Hemoptysis is the expectoration of blood from the respiratory tract. It can arise from any part of the respiratory tract, from the alveoli to the glottis. It is important, however, to distinguish hemoptysis from epistaxis (i.e., bleeding from the nasopharynx) and hematemesis (i.e., bleeding from the upper gastrointestinal tract). Hemoptysis can range from blood-tinged sputum to life-threatening large volumes of bright red blood. For most patients, any degree of hemoptysis can be anxiety-producing and often prompts medical evaluation.
While precise epidemiologic data are lacking, the most common etiology of hemoptysis is infection of the medium-sized airways. In the United States, this is usually due to a viral or bacterial bronchitis. Hemoptysis can arise in the setting of either acute bronchitis or during an exacerbation of chronic bronchitis. Worldwide, the most common cause of hemoptysis is tuberculous infection presumably owing to the high prevalence of the disease and its predilection for cavity formation. While these are the most common causes, there is an extensive differential diagnosis for hemoptysis, and a step-wise approach to the evaluation of this symptom is appropriate.
One way to approach the source of hemoptysis is systematically to assess 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 with hemoptysis, although this is not always the case. Causes of DAH can be divided into inflammatory and noninflammatory types. Inflammatory DAH is due to small vessel vasculitis/capillaritis from a variety of diseases, including granulomatosis with polyangiitis (Wegener's) and microscopic polyangiitis. Similarly, systemic autoimmune disease, such as systemic lupus erythematosus (SLE), can manifest as pulmonary capillaritis and result in DAH. Antibodies to the alveolar basement membrane, as are seen in Goodpasture's disease, can also result in alveolar hemorrhage. In the early time period after a bone marrow transplant (BMT), patients can also develop a form of inflammatory DAH, which 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 a BMT.
Alveoli can also bleed due to noninflammatory causes, most commonly due to direct inhalational injury. This category includes 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 have an increased risk of developing hemoptysis.
As already noted, the most common site of hemoptysis is bleeding from the small- to medium-sized airways. Irritation and injury of the bronchial mucosal can lead to small-volume bleeding. More significant hemoptysis can also occur because of the proximity of the bronchial artery and vein to the airway, 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, therefore, lesser degrees of inflammation or injury can result in rupture of these vessels into the airways. Of note, while alveolar hemorrhage arises from capillaries that are part of the low-pressure pulmonary circulation, bronchial bleeding is generally from bronchial arteries, which are under systemic pressure and, therefore, predisposed to larger-volume bleeding.
Any infection of the airways can result in hemoptysis, although, most commonly, acute bronchitis is caused by viral infection. In patients with a history of chronic bronchitis, bacterial super infection with organisms such as Streptococcus pneumoniae, Hemophilus influenzae, or Moraxella catarrhalis can also result in hemoptysis. Patients with bronchiectasis, a permanent dilation and irregularity of the airways, are particularly prone to hemoptysis due to anatomic abnormalities that bring the bronchial arteries closer to the mucosal surface and the associated chronic inflammatory state. One common presentation of patients with advanced cystic fibrosis, the prototypical bronchiectatic lung disease, is hemoptysis, which, at times, 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. 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 more likely to cause necrotizing lung infections and, thus, are more often associated with hemoptysis. Previous severe pneumonias can cause scarring and abnormal lung architecture, which may predispose a patient to hemoptysis with subsequent infections.
While it is not commonly seen in North America, pulmonary paragonimiasis (i.e., infection with the lung fluke Paragonimus westermani) often presents with fever, cough, and hemoptysis. This infection is a public health issue in Southeast Asia and China and is commonly confused with active tuberculosis, because the clinical pictures can be similar. Paragonimiasis should be considered in recent immigrants from endemic areas with new or recurrent hemoptysis. In addition, there are reports of pulmonary paragonimiasis in the United States secondary to ingestion of crayfish or small crabs.
Other causes of irritation of the airways resulting in hemoptysis include inhalation of toxic chemicals, thermal injury, direct trauma from suctioning of the airways (particularly in intubated patients), and irritation from inhalation of foreign bodies. All of these etiologies should be suggested by the individual patient's history and exposures.
Perhaps the most feared cause of hemoptysis is bronchogenic lung cancer, although hemoptysis is not a particularly common presenting symptom of this disease with only approximately 10% of patients having frank hemoptysis on initial assessment. Cancers arising in the proximal airways are much more likely to cause hemoptysis, although any malignancy in the chest can do so. Because both squamous cell carcinoma and small cell carcinoma are more commonly central 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 almost exclusively found 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 also bleed. Malignancies that commonly metastasize to the lungs include renal cell, breast, colon, testicular, and thyroid cancers as well as melanoma. While they are not a common way for metastatic disease to present, multiple pulmonary nodules and hemoptysis should raise the suspicion for this etiology.
