Characteristics, risk factors and outcomes of carbapenem-resistant Klebsiella pneumoniae infections in the intensive care unit.

OBJECTIVE

To study the characteristics, risk factors and outcomes of intensive care unit (ICU) patients with carbapenem-resistant (CRKp) and carbapenem-susceptible (CSKp) Klebsiella pneumoniae infections.

METHODS

A retrospective cohort of patients with K. pneumoniae infections in an eight-bed ICU between January 2006 and October 2009.

RESULTS

During the study period, 104 patients were diagnosed with K. pneumoniae infection (80 CRKp and 24 CSKp). Isolation of CRKp increased gradually during the study period, while isolation of CSKp remained constant. The mean age of patients was 66.3 ± 14.3 years. The mean APACHE II score was 17.9 ± 6.9. The median duration of ICU stay until the infection was 15 days. Thirty five patients (33.7%) had primary and 30 (28.8%) had secondary bacteremia. Seventy-two patients (69.2%) died in the ICU. No independent risk factors for development of CRKp infections were identified in the multivariate analysis. Treatment failure (p = 0.001) was the only independent predictor of mortality in the multivariate analysis (APACHE II, shock, multi-organ failure, respiratory failure, acute renal failure, acidosis and extensive-drug resistance were included in the model). No difference in mortality was found between patients with CRKp and CSKp isolates.

CONCLUSIONS

Infection due to K. pneumoniae in the ICU was associated with high mortality. Control of the infection was the most important determinant of the outcome of critically ill patients.