794 Admission Risk Factors as Predictors of In-Hospital Colectomy in Acute Severe Ulcerative Colitis

Abstract

INTRODUCTION: Ulcerative colitis is an immune-mediated disorder characterized by chronic inflammation of the gastrointestinal tract. In the setting of hospitalization and presentation with acute severe ulcerative colitis (ASUC), the risk of colectomy approaches 30-40%. In an effort to improve medical therapies, identifying early predictors for colectomy has the potential to reduce the risk of surgery in ASUC. METHODS: We designed a retrospective study including all patients >18 years of age with an admission for ASUC at the University of Chicago Medical Center between the 1/1/2013 and 4/1/2018. Cases of were identified using the ICD-9 code 556.X and ICD-10 code K51.X and separately reviewed based on clinical, radiographic, histologic and endoscopic information. Additional electronic variables of interest were extracted from the electronic data warehouse. Data were analyzed using Wilcoxon rank-sum test for continuous variables and Fischer's exact test for categorical variables. Multivariate logistic regression was performed to identify independent factors predictive of inpatient colectomy. RESULTS: We identified 260 unique patient encounters admitted for ASUC, of which 59 (22.7%) underwent inpatient colectomy. Risk factors for inpatient colectomy are demonstrated in Table 1. Among individuals requiring colectomy in univariate analysis, a prior history of DVT/PE, prior admission for intravenous steroids or recent hospitalization were predictive of colectomy. Presenting endoscopic Mayo score, number of prior biologic therapy exposures, and laboratory values suggestive of active inflammation were predictive of colectomy. In a final multivariate model, risk factors of inpatient colectomy included: number of prior biologic exposure (OR: 2.27, 95% CI 1.5-3.4), transfer from an outside hospital (OR: 5.03, 95% CI 1.97-12.86) and platelet count on admission (OR: 1.01, 95% CI 1-1.01). CONCLUSION: Early identification of potentially medically refractory disease has the potential to reduce need for colectomy in ASUC. Number of prior exposures to biologic therapies, transfer from an outside institution and platelet count are independently associated with risk of colectomy. Additional studies are required to improve the medical therapies offered to high-risk patients in order to reduce colectomy risk.