Clinical Impact of Chronic Substance Abuse in a Norwegian ICU-population.

Background The clinical impact of chronic substance abuse of alcohol and drugs-referred to as substance use disorders (SUD)-is often overlooked in the intensive care (ICU) setting. The aims of the present study were to identify patients with SUD-regardless of cause of admission-in a mixed Norwegian ICU-population, and to compare patients with and without SUD with regard to clinical characteristics and mortality. Methods Cross-sectional prospective study of a mixed medical and surgical ICU-population aged >= 18 years in Oslo, Norway. Data were collected consecutively, using a questionnaire including the AUDIT-C test, medical records and toxicology results. Patients classified with SUD were divided into the subgroups alcohol use disorders (AUD) and drug use disorders (DUD). Results Overall, 222 (26%) of the 861 patients included were classified with SUD; 137 (16%) with AUD and 85 (10%) with DUD. 130/222 (59%) of the SUD-patients had substance abuse-related cause of ICU-admission. Compared to non-SUD patients, DUD-patients were younger (median age 42 vs 65 years) and had lower SAPS II scores (41 vs 46), while AUD-patients had higher SOFA scores (8.0 vs 7.3). Overall, age-adjusted logistic regression analysis showed similar hospital mortality for SUD-patients and non-SUD patients, but AUD was associated with increased mortality among medical patients and in patients with sepsis (OR 1.7 (95% CI 1.0-2.8), and OR 2.6 (95% CI 1.1-6.2)). Conclusion One in four ICU-patients had SUD regardless of cause of admission. Alcohol use disorder was associated with increased mortality in medical patients and in patients with sepsis.