Chronic bronchitis has irreversible airflow limitation, especially during forced expiration. This is due to the destruction of lung tissue and increase in resistance to flow in the conducting airways. Thus, it doesn't show an improvement in FEV1 post bronchodilator administration, unlike asthma. This characteristic feature is used as an diagnostic criterion for COPD, i.e. a COPD is diagnosed by spirometry if FEV1/FVC < 70% for a matched control. Arterial blood gas may show hypoxemia with or without hypercapnia depending on the disease severity. pH may be normal due to renal compensation. A pH less than 7.3 usually indicates severe respiratory compromise. A blood sample taken from an artery, i.e. Arterial Blood Gas (ABG), can be tested for blood gas levels which may show low oxygen (hypoxemia) and/or high carbon dioxide (respiratory acidosis if pH is also decreased). A blood sample taken from a vein may show a high blood count (reactive polycythemia), a reaction to long-term hypoxemia.
Chronic bronchitis laboratory findings
Bronchiectasis laboratory findings
Chronic obstructive pulmonary disease laboratory findings
Chronic bronchitis physical examination
Alpha 1-antitrypsin deficiency laboratory findings
Occupational lung disease other diagnostic studies
Chronic obstructive pulmonary disease other diagnostic studies
Pulmonary embolism laboratory findings