Table 2—

Proposed clinical definitions of chronic obstructive pulmonary disease(COPD) syndromes by analogy to syndromes in coronary artery disease

Unstable COPDWorsening of dyspnoea cough or sputumRR <24Dyspnoea <4 on 0–10 scaleNormal laboratory investigations
ExacerbationWorsening of dyspnoea, cough or sputumDyspnoea ≥4 on a 0–10 scaleNormal chest radiographWBC count >9000 cells·dL−1 or CRP >10 mg·dL−1
Ventilatory insufficiencySame plus elevation of Pa,CO2 in arterial blood gases
Coronary artery disease
 Unstable anginaWorsening of chest painNo ECG changesNormal laboratory results
 Myocardial infarctionChest painAbnormal ECGAbnormal serum enzyme pattern
 Cardiogenic shockSame syndrome plus shock
  • RR: relative risk; WBC: white blood cell; CRP: C-reactive protein; Pa,CO2: carbon dioxide arterial tension.