Use of Oscillometry for the Evaluation of Pulmonary Function Following Pediatric Acute Respiratory Failure. - PROJECT SUMMARY Acute respiratory failure, typically resulting from conditions such as pneumonia, bronchiolitis, or asthma, is the most common cause of critical illness among U.S. children. The prevalence of acute respiratory failure has risen four-fold in the past two decades to nearly half of children admitted to an ICU. As pediatric ICU mortality has fallen to <3% of all admissions, there is a growing population of children surviving acute respiratory failure. Little is known, however, about the impact of acute lung injury on long-term pulmonary function in children. Multiple small studies have found that 30-80% of children surviving severe hypoxemic respiratory failure have abnormal lung function following hospital discharge when assessed with spirometry, the most common method of pulmonary function testing. This led the 2023 Pediatric Acute Lung Injury Consensus Conference to recommend pulmonary function testing for all children surviving pediatric acute respiratory distress syndrome who are able to perform spirometry. To participate in spirometry, however, children must be at least 6 years of age with the cognitive ability to perform a forced expiratory maneuver. An estimated 70% of children who become critically ill with acute respiratory illnesses are younger than 6 years or have cognitive impairment, and there are no established methods to feasibly assess pulmonary function in these populations. Oscillometry is a passive breathing technique to assess lung function that requires no patient effort, and the introduction of small, portable oscillometry devices has led to an increase in its use in recent years among children with chronic lung diseases. It has not been tested among children with acute pulmonary processes, which have different pathophysiologic mechanisms and anticipated trajectories than chronic lung diseases. The overall objective of this proposal is to assess the ability of oscillometry to identify and characterize recovery of pulmonary function among children surviving acute respiratory failure. We will conduct a longitudinal cohort study of 150 children surviving acute respiratory failure in three quaternary care pediatric ICUs, using oscillometry to measure pulmonary function at hospital discharge and 3 months post-discharge among two cohorts of children who are and are not able to participate in spirometry. We aim to 1) compare change in pulmonary function from discharge to 3 months measured by oscillometry stratified by age group, primary pulmonary pathophysiologic process, and severity of lung disease; 2) assess the correlation between oscillometry and spirometry at each timepoint and compare change from discharge to 3 months among children performing both measures; and 3) evaluate associations between oscillometry and health-related quality of life, activity participation, and respiratory symptoms, and the factors associated with recovery in each domain. We will for the first time evaluate pulmonary function among children surviving acute respiratory failure who are unable to cooperate with spirometry, allowing identification of a new set of patients who may benefit from intervention previously excluded from screening for pulmonary dysfunction due to age or cognitive status.
