One way to approach the source of hemoptysis is to search systematically for potential sites of bleeding from the alveolus to the mouth. Diffuse bleeding in the alveolar space, often referred to as diffuse alveolar hemorrhage (DAH), may present as hemoptysis. Causes of DAH can be inflammatory or noninflammatory. Inflammatory DAH is due to small-vessel vasculitis/capillaritis from a variety of diseases, including granulomatosis with polyangiitis and microscopic polyangiitis. Similarly, systemic autoimmune diseases such as systemic lupus erythematosus can manifest as pulmonary capillaritis. Antibodies to the alveolar basement membrane, as are seen in Goodpasture’s disease, can also result in alveolar hemorrhage. In the early period after bone marrow transplantation, patients can develop a form of inflammatory DAH that can be catastrophic and life-threatening. The exact pathophysiology of this process is not well understood, but DAH should be suspected in patients with sudden-onset dyspnea and hypoxemia in the first 100 days after bone marrow transplantation.
Alveoli can also bleed due to direct inhalational injury, including thermal injury from fires, inhalation of illicit substances (e.g., cocaine), and inhalation of toxic chemicals. If alveoli are irritated from any process, patients with thrombocytopenia, coagulopathy, or antiplatelet or anticoagulant use will be at increased risk of hemoptysis.
Bleeding in hemoptysis most commonly arises from the small- to medium-sized airways. Irritation and injury of the bronchial mucosa can lead to small-volume bleeding. More significant hemoptysis can result from the proximity of the bronchial artery and vein to the airway, with these vessels and the bronchus running together in what is often referred to as the bronchovascular bundle. In the smaller airways, these blood vessels are close to the airspace, and lesser degrees of inflammation or injury can therefore result in their rupture into the airways. While alveolar hemorrhage arises from capillaries that are part of the low-pressure pulmonary circulation, bronchial bleeding generally originates from bronchial arteries, which are under systemic pressure and thus are predisposed to larger-volume bleeding.
Any infection of the airways can result in hemoptysis, although acute bronchitis is most commonly caused by viral infection. In patients with a history of chronic bronchitis, bacterial superinfection with organisms such as Streptococcus pneumoniae, Haemophilus influenzae, or Moraxella catarrhalis can also result in hemoptysis. Patients with bronchiectasis (a permanent dilation of the airways with loss of mucosal integrity) are particularly prone to hemoptysis due to chronic inflammation and anatomic abnormalities that bring the bronchial arteries closer to the mucosal surface. One common presentation of patients with advanced cystic fibrosis—the prototypical bronchiectatic lung disease—is hemoptysis, which can be life-threatening.
Pneumonias of any sort can cause hemoptysis. Tuberculous infection, which can lead to bronchiectasis or cavitary pneumonia, is a very common cause of hemoptysis worldwide. Patients may present with a chronic cough productive of blood-streaked sputum or with larger-volume bleeding. Rasmussen’s aneurysm (the dilation of a pulmonary artery in a cavity formed by previous tuberculous infection) remains a source of massive, life-threatening hemoptysis in the developing world. Community-acquired pneumonia and lung abscess can also result in bleeding. Once again, if the infection results in cavitation, there is a greater likelihood of bleeding due to erosion into blood vessels. Infections with Staphylococcus aureus and gram-negative rods (e.g., Klebsiella pneumoniae) are especially likely to cause necrotizing lung infections and thus to be associated with hemoptysis.
While not common in North America, pulmonary paragonimiasis (i.e., infection with the lung fluke Paragonimus westermani) often presents as fever, cough, and hemoptysis. This infection is a public health issue in Southeast Asia and China and is frequently confused with active tuberculosis, in which the clinical picture can be similar. Paragonimiasis should be considered in recent immigrants from endemic areas who have new or recurrent hemoptysis. In addition, pulmonary paragonimiasis has been reported secondary to ingestion of crayfish or small crabs in the United States.
Other causes of airway irritation resulting in hemoptysis include inhalation of toxic chemicals, thermal injury, and direct trauma from suctioning of the airways (particularly in intubated patients). All of these etiologies should be considered in light of the individual patient’s history and exposures.
Perhaps the most feared cause of hemoptysis is bronchogenic lung cancer, although hemoptysis is a presenting symptom in only ∼10% of patients. Cancers arising in the proximal airways are much more likely to cause hemoptysis, but any malignancy in the chest can do so. Because both squamous cell carcinomas and small-cell carcinomas are more commonly in or adjacent to the proximal airways, and large at presentation, they are more often a cause of hemoptysis. These cancers can present with large-volume and life-threatening hemoptysis because of erosion into the hilar vessels. Carcinoid tumors, which are found almost exclusively as endobronchial lesions with friable mucosa, can also present with hemoptysis.
In addition to cancers arising in the lung, metastatic disease in the pulmonary parenchyma can bleed. Malignancies that commonly metastasize to the lungs include renal cell, breast, colon, testicular, and thyroid cancers as well as melanoma. While hemoptysis is not a common manifestation of pulmonary metastases, the combination of multiple pulmonary nodules and hemoptysis should raise suspicion of this etiology. Finally, disease of the pulmonary vasculature can cause hemoptysis. Perhaps most frequently, congestive heart failure with transmission of elevated left atrial pressures can lead to rupture of small alveolar capillaries. These patients rarely present with bright red blood but more commonly have pink, frothy sputum or blood-tinged secretions. Patients with a focal jet of mitral regurgitation can present with an upper-lobe opacity on chest radiography together with hemoptysis. This finding is thought to be due to focal increases in pulmonary capillary pressure due to the regurgitant jet. Pulmonary arteriovenous malformations are prone to bleeding. Pulmonary embolism can also lead to the development of hemoptysis, which is generally associated with pulmonary infarction. Pulmonary arterial hypertension from other causes rarely results in hemoptysis.
