Reappraisal of Pseudomonas aeruginosa hospital-acquired pneumonia mortality in the era of metallo-beta-lactamase-mediated multidrug resistance: a prospective observational study.
BACKGROUND
Hospital-acquired pneumonia (HAP) due to Pseudomonas aeruginosa is associated with high mortality rates. The metallo-beta-lactamases (MBLs) are emerging enzymes that hydrolyze virtually all beta-lactams. We aimed to assess P. aeruginosa HAP mortality in a setting of high-rate MBL production


METHODS
A prospective cohort study was performed at two tertiary-care teaching hospitals. A logistic regression model was constructed to identify risk factors for 30-day mortality.


RESULTS
One-hundred and fifty patients with P. aeruginosa HAP were evaluated. The 30-day mortality was 37.3% (56 of 150): 57.1% (24 of 42) and 29.6% (32 of 108) for patients with HAP by MBL-producing P. aeruginosa and by non-MBL-producing P. aeruginosa, respectively (relative risk, 1.93; 95% confidence interval (CI), 1.30-2.85). The logistic regression model identified a higher Charlson comorbidity score (odds ratio, 1.21; 95% CI, 1.04-1.41), presentation with severe sepsis or septic shock (odds ratio, 3.17; 95% CI, 1.30-7.72), ventilator-associated pneumonia (odds ratio, 2.92; 95% CI, 1.18-7.21), and appropriate therapy (odds ratio, 0.24; 95% CI, 0.10-0.61) as independent factors for 30-day mortality. MBL production was not statistically significant in the final model.


CONCLUSIONS
MBL-producing P. aeruginosa HAP resulted in higher mortality rates, particularly in patients with ventilator-associated pneumonia, most probably related to the less frequent institution of appropriate antimicrobial therapy. Therapeutic approaches should be reviewed at institutions with a high prevalence of MBL.
Zavascki
Alexandre Prehn
AP
Infectious Diseases Service, Hospital São Lucas da Pontifícia Universidade Católica do Rio Grande do Sul, Porto Alegre - RS, Brazil. apzavascki@terra.com.br
Barth
Afonso Luís
AL
Fernandes
Juliana Fernandez
JF
Moro
Ana Lúcia Didonet
AL
Gonçalves
Ana Lúcia Saraiva
AL
Goldani
Luciano Zubaran
LZ
D000328:Adult; D000368:Aged; D015331:Cohort Studies; D003428:Cross Infection / Q000188:drug therapy / Q000401:mortality*; D018432:Drug Resistance, Multiple / Q000187:drug effects; D005260:Female; D017052:Hospital Mortality; D006801:Humans; D066298:In Vitro Techniques; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D011552:Pseudomonas Infections / Q000188:drug therapy / Q000401:mortality*; D011550:Pseudomonas aeruginosa; D018440:beta-Lactam Resistance / Q000187:drug effects; D001618:beta-Lactamases / Q000494:pharmacology / Q000627:therapeutic use*
D001618:beta-Lactamases