The call-back is Kim Lynch of the ACCP. She can be reached by phone at (847) 498-8341 or by email at [email protected].
For Release: June 13, 2000
SPUTUM COLOR MAY DETERMINE WHETHER ANTIBIOTIC THERAPY IS NEEDED FOR PATIENTS WITH LUNG DISEASE
Classifying patients with acute exacerbations of lung disease by sputum color may help physicians avoid over-prescription of antibiotics, according to a new study appearing in the June issue of CHEST, the peer-reviewed journal of the American College of Chest Physicians.
About 14 million Americans have chronic obstructive pulmonary disease (COPD) which is the fifth leading cause of death in the U.S. Unlike other major chronic diseases, the death rate has been on the rise. Acute exacerbations of COPD manifest themselves as dyspnea (shortness of breath), wheeze, cough, sputum volume, and the development of sputum purulence. The cause of such exacerbations is variable, including increased airflow obstruction, mucus plugging and retention, and fluid retention, as well as bacterial and viral infections. The varied causes often make it difficult for physicians to decide on the optimal therapy for the acute episode.
Although widely used for this condition, the evidence of efficacy for antibiotic therapy is debatable, according to researchers at Queen Elizabeth Hospital in Birmingham, England. They noted that some controlled studies show a clear benefit, whereas others do not. They also pointed out that although sputum culture may be expected to clarify the role of antibiotics, the results can also be confusing because even in the stable clinical state, some patients have a sputum culture that is positive for bacteria.
The British investigators initiated a prospective study of acute exacerbations of COPD and enrolled 121 patients, 89 of whom presented a satisfactory sputum sample for analysis. The objective was to stratify these patients on the basis of sputum color and relate this to the isolation and viable numbers of bacteria recovered on culture.
Expectoration of green (purulent) sputum was taken as the primary indication for antibiotic therapy, whereas white or clear sputum was not considered representative of a bacterial episode and the need for antibiotic therapy.
Sputum samples were allocated a number by reference to a standard color chart. This chart was based on the principle that neutrophil myeloperoxidase (a green-colored enzyme) concentrations in the sputum reflect the number of neutrophils present and that this would relate to the degree of yellow-green coloration of the sample. Values of 1 and 2 reflected the nature of mucoid sputum that was opaque or milky in color. Values 3 to 8 reflected increasing yellow-green coloration. Thirty-four patients were graded with values of 1 or 2; 12 with values of 2; 42 with values of 4; 29 with values of 5; and, four with values of 6. Those with mucoid samples of the sputum did not receive antibiotic therapy. Those with clearly purulent sputum did receive antibiotic therapy.
Thirty-two of the 34 patients with mucoid exacerbation showed resolution of their symptoms without antibiotic therapy. Seventy-seven of those with purulent exacerbation had resolution of their symptoms after antibiotic treatment.
The researchers described some of the complexities in relying on Gram stains and the number of neutrophils to determine whether bacteria played in a role in the acute exacerbations and whether antibiotic therapy was warranted. On the other hand, they noted, sputum purulence is Clinically detectable and indicative of a new or significant bacterial stimulus. In thepresence of breathlessness and sputum volume, it would suggest benefit from antibiotics.
Robert A. Stockley, M.D., lead author of the new report, said that the study showed that subdivision of the acute lung exacerbations by sputum color identifies a group in whom recovery occurs without antibiotic therapy. "Classification of exacerbations by sputum color may enable antibiotic therapy to be withheld at present in some patients," he said. Dr. Stockley also noted that green sputum was nearly always associated with the presence of a significant bacterial load. He said that the choice of antibiotics for such episodes will depend specifically on local susceptibility patterns.
CHEST is published by the American College of Chest Physicians, which represents 15,000 members who provide clinical, respiratory, and cardiothoracic patient care in the U.S. and throughout the world.
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Reporters may wish to contact Kimberly Lynch of the ACCP at (847) 498-8341 for a copy of the article. She can also be reached by fax at (847) 498-5460 or by email at [email protected]. Dr. Stockley can be reached by phone at 44-121-697-8257 or 44-121-697-8398 or by fax at 44-121-697-8256. He can also be reached by email at [email protected].
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