Table 4. Characteristics of the PSII and PROSEVA randomised controlled trials on prone positioning in acute respiratory disease syndrome patients
Centres n2527
SupportRotoprone in 20 centresStandard bed
Patients n
    Supine position168229
    Prone position174237
Inclusion criteriaPaO2/FIO2 ≤200 mmHg + PEEP 5–10 cmH2OPaO2/FIO2 <150 mmHg + PEEP ≥5 cmH2O + FIO2 ≥0.60
Stratification of randomisationYesNo
Stabilisation periodNoYes
Stopping prone criteriaResolution of ARFImprovement in oxygenation (PaO2/FIO2 >150 mmHg + PEEP <10 cmH2O + FIO2 <0.60)
Target tidal volume mL·kg−18 PBW6 PBW
PEEP managementLocal PEEP/FIO2 tablePEEP/FIO2 table used in the ARMA trial
Target oxygenationPaO2 70–90 mmHgPaO2 55–80 mmHg
Target plasma pH7.30–7.457.20–7.45
SAPS II41±1546±16
SOFA score6.8±3.910.0±3.3
PaO2/FIO2 at inclusion mmHg113±39104±25
PEEP at inclusion cmH2O10±310±4
Tidal volume at inclusion mL·kg−18.0±1.7 PBW6.1±0.6 PBW
Pplat at inclusion cmH2ONot available24±5
Average prone session duration h18±417±4
Time in prone# %5073
Average prone position sessions per patient in the prone position group8±64±4
  • Data are presented as mean±sd, unless otherwise stated. PSII: Prone Supine II: PROSEVA: Prone Severe ARDS Patients; PaO2: arterial oxygen tension; FIO2: inspiratory oxygen fraction; PEEP: positive end-expiratory pressure; ARF: acute respiratory failures; SAPS: Simplified Acute Physiology Score; SOFA: Sequential Organ Function Assessment; Pplat: plateau pressure; PBW: predicted body weight. #: time spent in the prone position between the start of the first session and the end of the last session.