Chest
Volume 114, Issue 6, December 1998, Pages 1594-1598
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Clinical Investigations
Infection
The Effect of Pseudomonas aeruginosa Infection on Clinical Parameters in Steady-State Bronchiectasis

https://doi.org/10.1378/chest.114.6.1594Get rights and content

Study objective

To investigate the effect of Pseudomonas aeruginosa infection on clinical parameters in Chinese patients with noncystic fibrosis and steady-state bronchiectasis.

Design

Prospective, cross-sectional clinicomicrobiological study with informed consent.

Setting

Consecutive outpatient recruitment from a specialist bronchiectasis respiratory clinic.

Patients

Outpatients (n = 100; 62 women; 55.1 ±16.7 years old; FEV1/FVC 1.4 ± 0.7/2.1 ± 0.9 L), who had stable respiratory symptoms for more than 3 weeks.

Measurements and results

Respiratory pathogens isolated from the sputum were: Pseudomonas aeruginosa (33), Haemophilus influenzae (10), Moraxella catarrhalis (2), other Gram-negative bacilli (5), Streptococcus pneumoniae (6), Staphylococcus aureus (5), mycobacteria (3), and yeast (1). Clinical parameters in patients with positive isolation of P aeruginosa were compared with those without the organism in the sputum culture (non-P aeruginosa). In the P aeruginosa group, the FEV1/FVC ratio and sputum volume were lower (p < 0.005) and higher (p < 0.0001), respectively, than those of the non-P aeruginosa group. The FEV1/FVC ratio (< 60%) and sputum volume (grading > 5) were independently associated with a positive sputum isolation of P aeruginosa with odds ratios of 3.1 (confidence interval [CI] 1.2 to 8.4; p < 0.01) and 4.7 (CI 1.6 to 13.3; p < 0.001), respectively.

Conclusions

P aeruginosa is the predominant respiratory pathogen isolated in the sputum of Chinese patients with steady-state bronchiectasis, and its isolation is associated with high sputum output (≥ 75th quartile) and moderately severe airflow obstruction (FEV1/FVC < 60%).

Section snippets

Study Design and Patient Recruitment

Consecutive patients with bronchiectasis, confirmed with high-resolution computed tomography, were recruited with informed consent into a baseline period (three consecutive weekly visits) to ensure that they were in steady-state bronchiectasis. The measurements of clinical and laboratory parameters were performed by a clinician and a technician who were unaware of the study protocol. A “steady-state” bronchiectasis was defined where there was an alteration of < 10% of a 24-h sputum volume, FEVl

Patient Demography and Clinical Details

Between September 1996 and July 1997, 100 consecutive patients with bronchiectasis with apparently stable symptoms and sputum production (mean age ± SD, 55.1 ± 16.7 years; 62 women) were recruited. Of the patients recruited, 33 were current smokers, 6 were ex-smokers, and 61 were nonsmokers. The other patient characteristics, including etiology of bronchiectasis, current medications, duration from onset of regular sputum production, spirometry, 24-h sputum volume grading, and sputum purulence

Discussion

The relative frequencies of bacteria isolated in this study among Chinese with bronchiectasis were different from those reported in sputum studies from the West.1, 2, 3, 4, 5,12,13 In studies performed on white patients in the 1970s and 1980s, H influenzae, S pneumoniae, and S aureus were the predominant bacteria isolated. The relative frequencies of these organisms were reported to be 83%, 35%, and 29%, respectively.14 Although there was a trend toward more P aeruginosa (23%) and less H

Acknowledgments

We thank Dr. Ian Lauder for his expert statistical advice and Mr. Raymond Leung for technical support. We are grateful to the patients who participated in this study.

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