Finally, disease of the pulmonary vasculature can cause hemoptysis. Perhaps most commonly, congestive heart failure with transmission of elevated left atrial pressures, if severe enough, 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 infiltrate on chest radiograph together with hemoptysis. This is thought to be due to focal increases in pulmonary capillary pressure due to the regurgitant jet. Pulmonary arterio-venous 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 symptoms, the initial step in the evaluation of hemoptysis is a thorough history and physical examination (Fig. 34-2). As already mentioned, questioning should begin with determining if the bleeding is truly from the respiratory tract and not the nasopharynx or gastrointestinal tract, because these sources of bleeding require different evaluation and treatment approaches.
Flowchart—evaluation of hemoptysis. Decision tree for evaluation of hemoptysis. CBC, complete blood count; CT, computed tomography; CXR, chest x-ray; UA, urinalysis.
History and Physical Exam
The nature of the hemoptysis, whether they are blood-tinged, purulent secretions; pink, frothy sputum; or frank blood, may be helpful in determining an etiology. Specific triggers of the bleeding, such as 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. The volume of the hemoptysis is also important not only in determining the cause, but 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 greater than 200–600 cc in 24 h. Massive hemoptysis should be considered a medical emergency. The medical urgency related to hemoptysis depends on both the amount of bleeding and the severity of underlying pulmonary disease.
All patients should be asked about current or former cigarette smoking; this behavior predisposes to both chronic bronchitis and increases the likelihood of bronchogenic cancer. Symptoms suggestive of respiratory tract infection— including fever, chills, and dyspnea—should be elicited. The practitioner should inquire about recent inhalation exposures or use of illicit substances as well as risk factors for venous thromboembolism.
Past medical history of malignancy or treatment thereof, rheumatologic disease, vascular disease, or underlying lung disease such as bronchiectasis may be relevant to the cause of hemoptysis. Because many of the causes of DAH can be part of a pulmonary-renal syndrome, specific inquiry into a history of renal insufficiency also 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 should dictate a more expedited evaluation of hemoptysis. Specific focus on respiratory and cardiac examinations are important and 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, a CT of the chest should be obtained. CT allows better delineation of bronchiectasis, alveolar filling, cavitary infiltrates, and masses than does chest x-ray; it also gives further information on mediastinal lymphadenopathy, which may support a diagnosis of thoracic malignancy. The practitioner should consider a CT protocol to assess for pulmonary embolism if the history or examination suggests venous thromboembolism as a cause of the bleeding.
Laboratory studies should include a complete blood count to assess both the hematocrit as well as platelet count and coagulation studies. Renal function and urinalysis should be assessed because of the possibility of pulmonary-renal syndromes presenting with hemoptysis. Acute renal insufficiency, or red blood cells or red blood cell casts on urinalysis should increase suspicion for small-vessel vasculitis, and studies such as antineutrophil cytoplasmic antibody (ANCA), antiglomerular basement membrane antibody (anti-GBM), and antinuclear antibody (ANA), should be considered. If a patient is producing sputum, Gram and acid-fast stains as well as culture should be obtained.
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 hemoptysis. Because these patients are at increased risk of bronchogenic carcinoma, and endobronchial lesions are often not reliably visualized on computed tomogram, bronchoscopy should be seriously considered to add to the completeness of the evaluation.
For the most part, the treatment of hemoptysis will vary based on 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 most large-volume hemoptysis arises from an airway lesion, it is ideal if the site of the bleeding can be identified either by chest imaging or bronchoscopy (more commonly rigid than flexible). The goal is then to isolate the bleeding to one lung and not allow the preserved airspaces in the other lung to be filled with blood, further impairing gas exchange. 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 therapies of the underlying cause and passage of time, severe hemoptysis from bronchial arteries can be treated with angiographic embolization of the culprit bronchial artery. This intervention should only be entertained in the most severe and life-threatening cases of hemoptysis because there is a risk of unintentional spinal-artery embolization and consequent paraplegia with this procedure. Endobronchial lesions can be treated with a variety of bronchoscopically directed interventions, including cauterization and laser therapy. In extreme conditions, surgical resection of the affected region of lung is considered. Most cases of hemoptysis will resolve with treatment of the infection or inflammatory process or with removal of the offending stimulus.