Bronchoscopic validation of the significance of sputum purulence in severe exacerbations of chronic obstructive pulmonary disease.
BACKGROUND
Antibiotics are commonly prescribed in exacerbations of chronic obstructive pulmonary disease (COPD). However, the role of bacteria in these exacerbations is controversial.


OBJECTIVE
To identify clinical predictors of bacterial infection as a cause of exacerbation, considering the protected specimen brush (PSB) as the gold standard.


METHODS
Clinical data, sputum and PSB samples were collected from 40 patients with COPD requiring hospitalisation due to severe exacerbations who had not received previous antibiotic treatment.


RESULTS
Quantitative cultures of PSB samples (n = 40) yielded 23 potential pathogenic microorganisms (PPMs) at concentrations of > or =10(2) colony-forming units/ml in 18 (45%) patients. Sputum samples were obtained from all 40 patients. Culture of good-quality sputum samples (n = 18) yielded 16 PPMs corresponding to 14 (35%) patients. The concordance between the PSB and sputum rate was high (kappa = 0.85, p < 0.002). The self-reporting patient observation of sputum purulence (odds ratio (OR) 27.20 (95% confidence interval (CI) 4.60 to 60.69), p = 0.001), the percentage predicted forced expiratory volume in 1 s (FEV(1)%) <50 (OR 2.27 (95% CI 1.55 to 3.21), p = 0.014), >4 exacerbations in the past year (OR 6.9 (95% CI 0.08 to 1.08), p = 0.028) and previous hospitalisations due to COPD (OR 4.13 (95% CI 1.02 to 16.07), p = 0.041) were associated with the presence of PPMs in the distal airways. The operative characteristics for predicting distal airway infection when patients presented with purulent exacerbation were as follows: sensitivity 89.5%, specificity 76.2%, positive predicted value 77.3% and negative predicted value 88.9%.


CONCLUSIONS
The self-reporting presence of purulence in the sputum, as well as common previous exacerbations and hospitalisations due to COPD in patients with severe airflow obstruction (FEV1% <50) predict the presence of bacterial infection in the distal airways. The use of these clinical variables may help in selecting candidates to receive antibiotic treatment.
Soler
Néstor
N
Servei de Pneumologia, Institut Clínic del Tòrax, Hospital Clínic, IDIBAPS Universitat de Barcelona, Villarroel 170, 08036 Barcelona, Spain.
Agustí
Carlos
C
Angrill
Joaquim
J
Puig De la Bellacasa
Jorge
J
Torres
Antoni
A
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000900:Anti-Bacterial Agents / Q000627:therapeutic use*; D001424:Bacterial Infections / Q000188:drug therapy* / Q000382:microbiology; D001999:Bronchoscopy; D005260:Female; D005541:Forced Expiratory Volume; D006760:Hospitalization; D006801:Humans; D008297:Male; D008875:Middle Aged; D029424:Pulmonary Disease, Chronic Obstructive / Q000188:drug therapy / Q000382:microbiology*; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index; D013183:Sputum / Q000382:microbiology*; D013492:Suppuration / Q000382:microbiology; D014797:Vital Capacity
D000900:Anti-Bacterial Agents