Update on Pharmaceutical and Minimally Invasive Management Strategies for Chronic Obstructive Pulmonary Disease

Table 1

Spirometric classification of COPD severity: gold staging criteria.

Stage I: mild	FEV1/FVC < 0.70
	FEV1 ≥ 80% predicted
Stage II: moderate	FEV1/FVC < 0.70
	50% ≤ FEV1 < 80% predicted
Stage III: severe	FEV1/FVC < 0.70
	30% ≤ FEV1 < 50% predicted
Stage IV: very severe	FEV1/FVC < 0.70
	FEV1 < 30% predicted or FEV1 < 50% predicted plus chronic respiratory failure

FEV₁: forced expiratory volume in the first second (postbronchodilator).
FVC: forced vital capacity.
Respiratory failure: arterial partial pressure of oxygen (PaO₂) less than 8.0 kPa (60 mm Hg) with or without arterial partial pressure of CO₂ (PaCO₂) greater than 6.7 kPa (50 mm Hg) while breathing air at sea level.
Adapted from http://www.goldcopd.com/, updated 2009.