Diagnosis of Hemoptysis
Laboratory Tests for Hemoptysis
A variety of laboratory tests may be done to help in the diagnosis. They usually involve collecting bodily fluids (blood, urine, coughed-up sputum) and looking at them through a microscope or analyzing their components using specialized machinery.
Depending on the medical history and symptoms, laboratory tests might include a complete blood count (an analysis of the various components of the blood), a coagulation profile (an analysis of the clotting capabilities of the blood), an AFB smear (a test that looks for the presence of mycobacterium in the sputum), a sputum culture (a test for other signs of infection in the sputum), arterial blood gas studies (measuring the levels of oxygen and carbon dioxide in the blood), and urinalysis (a test that examines the urine).
If there is still any question about whether the patient is experiencing hemoptysis or hematemesis, these tests can confirm the diagnosis. For example, if the pH of the blood is alkaline, the patient likely has hemoptysis, and if the blood is acidic, the patient probably has pseudohemoptysis.
If alveolar macrophages (immune system cells in the alveolithe lung's first line of defense against the foreign particles in the air) are present in the sputum, the blood is likely hemoptysis, and if there are food particles, it is likely hematemesis.
Chest X-ray to Diagnose Hemoptysis
The chest x-ray is an integral part of the diagnosis and involves exposing the chest to radiation to produce an image of the lungs, heart, bones, and other tissue in the chest region. The radiologist (a physician trained to read and interpret x-ray images) can spot abnormalities that may be related to the hemoptysis.
Certain radiological features are helpful in narrowing the diagnostic choices or confirming a particular diagnosis. Many relatively mild causes of hemoptysis present with a clear chest x-ray. However, other diagnostic tests, including laboratory tests and possibly a bronchoscopy, may be indicated if the cause of the bleeding cannot be determined.
CT Scan to Diagnose Hemoptysis
A CT scan (also known as a "CAT" scan, computerized axial tomography) is a painless procedure that uses x-ray images with the aid of a computer to obtain 3-dimensional, cross-sectional pictures of the internal anatomy. A chest CT produces more detailed pictures than a normal chest x-ray and is more sensitive to abnormalities that may not be present on the chest x-ray.
Some physicians recommend CTs only when abnormalities show up on the chest x-ray or the patient is at risk for cancer. Because of its detailed sensitivity and diagnostic power, others think CTs should always be performed. Chest CT benefits vary and it is especially helpful for diagnosing bronchiectasis (see bronchiectasis). If a doctor suspects bronchiectasis (the patient is less than 40 years old and is not at risk for cancer), a chest CT may be indicated.
Fiberoptic Bronchoscopy (with or without biopsy) to Diagnose Hemoptysis
Bronchoscopy involves inserting a flexible tube through the mouth or nose, into the airway, and into the lungs. It enables the doctor to view the tissue inside the lungs (directly or on a monitor) and biopsy (collect a small sample) abnormal tissue for microscopic examination. The tissue is later examined under a microscope to confirm the diagnosis. The procedure is painless (patients are given relaxation medication and a local anesthetic) and takes from 15 minutes to an hour.
There are several different ways to biopsy the airway or lung tissue. If the abnormal area is on the wall of an airway, the tissue can be washed with a saline solution and suctioned, or it can be brushed with a soft brush. If the abnormal tissue is not easily accessible, a needle biopsy or a forceps biopsy is usually done.
A needle biopsy involves using a small needle to collect cells on the other side of the airway wall. A forceps biopsy involves using forceps to sample an area of tissue.
If the lesion or abnormal tissue is deep within the lung, a technique called fluoroscopy may be used during the bronchoscopy. Fluoroscopy involves using x-rays to examine tissue deep within the body and guide the biopsy. Once the biopsy is done, the tissue sample is sent to the laboratory for microscopic evaluation, the cells are observed, and abnormalities detected.
The decision to perform a bronchoscopy depends on several factors, including the patient's risk factors for lung cancer, the timing of the procedure, and the risks associated with bronchoscopy. Patients should discuss the procedure thoroughly with the physician before making a decision.
There is general agreement that if potentially cancerous abnormalities are found on the chest x-ray, a patient with hemoptysis should have a bronchoscopy. A bronchoscopy allows the physician to examine the lung and bronchial tissue and collect samples of abnormal or potentially cancerous tissue.
About 30 to 60 percent of bronchogenic cancer patients have hemoptysis, so if the chest x-ray shows a potential malignancy (cancerous growth), the bronchoscopy is an important diagnostic tool.
There is controversy about whether a bronchoscopy is necessary if no abnormalities are detected on the chest x-ray. About 5 percent of hemoptysis patients who do not have bronchoscopies do have cancer. Certain risk factors for cancer may indicate the need for a bronchoscopy, including: the patient is male; older than 40 years old; has a history of smoking; has long-lasting hemoptysis (more than a week); and has spit up more than 30 mL of blood per episode.
If no abnormalities are seen on the chest x-ray and the patient is not at risk for lung cancer, is a bronchoscopy necessary or recommended? If the bleeding has been persistent, a bronchoscopy is probably a good idea. If the patient is not at risk for lung cancer, and the bleeding has not been persistent, a bronchoscopy most likely would prove unnecessary.
Some physicians think that it is very important that the bronchoscopy be done early on. It is usually easier to localize the source of the bleeding if the procedure is done less than 48 hours after the onset of bleeding. It is not clear that the timing of the bronchoscopy affects the clinical diagnosis, but an early bronchoscopy allows more immediate treatment.
As in any medical procedure, there are potential complications; but, the complications of this procedure are rare and usually minor. They include nosebleed, vocal cord injury, temporary lack of oxygen, heart injury (due to either the lack of oxygen or medication), bleeding from the site where the tissue is sampled, and a punctured lung.
Rigid Bronchoscopy to Diagnose Hemoptysis
Rigid bronchoscopy has largely been replaced by the newer, less invasive, easier fiberoptic techniques. It is still sometimes used for cases of massive hemoptysis, since the optics are better (providing better visibility through the blood) and the suction channel is better (making it easier to clean out the blood so the source of the bleeding can be seen and biopsied). A rigid bronchoscopy requires general anesthesia, meaning the patient is unconscious during the procedure.
Pulmonary Angiography to Diagnose Hemoptysis
Angiography is the use of x-rays to produce a picture called an "angiogram." It requires injecting a radiopaque substance (a contrast agent, or dye, that is impenetrable to x-rays) into the blood vessels, making them easier to see than in a conventional x-ray. Angiograms are most commonly used to examine the coronary arteries in patients with coronary artery disease; but they can also be used to examine the lungs in patients with hemoptysis. The lungs receive their blood supply from the pulmonary arteries and the bronchial arteries.
In cases of bronchiectasis, a bronchial angiogram may be performed instead of, or as well as, a pulmonary angiogram. The technique is sometimes used to diagnose vascular causes of hemoptysis (i.e., causes related to abnormalities or blockage in the blood vessels).