Outcome of carbapenem or colistin resistant Klebsiella pneumoniae bacteremia in the intensive care unit.

Carbapenem-resistant Klebsiella pneumoniae (CRKp) infections continue to be an important cause of mortality. In this retrospective study, the effect of carbapenem or colistin resistance on mortality in Klebsiella pneumoniae bacteremia and combined meropenem + colistin administration in CRKp bacteremia was evaluated. In addition to that, a mathematical model is applied to explore the relationships between the resistance and mortality. A total of 139 adult patients diagnosed with K. pneumoniae bacteremia(73 carbapenem sensitive and 66 carbapenem resistant) between 01/01/2000 and 31/07/2019 were included in the study. The 30-day mortality in entire cohort were 19.4%. 30-day mortality was significantly higher in the carbapenem resistant-colistin sensitive group and in the carbapenem resistant-colistin resistant group compared to the carbapenem susceptible group. Meropenem + colistin combination was administered to 37 (95%) of carbapenem resistant-colistin sensitive (n = 39) and 25 (93%) of carbapenem resistant-colistin resistant patients(n = 27). Notably, mortality was not significantly affected regardless of whether CRKp was colistin sensitive and whether a high dose and prolonged infusion of meropenem was administered. Mortality is higher in carbapenem resistant Klebsiella pneumoniae bacteremia compared to carbapenem susceptible group. In cases of combined meropenem and colistin administration, high dose and prolonged infusion of meropenem is not superior to standard dose and infusion in both carbapenem resistant-colistin sensitive and carbapenem resistant-colistin resistant K. pneumoniae bacteremia.