Multiple-drug-resistant bacteria in patients with severe acute exacerbation of chronic obstructive pulmonary disease: Prevalence, risk factors, and outcome.
OBJECTIVE
To determine prevalence, risk factors, and effect on outcome of multiple-drug-resistant (MDR) bacteria in patients with severe acute exacerbation of chronic obstructive pulmonary disease.


METHODS
Prospective, observational, cohort study.


METHODS
Thirty-bed medical intensive care unit (ICU) in a university hospital.


METHODS
All chronic obstructive pulmonary disease patients with acute exacerbation who required intubation and mechanical ventilation for >48 hrs were eligible during a 4-yr period. Patients with pneumonia or other causes of acute respiratory failure were not eligible. In all patients, quantitative tracheal aspirate was performed at ICU admission (positive at 10 colony-forming units [cfu]/mL). MDR bacteria were defined as methicillin-resistant Staphylococcus aureus, ceftazidime- or imipenem-resistant Pseudomonas aeruginosa, Acinetobacter baumannii, Stenotrophomonas maltophilia, and extended-spectrum beta-lactamase-producing Gram-negative bacilli. All patients received empirical antibiotic treatment at ICU admission. Univariate and multivariate analyses were used to determine variables associated with MDR bacteria and variables associated with ICU mortality.


RESULTS
A total of 857 patients were included, and 304 bacteria were isolated (>/=10 cfu/mL) in 260 patients (30%), including 75 MDR bacteria (24%) in 69 patients (8%). When patients with MDR bacteria were compared with patients without MDR bacteria, previous antimicrobial treatment (odds ratio [OR], 2.4; 95% confidence interval [95% CI], 1.2-4.7; p = .013) and previous intubation (OR, 31; 95% CI, 12-82; p < .001) were independently associated with MDR bacteria. When patients with bacteria other than MDR or patients with no bacteria were used as a reference group, these risk factors were still independently associated with MDR bacteria. Although ICU mortality rate was higher in patients with MDR bacteria than in patients without MDR bacteria (44% vs. 25%; p = .001; OR, 2.3; 95% CI, 1.4-3.8), MDR bacteria were not independently associated with ICU mortality. Inappropriate initial antibiotic treatment (88% vs. 5%; p = <.001; OR, 6.7; 95% CI, 3.8-12) and ventilator-associated pneumonia (23% vs. 5%; p = <.001; OR, 1.3; 95% CI, 1-1.8) rates were significantly higher in patients with MDR bacteria than in patients with bacteria other than MDR. Inappropriate initial antibiotic treatment was independently associated with increased ICU mortality (OR, 7.1; 95% CI, 1.9-30; p = .003).


CONCLUSIONS
MDR bacteria are common in patients with acute exacerbation of chronic obstructive pulmonary disease requiring intubation and mechanical ventilation. Previous antimicrobial treatment and previous intubation are independent risk factors for MDR bacteria. Although MDR bacteria are not independently associated with ICU mortality, inappropriate initial antibiotic treatment is an independent risk factor for ICU mortality in these patients. Further studies are needed to determine whether broad-spectrum antibiotic treatment is cost-effective in these patients.
Nseir
Saad
S
Intensive Care Unit, Calmette Hospital, University Hospital of Lille, Lille, France.
Di Pompeo
Christophe
C
Cavestri
Béatrice
B
Jozefowicz
Elsa
E
Nyunga
Martine
M
Soubrier
Stéphane
S
Roussel-Delvallez
Micheline
M
Saulnier
Fabienne
F
Mathieu
Daniel
D
Durocher
Alain
A
D000208:Acute Disease; D000368:Aged; D000900:Anti-Bacterial Agents / Q000008:administration & dosage / Q000627:therapeutic use*; D001424:Bacterial Infections / Q000382:microbiology / Q000517:prevention & control*; D015331:Cohort Studies; D024901:Drug Resistance, Multiple, Bacterial; D004363:Drug Utilization; D005260:Female; D017052:Hospital Mortality; D006785:Hospitals, University; D006801:Humans; D007362:Intensive Care Units; D007442:Intubation, Intratracheal / Q000706:statistics & numerical data; D008297:Male; D015995:Prevalence; D011446:Prospective Studies; D029424:Pulmonary Disease, Chronic Obstructive / Q000188:drug therapy* / Q000382:microbiology*; D012121:Respiration, Artificial / Q000706:statistics & numerical data; D012307:Risk Factors; D014132:Trachea / Q000382:microbiology*; D016896:Treatment Outcome
D000900:Anti-Bacterial Agents