Comparison of Outcomes of Management of Bowel Obstruction Pilot Study

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.

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;

• CT findings consistent with diagnosis of SBO; and
• signs and symptoms consistent with SBO; and
• 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.