Internal Medicine/Hemoptysis

Hemoptysis refers to the coughing up of blood from the respiratory tract. It can sometimes be confused with bleeding from the gastrointestinal tract (hematemesis) or the nose (epistaxis). In cases where hemoptysis is confirmed, the next step involves assessing the amount and frequency of blood expectoration. When the bleeding is massive or life-threatening (exceeding 400 mL of blood in 24 hours or 150 mL at one time), immediate intervention is necessary. This chapter primarily focuses on non-life-threatening cases of hemoptysis. Identifying the source and cause of the bleeding comes next when evaluating a patient with hemoptysis.

Anatomy and Physiology of Hemoptysis: Hemoptysis can originate anywhere within the respiratory tract, spanning from the glottis to the alveolus. Typically, bleeding occurs in the bronchi or medium-sized airways, but a comprehensive evaluation of the entire respiratory system is crucial. The lungs receive blood supply from both the pulmonary and bronchial circulations. While the pulmonary circulation serves gas exchange in the alveoli and is a low-pressure system, the bronchial circulation originates from the aorta and operates as a high-pressure system. Most hemoptysis cases arise from the bronchial circulation, and bleeding from this higher-pressure system can be challenging to control.

Etiology: Hemoptysis commonly results from infection, malignancy, or vascular disease. However, the potential causes of respiratory bleeding are diverse. In the United States, common causes include viral bronchitis, bronchiectasis, and malignancies. In other parts of the world, tuberculosis is a prevalent cause. Viral bronchitis typically leads to blood-tinged sputum and minor hemoptysis. Patients with chronic bronchitis are susceptible to bacterial superinfections, which can exacerbate airway inflammation and bleeding. Bronchiectasis, characterized by dilated, inflamed, and highly vascular airways, is a leading cause of massive hemoptysis.

Tuberculosis was historically the primary global cause of hemoptysis but has been surpassed by bronchitis and bronchiectasis in industrialized countries. In tuberculosis cases, bleeding often originates from cavitary disease, but complications like erosion of a pulmonary artery aneurysm into an existing cavity (Rasmussen's aneurysm) can also be the source.

Other infectious agents like endemic fungi, Nocardia, and nontuberculous mycobacteria can lead to cavitary lung disease with associated hemoptysis. Aspergillus species can form mycetomas within preexisting cavities, causing bleeding due to neovascularization. Pulmonary abscesses and necrotizing pneumonia can induce bleeding by damaging lung tissue. Common culprits include Staphylococcus aureus, Klebsiella pneumoniae, and oral anaerobes.

Paragonimiasis, a condition prevalent in Southeast Asia and China, can mimic tuberculosis and is a significant global cause of hemoptysis, even occurring in North America among recent immigrants.

Vascular causes of hemoptysis may be associated with cardiac issues, pulmonary embolism, arteriovenous malformations, or diffuse alveolar hemorrhage. While the classic description of pulmonary edema-related sputum is "pink and frothy," hemoptysis can also occur, particularly with the increased use of anticoagulants and antiplatelet medications.

Pulmonary embolism can lead to hemoptysis, but it is not a common cause. Ectatic vessels in airways or pulmonary arteriovenous malformations can also be sources of bleeding. A rare vascular cause is the rupture of an aortobronchial fistula, which arises in the context of aortic pathology like an aneurysm and can cause minor bleeding episodes that precede massive hemoptysis.

Diffuse alveolar hemorrhage (DAH) involves significant bleeding into lung tissue but is not typically associated with hemoptysis. DAH usually presents with diffuse ground glass opacities on chest imaging and can result from various factors, including immune-mediated capillaritis, toxicity from substances like cocaine, and stem cell transplantation.

While there is no universally agreed-upon volume, a blood loss of 400 mL in 24 hours or 100-150 mL at one time is considered life-threatening hemoptysis. These estimates are based on the blood volume within the tracheobronchial tree (generally 100-200 mL). Most patients do not accurately measure the volume of their hemoptysis in milliliters, so using approximations like cups (one U.S. cup is 236 mL) can be helpful. Thankfully, life-threatening hemoptysis only accounts for a small percentage of hemoptysis cases (5-15%).

A patient's medical history can provide clues to the cause of hemoptysis. Symptoms like fever, chills, or a prior cough may suggest an infection. Smoking history or unintentional weight loss may increase suspicion of malignancy. Patients should also be questioned about inhalational exposures, including vaping. A thorough medical history, with special attention to chronic pulmonary diseases and risk factors for malignancy and bronchiectatic lung disease (e.g., cystic fibrosis, sarcoidosis), is essential.

Physical Examination: Reviewing vital signs is the first step in assessing a patient with hemoptysis. Those with life-threatening hemoptysis can exhibit hypoxemia, tachycardia, and hemodynamic instability. Evaluating the nasal and oral cavities is crucial to identify any potential sources of bleeding. Additionally, listening to the lungs and searching for other relevant physical findings such as clubbing can help pinpoint the cause of hemoptysis. Wheezing in a specific area may indicate foreign body aspiration. Signs of a bleeding diathesis, like skin or mucosal ecchymoses and petechiae, or the presence of telangiectasias may suggest other underlying causes of hemoptysis.

Diagnostic Studies: Initial diagnostic studies should encompass a complete blood count to assess for signs of infection, anemia, or thrombocytopenia; coagulation parameters; electrolyte and renal function measurements; and urinalysis to rule out pulmonary-renal disease. Chest imaging is a crucial component of the evaluation for every patient.

