Association of childhood asthma with postoperative pneumonia

Bronchial asthma is the most pervasive chronic disease among children in the United States. Pneumonia, an acute pulmonary disorder, is also quite common, affecting individuals with chronic respiratory conditions. Despite the widespread recognition of bronchial asthma as a common, potentially life-threatening disease, its impact on the risk of serious pulmonary infections such as postoperative pneumonia is under-appreciated. We examined the association of bronchial asthma with postoperative pneumonia in a matched cohort of children who underwent inpatient surgical procedures.

We assembled a propensity score-matched retrospective cohort of children (<18 years of age) who underwent inpatient surgery between 2012 and 2015, in hospitals participating in the National Surgical Quality Improvement Program. Our primary outcome was the incidence of postoperative pneumonia. We used Fine-Gray sub-distributional hazard regression to estimate the hazard ratio of postoperative pneumonia, while accounting for the competing risk by mortality.

The unmatched cohort comprised of 93 061 children who met the eligibility criteria, of whom 7.8% (n = 7237) had a preoperative diagnosis of bronchial asthma. The cumulative incidence of pneumonia was 4.5% (95% confidence interval: 2.8%, 8.3%) among children without bronchial asthma and 8.5% (95% confidence interval: 5.8%, 11.8%) among those with bronchial asthma. Throughout the 30-day postoperative period, the risk of pneumonia almost doubled among children with bronchial asthma compared to their nonasthmatic peers (hazard ratio: 1.71; 95% confidence interval: 1.24, 2.35; P = .001).

Children with bronchial asthma had a significantly greater risk of postoperative pneumonia. Further studies are needed to understand the mechanisms underlying these associations and determine if perioperative interventions can mitigate this association.