Mortality of COPD Patients Infected with Multi-Resistant Pseudomonas aeruginosa : A Case and Control Study

Abstract Background:   The incidence of infections caused by multiresistant Pseudomonas aeruginosa (MDRP) is increasing, especially in critically ill patients. The relevance of MDRP in the prognosis of chronic obstructive pulmonary disease (COPD) acute exacerbation in patients admitted to the hospital’s general ward is not well known. Patients and Methods:   Case and control study. Cases were patients admitted for COPD acute exacerbation in which a MDRP was isolated from spontaneous sputum. MDRP was defined as the absence of susceptibility to three or more antibiotic families (betalactams, quinolones, carbapenems and aminoglycosides). Patients currently or previously admitted to the intensive care unit (ICU), who had a recent surgery, neoplasia or immunosuppressive treatment were excluded from the study. Patients from the control group were admitted for COPD acute exacerbation and matched 1:1 with each case-patient in terms of age, sex, date of admission and degree of airway obstruction. Pseudomonas aeruginosa susceptible to all antimicrobials or other microorganisms was isolated from sputum. Results:   During the study period (2000–2005), 50 casepatients and 50 controls were included. Crude mortality at 2 years was 60% for the case-patients and 28% for the control group. In the logistic regression analysis adjusted for age, FEV₁ and number of previous hospital admissions, MDRP infection was associated to an increased mortality in comparison to patients without MDRP (OR = 6.2; IC 95%: 1.7–22.1; p < 0.01). Conclusions:   In COPD patients admitted to the general ward, acute exacerbation with MDRP in sputum was associated with higher mortality.