LAUSR

Supplemental Digital Content is available in the text. Background Organ failure is both a frequent and dangerous condition among adult patients on arrival to an emergency department (ED). The risk of an unfavourable outcome could depend on the underlying aetiology. Knowledge of the relation between aetiology and prognosis could improve the risk stratification at arrival. Objectives To describe the relation between organ failure, aetiology and prognosis through 7-day all-cause mortality. Methods An observational three-year cohort study at the ED at Odense University Hospital, Denmark, including all acute adult patients. First-measured vital signs and laboratory values were included to evaluate the presence of the following organ failures: respiratory, coagulation, hepatic, circulatory, cerebral or renal. The primary outcome was 7-day all-cause mortality. Aetiological disease categories were based on primary discharge diagnoses. We described the association between 7-day mortality, aetiology category, site of organ failures and number of patients at risk. Results Of 40 423 patients with a first-time visit at the ED, 5883(14.6%) had an organ failure on arrival. The median age was 69 (IQR 54–80), and 50% were men. The most frequent aetiology was infection (1495, 25.4%). Seven-day all-cause mortality ranged between aetiologies from 0.0% (95% confidence interval [CI], 0.0–14.2) allergy) to 45.6% (95% CI, 41.3–50.0) (cardiac). Combining aetiology and site of organ failure, 7-day all-cause mortality was the highest in the cardiac category, from 14.8% (95% CI, 4.2–3.7) with hepatic failure to 79.2% (95% CI, 73.6–84.1) with cerebral failure. The combination of infection and respiratory failure characterised most patients (n = 949). Conclusion Infection was the most prevalent aetiology, and 7-day all-cause mortality was highly associated with the site of organ failure and aetiology.