A 44-year-old man comes to the emergency room because of light-headedness and fatigue. He says he has had several similar but milder episodes in the last several months. He also mentions that he thinks he has been coughing up blood. He says he has no major medical or surgical problems of which he is aware, but he appears confused and unable to give an accurate history. No family members can be contacted for further history at the moment.
Physical examination reveals nothing remarkable, but the patient does cough up some blood during the examination. His hemoglobin level is 6.0 g/dL (reference range 13.5–17.5).
What imaging tests would be helpful in this patient’s evaluation?
HEMOPTYSIS HAS MANY CAUSES
Hemoptysis is defined as the expectoration of blood originating from the tracheobronchial tree or the pulmonary parenchyma.
Most cases of hemoptysis are benign and self-limited; life-threatening hemoptysis is rare.1–3 However, hemoptysis can be a sign of serious tracheopulmonary disease.
The bleeding can be from the large (Table 1) or the small (Table 2) pulmonary vessels. Bleeding from the small vessels is known as diffuse alveolar hemorrhage, and it characteristically presents as alveolar infiltrates on chest radiography. In these cases, further imaging studies provide little benefit.4 This paper will focus on the imaging of and radiographic interventions for large-vessel bleeding.The causes of hemoptysis are numerous; common causes of bleeding from the large vessels nowadays include bronchiectasis, fungal infections, tuberculosis, and cancer.1,5,6 Still, no cause is identified in 15% to 30% of all cases,1,2,5 even after extensive evaluation.Definition of ‘massive’ hemoptysis can vary
Various definitions of the severity of hemoptysis have been proposed. The threshold of “massive” hemoptysis has been defined as as low as 100 mL/24 hours and as high as 1 L/24 hours; the most common definition is 300 mL, or about 1 cup.2,3,5–10
However, the patient’s cardiorespiratory status must also be considered.5,6,9 If the patient cannot maintain his or her airway, a small amount of bleeding could be life-threatening and should be considered significant or massive. Thus, we define massive hemoptysis as more than 300 mL of blood within 24 hours or any amount of blood with concurrent cardiorespiratory compromise.
It is important to recognize massive hemoptysis quickly, because without urgent treatment, up to 80% of patients may die.5,6,11 This can sometimes pose a challenge, as the history may not always be helpful and the patient’s perception of massive hemoptysis may differ from the clinically accepted definition. For example, in a patient without respiratory compromise, we would not consider bloodtinged sputum or small amounts of blood that add up to 1 to 2 teaspoons (5–10 mL) to be massive, although the patient might. On the other hand, hemoptysis with cardiorespiratory compromise must be considered significant (and very possibly massive) until proven otherwise, even if the amount of blood is small.
Massive hemoptysis is usually the result of erosion of systemic (rather than pulmonary) arteries by bronchial neoplasm, active tuberculosis, or aspergilloma.6,9,12,13 Arteriovenous malformations and pulmonary artery aneurysms are much less common causes.5,11,13
IMAGING AND DIAGNOSTIC OPTIONS
Most cases of hemoptysis have an identifiable source and cause of the bleeding at the time of initial diagnosis.14 Currently, there is no consensus on what is the best workup for hemoptysis. Still, a complete evaluation includes patient history, physical examination, bronchoscopy, laboratory tests, and imaging studies (Figure 1). Imaging studies that can be helpful include chest radiography, conventional computed tomography (CT), multi-detector CT angiography, and conventional angiography.Chest radiography
In as many as 40% of cases of hemoptysis, however, the findings on chest radiography are normal or do not reveal the source of the bleeding.15,16 Approximately 5% to 6% of patients with hemoptysis and normal results on radiography are eventually found to have lung cancer.14 Thus, while a localizing finding on radiography is helpful, a normal or nonlocalizing finding warrants further evaluation by other means, including conventional CT, multidetector CT angiography, or bronchoscopy.