Prone Positioning in Infants With Acute Bronchiolitis: The PROPOSITIS Randomized Clinical Trial

Clinical Snapshot

Key Findings

• P Value: P = .09 (non-significant at conventional α = 0.05 threshold)

• Effect Size: Adjusted odds ratio 0.66 (favours prone positioning); absolute risk reduction 5.8 percentage points

• Primary Outcome: Escalation of care to noninvasive or invasive ventilation within 72 hours: 15.0% (33/220) in prone group vs 20.8% (47/226) in supine group — no statistically significant difference

• Nnt Or Sensitivity: NNT approximately 17 (based on observed ARR of 5.8%), but this is derived from a non-significant result and should be interpreted with caution; serious adverse events: 1.1% prone vs 0.8% supine (NNH not calculable from available data)

• Confidence Interval: 95% CI for adjusted OR: 0.40 to 1.07

Clinical Application

Prone positioning is a low-cost, non-pharmacological intervention requiring no additional equipment but demands trained nursing staff for safe implementation in infants, particularly regarding airway monitoring, IV line management, and nasogastric tube positioning. The ≥24-hour duration over 48 hours requires sustained nursing vigilance and parental communication. Bronchiolitis is the leading cause of infant hospitalisation in Australia, with RSV responsible for the majority of cases. HFNC is standard of care in Australian paediatric ICUs and high-dependency units and is supported by PREDICT network guidelines. Prone positioning is not currently a standard recommendation in Australian bronchiolitis management guidelines (PREDICT/RCPA). This trial does not provide sufficient evidence to change current practice but supports the feasibility and safety of prone positioning as a research intervention. HFNC devices used in Australian PICUs (e.g., Fisher & Paykel Optiflow Junior) are comparable to those used in French centres. No PBS or TGA implications — this is a positional intervention. Future adequately powered trials, potentially within the PREDICT network, would be warranted given the promising directional signal. Infants aged ≤6 months with moderate to severe acute viral bronchiolitis requiring HFNC support admitted to paediatric intensive or high-dependency care units

Abstract

IMPORTANCE: Prone positioning has been shown to improve respiratory mechanics and oxygenation, but its clinical benefit in infants with acute viral bronchiolitis receiving high-flow nasal cannula (HFNC) support remains unknown. OBJECTIVE: To investigate whether prone positioning in infants with moderate to severe acute bronchiolitis and HFNC support reduces escalation to noninvasive or invasive ventilation. DESIGN, SETTING, AND PARTICIPANTS: Multicenter, randomized, open-label trial conducted in 15 pediatric intermediate or intensive care units in France. Infants aged 6 months or younger admitted for 24 hours or less with a diagnosis of acute bronchiolitis with moderate to severe respiratory distress requiring HFNC support were enrolled between January 2021 and November 2023 and followed up until hospital discharge (last patient discharged on December 11, 2023). INTERVENTIONS: Participants were randomly assigned to the prone position (n = 221) or supine position (n = 230). Infants in the prone position group received prone positioning for 24 hours or longer during the first 48 hours. All participants received standardized HFNC support at 2 L/kg/min. MAIN OUTCOMES AND MEASURES: The primary outcome was the need for escalation of care to noninvasive or invasive ventilation within the first 72 hours, according to prespecified criteria. Secondary outcomes included treatment failure, determined by an independent clinical adjudication committee; tolerance of prone positioning; length of hospital stay; duration of respiratory support; infant comfort; and adverse events. RESULTS: Among 451 infants randomized, 446 were included in the primary analysis (median age, 41 [IQR, 19-72] days; 54% male). Escalation of care occurred in 80 infants (17.9%), with no significant difference between the prone position (33/220 [15.0%]) and supine position (47/226 [20.8%]) groups (adjusted odds ratio, 0.66 [95% CI, 0.40-1.07]; P = .09). Secondary outcomes did not differ significantly between the 2 groups. In the safety analysis, serious adverse events occurred in 2 of 180 infants (1.1%) in the prone position group and 2 of 264 (0.8%) in the supine position group. CONCLUSIONS AND RELEVANCE: Prone positioning in infants with moderate to severe bronchiolitis receiving HFNC support did not significantly reduce escalation of care. However, the wide 95% confidence interval around the observed odds ratio suggests that this study was not definitive and further research is warranted. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT03976895.

References

1. 1.Baudin, F., Pouyau, R., Subtil, F., Jarrasse, C., Tochon, M., Afanetti, M., Milési, C., Piloquet, J.-E., Mortamet, G., Nallet Amate, M., Launay, V., Cour Andlauer, F., Roche, S., Levy, M., Rambaud, J., Portefaix, A., & Javouhey, E. (2026). Prone positioning in infants with acute bronchiolitis: The PROPOSITIS randomized clinical trial. JAMA. https://doi.org/10.1001/jama.2025.24082