Infections from MDR strains (K. pneumoniae, P. aeruginosa, A. Baumannii complex) in a multivalent ICU

Introduction

The infection incidences from MDR strains in our ICU are in accordance with the results of respective studies in other ICUs of our country. Our aim is to identify potential risk factors for the development of MDR infection in ICU patients.

Methods

The sample consisted of 882 patients, admitted to our ICU from 1 January 2010 until 30 June 2013. The factors studied were: age, gender, length of stay in the ICU, origin of patient (for example, home or transferred from another institution), APACHE II score, adjusted mortality score, previous colonization with MDR, prior use of antimicrobial agents, duration of ventilator use, immunosuppression, diabetes, hypoproteinemia and presence of central venous catheter (CVC). Bivariable analyses were conducted to determine the association between potential risk factors and development of MDR infection. Categorical variables were compared using the Fisher test. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated to evaluate the strength of any association. Continuous variables were compared using the Student t test or the Wilcoxon test where appropriate. Multivariable analysis was performed using multiple logistic regression. Variables with P < 0.20 in bivariable analyses were considered for inclusion in a multivariable model.

Results

Out of 882 patients, 135 (15.3%) developed MDR infection. The following factors showed statistical significant difference (P ≪ 0.01): length of stay in the ICU, origin of patient, APACHE II score, previous colonization, previous use of carbapenems, duration of mechanical ventilation, immunosuppression, diabetes mellitus, hypoproteinemia and the presence of CVC. The multivariant analysis showed statistically significant correlations for the following independent risk factors: previous use of carbapenems (OR = 632.64, P ≪0.01), origin of patient (OR = 19.60, P = 0.014), presence of CVC (OR = 14.19, P = 0.015), previous colonization (OR = 4.71, P = 0.037) and duration of ventilator use (OR = 1.10, P = 0.029).

Conclusion

The analysis showed a very strong correlation between prior use of carbapenems and development of MDR infection. Other significant factors are presence of CVC, origin of patient, previous colonization and duration of ventilator use. The identification of the above factors and the effort for their restriction redound to the reduction of the MDR infections and, consequently, to the reduction of the morbidity and the mortality of the patients hospitalized in ICUs.