Asbestosis - A sometimes challenged diagnosis

Sunday, October 23, 2005

To the average person, getting a diagnosis of asbestosis, that is non-cancerous lung damage from asbestos should seem straightforward. Unfortunately it can be a long and frustrating path for some, primarily because of the issues of liability and compensation for injury. It is in the asbestos compensation fund member's interest to limit the number of people declared to have asbestosis. To be fair, the diagnosis can be tricky because there is a huge list of chemicals, minerals and diseases that can cause similar types of lung damage.

When a person inhales asbestos fibers, many of the larger fibers are caught on the mucous membranes of the upper respiratory system. Tiny cilia are constantly moving materials caught on the membrane out of the body by directing them to the upper respiratory system where they can be coughed or sneezed out. Small fibers can reach deep into the lung where a type of white blood cell called macrophages attempt to engulf the fibers. In the process these macrophages send out chemical signals called cytokines that produce a variety of physical changes in the lung. One of the major ones is the development of fibers that reduce the flexibility of the lung and its ability to absorb oxygen. Often patients with serious asbestosis have signs of chronic hypoxia, or low body oxygen levels. This causes pulmonary hypertension that could lead to severe heart problems. Asbestosis patients are also at a higher risk for various cancers including lung cancer and mesothelioma.

A procedure sometimes used to diagnose asbestosis is called Brochoalveolar Lavage or BAL. In this procedure a small amount of fluid is placed in the lung and then removed to be examined. Sometimes coated asbestos fibers called asbestos bodies can be seen in the fluid. This is a good indication that the disease in question was caused by the fibers. It may also help to quantify the intensity of exposure. The presence of asbestos bodies is not 100% diagnostic of asbestosis since they may sometimes be found in individuals with no known exposure and no disease. Asbestos fibers, because they were so widely used, can be found in many Americans. Disease is related to both the dose and genetic susceptibility.

A lung biopsy is sometimes also used, but it is invasive and is more commonly done at autopsy.

There is no gold standard for a diagnosis. Diagnosis is usually based on several criteria that do not require the actual detection of asbestos fibers. First, a history of significant asbestos exposure with a plausible latency period (usually years) for the disease to develop. Next, the patient must have changes in lung function and structure, which are documented by lung imaging. Other diseases that mimic asbestosis need to be excluded. The patient usually has trouble breathing after exertion with lung function is measurably impaired.

The liability fund participants (Asbestos Companies) sometimes challenge even relatively straightforward cases of asbestosis. Because of the sometimes subjective diagnosis, there is room to dispute the findings. This frustration highlights the need for careful documentation of exposure and clinical findings and the need for an aggressive attorney.