Prone positioning may reduce escalation to noninvasive or invasive ventilation among infantile patients with moderate to severe bronchiolitis receiving high-flow nasal cannula support, although the differences may not be statistically significant between prone and supine positioning.
Researchers enrolled 451 infants aged 6 months or younger at 15 pediatric intermediate care and intensive care units (ICU) in France between January 2021 and November 2023. The patients had acute viral bronchiolitis with moderate to severe respiratory distress requiring high-flow nasal cannula (HFNC) support and were randomly assigned to prone positioning for at least 24 hours during the first 48 hours or to standard supine positioning. Five of the patients were excluded because complete consent could not be obtained, leaving 446 infants in the primary analysis. The primary outcome was escalation of care to noninvasive or invasive ventilation within 72 hours. Secondary outcomes included treatment failure assessed by an independent clinical adjudication committee, duration of respiratory support, length of stay, comfort, tolerance of prone positioning, and adverse events.
Escalation of care occurred in 15% of the infants assigned to prone positioning compared with about 21% of those assigned to supine positioning. Although the outcomes favored prone positioning, the difference did not meet the study's primary endpoint.
The secondary outcomes were similar between the two groups. Treatment failure occurred in 24% of infants in the prone position and 26% of those in the supine position. Duration of respiratory support, ICU stay, hospital stay, and intubation rates did not differ statistically between the groups. Three infants required intubation during the study, two of whom were in the supine-position group.
The researchers reported limited tolerance of prone positioning. Forty-two percent of infants assigned to prone positioning were switched permanently to the supine position before completing 24 hours of prone positioning, and 20% received less than eight cumulative hours in the prone position.
In a per-protocol analysis that included infants who received at least eight hours of prone positioning, escalation of care occurred in 9% of patients in the prone-position group compared with 20% in the supine-position group. The patients receiving prone positioning had about one-third the odds of escalation compared with those managed in the supine position. The researchers cautioned that the analysis excluded a substantial proportion of the randomized patients and should be interpreted carefully because of the potential for bias.
The study's ability to detect a difference may have been limited by lower-than-expected event rates. The researchers had anticipated a substantially higher rate of treatment escalation when calculating sample size. In addition, clinicians and caregivers could not be blinded to patient positioning, and decisions regarding escalation of respiratory support may have been influenced by clinical judgment. The researchers also noted that increasing use of HFNC may have changed the population receiving this therapy over time.
In an accompanying editorial, Joseph G. Kohne, MD, MSc, of the Rainbow Babies and Children's Hospital and Case Western Reserve University, and colleagues wrote that the findings highlighted the heterogeneity of bronchiolitis and suggested future research may need to identify patients most likely to respond to prone positioning.
"This large randomized clinical trial did not identify a statistically significant benefit of prone positioning in infants with moderate to severe bronchiolitis treated with HFNC," wrote lead study author Florent Baudin, MD, PhD, of Hospices Civils de Lyon at the Hôpital Femme Mère Enfant at the Service d’Urgences et de Réanimation Pédiatriques in France, and colleagues. The researchers noted that the observed effect favored prone positioning, but that the findings were not definitive and warrant further investigation.
The study was funded by the French Ministry of Health. Dr. Baudin reported receiving travel reimbursement, consulting fees, or nonfinancial support from Dräger, Lowenstein, Fisher & Paykel, and Sedana Medical. Senior editorial author Steven L. Shein, MD, reported serving as Vice Chair of Society of Critical Care Medicine's guidelines for pediatric management of bronchiolitis under development. No other conflicts of interest were reported by the study or editorial authors.
