Sputum is expectorant from the lungs and respiratory passages that contains mucus and pus and is a clue to the severity of respiratory illness. While microscopic examination provides the most accurate clues to illness, gross examination provides valuable information. Color, consistency, and volume are features that provide insight to the cause and severity of illness. Bloody sputum or hemoptysis (see Fig. 25.47) may occur in streaks or in life-threatening amounts. Acute bronchitis, pneumonia, lung cancer, tuberculosis, bronchiectasis, lung abscess, pulmonary embolism, and pulmonary infarction are causes of hemoptysis. Pink or white frothy sputum suggests pulmonary edema.
Hemoptysis. Coughing up of blood or blood-stained mucus. (Photo contributor: Lawrence B. Stack, MD.)
Green sputum suggests chronic respiratory infection, as in chronic bronchitis, cystic fibrosis, and ruptured lung abscess. Rust-colored sputum suggests pneumococcal pneumonia, pulmonary embolism, lung cancer, or tuberculosis. Yellow sputum (see Fig. 25.48) in a healthy patient suggests viral bronchitis. However, in chronic obstructive pulmonary disease patients, yellow sputum may represent a bacterial infection where antibiotics are likely to be effective. Black sputum (see Fig. 25.49) suggests pneumoconiosis and acute or chronic smoke exposure (as in seen fire fighters).
Sputum—Viral Bronchitis. Yellowish-gray sputum seen in patients with viral bronchitis. (Photo contributor: Lawrence B. Stack, MD.)
Carbonaceous Sputum. Smoke inhalation in a patient removed from a house fire. (Photo contributor: R. Jason Thurman, MD.)
Management and Disposition
Life-threatening hemoptysis, defined as greater than 150 mL in 24 hours should prompt computed tomography (CT) angiography of the chest and hospital admission. Causes of non–life-threatening hemoptysis should be treated accordingly.
Colored sputum will prompt a search for the cause of the finding. A chest x-ray or chest CT is likely to be helpful. A complete blood count, blood culture, and inflammatory markers may provide clues to the cause and guide treatment.
Hypoxic patients with life-threatening hemoptysis from unilateral disease may benefit from a “bad lung down” position to keep bleeding confined to a single lung.
Neutrophil myeloperoxidase has a heme pigment that causes a green color in mucus and pus with a high neutrophil count.
Green or yellow sputum is a weak diagnostic marker for determining the presence of an acute pulmonary bacterial illness.