Ibrahim 2007.

Methods	Two‐group parallel RCT, 1 centre ITT: no Overall study quality: high risk of bias
Participants	32 children 8 weeks to 10 years of age with the diagnosis of ARDS and on mechanical ventilation (PaO2/FiO2 ≤ 200 mm Hg, positive inspiratory pressure ≥ 30 cm H2O, FiO2 ≥ 0.5 for > 12 hours), divided into 3 groups. Study period of 24 hours Exclusion criteria: cardiac or neurological disease (cyanotic), chest or abdominal trauma, neurological surgeries, haemodynamic instability, extracorporeal membrane oxygenation
Interventions	INO group with children in supine position during 24‐hour study period: 11 participants INO group with children in prone position during 24‐hour study period: 11 participants INO used continuously for 20 hours (5 ppm for 18 hours, then decreased to 1 ppm in the last 2 hours) INO administered at 5 ppm for 18 hours, then decreased to 1 ppm Control group: 10 participants kept in prone position for 20 hours, then back to supine position for remaining 4 hours. No placebo. No cross‐overs Standard care. Lung protective strategy (tidal volume 5 to 10 mL/kg), permissive hypercapnia (PaCO2 > 50 mm Hg) as long as arterial pH > 7.2. Ventilation and weaning protocol for all participants
Outcomes	PaO2/FiO2, oxygenation index, methaemoglobin, NO2, critical incidents related to prone position or repositioning
Notes	Country: Egypt Letter sent to study authors in June 2009. No reply received. Two children withdrawn from the trial and did not have oxygenation measured For PaO2/FiO2 and oxygenation index meta‐analyses, we have chosen to include data from the control group (prone position) and INO with prone position group, thus having the same co‐intervention (prone position). No mortality data provided. Although bilateral infiltrates are not explicitly mentioned as a criterion for inclusion, it does appear from reading the article that they have been used clinically to include participants. Thus this trial has been characterized as fulfilling the American‐European Consensus Conference definition of ARDS Length of follow‐up: 24 hours Study authors' conclusion: "The present study showed that in mechanically ventilated paediatric patients with ARDS, the combined use of prone position and INO is safe and has an additive effect, which causes a greater sustained improvement in oxygenation than either treatment strategy alone" Funding: unknown
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Unclear, no information provided
Allocation concealment (selection bias)	High risk	Alternate allocation
Blinding (performance bias and detection bias) All outcomes	High risk	No blinding
Incomplete outcome data (attrition bias) All outcomes	Low risk	Follow‐up: adequate, no post‐trial follow‐up
Selective reporting (reporting bias)	Low risk	Yes. Unable to compare with protocol but appears to be free of selective reporting
Other bias	Unclear risk	No apparent other type of bias except that no sample size calculation or funding reported