Pseudomonas aeruginosa Infections: Factors Relating to Mortality with Emphasis on Resistance Pattern and Antimicrobial Treatment

A retrospective case-control study was conducted to investigate the risk factors for death among intensive care unit patients with Pseudomonas aeruginosa infection. Out of 131 patients investigated, 67 (51.1%) died within 30 days of being diagnosed with this infection. The mean duration of hospital stay before this diagnosis was 28.5 +/- 26.5 days. No association was found between bacterial resistance and death in this study (multiresistant p=0.26; panresistant p=0.42), but the adequacy of the initial treatment was inversely proportional to the degree of resistance. There was a tendency towards greater mortality among patients who received combination therapy (empirical p=0.09; definitive p=0.08), despite the greater frequency of appropriate treatment in these patients and the similar degree of severity in the two groups. This finding may be explained by pharmacodynamic parameters that were not studied or by the extensive use of aminoglycosides in the combination therapy, which play a controversial role in combination therapy due to their potential for renal toxicity. The multivariate analysis in our study demonstrated that age [odds ratio (OR) 1.04], septic shock (OR 15.4) and hypoalbuminemia (OR 0.32) were independent risk factors for death.