As with most signs of possible illness, the initial step in the evaluation of hemoptysis is a thorough history and physical examination (Fig. 48-2). As already mentioned, initial questioning should focus on ascertaining whether the bleeding is truly from the respiratory tract and not the nasopharynx or gastrointestinal tract; bleeding from the latter sources requires different approaches to evaluation and treatment.
Decision tree for evaluation of hemoptysis. CBC, complete blood count; CT, computed tomography; CXR, chest x-ray; UA, urinalysis.
History and Physical Examination
The specific characteristics of hemoptysis may be helpful in determining an etiology, such as whether the expectorated material consists of blood-tinged, purulent secretions; pink, frothy sputum; or pure blood. Information on specific triggers of the bleeding (e.g., recent inhalation exposures) as well as any previous episodes of hemoptysis should be elicited during history-taking. Monthly hemoptysis in a woman suggests catamenial hemoptysis from pulmonary endometriosis. Moreover, the volume of blood expectorated is important not only in determining the cause but also in gauging the urgency for further diagnostic and therapeutic maneuvers. Patients rarely exsanguinate from hemoptysis but can effectively “drown” in aspirated blood. Large-volume hemoptysis, referred to as massive hemoptysis, is variably defined as hemoptysis of >200–600 mL in 24 h. Massive hemoptysis should be considered a medical emergency. All patients should be asked about current or former cigarette smoking; this behavior predisposes to chronic bronchitis and increases the likelihood of bronchogenic cancer. Practitioners should inquire about symptoms and signs suggestive of respiratory tract infection (including fever, chills, and dyspnea), recent inhalation exposures, recent use of illicit substances, and risk factors for venous thromboembolism.
A medical history of malignancy or treatment thereof, rheumatologic disease, vascular disease, or underlying lung disease (e.g., bronchiectasis) may be relevant to the cause of hemoptysis. Because many causes of DAH can be part of a pulmonary-renal syndrome, specific inquiry into a history of renal insufficiency is important.
The physical examination begins with an assessment of vital signs and oxygen saturation to gauge whether there is evidence of life-threatening bleeding. Tachycardia, hypotension, and decreased oxygen saturation mandate a more expedited evaluation of hemoptysis. A specific focus on respiratory and cardiac examinations is important; these examinations should include inspection of the nares, auscultation of the lungs and heart, assessment of the lower extremities for symmetric or asymmetric edema, and evaluation for jugular venous distention. Clubbing of the digits may suggest underlying lung diseases such as bronchogenic carcinoma or bronchiectasis, which predispose to hemoptysis. Similarly, mucocutaneous telangiectasias should raise the specter of pulmonary arterial-venous malformations.
For most patients, the next step in evaluation of hemoptysis should be a standard chest radiograph. If a source of bleeding is not identified on plain film, CT of the chest should be performed. CT allows better delineation of bronchiectasis, alveolar filling, cavitary infiltrates, and masses than does chest radiograph. The practitioner should consider a CT protocol to assess for pulmonary embolism if the history or examination suggests venous thromboembolism as a cause of bleeding.
Laboratory studies should include a complete blood count to assess both the hematocrit and the platelet count as well as coagulation studies. Renal function should be evaluated and urinalysis conducted because of the possibility of pulmonary-renal syndromes presenting with hemoptysis. The documentation of acute renal insufficiency or the detection of red blood cells or their casts on urinalysis should elevate suspicion of small-vessel vasculitis, and studies such as antineutrophil cytoplasmic antibody, antiglomerular basement membrane antibody, and antinuclear antibody should be considered. If a patient is producing sputum, Gram’s and acid-fast staining as well as culture should be undertaken.
If all of these studies are unrevealing, bronchoscopy should be considered. In any patient with a history of cigarette smoking, airway inspection should be part of the evaluation of new-onset hemoptysis as endobronchial lesions are not reliably visualized on CT.
For the most part, the treatment of hemoptysis varies with its etiology. However, large-volume, life-threatening hemoptysis generally requires immediate intervention regardless of the cause. The first step is to establish a patent airway, usually by endotracheal intubation and subsequent mechanical ventilation. As large-volume hemoptysis usually arises from an airway lesion, it is ideal to identify the site of bleeding by either chest imaging or bronchoscopy (more commonly rigid rather than flexible). The goals are then to isolate the bleeding to one lung and not to allow the preserved airspaces in the other lung to be filled with blood so that gas exchange is further impaired. Patients should be placed with the bleeding lung in a dependent position (i.e., bleeding-side down), and, if possible, dual-lumen endotracheal tubes or an airway blocker should be placed in the proximal airway of the bleeding lung. These interventions generally require the assistance of anesthesiologists, interventional pulmonologists, or thoracic surgeons.
If the bleeding does not stop with treatment of the underlying cause and the passage of time, severe hemoptysis from bronchial arteries can be treated with angiographic embolization of the responsible bronchial artery. This intervention should be entertained only in the most severe and life-threatening cases of hemoptysis because of the risk of unintentional spinal-artery embolization and consequent paraplegia. Endobronchial lesions can be treated with a variety of bronchoscopically directed interventions, including cauterization and laser therapy. In extreme circumstances, surgical resection of the affected region of the lung is considered. Most cases of hemoptysis resolve with treatment of the infection or inflammatory process or with removal of the offending stimulus.