

Comparison of Outcomes of Management of Bowel Obstruction (COMBO) Pilot

The Comparison of Outcomes of Management of Bowel Obstruction (COMBO Pilot) Pilot trial is a patient-level randomized trial of a short course of dexamethasone + supportive care vs supportive care alone for patients with adhesion-related small bowel obstruction (aSBO). The goal of the COMBO trial is to answer the question: Can Dexamethasone increases the proportion of patients with resolution of aSBO with non-operative management (without complication) based on an established minimal important clinical difference.

Study Overview

• Status: Enrolling by invitation
• Conditions: Adhesive Small Bowel Obstruction
• Intervention / Treatment: Drug: Dexamethasone; Other: Supportive Care

Detailed Description

Millions of Americans each year experience adhesion-related small bowel obstruction (aSBO), a condition associated with significant morbidity and prolonged hospitalization. Adhesions formed after previous abdominopelvic surgery can cause twisting of the bowel resulting in injury and a cascade of inflammation that results in progressive bowel wall edema with narrowing of the bowel lumen. This leads to or worsens the bowel obstruction. Reversing this inflammation has the potential to reduce the severity and impact of aSBO, hasten the return of bowel function and avoid an emergency operation to treat the obstruction. Dexamethasone, administered intravenously 2-3 times/day for 5-7 days, has been found effective in patients with a form of SBO related to malignancy (malignant ascites or metastatic disease). A Cochrane review evaluated three RCTs of dexamethasone in patients with malignant SBO and found "evidence that dexamethasone…may bring about the resolution of bowel obstruction" and avoid the need for surgical interventionxx . An underappreciated aspect of these RCTs is that almost all patients had a history of abdominopelvic surgery. Since it is difficult to distinguish the extent to which an SBO is caused by adhesions from prior surgery or mass effect related to malignant ascites or metastases, we hypothesize that dexamethasone may be efficacious in resolving aSBO as well.

The Comparison of Outcomes of Management of Bowel Obstruction (COMBO) study is a double-blinded randomized study of a short course of dexamethasone and supportive care vs. supportive care alone for patients with aSBO. The primary outcome is resolution of SBO without operative management and/or major complications as defined using modified National Surgical Quality Improvement Program (NSQIP) criteria. Differences in secondary outcomes-clinical, healthcare utilization and patient-reported outcomes will be explored overall and across subgroups (e.g., based on severity of aSBO, history of aSBO, sex). Reducing inflammation with dexamethasone- a readily available and safe intervention - may improve the likelihood of non-operative management of aSBO and could change the management of millions of patients with this condition.

• Study Type: Interventional
• Enrollment (Estimated): 10
• Phase: Phase 4

Contacts and Locations

Study Locations

• United States
  • Washington
    • Seattle, Washington, United States, 98195
      • University of Washington Medical Center

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Adults ≥18 years of age recruited from UWMC
• Patients presenting to surgical services through the Emergency Department, diagnosis of SBO, consulted by surgeon, and an urgent or emergency operation is deemed not necessary by surgeon.

• Diagnosis of aSBO is established by;

  1. CT findings consistent with diagnosis of SBO; and
  2. signs and symptoms consistent with SBO; and
  3. Adhesions are the likely cause of SBO (absence of incarcerated hernia, internal hernia, masses, fistula, stricture, volvulus, acute episode of inflammatory bowel disease (IBD) flare, etc.).
• Ability to provide written or electronic informed consent in English and answer teach-back questions

Exclusion Criteria:

• Signs and symptoms of peritonitis with emergency operation planned
• Planned urgent operation within the next 12 hours
• Allergy to dexamethasone
• Surgery within prior 6 weeks
• Unable or unwilling to return or be contacted for and/or complete research surveys
• Currently incarcerated in a detention facility or in police custody (patients wearing a monitoring device can be enrolled) at baseline/screening
• Individuals with latent infections who have an increased risk of infection.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: None (Open Label)

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Active Comparator: Dexamethasone; 8 mg IV daily in the morning continued for up to 5 days until SBO is resolved or patient becomes surgical candidate.	Drug: Dexamethasone; *Please see description for dexamethasone + supportive care arm.; Other: Supportive Care; *Please see description for supportive care arm.
Placebo Comparator: Supportive Care; Supportive care in both arms includes nasogastric tube (NGT) decompression, hydration, and serial exams to rule out bowel compromise.	Other: Supportive Care; *Please see description for supportive care arm.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Resolution of aSBO	The primary outcome is the resolution of aSBO, defined as the absence of obstruction symptoms, in patients receiving dexamethasone + supportive care compared to those receiving supportive care alone.	30 days

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Hospital readmissions - 1 Year	The outcome for this aim is the comparison of healthcare utilization (e.g., readmissions) between the dexamethasone and supportive care groups	1 Year
Patient-Reported Outcomes (PROs) - GIQLI	The outcome will be the comparison of patient-reported outcomes of gastrointestinal quality of life (GIQLI) between the dexamethasone and supportive care groups.	30 days
Hospital readmissions - 30 day	The outcome for this aim is the comparison of healthcare utilization (e.g., readmissions) between the dexamethasone and supportive care groups	30 day

Collaborators and Investigators

• Sponsor: University of Washington
• Investigators: Principal Investigator: David Flum, MD, MPH, University of Washington

Study record dates

Study Major Dates

• Study Start (Actual): March 1, 2025
• Primary Completion (Estimated): December 1, 2025
• Study Completion (Estimated): March 1, 2026

Study Registration Dates

• First Submitted: January 29, 2025
• First Submitted That Met QC Criteria: February 4, 2025
• First Posted (Actual): March 25, 2025

Study Record Updates

• Last Update Posted (Actual): March 25, 2025
• Last Update Submitted That Met QC Criteria: March 7, 2025
• Last Verified: March 1, 2025

More Information

Terms related to this study

• Keywords: dexamethasone; small bowel obstruction; asbo; sbo
• Additional Relevant MeSH Terms: Intestinal Diseases; Digestive System Diseases; Gastrointestinal Diseases; Intestinal Obstruction; Antineoplastic Agents; Physiological Effects of Drugs; Anti-Inflammatory Agents; Antiemetics; Autonomic Agents; Peripheral Nervous System Agents; Gastrointestinal Agents; Glucocorticoids; Hormones; Hormones, Hormone Substitutes, and Hormone Antagonists; Antineoplastic Agents, Hormonal; Dexamethasone
• Other Study ID Numbers: STUDY00022003

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