Differences Between Pulmonary and Extrapulmonary Pediatric Acute Respiratory Distress Syndrome: A Multicenter Analysis

Abstract

Objectives: Extrapulmonary pediatric acute respiratory distress syndrome and pulmonary pediatric acute respiratory distress syndrome are poorly described in the literature. We aimed to describe and compare the epidemiology, risk factors for mortality, and outcomes in extrapulmonary pediatric acute respiratory distress syndrome and pulmonary pediatric acute respiratory distress syndrome.

Design: This is a secondary analysis of a multicenter, retrospective, cohort study. Data on epidemiology, ventilation, therapies, and outcomes were collected and analyzed. Patients were classified into two mutually exclusive groups (extrapulmonary pediatric acute respiratory distress syndrome and pulmonary pediatric acute respiratory distress syndrome) based on etiologies. Primary outcome was PICU mortality. Cox proportional hazard regression was used to identify risk factors for mortality.

Setting: Ten multidisciplinary PICUs in Asia.

Patients: Mechanically ventilated children meeting the Pediatric Acute Lung Injury Consensus Conference criteria for pediatric acute respiratory distress syndrome between 2009 and 2015.

Interventions: None.

Measurements and main results: Forty-one of 307 patients (13.4%) and 266 of 307 patients (86.6%) were classified into extrapulmonary pediatric acute respiratory distress syndrome and pulmonary pediatric acute respiratory distress syndrome groups, respectively. The most common causes for extrapulmonary pediatric acute respiratory distress syndrome and pulmonary pediatric acute respiratory distress syndrome were sepsis (82.9%) and pneumonia (91.7%), respectively. Children with extrapulmonary pediatric acute respiratory distress syndrome were older, had higher admission severity scores, and had a greater proportion of organ dysfunction compared with pulmonary pediatric acute respiratory distress syndrome group. Patients in the extrapulmonary pediatric acute respiratory distress syndrome group had higher mortality (48.8% vs 24.8%; p = 0.002) and reduced ventilator-free days (median 2.0 d [interquartile range 0.0-18.0 d] vs 19.0 d [0.5-24.0 d]; p = 0.001) compared with the pulmonary pediatric acute respiratory distress syndrome group. After adjusting for site, severity of illness, comorbidities, multiple organ dysfunction, and severity of acute respiratory distress syndrome, extrapulmonary pediatric acute respiratory distress syndrome etiology was not associated with mortality (adjusted hazard ratio, 1.56 [95% CI, 0.90-2.71]).

Conclusions: Patients with extrapulmonary pediatric acute respiratory distress syndrome were sicker and had poorer clinical outcomes. However, after adjusting for confounders, it was not an independent risk factor for mortality.