A chest radiograph is typically the first imaging modality employed, although it may not always localize the bleeding source and can appear normal in some cases. Patients without risk factors for malignancy or other abnormalities in their initial evaluation and with a normal chest radiograph may be treated for bronchitis with close follow-up, as it represents a reasonable strategy in such cases. Conversely, patients with risk factors for malignancy (e.g., age over 40 or a history of smoking) should undergo further testing. This often includes contrast-enhanced chest computed tomography (CT) to better identify masses, bronchiectasis, and parenchymal lesions. A CT scan to check for pulmonary embolism may also be considered if the patient's history and physical examination align with that diagnosis. After a CT scan, a flexible bronchoscopy is usually performed to exclude bronchogenic carcinoma unless imaging reveals a lesion that can be sampled without bronchoscopy. Small case series suggest that patients with hemoptysis and unremarkable bronchoscopies tend to have favorable outcomes.

Interventions: In cases where hemoptysis is massive or life-threatening, three simultaneous goals must be pursued: protecting the nonbleeding lung, identifying the site of bleeding, and controlling the bleeding.

Protecting the airway and the nonbleeding lung is of utmost importance when managing massive hemoptysis, as asphyxiation can occur rapidly. If the bleeding site is known, positioning the patient with the bleeding side down can help prevent blood from entering the nonbleeding lung. Endotracheal intubation should be reserved for cases where it is absolutely necessary, as suctioning through an endotracheal tube is less effective than the cough reflex in removing blood and clots. If intubation becomes necessary, steps should be taken to protect the nonbleeding lung, either through selective intubation of one lung (the nonbleeding one) or the use of a double-lumen endotracheal tube.

Identifying the bleeding site can be straightforward in some cases but challenging in others. A chest radiograph can provide some localization information if it shows new opacities, although it is not sufficient on its own. CT angiography can be helpful by pinpointing active extravasation. Flexible bronchoscopy may aid in identifying the side of bleeding, although it has a 50% chance of success at best. Experts do not universally agree on the timing of bronchoscopy; in some cases, such as cystic fibrosis, it may not be recommended, as it could delay definitive management. Proceeding directly to angiography is also a reasonable strategy, as it offers both diagnostic and therapeutic capabilities.

Controlling bleeding during a life-threatening episode of hemoptysis can be achieved in one of three ways: from the airway lumen, from the involved blood vessel, or through surgical resection of both the affected airway and vessel. Bronchoscopic measures are generally temporary solutions. A flexible bronchoscope can be used to remove clots and insert a balloon catheter or bronchial blocker to block the affected airway temporarily. Rigid bronchoscopy, performed by an interventional pulmonologist or thoracic surgeon, may enable therapeutic interventions for bleeding airway lesions, such as photocoagulation and cautery. Since most life-threatening hemoptysis cases arise from the bronchial circulation, bronchial artery embolization is the preferred procedure for controlling bleeding. However, bronchial artery embolization can carry significant complications, such as embolization of the anterior spinal artery. Nevertheless, it is generally effective in the short term, with a success rate of over 80% in immediately controlling bleeding, although recurrence is possible if the underlying disease (e.g., a mycetoma) is not treated. Surgical resection should be considered only if initial measures fail and bleeding persists. Ideal candidates for surgery have localized disease but otherwise normal lung tissue.

Summary of Approach to Hemoptysis Management:

1. History and Examination: The initial assessment involves gathering a detailed patient history and conducting a physical examination. The history should include inquiries about the amount and characteristics of the bleeding, associated symptoms, risk factors, smoking history, and possible inhalational exposures. Vital signs, including oxygen saturation, heart rate, and blood pressure, should be reviewed. Examination should focus on identifying signs of active bleeding, the source of bleeding, and other relevant physical findings.
2. Diagnostic Studies: Depending on the patient's history and risk factors, initial diagnostic studies may include:
   • Complete blood count (CBC) to assess for infection, anemia, or thrombocytopenia.
   • Coagulation parameters to evaluate the patient's clotting function.
   • Measurement of electrolytes and renal function.
   • Urinalysis to exclude pulmonary-renal disease.
   • Chest imaging, typically starting with a chest radiograph, which may be followed by contrast-enhanced chest computed tomography (CT) in high-risk patients.
3. Interventions: The approach to managing hemoptysis depends on the severity of bleeding:
   • In cases of nonmassive hemoptysis without risk factors, treating the underlying cause (usually infection) may suffice.
   • In massive or life-threatening hemoptysis, immediate action is essential:
     • Protecting the airway and the nonbleeding lung is a priority. The patient may be positioned with the bleeding side down, and endotracheal intubation should be considered if necessary.
     • Identifying the bleeding site may require imaging modalities like CT angiography or flexible bronchoscopy.
     • Controlling bleeding can be achieved through bronchoscopic measures, bronchial artery embolization, or, as a last resort, surgical resection.
4. Bronchoscopy: Flexible bronchoscopy can help visualize and locate the bleeding source in the airways. However, its success rate in identifying the site is limited.
5. Bronchial Artery Embolization: This is the preferred method for controlling bleeding in cases where hemoptysis originates from the bronchial circulation. It involves blocking the bronchial arteries that supply the bleeding area, effectively stopping the bleeding.
6. Surgical Resection: Surgical removal of the affected airway and vessel is considered in cases where initial measures fail, and bleeding persists. This is a high-risk procedure and is typically reserved for localized disease with otherwise normal lung tissue.

Conclusion: Hemoptysis, or the coughing up of blood from the respiratory tract, can have various causes, including infection, malignancy, and vascular issues. Proper evaluation and management are crucial, with a focus on protecting the airway, identifying the bleeding source, and controlling the bleeding. The approach to management depends on the severity of hemoptysis, with massive or life-threatening cases requiring urgent intervention, including bronchial artery embolization or surgical resection in extreme cases. Early diagnosis and appropriate treatment are essential for the successful management of hemoptysis.