Table 2.

Six possible causes of dyspnea and their diagnostic criteria

Respiratory failure pattern	Diagnostic criteria
AHF	Signs and symptoms of heart failure preserved or reduced systolic function of the left ventricle, CXR congestion
Acute exacerbation of COPD and asthma	History of COPD or asthma, typical findings at lung examination, airflow limitation, not fully reversible in COPD, fully reversible in asthma
Pneumonia	Fever, cough, leukocytosis, rales or abolished vesicular murmur, pulmonary infiltrate at CXR, positive cultures (eventually)
ARDS	Acute presentation within 1 week of a known clinical insult or new/worsening respiratory symptoms; chest imaging with bilateral opacities-not fully explained by effusions, lobar/lung collapse, or nodules; respiratory failure not fully explained by cardiac failure or fluid overload; PiO2/FiO2 < 200
Massive pleural effusion	Vesicular murmur abolished at lung auscultation and dullness at percussion, massive pleural effusion at CXR or US
Acute pulmonary embolism	Signs and symptoms, prediction rules indicating high probability; multidetector computed tomography positive for pulmonary embolism; dilated, hypokinetic right ventricle with pressure overload signs (when the embolism determines a significatively hemodynamic impairment)