Hemoptysis overview

# Overview
Lung has two main vascular systems that include pulmonary circulation and bronchial circulation. There are multiple anastomoses between pulmonary and bronchial arterieswhich create physiologic right to left shunts. Blood in the hemoptysis is mostly originated from the Lung. However, it could be from the gastrointestinal system as well. Primary origin of the blood comes from bronchial arteries. Hemoptysis is an important symptom that has different etiologies and pathogenesis mechanisms. Hemoptysis may happen following infarction and ischemia of pulmonaryparenchyma and vascular engorgement with erosion. Hemoptysis may be classified according to severity into 3 groups of mild, moderate, and massive bleeding. Life-threatening causes of hemoptysis include pulmonary embolism. Common causes of hemoptysis include bronchiectasis, acute respiratory tract infections, chronic obstructive pulmonary disease, bronchitis, pneumonia, lung cancer, tuberculosis, cystic fibrosis, and idiopathic.

# Historical Perspective
During 129-199 A.D., Galen identified the bronchial arteries as internal vessels of the lung. Leonardo da Vinci illustrated lung circulation. In the 1960s, angiography of the thoracic aorta and bronchial tree was done. In 1963, angiography of bronchial arteries was described by Viramonte. In 1974, Remy introduced bronchial artery embolization(BAE) as a successful, effective, non-invasive procedure to treat hemoptysis.

# Classification
Hemoptysis may be classified into several subtypes based on duration of symptoms, severity and origin of the bleeding. Based on the duration of symptoms, hemoptysis may be classified as either acute or chronic. Hemoptysis may be classified according to severity into 3 groups of mild, moderate, and massive bleeding. Based on the origin of bleeding, hemoptysis may be classified into two groups of pulmonary vs extrapulmonary bleeding.

# Pathophysiology
Lung has two main vascular systems that include pulmonary circulation and bronchial circulation. There are multiple anastomoses between pulmonary and bronchial arterieswhich create physiologic right to left shunts. Blood in the hemoptysis is mostly originated from the Lung. However, it could be from the gastrointestinal system as well. Primary origin of the blood comes from bronchial arteries. However, other sources of bleeding might be pulmonary vessels, aorta, intercostal, coronary, thoracic, and phrenic arteries. Hemoptysis is an important symptom that has different etiologies and pathogenesis mechanisms. Hemoptysis may happen following infarction and ischemia of pulmonaryparenchyma as seen in pulmonary embolism, vasculitis, and infections. Another mechanism of hemoptysis is vascular engorgement with erosion as seen in bronchitis, bronchiectasis, and toxic exposure to cigarette and other irritants. In some cases underlying cause can not be identified and they are considered as idiopathic. However, they might present with massive hemoptysis. There are multiple conditions that are associated with hemoptysis which include granulomatosis with polyangiitis, sarcoidosis, immunodeficiency, and indoor ice hockey play.

# Causes
Life-threatening causes of hemoptysis include pulmonary embolism. Common causes of hemoptysis include bronchiectasis, acute respiratory tract infections, chronic obstructive pulmonary disease, bronchitis, pneumonia, lung cancer, tuberculosis, cystic fibrosis, and idiopathic. Less common causes of hemoptysis include ruptured aneurysms, lung abscess, aspergilloma, idiopathic pulmonary fibrosis, behcet's disease, aortobronchial fistula, pulmonary endometriosis, goodpasture syndrome, and foreign body aspiration.

# Differentiating Hemoptysis from Other Diseases

# Epidemiology and Demographics
The incidence of hemoptysis is approximately 100 per 100,000 individuals in the outpatient setting. There is no enough data on prevalence of hemoptysis. The mortality rate of patients with massive hemoptysis is approximately 50-100%, if left untreated. During 1995-2005, in-hospital mortality rate of massive hemoptysis was 0-15%. Patients of all age groups may develop hemoptysis. There is no racial predilection to hemoptysis. Hemoptysis affects men and women equally. Hemoptysis is a symptom that might affect everyone. Underlying causes of hemoptysis might be different in developed countries than in developing countries. In the United States, incidence of tuberculosis in patients with massive hemoptysis is 7%, while in south africa it is 85%.

# Risk Factors
Common risk factors in the development of hemoptysis include cigarette smoking, chronic obstructive pulmonary disease, anticoagulant medications. Risk factors in the recurrence of hemoptysis include persistent residual mild bleeding following bronchial artery embolization, blood transfusion before the procedure, and aspergilloma. Less common risk factors in the development of hemoptysis include congestive heart failure and mitral regurgitation.

# Screening
There is insufficient evidence to recommend routine screening for hemoptysis.

# Natural History, Complications, and Prognosis
Hemoptysis is an important symptom that indicates an underlying pulmonary or extrapulmonary causes. Hemoptysis usually happens following bronchitis as an acute symptomand it resolves spontaneously or with antibiotic therapy within a week. Watchful observation in a patient with hemoptysis and normal chest x-ray is recommended. However, persistent and massive hemoptysis requires further investigations. Asphyxia and airway obstruction are common after massive hemoptysis. Prognosis of hemoptysis is generally excellent. However, massive hemoptysis has a poor prognosis and the mortality rate of patients with hemoptysis is approximately 50-100%, if left untreated.

