American Thoracic Society Journal news tips for October 2005 (second issue)



Californians who live close to naturally occurring asbestos source rocks and who are exposed to low levels of the mineral are at increased risk for malignant mesothelioma, a serious cancer of the pleural membrane covering the lungs, according to a new study.

For the research, investigators looked at 2,908 malignant mesothelioma cases reported over a 10-year period. Over 50 percent of the men and 58 percent of the women listed in the California Cancer Registry either had no or low occupational exposure to asbestos.

(Asbestos fibers can cause tumors in the two layers of membrane covering the lung (the pleura) or, with greater exposure, the membranes of the abdomen. Considered a rare cancer, meosothelioma usually takes 30 to 40 years after exposure to develop.)

According to the authors, California has more naturally occurring asbestos source rocks than any other state in the U.S., but their distribution is patchy, with exposed areas separated from unexposed areas.

The authors noted that the odds of being a mesothelioma case were 6.3 percent lower than the odds of being a study control patient with pancreatic cancer for each 6 miles (10 kilometers) they lived from the nearest asbestos source rocks.

Yet people who lived closer to naturally occurring asbestos deposits had a greater chance of developing the disease.

The authors explained that a major strength of the study was the very large number of mesothelioma cases used to assess the potentially weak association between exposure to naturally occurring asbestos and mesothelioma incidence.

The research appears in the second issue for October 2005 of the American Thoracic Society's peer-reviewed American Journal of Respiratory and Critical Care Medicine.


Researchers have developed a new clinical prediction rule that accurately classifies patients who have pulmonary embolism into five disease stages that show increasing risk of death or other adverse outcome.

To develop and test the rule, the investigators studied data from 15,531 discharged patients who had been hospitalized for pulmonary embolism at 186 Pennsylvania hospitals. For the study, the authors divided these patients into two groups: one to develop the rule and the other to verify their conclusions.

Acute pulmonary embolism represents a serious medical problem. It usually involves a blood clot that travels through the blood stream and suddenly blocks an artery of the lung. The most common type involves a blood clot that begins in either a leg or pelvic vein. Blood clots tend to develop where blood is flowing slowly such as can occur when an individual stays in one position too long. Once a clot breaks loose, it tends to travel to the lung.

According to the study, data from the National Hospital Discharge Survey show that in 2002, 101,000 patients with a primary diagnosis of pulmonary embolism were hospitalized in acute care hospitals in the United States, resulting in 676,700 inpatient days.

The researchers looked at 11 patient factors independently associated with 30-day patient mortality from pulmonary embolism. These were: two demographic factors (age and male sex); three illnesses (cancer, heart failure, and chronic lung disease); and six clinical findings related to such measurements as pulse, systolic blood pressure, respiratory rate, temperature, altered mental state (disorientation, lethargy, or stupor), plus the arterial oxygen saturation level. These readily available clinical parameters each were assigned a numerical score to quantify them with the patient's potential for death.

According to the authors, the rule identifies patients who are at either low or high risk of fatal and nonfatal medical outcomes associated with pulmonary embolism. For example, the 30-day mortality rate for a class I score was 1.6 percent or less. For class II, it was 3.5 percent. At class V, it ranged from 10 to 24.5 percent.

The investigators point out that, either through outpatient management or early hospital discharge of patients identified as very low risk in class I or low risk in class II, the rule could provide the potential for large cost savings without added risk to the patient. However, before the rule can be implemented in clinical practice, its clinical usefulness should be tested in a prospective study.

The research appears in the second issue for October 2005 of the American Thoracic Society's peer-reviewed American Journal of Respiratory and Critical Care Medicine.

Source: Eurekalert & others

Last reviewed: By John M. Grohol, Psy.D. on 21 Feb 2009
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