Fig. 5: Classification of the severity of COPD exacerbations.

Definition of abbreviations: VAS: visual analog scale; RR: respiratory rate; HR: heart rate; CRP: C-reactive protein. SaO2: arterial oxygen saturation; PaO2: arterial partial pressure of oxygen; ABG: arterial blood gases; ABG should show new onset/worsening hypercapnia or acidosis since a few patients may have chronic hypercapnia. Adapted from ref. 68. Reproduced with permission from www.goldcopd.org.