# Diagnosis

## Diagnostic Study of Choice
The initial diagnostic study in a patient with hemoptysis is chest x-ray. If diagnosis is not found on chest x-ray, the next step is to perform high resolution CT scan or bronchoscopy. HRCT is better for diagnosis of bronchiectasis or lung carcinoma. Flexible bronchoscopy is better for diagnosis of mucosal abnormalities such as bronchitis, Dieulafoy disease or kaposi sarcoma.

## History and Symptoms
Patients with hemoptysis may have a positive history of upper respiratory tract infection, gastrointestinal disease, exposure to patients with tuberculosis, bleeding disorders, medications (anticoagulants), and cigarette smoking. Common symptoms of hemoptysis include bloody sputum, chronic cough, shortness of breath, pleuritic chest pain, and wheezing. Less common symptoms of hemoptysis depends on the etiology include weight loss, change in cough, fatigue.

## Physical Examination
Physical examination of patients with hemoptysis might be normal. However, patients might show different findings depend on underlying causes. Patients with hemoptysis usually appear anxious and depend on the severity of bleeding they might be critically ill. Patients with hemoptysis usually have abnormal vital signs indicating dehydration, other signs of mucosal bleeding, purulent bloody sputum, and abnormal lung exam indicating underlying pulmonary causes.

## Laboratory Findings
There are laboratory tests that are helpful for diagnosis the underlying cause of hemoptysis. Sputum must be evaluated for the cytology, gram stain, culture, and acid-fast stain. Arterial blood gases might show hypoxia. Complete blood count (CBC) might show elevated WBC, low platelet, and anemia. Signs of dehydration might be detected in laboratorytests such as BUN, Cr, urinalysis, or electrolytes. Coagulation studies might be abnormal.

## Electrocardiogram
There are no electrocardiogram findings associated with hemoptysis. However, electrocardiogram might be abnormal with some of the underlying causes of hemoptysis.

## X-ray
Chest x-ray is the first diagnostic modality that is used in a patient with hemoptysis. Chest x-ray might differentiate underlying causes of hemoptysis. Chest x-ray is usually used to compare with previous or later imagings in order to evaluate the progression and resolution of the underlying cause. However, chest x-ray might be completely normal in patients with hemoptysis.

## Echocardiography and Ultrasound
There are no echocardiography/ultrasound findings associated with hemoptysis. However, echocardiography or ultrasound might be abnormal with some of the underlying causes of hemoptysis.

## CT scan
Chest CT scan and CT angiography may be helpful in the evaluation of a patient with hemoptysis. It is useful for assessing the cause of hemoptysis, localizing the origin of the blood, providing prognostic information by correlating between the extent of lobar involvement on high-resolution CT and the amount of bleeding, and assisting the interventional radiologist prior to treatment. CT scan is not helpful in unstable patients, patients with active bleeding who require bronchoscopy intervention, and patients with bilateral lung abnormalities.

## MRI
Chest MRI may be helpful in the diagnosis of underlying causes of hemoptysis.

## Other Imaging Findings
Other imaging findings may be helpful in the diagnosis of underlying causes of hemoptysis.

## Other Diagnostic Studies
Rigid bronchoscopy may be helpful in the differentiating underlying etiologies of hemoptysis, localizing the bleeding site, identifying lung cancer, and even treatment of the underlying cause of hemoptysis in case of visible endoluminal lesions. Other diagnostic studies for localizing the site of bleeding in a patient with hemoptysis include angiographyand aortography.

# Treatment

## Medical Therapy
Hemoptysis is a symptom that indicates an underlying pulmonary or extrapulmonary cause. Pharmacologic medical therapy depends on an underlying cause. However, the mainstay of treatment for massive hemoptysis is supportive and surgical therapy.

## Surgery
Massive hemoptysis is a life-threatening condition and requires prompt intensive care. Surgery is indicated in patients with hemoptysis who are resistant to embolization. Interventional techniques are used to stop bleeding which include bronchial arterial embolization, different bronchoscopic strategies such as cold saline lavage, topical vasoconstrictor agents, balloon tamponade, endobronchial stent placement, endobronchial spigot, oxidized regenerated cellulose, N-Butyl cyanoacrylate glue, fibrinogenthrombin, tranexamic acid, laser photocoagulation, argon plasma coagulation, and electrocautery. Surgical techniques that are used for management of hemoptysis include pulmonary resection, lobectomy, and bilobectomy. Surgical techniques are definitely curative, effective for localized lesions. However, surgery has a mortality rate of 10-30%. Currently, bronchial arterial embolization considered as a first line therapy for both new and recurrent hemoptysis.

## Primary Prevention
Effective measures for the primary prevention of hemoptysis include smoking cessation, avoiding air pollutants, and use of physical barriers such as masks and gown.

## Secondary Prevention
There are no established measures for the secondary prevention of hemoptysis.