The Association between Absence of Abdominal Pain and Mortality in Lower Intestinal Perforation in Patients with Autoimmune Rheumatic Diseases

OBJECTIVE: To determine mortality and predictive factors for lower intestinal perforation (LIP) among patients with autoimmune rheumatic diseases. METHODS: This retrospective, single-center, observational study analyzed mortality rates in 31 autoimmune rheumatic disease patients with LIP who were admitted to our hospital from January 2002 to June 2017. The primary outcome was the mortality rate during hospitalization. RESULTS: The median age at the time of LIP was 61 years, and the survival rate at discharge was 64.5%. Eleven patients died of sepsis during hospitalization. Cox univariable analysis for mortality during hospitalization showed that absence of abdominal pain (hazard ratio (HR) 5.61, 95% confidence interval (CI) 1.38–22.9), higher age (HR 1.06, 95% CI 1.01–1.11), chronic kidney disease (HR 6.89, 95% CI 1.85–25.7), systemic vasculitis (HR 3.95, 95% CI 1.14–13.6), higher blood urea nitrogen (HR 1.02, 95% CI 1.01–1.04), higher serum creatinine (HR 1.41, 95% CI 1.06–1.87), and LIP due to malignancy (HR 14.3, 95% CI 1.95–105.1) significantly increased mortality. CONCLUSION: Abdominal pain was absent in 16% of LIP patients with autoimmune rheumatic diseases, and this absence was a poor prognostic factor in this cohort. Moreover, higher age, chronic kidney disease, systemic vasculitis, and LIP due to malignancy were associated with significantly increased mortality. Physicians should be aware of LIP in autoimmune disease patients with higher age, chronic kidney diseases, or systemic vasculitis even if patients reveal mild abdominal symptoms.