Bowel Ultrasound Scan Predicts Corticosteroid Failure in Children With Acute Severe Colitis

Acute severe colitis (ASC) is a potentially life-threatening event. Optimal timing for second-line treatment in children is mainly based on the clinical score Pediatric Ulcerative Colitis Activity Index. The aim of our study was to evaluate the potential role of bowel ultrasound scan (BUS) in predicting the need of second-line therapy in ASC.

Patients younger than 18 years admitted to a single tertiary referral center with ASC were included. We retrospectively reviewed medical records collecting clinical and BUS data. Colonic wall thickness (CWT), loss of colonic wall stratification (CWS), presence of hyperechoic lymph nodes, and colonic wall flow evaluated at power Doppler were assessed at BUS performed within the third day of hospitalization.

Sixty-nine ASC episodes from 52 different patients were identified. CWT showed significantly higher values in patients who required second-line therapy (5.14 vs 3.69 mm; P < 0.001). Loss of CWS was present in 17 of 36 (47.2%) of steroid-resistant ASC versus only 1 of 33 of those responding to intravenous corticosteroids (P < 0.001, sensitivity = 47%, specificity = 97%). Using a receiver operating characteristic curve, a cut-off of 3.4 mm was individuated for CWT to predict steroid treatment failure, showing a sensitivity of 92% and a specificity of 52%. The multivariable binary logistic regression analysis identified thickened colonic wall (CWT >3.4 mm) and loss of CWS as independent predictors of steroid resistance.

BUS is a noninvasive, easily accessible, and cost-effective resource that may identify at an early stage first-line therapy failure in pediatric ASC.