Patient characteristics, management and outcomes in a Nordic subset of the "Large observational study to understand the global impact of severe acute respiratory failure" (LUNG SAFE) study

Background: The “Large observational study to understand the global impact of severe acute respiratory failure” (LUNG SAFE) study described the worldwide epidemiology and management of patients with acute hypoxaemic respiratory failure (AHRF). Here, we present the Nordic subset of data from the LUNG SAFE cohort. Methods: We extracted LUNG SAFE data for adults fulfilling criteria for AHRF in intensive care units (ICU) in Denmark, Norway and Sweden, including demographics, co-morbidities, clinical assessment and management characteristics, 90-day survival and length-of-stay (LOS). We analysed ICU LOS with linear regression, and associations between risk factors and mortality were quantified using Cox regression. Results: We included 192 patients, with a median age of 64 years (IQR 55, 72), and a male-to-female ratio of 2:1. The majority had one or more co-morbidities, and clinicians identified pneumonia as the primary cause of respiratory failure in 56% and acute respiratory distress syndrome (ARDS) in 21%. Median ICU LOS and duration of invasive mechanical ventilation (IMV) were 5 and 3 days. Tidal volumes (TV) were frequently larger than that supported by evidence and IMV allowing for spontaneous ventilation was common. Younger age, co-morbidity, surgical admission and ARDS were associated with ICU LOS. Sixty-one patients (32%) were dead at 90 days. Age and a non-surgical cause of admission were associated with death. Conclusions: In this subset of LUNG SAFE, ARDS was often not recognised in patients with AHRF and management frequently deviated from evidence-based practices. ICU LOS was generally short, and mortality was attributable to known risk factors.