Residual airways: the lingering legacy of severe respiratory syncytial virus bronchiolitis

Extract

Bronchiolitis has long been viewed as a self-limiting illness of infancy, but recent data challenge this narrative. The study from Vrijlandt et al. [1] in ERJ Open Research contributes to mounting evidence that severe respiratory syncytial virus (RSV) infection requiring mechanical ventilation is associated with prolonged respiratory morbidity. This compels us to reconsider the adequacy of current post-discharge protocols, especially regarding long-term respiratory health.

Shareable abstract

A significant proportion of infants ventilated for respiratory syncytial virus developed subclinical airway dysfunction; structured follow-up and early pulmonary rehabilitation may redefine recovery in paediatric bronchiolitis care https://bit.ly/41xOVM8

To the Editor:

Bronchiolitis has long been viewed as a self-limiting illness of infancy, but recent data challenge this narrative. The study from Vrijlandt et al. [1] in ERJ Open Research contributes to mounting evidence that severe respiratory syncytial virus (RSV) infection requiring mechanical ventilation is associated with prolonged respiratory morbidity. This compels us to reconsider the adequacy of current post-discharge protocols, especially regarding long-term respiratory health.

The transition from the paediatric intensive care unit (PICU) to home care often neglects the latent pulmonary sequelae that emerge long after discharge. De Sonnaville et al. [2] documented a remarkably high incidence of lingering pulmonary abnormalities at a median follow-up of 2.6 years, even in children who did not require respiratory support at the time of PICU admission. These findings highlight the extent to which long-term pulmonary dysfunction can be clinically silent until it leads to functional impairment. Marlow et al. [3] further reinforced this by identifying overlapping risk factors – such as systemic inflammation and critical illness-related myopathy – that predispose to both neurodevelopmental and pulmonary deficits in PICU survivors. Compounding this, Hennus et al. [4] demonstrated that even short-term mechanical ventilation can cause enduring changes in lung structure, potentially laying the groundwork for chronic obstructive or restrictive patterns in later life.

Given these risks, early rehabilitation interventions require greater attention. Huang et al. [5] have shown that structured paediatric rehabilitation programmes aimed at both musculoskeletal and respiratory recovery substantially enhance outcomes following critical illness. Xingyu et al. [6] similarly observed that initiating pulmonary rehabilitation during or soon after ICU stay resulted in improved exercise capacity, pulmonary function and quality of life in paediatric patients. While pulmonary rehabilitation has been widely studied in adult ICU populations, including COVID-19 survivors [7], structured paediatric protocols remain underdeveloped. A few programmes exploring respiratory-focused rehabilitation and longitudinal lung function follow-up in infants post-bronchiolitis may offer a foundation, but broader consensus and infrastructure are required. To clarify, we recommend:

• A single paediatric pulmonology evaluation within 6 months post-PICU discharge to assess for ongoing symptoms and rule out missed diagnoses.

• Utilisation of tools like the Expiratory Variability Index to stratify follow-up intensity in infants.

• Development of context-specific follow-up models, ranging from community-based programmes to tertiary centre visits, adaptable to different health systems.

The challenge, however, lies in early identification of children at risk. Novel, non-invasive metrics such as the Expiratory Variability Index have shown promise in correlating with both current disease severity and future asthma risk in infants with recurrent symptoms, as reported by Seppä and co-workers [8, 9]. Integrating such tools into post-discharge follow-up could allow for stratified care and timely intervention.

The editorial by Killien [10] serves to highlight that adverse pulmonary outcomes after bronchiolitis are not merely academic – they affect real children with real morbidity. The current study by Vrijlandt et al. [1] must serve as a clarion call to critically reassess our entire continuum of care, moving beyond survival to include restoration of respiratory health.

Looking ahead, we believe a dual approach is essential: first, to ensure equitable rollout and uptake of RSV preventive strategies including vaccination; second, to investigate useful, scalable biomarkers and functional measures that can guide individualised follow-up. Bridging acute care with long-term respiratory recovery must become a global paediatric priority.