Haemoptysis refers to the coughing up of blood from the lungs, below the vocal cords or glottis. To make the right diagnosis, it is important to first differentiate haemoptysis from mimickers like the vomiting of blood from the gastrointestinal tract (haematemesis) or bleeding from the gums and nasal passages.
Haemoptysis can be a common symptom. In a study of patients in primary care, approximately one in 1,000 patients per year experienced it, but these cases tend to be mild.
On the other end of the spectrum, massive haemoptysis can be life-threatening. It is less common and occurs in 5-15 percent of patients presenting with the condition. Generally, bleeding rates more than 100 ml of blood (1/3 cup) over one hour or 500 ml in 24 hours are considered massive. Patients with lower cardiopulmonary reserves are at higher risk, even with lower bleeding rates (50 ml/hour).
Haemoptysis has numerous causes as the bleeding can arise from different regions in the lung:
Tracheobronchial airways
Pulmonary parenchymal (lung tissue)
Pulmonary vessels
Common causes include acute bronchitis, pneumonia, tuberculosis, lung cancer, and chronic lung disease, such as chronic bronchitis and bronchiectasis.
Less common causes include the presence of an aspergilloma (a fungal ball, within a chronic lung cavity), fungal infections in immunocompromised patients, and pulmonary embolism.
Patients should see a doctor to determine the underlying cause for targeted treatment. Most cases are mild and self-limiting. However, if there are features and risk factors for an underlying cancer or chronic lung disease, further lung imaging and examination with scopes might be needed.
If the haemoptysis is massive, patients will have to proceed to the ER. Massive haemoptysis can be life-threatening because the windpipe can become obstructed, resulting in respiratory failure or cardiac arrest.
The patients who are at higher risk of asphyxiation from massive haemoptysis are usually older and have weaker physical and cardiorespiratory reserves due to underlying comorbid diseases such as heart disease, cancer, or stroke.
The treatments target the underlying causes, which are varied. In patients with chronic lung disease such as bronchiectasis and chronic bronchitis, vaccinations and long-term macrolide therapy might prevent lung infections or infective exacerbations.
If patients are hospitalised, intravenous or nebulised tranexamic acid can be used to reduce bleeding; cough suppressants and antibiotics can reduce coughing.
In massive haemoptysis, emergency procedures might be required, such as intubation to secure the airway, a bronchoscopy, and the use of an endobronchial blocker to seal off the bleeding lung segment.
As the bleeding source is typically from hypertrophied bronchial arteries, bronchial arterial embolisation is often the definitive emergency treatment. An arteriogram is first performed to locate the bleeding bronchial artery which is then blocked off with various endovascular agents, e.g., a gelatin sponge, polyvinyl alcohol particles, microspheres, or even metallic coils, to stem the bleeding.
The success rates of these procedures range from 60-90 percent, but the risk of recurrent bleeding can be as high as 30-50 percent in patients with an aspergilloma or lung cancer, respectively.
