TABLE 2

Potential new exacerbation definition (analogous to events in coronary artery disease)

Coronary artery diseaseCOPD
Myocardial infarction (heart attack)
 Chest pain
and
 Abnormal ECG
and
 Elevated troponin
COPD exacerbation (lung attack)
 Increased dyspnoea (≥5 on a visual analogue scale that ranges from 0 to 10)
and
 O2 desaturation ≤4% below that of stable state, or O2 saturation ≤90% if no baseline value available
and
 CRP ≥3 mg·L−1
and
 Circulating blood neutrophils ≥9000 cells·mm−3 or circulating blood eosinophils ≥2%
and
 No pneumonia or congestive heart failure or pneumothorax or pleural effusion on chest radiography
Cardiogenic shock
 Same syndrome, plus shock
Respiratory failure
 Same syndrome, plus PaCO2 >45 mmHg

Adapted from references [65, 66]. COPD: chronic obstructive pulmonary disease; CRP: C-reactive protein; PaCO2: arterial carbon dioxide tension.