Mortality risk rises between ages 11 and 65 years in acute respiratory distress syndrome

Key takeaways:

• The association between age and 90-day mortality in acute respiratory distress syndrome was nonlinear.
• The risk for death stayed elevated after a patient turned 65 years old but rose in a slower fashion.

Patients with acute respiratory distress syndrome faced an accelerated and heightened risk for 90-day mortality between ages 11 and 65, according to results published in American Journal of Respiratory and Critical Care Medicine.

“We identified a nonlinear relationship between age and mortality in pediatric and adult ARDS, with mortality risk increasing at an accelerating rate between 11 and 65 years of age, after which mortality risk increased more slowly,” Bhavesh M. Patel, MD, pediatric critical care medicine fellow in the pediatric ICU at Children’s Hospital of Philadelphia, and colleagues wrote.

In a retrospective cohort study, Patel and colleagues analyzed 1,236 pediatric patients (median age, 4 years) with ARDS from two observational cohorts, 1,079 adults (median age, 61 years) with ARDS from one observational cohort and 5,547 adults (median age, 52 years) with ARDS from several randomized controlled trials (RCTs) to find out how age is linked to 90-day mortality in this disease.

Logistic regression using fractional polynomials was adjusted for five variables: sex, PaO2/FiO2, immunosuppressed status, study year and observational vs. RCT.

Within the total cohort, 44% of patients had severe ARDS, 43% had moderate ARDS and 13% had mild ARDS, all according to Berlin criteria.

The adult observational cohort had the highest proportion of patients who died by day 90 at 67%. In the adult RCTs set of patients, 33% of the adults died by day 90, whereas this percentage was smaller in the pediatric cohorts at 19%.

When divided into 10 age groups, aspiration as an etiology of ARDS was not as prevalent in patients aged younger than 1 year compared with the older age groups (6% vs. 10% to 18%).

After the age of 40, trauma as an etiology of ARDS was observed in fewer patients vs. between ages 1 and 40 (2% to 5% vs. 6% to 12%), according to researchers.

The prevalence of patients with pneumonia, nonpulmonary sepsis and “other” etiologies of ARDS was relatively similar between the 10 age groups.

Between the ages of 11 and 65 years, researchers observed an accelerated and heightened risk for 90-day mortality. The risk for death continued to be elevated after a patient turned 65 years old but rose in a slower fashion.

“Differences in ARDS outcomes on the basis of age deserve further research to determine whether age is a source of heterogeneity of treatment effect,” Patel and colleagues wrote. “Although the basis for this difference is potentially pathobiology specific to lung development and ARDS propagation, the nonlinear association of age and mortality may also reflect the accumulation of comorbidities and multiplicative risk for nonpulmonary organ failures as one ages.”