Haemoptysis (coughing up blood)
Haemoptysis is the expectoration of blood that originates below the vocal cords. It is commonly classified as trivial, mild, or massive the latter defined as more than 200–600 mL (about 1–2 cups) in 24 hours. Massive hemoptysis can be usefully defined as any amount that is haemodynamically significant or threatens ventilation.
The causes of haemoptysis can be classified anatomically.
Blood may arise from the airways in COPD, bronchiectasis, and bronchogenic carcinoma; from the pulmonary vasculature in left ventricular failure, mitral stenosis, pulmonary embolism, pulmonary arterial hypertension, and arteriovenous malformations; or from the pulmonary parenchyma in pneumonia, fungal infections, inhalation of crack cocaine, or granulomatosis with polyangiitis (formerly Wegener granulomatosis).
Diffuse alveolar hemorrhage manifested by alveolar infiltrates on chest radiography is due to small vessel bleeding usually caused by autoimmune or hematologic disorders, or rarely precipitated by warfarin.
Most cases of haemoptysis presenting in the outpatient setting are due to infection (eg, acute or chronic bronchitis, pneumonia, tuberculosis, aspergillosis). Haemoptysis due to lung cancer increases with age, causing up to 20% of cases among older adults.
Most cases of haemoptysis that have no visible cause on CT scan or bronchoscopy will resolve within 6 months without treatment, with the notable exception of patients at high risk for lung cancer (smokers older than 40 years)
True haemoptysis versus pseudohaemoptysis
When evaluating a patient presenting with expectoration of blood, one must determine the source of the bleeding and determine whether the patient is presenting with true haemoptysis or pseudohaemoptysis. Aetiologies of pseudohaemoptsis include the upper gastrointestinal tract and upper respiratory tract.
Differential diagnosis for haemoptysis
Infective causes: Pneumonia is a common cause of haemoptysis; in such patients, physicians must look for symptoms and signs of infection such as fever, chest pain and productive cough. It is also important to obtain any relevant contact and/or travel history. Tuberculosis is a common cause of massive haemoptysis. It is hence prudent for a practitioner to look for risk factors of tuberculosis. This includes immunosuppression, which may be secondary to immunosuppressive medications or conditions such as human immunodeficiency virus infection or diabetes mellitus.
Neoplastic causes: Neoplastic lesions that can cause haemoptysis can be divided into primary pulmonary lesions and metastatic lesions. If a malignant cause is suspected, physicians should consider a thorough history and examination to look for other primary malignancies such as history of breast, kidney, gastrointestinal, ovarian and cervical cancers. It is important to also elicit constitutional symptoms such as loss of weight and appetite, and to consider the risk factors for primary lung carcinoma such as smoking and occupational exposure.
Vascular causes: Vascular causes of haemoptysis include pulmonary embolism. In patients with suspected pulmonary embolism, the physician should ask if they have a history of recent surgery or immobilisation. The limbs should be assessed for any signs of deep vein thrombosis as well. Other signs and symptoms to look out for include dyspnoea, chest pain, tachypnoea and tachycardia.
Autoimmune causes: Vasculitic rash, haematuria, joint pain or swelling may be suggestive of underlying autoimmune diseases such as Wegener’s granulomatosis (granulomatosis with polyangiitis), systemic lupus erythematosus (SLE) or Goodpasture syndrome. The characteristic butterfly rash or other skin lesions such as alopecia in SLE may also be found. If autoimmune disease is suspected, the patient should be referred to a specialist centre for further evaluation.
Drug-related causes: Common drugs that may cause haemoptysis include anticoagulants and antiplatelet agents. It is important to elicit further history (i.e. medication history) in order to predict the consequence of stopping medications as part of management.
When approaching a patient with haemoptysis, a proper history has to be taken to narrow down the aetiology of the patient’s symptoms. The physician should first exclude the possibility of pseudohaemoptysis and then narrow down the groups of causes for true haemoptysis. It is also paramount to quantify the amount of blood loss and evaluate for any complications due to blood loss. This includes evaluation of signs and symptoms of anaemia and searching for signs of haemodynamic compromise.
The patient’s vital signs should be measured and documented. Criteria for admission to the emergency department or referral to specialist clinics are as follows: (a) high risk of massive bleed; (b) gas exchange abnormalities (respiratory rate > 30 breaths/minute, oxygen saturation < 88% room air); (c) haemodynamic instability (e.g. tachycardic, tachypnic, hypotensive patient); (d) other respiratory comorbidities (e.g. previous pneumonectomy, chronic obstructive pulmonary disease); and (e) other comorbidities (e.g. ischaemic heart disease, need for anticoagulants/antiplatelet agents).
Chest radiography is typically recommended for all patients who present with haemoptysis. It is a quick, readily available and cheap modality that can assist in revealing any focal or diffuse parenchymal involvement as well as pleural abnormalities. Other diagnostic modalities include bronchoscopy, multidetector computed tomography (CT), multidetector CT angiography and digital subtraction angiography.
Management of mild haemoptysis consists of identifying and treating the specific cause. Massive hemoptysis is life-threatening. The airway should be protected with endotracheal intubation, ventilation ensured, and effective circulation maintained. If the location of the bleeding site is known, the patient should be placed in the decubitus position with the involved lung dependent. Uncontrollable hemorrhage warrants rigid bronchoscopy and surgical consultation.
In stable patients, flexible bronchoscopy may localize the site of bleeding, and angiography can embolize the involved bronchial arteries. Embolization is effective initially in 85% of cases, although rebleeding may occur in up to 20% of patients during the following year. The anterior spinal artery arises from the bronchial artery in up to 5% of people, and paraplegia may result if it is inadvertently cannulated and embolized. There is some evidence that antifibrinolytics may reduce the duration of bleeding.