Trial finds no benefit from prone positioning or high-frequency ventilation in pediatric ARDS

Overview

Updated 2 hours ago

For more than 30 years, pediatric intensive care doctors have argued over whether turning a desperately ill child face-down, or ventilating them with hundreds of tiny rapid breaths per minute, helps more than standard care. A 424-patient international trial published in The Lancet found neither did.

The trial, called PROSpect, ran a two-by-two design across 75 pediatric intensive care units in 18 countries. It stopped early for futility and slow enrolment, and both interventions produced ventilator-free day counts statistically indistinguishable from conventional care.

Why it matters

Two of the most debated first-line therapies in pediatric critical care now lack supporting evidence, pushing clinicians toward rescue use and better-targeted trials.

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Key Indicators

424

Patients enrolled

Out of 600 planned, before the trial stopped early.

Pediatric intensive care units

Participating sites across 18 countries.

0.0 days

Adjusted difference in ventilator-free days, prone vs supine

95% confidence interval ran from 0.8 days fewer to 1.0 day more.

10%

Day-28 mortality

41 deaths, with no difference between treatment groups.

4.8×

Higher rate of artificial airway blockage with prone positioning

Rate ratio 4.83, 95% confidence interval 1.38 to 16.82.

Voices

Curated perspectives — historical figures and your fellow readers.

People Involved

Martha A.Q. Curley

Lead investigator, PROSpect; Ruth M. Colket Endowed Chair in Pediatric Nursing

Professor at the University of Pennsylvania School of Nursing and researcher at Children's Hospital of Philadelphia

Robinder G. Khemani

Pediatric critical care physician and co-author of The Lancet commentary on PROSpect

Researcher at the University of Southern California

Organizations Involved

Children's Hospital of Philadelphia

Pediatric academic medical center

Coordinated the PROSpect trial

Philadelphia children's hospital that organized the 18-country PROSpect trial.

The Lancet

Medical journal

Published the trial and a companion commentary

British medical journal that published the PROSpect results and an invited commentary on them.

National Heart, Lung, and Blood Institute

Federal research funder

Funded PROSpect

Part of the US National Institutes of Health and the trial's stated funder.

Timeline

2015 October 2026

5 events Latest: 2 days ago

Tap a bar to jump to that date

October 2026
The Lancet publishes PROSpect and a companion commentary
Latest Publication

The trial reports no difference in ventilator-free days for either intervention, and more airway blockages with prone positioning.
2 days ago
Children's Hospital of Philadelphia announces the result
Announcement

The lead investigator says the findings give the field a level of evidence it previously lacked.
3 days ago
January 2026
Enrolment closes early at 424 of 600 planned
Trial

The trial stops for futility and slow enrolment after seven years.
January 13th, 2026
May 2019
PROSpect begins enrolling
Trial launch

Sites in 18 countries start randomizing children with early, moderate-to-severe pediatric ARDS.
May 1st, 2019
2015
Pediatric ARDS guidance notes the evidence gap
Guideline

The Pediatric Acute Lung Injury Consensus Conference published pediatric-specific ARDS recommendations and found insufficient evidence to favor prone positioning or high-frequency oscillatory ventilation.
2015

Scenarios

Guidelines demote prone positioning and HFOV to rescue use

Likely Resolves by End of 2028

Discussed by: The Lancet commentary and the trial authors, who call for de-implementation as first-line therapy

A pediatric critical care society updates its ARDS recommendations to say neither intervention should be used routinely up front, while leaving room for them after conventional measures fail. This is the outcome the trial's own interpretation points toward.

No guideline change, and practice stays split

Possible Resolves by End of 2028

Discussed by: Critics of the trial's early stop and its unblinded design, raised in the Lancet commentary and in French coverage of the result

Societies decline to issue new recommendations, citing the early termination, the inability to mask clinicians, and unresolved questions about rescue use. Individual units keep deciding case by case, as they did before the trial.

A narrower trial follows, targeting a defined PARDS subgroup

Possible Resolves by Q2 2029

Discussed by: Martha Curley, who said the result opens the door to precision-based therapies

Researchers conclude the average effect was null but some children may still benefit, and register a new trial testing prone positioning or HFOV in a restricted subgroup, such as patients with severe hypoxemia or a specific lung-injury pattern.

Historical Context

3 moments from history that rhyme with this story — and how they unfolded.

2013

PROSEVA trial of prone positioning in adults (2013)

A French-led trial randomized 466 adults with severe acute respiratory distress syndrome to lie face-down for long stretches or stay on their backs. Prone positioning nearly halved 28-day mortality.

Then

Prone positioning moved into adult ARDS guidelines for the most severe cases.

Now

It became the standard example of a cheap physical intervention that saves lives in adults, which made the pediatric question harder to leave open.

Why this matters now

The same maneuver that worked in adults produced no measurable benefit in children, a gap PROSpect was built to test rather than assume away.

2013

OSCAR and OSCILLATE trials of high-frequency oscillatory ventilation (2013)

Two large adult trials reported the same year on high-frequency oscillatory ventilation. OSCILLATE was stopped early after more deaths in the oscillation arm; OSCAR found no significant survival benefit.

Then

Adult intensive care units pulled back from routine oscillatory ventilation.

Now

The therapy survived mainly as a rescue option, and the adult experience set expectations for pediatric testing.

Why this matters now

PROSpect repeats the pattern in children: a therapy that looked physiologically promising did not improve outcomes when tested at scale.

2015

Pediatric Acute Lung Injury Consensus Conference (2015)

A consensus panel published pediatric-specific definitions for acute respiratory distress syndrome and recommendations for management. It found insufficient evidence to recommend for or against prone positioning or high-frequency oscillatory ventilation.

Then

Practice varied widely between pediatric intensive care units.

Now

The gap stayed open for a decade, until a trial large enough to answer it could be finished.

Why this matters now

PROSpect was designed to fill exactly the evidence hole the 2015 panel identified.