A new clinical severity score for the management of acute small bowel obstruction

Objective

Small bowel obstruction (SBO) is a common hospital admission diagnosis. Identification of patients who will require a surgical resection because of a non-viable small bowel remains a challenge. We aimed to identify risk factors for intestinal resection in patients with SBO and to develop a practical clinical score designed to guide surgical vs. conservative management.

Methods

We performed a prospective cohort study and included all patients admitted for an acute SBO between 2007 and 2016 in our center. Patients were divided in three categories: conservative management, surgical treatment with or without bowel resection. Clinical variables were assessed and compared between groups. Logistic regression models were used to identify the best predictors.

Results

604 patients were included in this study. 438 (73%) had surgery of which 127 (21%) had small bowel resection. 166 (27%) patients were treated conservatively. Among 13 clinical variables, univariate and multivariate logistic regression models identified 8 variables with a strong association with small bowel resection: age ≥70 years, a first episode of SBO, absence of bowel movement for ≥3 days, abdominal guarding, C-reactive protein ≥50, and 3 signs on abdominal CT-scan, namely, small bowel transition point, lack of small bowel contrast enhancement, and the presence of > 500 mL of intra-abdominal fluid. Each variable was given one point. We observed that 71-100% of patients with ≥4 points required a surgical resection. Sensitivity and specificity of this score were 65% and 88%, respectively and the area under the curve (AUC) was 0.84 (95% CI 0.80-0.89). Additionally, we propose two variants of the 8-tem score: a 7-item score excluding the lack of contrast enhancement, specifically designed for patient with contrast allergies or renal insufficiency, and a simplified 4-item score leaving age, guarding, transition zone on CT-scan, and the presence of 500 mL of fluid on CT scan. Both scores showed similar performances compared to the 8-item score with an AUC of 0.83 and 0.80 for the 7- and 4-item scores, respectively.

Conclusion

We developed a practical clinical severity score designed to tailor management of patients presenting with a SBO. A score of ≥ 4 points indicates the need for surgical exploration given the high likelihood of small bowel ischemia in these patients.