Feeding during High-Flow Nasal Cannula for Bronchiolitis: Associations with Time to Discharge

This observational study found that being fed during HFNC was associated with shorter time to discharge after HFNC support was completed. Exclusive oral feeding was associated with the shortest time to discharge, and these results were consistent across a variety of analytical approaches. Adverse events were rare and occurred in both fed and unfed children.

These findings advance research on relationships between nutrition and bronchiolitis outcomes. Studies of general care patients with bronchiolitis without HFNC have observed associations between poor nutrition and prolonged LOS.^19,20 Two previous studies of patients receiving HFNC therapy for bronchiolitis concluded that frequent interruption¹¹ and later initiation of enteral nutrition¹⁰ during ICU stay was associated with longer time to discharge.¹¹ To our knowledge, this is the first study of patients with bronchiolitis treated with HFNC in both general care and ICU settings that compared outcomes according to whether children were fed during HFNC therapy. Our results extend previous work demonstrating that delays in feeding may be associated with longer LOS.

Decisions to feed children with respiratory distress due to bronchiolitis are complex and often subjective. Readiness to feed may be based upon the assessment of a child’s work of breathing, trajectory of illness, institutional culture, and individual physician, nurse, respiratory therapist or speech-language pathologist comfort. In the absence of established feeding best practices,²¹ some institutions have developed guidelines based on local expert opinion; however, often these recommendations remain largely subjective and nonspecific.^5,10,22-24 Although decisions to feed may be influenced by concern about a child’s clinical stability and feeding risk, we found few objective clinical differences between children fed (orally or by enteral tube) or not fed. Moreover, our results were consistent even when we used a propensity-weighted model to account for measured factors that may have been associated with the decision to initiate feeding. This suggests the decision to feed could be more arbitrary than we assume and is important to investigate in future research.

Additionally, although a few early studies have aimed to standardize the process of weaning HFNC support in bronchiolitis,^25,26 this process is also largely subjective.^10,22,23 As such, the weaning process may be influenced by perceptions of the child’s overall health. Orally fed children may be viewed as more comfortable or well and thus, more readily weaned, which ultimately influences the length of HFNC therapy. Our study design attempted to account for this potential bias by measuring time to discharge following HFNC therapy, rather than measuring total LOS. Meeting adequate calorie, weight, or hydration goals prior to discharge may take longer if feeds have been withheld. We speculate that prolonged periods of NPO might also risk transient oral aversion or feeding discoordination that could influence LOS. Previous research involving broad intensive care unit populations has established the importance of providing nutrition to critically ill children as soon as possible as a means of improving outcomes.^27-29 Patients receiving HFNC support for bronchiolitis could plausibly experience similar benefits.

This single-center study with a relatively small sample size has important limitations to consider. The observational design limits our ability to draw conclusions about causal relationships between feeding, time to discharge, and adverse events. In particular, feeding exposure did not account for nuances in feeding timing, feeding density, and other elements of feeding exposure. Additionally, adverse events are rare, and this study is inadequately powered to detect differences between exposure groups. Although we included children cared for in general and intensive care units, our findings may not be generalizable to other hospitals with different placement criteria. Despite the creation of adjusted and propensity-weighted models, our results are still subject to possible residual indication bias. We cannot control for all possible confounders, particularly unmeasured factors which might simultaneously motivate decisions whether, when, and how to feed children receiving HFNC therapy and influence time to discharge after HFNC is finished. Although this study observed associations between feeding during HFNC and both our primary (time to discharge after HFNC was complete) and secondary (time to discharge after HFNC was initiated) outcomes, future work should evaluate how feeding strategies might impact total LOS, particularly as management becomes more standardized.

Prospective studies of feeding exposures during HFNC therapy in bronchiolitis, as well as rigorous interventional study designs, are needed to confirm shorter lengths of stay and safety with larger and more diverse samples. Future research should evaluate methods to safely and effectively feed children with severe bronchiolitis, which would inform standardized evidence-based approaches. Given the scale on which children with bronchiolitis are admitted each year, the implications of such work could be substantial.