TABLE 1

American–European Consensus Conference (AECC), Berlin and Kigali criteria for acute respiratory distress syndrome (ARDS)

AECC definitionBerlin criteriaKigali modification of Berlin criteria
TimingAcute onsetWithin 1 week of a known clinical insult or new or worsening respiratory symptomsWithin 1 week of a known clinical insult or new or worsening respiratory symptoms
OxygenationPaO2/FiO2 ≤200 mmHg (defined as acute lung injury if ≤300 mmHg)Mild: PaO2/FiO2 >200 mmHg but ≤300 mmHg
Moderate: PaO2/FiO2 >100 mmHg but ≤200 mmHg
Severe: PaO2/FiO2 ≤100 mmHg
SpO2/FiO2 ≤315
PEEP requirementNoneMinimum 5 cmH2O PEEP required by invasive mechanical ventilation (noninvasive acceptable for mild ARDS)No PEEP requirement, consistent with AECC definition
Chest imagingBilateral infiltrates seen on frontal chest radiographBilateral opacities not fully explained by effusions, lobar/lung collapse or nodules by chest radiograph or CTBilateral opacities not fully explained by effusions, lobar/lung collapse or nodules by chest radiograph or ultrasound
Origin of oedemaPulmonary artery wedge pressure <18 mmHg when measured or no evidence of left atrial hypertensionRespiratory failure not fully explained by cardiac failure or fluid overload (need objective assessment, such as echocardiography, to exclude hydrostatic oedema if no risk factor present)Respiratory failure not fully explained by cardiac failure or fluid overload (need objective assessment, such as echocardiography, to exclude hydrostatic oedema if no risk factor present)
  • PEEP: positive end-expiratory pressure; PaO2: arterial oxygen tension; FiO2: inspiratory oxygen fraction; SpO2: arterial oxygen saturation measured by pulse oximetry; CT: computed tomography.