Feeding during High-Flow Nasal Cannula for Bronchiolitis: Associations with Time to Discharge
BACKGROUND: High-flow nasal cannula (HFNC) is increasingly used to treat children hospitalized with bronchiolitis; however, the best practices for feeding during HFNC and the impact of feeding on time to discharge and adverse events are unknown. The study objective was to assess whether feeding exposure during HFNC was associated with time to discharge or feeding-related adverse events.
METHODS: This retrospective cohort study included inpatients aged 1-24 months receiving HFNC for bronchiolitis at an academic children’s hospital from January 1, 2015 to March 1, 2017. Feeding exposures during HFNC were categorized as fed or not fed. Among fed children, we further evaluated mixed (oral and tube) or exclusive oral feeding. The primary outcome was time to discharge after HFNC cessation. Secondary outcomes were aspiration, intubation after HFNC, and seven-day readmission.
RESULTS: Of 123 children treated with HFNC, 45 (37 %) were never fed. A total of 78 children (63%) were fed; 50 (41%) were exclusively orally fed and 28 (23 %) had mixed feeding. Median (interquartile range) time to discharge after HFNC was 29.5 hours (23.5-47.9) and 39.8 hours (26.4-61.5) hours in the fed and not fed groups, respectively. In adjusted models, time to discharge was shorter with any feeding (hazard ratio [HR] 2.17; 95% CI: 1.34-3.50) and with exclusive oral feeding (HR 2.13; 95% CI: 1.31-3.45) compared with no feeding. Time to discharge from HFNC initiation was shorter for exclusive oral feeding versus not feeding (propensity weighted HR 1.97 [95% CI: 1.13-3.43]). Adverse events (one intubation, one aspiration pneumonia, one readmission) occurred in both groups.
LIMITATIONS: Assessment of feeding exposure did not account for quantity and duration.
DISCUSSION: Children fed while receiving HFNC for bronchiolitis may have shorter time to discharge than those not fed. Feeding-related adverse events were rare regardless of the feeding method. Controlled prospective studies addressing residual confounding are needed to justify a change in the current practice.
© 2019 Society of Hospital Medicine
Patients were identified using the Virtual PICU Systems database, (VPS LLC, myvps.org, Los Angeles, California) and, by definition, all patients received at least some of their care in the intensive care unit. Patients with comorbid conditions of prematurity (<35 weeks) and those with cardiopulmonary, neuromuscular, and genetic diseases were included. Patients with preexisting dysphagia, defined as ongoing outpatient speech therapy for swallowing concerns, an admission diagnosis of aspiration pneumonia or on home respiratory support, were excluded. Children (n = 7) were excluded if they had more than one period of HFNC during admission. This study was determined to be exempt by the University of Wisconsin School of Medicine and Public Health’s Institutional Review Board.
Data Collection and Study Variables
The following variables were collected from VPS administrative data: patient gender, age, admission and discharge date and time, type and total hours of respiratory support, intensive care admission, and LOS (in hours). Additional demographic, clinical, and feeding exposure variables were abstracted manually from the electronic medical record (Epic, Verona, Wisconsin) using a structured data collection tool and stored in REDCap (Research Electronic Data Capture)15 including prematurity, race/ethnicity, insurance status, primary language, and passive tobacco smoke exposure. Clinical variables included duration of illness (days) at the time of admission, unit of HFNC initiation (emergency department, general care, intensive care, respiratory rate and oxygen saturation at HFNC initiation (<90%, 91%-92%, or >92%), acquisition of blood gas at HFNC admission, duration of time on HFNC (hours) and need for intubation or noninvasive ventilation prior to HFNC. The Pediatric Index of Mortality 2 Risk of Mortality (PIM 2 ROM)16 was used to estimate the severity of illness. The PIM2ROM uses clinical variables (systolic blood pressure, fixed pupils, measure of hypoxia using PaO2/FiO2 ratio, base excess, mechanical ventilation, elective admission, recovery from surgery, cardiac bypass, high-risk diagnosis, low-risk diagnosis) collected at the time of intensive care admission to generate a score that predicts the risk of mortality for an individual patient.17
Feeding exposures were documented in three-hour intervals from HFNC initiation to completion using a structured protocol. At each interval the following feeding information was abstracted from a review of nursing and physician documentation and relevant clinical flowsheets: presence or absence of feeding during the interval, route of feeding (oral, nasogastric [NG] or nasojejunal [NJ]). Feeding exposure was categorized a priori as fed at any point during HFNC (vs not fed at any point). Fed children were further characterized as (1) mixed feeding consisting of oral and tube feeds (NG or NJ) or (2) exclusive oral feeding throughout HFNC support (Appendix 1).
The primary outcome was the number of hours to discharge from HFNC cessation. Secondary outcomes were time to discharge from HFNC initiation, all-cause readmissions within seven days of discharge, and potential feeding-related adverse events. Potential adverse events included: (1) aspiration, defined as initiation of antibiotic AND either chest radiograph official interpreted as evidence for aspiration and/or documented concern for aspiration from the treating physician, or (2) intubation after feeding during HFNC.
