Key takeaways:
- High-flow nasal cannula (HFNC) therapy during bronchiolitis hospitalization was associated with a greater rate of subsequent asthma diagnosis in early childhood.
- Children treated with HFNC developed asthma sooner than those who did not receive the therapy.
- The HFNC group showed greater illness severity, including higher ED acuity, more bronchiolitis encounters, and increased 30-day readmissions.
- Human rhinovirus/enterovirus infection was more common among HFNC-treated children later diagnosed with asthma, while RSV was more frequent in those without asthma.
- Investigators suggest the increased asthma risk likely reflects underlying disease severity rather than a causal effect of HFNC, underscoring the need for prospective studies.
Researchers have found a link between high-flow nasal cannula (HFNC) therapy during bronchiolitis hospitalization and increased subsequent asthma diagnosis risk, publishing their findings in Pediatrics Open Science.1
An increase in HFNC therapy to manage bronchiolitis has been reported. However, bronchiolitis has been associated with subsequent childhood asthma risk, and while HFNC leads to short-term relief, data about long-term respiratory outcomes remains limited.
“Distinguishing severity-associated risk from intervention-associated risk is complex,” wrote investigators.
Identification of bronchiolitis and asthma outcomes
The retrospective cohort study was conducted to evaluate the link between HFNC use during bronchiolitis hospitalization and subsequent asthma diagnosis in early childhood. Participants included children aged under 2 years hospitalized for bronchiolitis from January 1, 2015, to March 4, 2024.
Bronchiolitis diagnoses were based on International Classification of Diseases, Tenth Edition (ICD-10) codes. ICD-10 codes were also used to compare asthma diagnoses between children exposed to HFNC and those not exposed during follow-up, collected during inpatient, emergency, and outpatient visits.
Exclusion criteria included pre-existing chronic lung disease, congenital heart disease, and complex medical conditions linked to respiratory outcomes. Demographic and emergency department (ED) visit data was collected, with time zero defined as the first hospitalization for bronchiolitis.
Assessing severity and patient characteristics
The emergency severity index was used to measure ED acuity, which determined the immediate severity of illness. ED acuity coding ranged from 1, meaning most urgent, to 5, meaning least urgent.
Asthma incidence following HFNC therapy vs no therapy was reported as the primary outcome. As the secondary outcome, investigators reported asthma incidence based on the cumulative duration and frequency of HFNC use among participants.
There were 4736 children hospitalized with bronchiolitis included in the final analysis, 43% of whom were given HFNC. Of these patients, 61% were male and 55% publicly insured, with a median age of 7 months reported.
Higher illness severity and asthma incidence following HFNC exposure
Increased ED acuity, bronchiolitis encounters, and 30-day hospitalization return rates were reported in the HFNC group, at 57%, 3 encounters, and 43.1%, respectively. In comparison, these figures were 43%, 2 encounters, and 32.5% among the non-HFNC group. Overall, 29% of participants were diagnosed with asthma.
The HFNC group had an increased rate of asthma diagnoses, at 37% vs 22% in the non-HFNC group. These patients also had a reduced median time to asthma diagnosis of 223 vs 299 days, respectively.
HFNC-treated children with asthma more commonly presented with human rhinovirus/enterovirus vs those without asthma, at 57.4% vs 37.7%, respectively. In comparison, a rate of 57.2% was reported for respiratory syncytial virus among patients not diagnosed with asthma, vs 33% among those with asthma.
Risk factors linked to asthma development
This data highlighted an increased risk of subsequent asthma diagnosis following HFNC use, with a hazard ratio (HR) of 1.40. Additional variables linked to increased asthma risk included older age, public insurance, more hospital encounters, and Florida hospitalization site, with HRs of 1.05, 1.17, 1.23, and 1.36, respectively.
Overall, these results indicated increased odds of asthma diagnosis in early childhood among children receiving HFNC during bronchiolitis hospitalization. According to investigators, the link likely reflects the severity of disease requiring HFNC use rather than direct influence from the intervention.
“Future prospective studies that incorporate standardized severity metrics, detailed respiratory support parameters, and objective longitudinal respiratory outcomes are needed to clarify the mechanisms linking early bronchiolitis phenotypes, respiratory support needs, and long-term asthma risk,” wrote investigators.
Clinical strategies to support children with asthma
Steps can be taken to support children with asthma, as discussed by Tyra Bryant-Stephens, MD, chief health equity officer at the Center for Health Equity at Children’s Hospital of Philadelphia, in an interview with Contemporary Pediatrics.2 According to Bryant-Stephens, during asthma checkups, parents and doctors should discuss the following topics:
- The child’s asthma triggers
- What the child needs from the doctor
- Talking to the child’s school
- Making sure patients are taking control medication
- Ensuring refills for the medicine are available
Bryant-Stephens also highlighted the importance of managing known triggers to reduce flares. Additionally, practical strategies may reduce the risk of adverse events.
“I often tell children to pace before and after exercise,” said Bryant-Stephens. “We talk about a slow warm-up and slow cool-down. An abrupt start or finish can trigger symptoms.”
