P. aeruginosa bacteria associated with increased hospitalizations in COPD patients

Patients with chronic obstructive pulmonary disease (COPD) who become infected with the bacterium Pseudomonas aerguinosa are more likely to have worse clinical outcomes and experience more hospitalizations during the course of their disease than COPD patients who are not infected, according to researchers from Buffalo, N.Y.

The study will be presented at the ATS 2012 International Conference in San Francisco.

Bacterial bronchial plays a key role in the course of COPD, causing as well as acute exacerbations of symptoms, and is related to increased levels of illness and mortality among COPD patients.

"Previous studies have shown that infection with P. aeruginosa is more common in patients with more severe COPD ," said study researcher Sanjay Sethi, MD, FACP, chief of the Pulmonary/Critical Care/ Division at the University at Buffalo, SUNY. "In this study, we wanted to determine if infection with P. aeruginosa was associated with poorer clinical outcomes, such as hospitalizations, need for intensive care, and greater numbers of exacerbations."

The study focused on 177 patients who participated in a COPD study at the Buffalo Veterans Affairs Medical Center from March 1994 to January 2011. Study participants had clinic visits every month and additional visits during exacerbations. During each visit, clinical information and sputum samples were taken. Patients with less than six months of follow-up were excluded from the study.

For this analysis, study participants were divided into two groups: those whose sputum samples showed evidence of P. aeruginosa (PA+) infection and those whose samples showed no evidence of the bacteria (PA-). In addition, follow-up times were divided into two phases, Phase 1 denoting the time period prior to acquiring P. aeruginosa and Phase 2 covering the time period after the bacteria had been identified in the sputum.

"As COPD progresses, hospitalizations and exacerbations tend to increase and we had to account for that in our analysis. Therefore, we matched PA+ subjects with PA- subjects having similar duration of follow-up in the study," Dr. Sethi said. "Rates of events, including hospitalizations, ICU admissions and COPD exacerbations, and relative risks of having at least one event were compared in the two phases within and between the two groups."

In the study's final analysis, 55 PA+ study participants were matched with 55 PA- control subjects. Although the two groups were well matched in terms of age, sex, pack years of smoking and lung function, the rates of hospitalization in the PA+ group after P. aeruginosa infection were significantly higher than those in the control group, and the relative risk of having at least one hospitalization, intensive care admission or exacerbation also were all greater.

"Similar analyses are being performed with other bacterial pathogens identified in our COPD study clinic data to determine if this observation is unique to P. aeruginosaor extends to other bacterial pathogens," Dr. Sethi said.

"The possibility exists that, in our study, P. aeruginosa may be simply a 'colonizing bacteria' – a marker for worsening COPD– rather than a cause of the worse ," he added. "However, we and others have shown that P. aeruginosa behaves as an infectious pathogen in COPD. Also, in related chronic airway diseases, such as cystic fibrosis, infection is a major cause of morbidity and mortality."

Dr. Sethi noted that to date, P. aeruginosa infection has received little attention as an important pathogen in COPD. As a result, studies of specific treatments to eradicate or contain this infection have not been conducted in COPD.

"This study suggests that we should pay more attention to these bacteria in COPD, and treatments to deal with this pathogen in COPD should be developed," he said.

More information: "Acquistion Of Pseudomonas Aeruginosa Is Associated With Adverse Clinical Outcomes In COPD" (Session D105, Wednesday, May 23, Room 2024, Moscone Center; Abstract 27711)

add to favorites email to friend print save as pdf

Related Stories

Commonly prescribed antibiotic reduces acute COPD attacks

Aug 24, 2011

Adding a common antibiotic to the usual daily treatment regimen for chronic obstructive pulmonary disease (COPD) can reduce the occurrence of acute exacerbations and improve quality of life, reports new results from a clinical ...

Recommended for you

Sierra Leone: WHO too slow to help doc with Ebola

3 hours ago

Sierra Leone accused the World Health Organization on Monday of being "sluggish" in facilitating an evacuation of a doctor who died from Ebola before she could be sent out of the country for medical care.

Dutch doctors feared to have Ebola leave hospital

3 hours ago

Two Dutch doctors flown home from west Africa after fears they might have been contaminated with the killer Ebola virus have left hospital "in good health," their employer, the Lion Heart Medical Centre, said Monday.

Strategic self-sabotage? MRSA inhibits its own growth

9 hours ago

Scientists at the University of Western Ontario have uncovered a bacterial mystery. Against all logic, the most predominant strain of methicillin-resistant Staphylococcus aureus (MRSA) in North American produces an enzyme ...

US works to step up Ebola aid, but is it enough?

11 hours ago

The American strategy on Ebola is two-pronged: Step up desperately needed aid to West Africa and, in an unusual step, train U.S. doctors and nurses for volunteer duty in the outbreak zone. At home, the goal ...

User comments