Pediatrics · Medical Literature
Prone Positioning in Infants With Acute Bronchiolitis
Abstract
This randomized trial assesses the effect of prone positioning in infants with moderate to severe bronchiolitis receiving high-flow nasal cannula (HFNC) support on the need for escalation of care to noninvasive or invasive ventilation within 72 hours.
Clinical relevance
Acute viral bronchiolitis is the leading cause of hospitalization in infants and one of the costliest diagnoses in pediatric acute care, yet evidence-based interventions remain scarce. HFNC failure rates of 35–50% leave a critical therapeutic gap for infants with moderate-to-severe disease. The PROPOSITIS trial is the first large randomized trial to rigorously evaluate prone positioning—a low-cost, readily available maneuver with established physiologic plausibility—as an adjunct strategy to reduce ventilatory escalation in this vulnerable population.
Key findings
1. Primary outcome — escalation of care to noninvasive or invasive ventilation within 72 hours occurred in 80/446 infants (17.9%) overall; rates were 15.0% (33/220) in the prone group vs. 20.8% (47/226) in the supine group (adjusted OR 0.66 [95% CI 0.40–1.07]; P = .09) — a numerically meaningful but statistically non-significant difference. 2. Trial design — multicenter, open-label RCT conducted across 15 pediatric intermediate or intensive care units in France; 451 infants ≤6 months randomized (prone n=221, supine n=230) between January 2021 and November 2023; 446 included in the primary analysis (median age 41 [IQR 19–72] days; 54% male). 3. Intervention protocol — infants in the prone group received prone positioning for ≥24 hours during the first 48 hours of hospitalization; standardized HFNC support was delivered at 2 L/kg/min in both arms. 4. Secondary outcomes — treatment failure (by independent adjudication), prone positioning tolerance, length of hospital stay, duration of respiratory support, and infant comfort did not differ significantly between groups. 5. Safety — serious adverse events were rare and comparable: 2/180 (1.1%) in the prone group vs. 2/264 (0.8%) in the supine group, indicating no meaningful excess harm from prone positioning in this age cohort. 6. Confidence interval interpretation — the wide 95% CI (0.40–1.07) around the OR precludes a definitive conclusion; the trial was likely underpowered to detect a clinically meaningful reduction, and the observed absolute risk difference of 5.8 percentage points warrants further investigation.
Practice implications
Prone positioning cannot yet be recommended as a standard adjunct to HFNC in infants with moderate-to-severe bronchiolitis, as the primary endpoint was not met; clinicians should not routinely alter positioning protocols based on this trial alone. However, given the favorable safety profile (serious adverse events <1.1% in the prone group) and the observed directional trend toward reduced escalation, individualized prone positioning trials may be reasonable in closely monitored PICU or intermediate care settings where nursing staffing allows continuous surveillance. Future adequately powered trials with refined infant selection criteria, standardized tolerance assessments, and longer prone exposure targets are warranted before definitive practice change can occur.