Factors predicting bacterial involvement in severe acute exacerbations of chronic obstructive pulmonary disease.
BACKGROUND
Strategies aiming at reducing antibiotic use are required in the intensive care unit (ICU). Although antibiotic treatment is recommended in patients with severe exacerbation of chronic obstructive pulmonary disease (COPD), a bacterial etiology is found in only a half of these patients.


OBJECTIVE
The aim of this study was to determine factors predicting bacterial isolation in severe acute exacerbations of COPD.


METHODS
All patients with severe acute exacerbation of COPD requiring intubation and mechanical ventilation were included in this prospective observational cohort study. At ICU admission, information on endotracheal aspirate purulence and hyperthermia was collected. In all patients, Gram stain and quantitative endotracheal aspirate culture (positive at 10(6) cfu/ml) were performed. In addition, leukocyte count, C-reactive protein and procalcitonin (PCT) levels were measured.


RESULTS
Ninety-eight severe acute exacerbations of COPD requiring intubation and mechanical ventilation were studied. Forty-nine bacteria were isolated at significant threshold in 40 exacerbations. Streptococcus pneumoniae (16%), methicillin-sensitive Staphylococcus aureus (16%) and Hemophilus influenzae (14%) were the most frequently isolated bacteria. PCT >0.5 ng/ml and positive Gram stain of endotracheal aspirate were independently associated with bacterial isolation in severe acute exacerbation of COPD. Positive Gram stain and PCT >0.5 ng/ml had a negative predictive value >95%. Similar results were found after excluding patients with prior antibiotic treatment.


CONCLUSIONS
Positive Gram stain of endotracheal aspirate and PCT >0.5 ng/ml are independently associated with bacterial isolation in severe acute exacerbation of COPD. These results could be helpful for future interventional studies aiming at reducing antibiotic use in these patients.
Intensive Care Unit, Calmette Hospital, University Hospital of Lille, Lille, France. s-nseir@chru-lille.fr
Saad
S
Nseir
Béatrice
B
Cavestri
Christophe
C
Di Pompeo
Maimouna
M
Diarra
Hélène
H
Brisson
Malcolm
M
Lemyze
Micheline
M
Roussel-Delvallez
Alain
A
Durocher
D000208:Acute Disease; D000368:Aged; D000465:Algorithms; D001992:Bronchoalveolar Lavage Fluid / Q000382:microbiology*; D002116:Calcitonin / Q000097:blood; D015740:Calcitonin Gene-Related Peptide; D005260:Female; D006090:Gram-Negative Bacteria / Q000302:isolation & purification*; D006094:Gram-Positive Bacteria / Q000302:isolation & purification*; D006801:Humans; D007362:Intensive Care Units; D007442:Intubation, Intratracheal; D008297:Male; D015999:Multivariate Analysis; D011237:Predictive Value of Tests; D011446:Prospective Studies; D011498:Protein Precursors / Q000097:blood; D029424:Pulmonary Disease, Chronic Obstructive / Q000382:microbiology*; D012121:Respiration, Artificial; D012680:Sensitivity and Specificity
C000606589:CALCA protein, human; D011498:Protein Precursors; D002116:Calcitonin; D015740:Calcitonin Gene-Related Peptide