Background Infection by Pseudomonas aeruginosa (PA) is a major cause of morbidity and mortality in hospitals, especially in immunocompromised patients. Mortality from bacteraemia by PA ranges from 25% to 62%, depending on the study consulted. There are multiple factors associated with mortality from bacteraemia by PA.
Purpose Primary: to determine mortality at 90 days, from positive blood culture, in patients with PA bacteraemia in our centre. Secondary: to determine risk factors associated with mortality.
Material and methods Retrospective observational study. Includes patients with positive blood culture for PA from 1 January 2011 to 31 December 2014. Patients with polymicrobial infections were excluded. Demographic and clinical variables were collected. The antibiotic treatment administered was recorded. Its relationship with mortality was analysed.
Results 67 episodes of bacteraemia were identified. Mean age was 64.4 years (DE 13.31). Men: 68.7% (n = 46). The rate of 90 day mortality was 48% (n = 32). 50% (n = 16) of the exitus was directly attributed to an infectious syndrome. Nosocomial bacteraemia: 49%; associated with healthcare: 45%. Average value Charlson Index: 6.75 (DE 3.2). More frequent comorbidity: neoplasia 19.7% (n = 28). McCabe classification: ultimately fatal disease: 48% (n = 32); rapidly fatal disease: 12% (n = 8). Store Pitt medium: 2.7 points. They had sepsis, severe sepsis and septic shock (42%, 10% and 27% of patients, respectively). 55% of patients had some immunodeficiency. Unidentified infection foci: 22% (n = 15). The foci were identified: urinary 23% (n = 12), use of central catheters 23% (n = 12), respiratory 34% (n = 18), abdominal-biliary 17% (n = 9), other 3% (n = 5). Analytical parameters (median and 25–75 percentiles): leukocytes (cells/µL): 11 950 (2150–210 509), neutrophils (cells/ µL): 9870 (852–18 350), platelets (units/µL): 160 500 (83 000–255 250), creatinine (mg/mL): 1.4 (0.9–2), urea (mg/dL): 62 (40–105), PTA (%): 64.6 (49.7–75.5), albumin (g/dL): 1.7 (1.6–2.4), PCR (mg/dL): 233.4 (141–340.8), PCT (ng/ml) 17.1 (1.8–36.8), lactate (mmol/L): 2.4 (1.9–4.5). Received combination therapy, 47.8% (n = 32) of patients. Empiric appropiate treatment: 83% (n = 52), definitive appropiate treatments: 92% (n = 60). Globally, appropriate treatments: 87% (n = 140). Factors independently associated with poor prognosis were neutrophils <500/µL (HR 3.15, 95% CI 1.29–7.65, p = 0.01), Charlson Index (HR 1.23, 1.09–1.39, p = 0.001) and the presence of shock septic (HR 2.4, 1.02–5.65, p = 0.044). No relationship between the inadequate treatment and mortality antipseudomonal (lack of statistical power). In the use of monotherapy versus combination therapy, no difference in terms of mortality.
Conclusion The mortality found in patients with PA bacteraemia in our study confirms the high lethality of this infectious disease. The high comorbidity of the patients included in the study could increase the mortality rate. The Charlson Index, presence of septic shock and a value of neutrophils <500/µL were independent variables of mortality for patients included in this study.
No conflict of interest.