Acute respiratory distress syndrome: nationwide changes in incidence, treatment and mortality over 23 years

Introduction The aim of this study was to assess population-based changes in incidence, treatment, and in short- and long-term survival of patients with acute respiratory distress syndrome (ARDS) over 23 years. Materials and Methods Analysis of all patients in Iceland who fulfilled the consensus criteria for ARDS in 19882010. Demographic variables, Acute Physiology and Chronic Health Evaluation II (APACHE II) scores and ventilation parameters were collected from hospital charts. Results The age-standardised incidence of ARDS during the study period was 7.2 cases per 100,000 person-years and was increased by 0.2 cases per year (P?<?0.001). The most common causes of ARDS were pneumonia (29%) and sepsis (29%). The use of pressure-controlled ventilation became almost dominant from 1993. The peak inspiratory pressure (PIP) has significantly decreased (-0.5?cmH2O/year), but the peak end-expiratory pressure (PEEP) has increased (0.1?cmH2O/year) during the study period. The hospital mortality decreased by 1% per year (P?=?0.03) during the study period, from 50% in 19881992 to 33% in 20062010. A multivariable logistic regression model revealed that higher age and APACHE II score increased the odds of hospital mortality, while a higher calendar year of diagnosis reduced the odds of mortality. This was unchanged when dominant respiratory treatment, PIP and PEEP were added to the model. The 10-year survival of ARDS survivors was 68% compared with 90% survival of a reference population (P?<?0.001). Conclusion The incidence of ARDS has almost doubled, but hospital mortality has decreased during the 23 years of observation. The 10-year survival of ARDS survivors is poor compared with the reference population.