Children with and without pre-existing asthma experience health resource use and symptoms in post-discharge outcomes following influenza critical illness, according to study findings published in The Journal of Allergy and Clinical Immunology: In Practice.
Researchers conducted a multicenter, prospective, observational study that included 179 children aged 8 months to 17 years who were admitted to a pediatric intensive care or step-down unit for influenza or another respiratory pathogen between December 2019 and April 2020. Results were stratified by pre-existing asthma. Only patients with respiratory infection due to influenza confirmed with clinical and research testing were evaluated. Patients who presented more than 10 days following illness onset, had pre-existing respiratory failure, were pregnant, or did not have a respiratory specimen collected within 72 hours of hospitalization were excluded.
Primary exposure was defined as parental report of asthma or reactive airways disease- health care provider-diagnosis, or electronic health record documentation of asthma or reactive airways disease. The primary endpoint was respiratory-specific health-resource use post-discharge.
The researchers excluded 14 patients labeled as loss to follow-up who were subsequently not included in study findings, and they excluded 26 patients labeled as lost to follow-up who were included in study findings prior to 90-day follow-up.
Of the 165 children with influenza, 56 had pre-existing asthma (median age, 6.3 years; interquartile range [IQR], 3.0-10.6) of whom 41.1% were fully vaccinated against influenza. The remaining 66.1% (median age, 5.1 years; IQR, 2.4-9.0) did not have pre-existing asthma, and 39.4% were fully vaccinated against influenza.
Among patients with pre-existing asthma, 28.5% had Hispanic ethnicity and 28.5% had Black ethnicity. Among patients without pre-existing asthma, 14.6% had Hispanic ethnicity and 9.1% had Black ethnicity.
Intubation occurred in 26.7% of patients with asthma and in 31.1% of patients without pre-existing asthma.
Patients with asthma received pharmacologic asthma treatments in hospital (76.7%) compared with patients without pre-existing asthma who received pharmacologic asthma treatments in hospital (28.4%). They noted 3 patients died in hospital (1 with pre-existing asthma).
Among the 136 patients with 90-day follow-up, 4.3% of patients with pre-existing asthma had an emergency department or urgent care visit vs 6.6% of patients without pre-existing asthma. The researchers noted 8.6% of patients with pre-existing asthma were readmitted to the hospital vs 3.3% without pre-existing asthma.
Asthma symptoms were experienced post-discharge in 78.2% of patients with pre-existing asthma compared with 3.3% of patients without pre-existing asthma. The researchers noted 52% of patients with pre-existing asthma had a respiratory specialist visit compared with 20% without pre-existing asthma. A total of 10 patients without pre-existing asthma reported a new diagnosis of asthma.
Limitations of the study include the observational design, underpowered sample size, and possible misclassification of pre-existing asthma.
The study authors conclude, “[W]e identified respiratory health resource use and symptoms as important post-discharge outcomes for children with critical influenza in those with and without pre-existing asthma.” They wrote, “The post-discharge respiratory sequelae underscore the importance of pulmonary follow-up in children with pre-existing asthma — as well as those without pre-existing asthma — given that one in ten children in our cohort were newly diagnosed with asthma after discharge.”
Maddux AB, Grunwell JR, Newhams MM, et al. Association of asthma with treatments and outcomes in children with critical influenza. J Allergy Clin Immunol Pract. Published online November 12, 2022. doi:10.1016/j.jaip.2022.10.045