Optimal Timing of First Abdominal Radiography after Gastrografin Administration for Small Bowel Obstruction.

BACKGROUND: Water-soluble contrast agent (WSCA) administration is commonly used to evaluate adhesive small bowel obstruction (SBO) either via a challenge or follow-through study. This analysis aimed to determine optimal timing to first abdominal radiograph after WSCA administration. MATERIALS AND METHODS: A post hoc review of the Eastern Association for the Surgery of Trauma SBO database was used to compare data from two institutions using different methodologies, either the small bowel follow through method or the challenge method, from March 2015-January 2018. The primary outcome was timing of contrast into the colon. Outcomes were also analyzed. A multivariate regression analysis controlled for age, sex, body mass index, previous SBO admissions, and abdominal surgeries. RESULTS: A total of 236 patients met inclusion and exclusion criteria (A, 119; B, 117). There were minor demographic differences between cohorts and no significant differences between institutions regarding the confirmed presence of WSCA in the colon, rates of operative intervention, length of operation, hospital length of stay, or 30-d readmission rates.Institution A, where the challenge method was practiced, had 95 (80%) patients with contrast to colon overall; four of 95 (4%) patients had confirmed contrast to colon at or before 7 h, and 89 of 95 (94%) patients had confirmed contrast to colon between 7.1 and 10 h. Institution B, where the small bowel follow through method was practiced, had 94 (80%) patients with contrast to colon overall; 73 of 94 (78%) patients had confirmed contrast to colon at or before 7 h, and 15 of 94 (16%) patients had confirmed contrast to colon between 7.1 and 10 h. CONCLUSIONS: Either method is effective for evaluation of SBO. Adding a radiograph at 4 h is feasible, could promote earlier disposition, be conducted as part of an emergency department protocol, and possibly allow for the selection of patients who are candidates for outpatient treatment.