40 - Severe Illness and Progression of Respiratory Severity among Young Infants with Bronchiolitis

Poster Number: 40
Publication Number: 40.111

Son H. McLaren, Columbia University Vagelos College of Physicians and Surgeons, New York, NY, United States; Julia Thompson, Columbia University, Brooklyn, NY, United States; Cheng-Shiun Leu, Columbia University, New York, NY, United States; Yaylin Toribio, Columbia University Irving Medical Center, brooklyn, NY, United States; Gittel L. Shaingarten, Columbia University Vagelos College of Physicians and Surgeons, Airmont, NY, United States; Daniel Green, Columbia University Vagelos College of Physicians and Surgeons, New York, NY, United States; Carlos A. Camargo, MGH/Harvard, Boston, MA, United States; Peter Dayan, Columbia University, Hastings on Hudson, NY, United States

Background: Age ≤90 days is a risk factor for severe bronchiolitis. There are sparse data describing risk factors for severe illness or progression in respiratory severity among these infants.

Objective: The primary aim was to identify factors associated with severe bronchiolitis in infants ≤90 days old presenting to the emergency department (ED). The secondary aim was to describe the prevalence of progression in respiratory severity.

Design/Methods: In this ongoing prospective cohort study, we enrolled infants ≤90 days old with bronchiolitis. ED clinicians completed standardized patient histories and exams on ED arrival and 2-4 hours later. All patients had nasopharyngeal viral testing (4-plex or multiplex), medical record review, and 2-week phone follow up. Severe bronchiolitis was defined as: intensive care unit (ICU) admission at any point, mechanical ventilation (MV), use of bilevel positive airway pressure (BIPAP), use of continuous positive airway pressure (CPAP) or high-flow nasal cannula ≥2 days, or apnea requiring intervention. Respiratory progression was defined as new use or escalation of respiratory support ≥4 hours after initial ED exam. Bivariate analyses were performed using chi-squared test and Kruskal-Wallis tests, as appropriate.

Results: Of 61 enrolled, median age was 49 days [IQR 37-70] (Table 1). Twenty-one infants (34%) had severe bronchiolitis, of whom 15 (71%) were admitted to the ICU at some point during hospitalization; in-hospital apnea (n=0) or use of MV (n=1) were rare (Figure). Infants with severe bronchiolitis had the following statistically significant findings (p< 0.05) in the ED compared to those with non-severe bronchiolitis: decreased urine output at home, higher triage respiratory rate, lower oxygen saturation, ill-appearance, head bobbing/ nasal flaring/ grunting, retractions, respiratory distress, worsening respiratory status on repeat exam, and RSV positivity (Table 2). Age (within 0-90 days) was not associated with severe bronchiolitis. Hospitalized infants without severe bronchiolitis (n=16) had median hospital length of stay of 0.9 days [IQR 0.5, 1.2]. Respiratory progression occurred in 7 (11%) infants (to CPAP in 1, BIPAP in 5, and MV in 1). Among infants discharged from the index ED visit (n=24, 39%), return visits were uncommon (1/24, 4%).

Conclusion(s): One-third of infants ≤90 days presenting to ED had severe bronchiolitis. One in ten infants had respiratory progression four hours after initial ED exam. Additional studies are needed to determine factors (other than young age) that are independently associated with bronchiolitis severity and respiratory progression.


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