gms | German Medical Science

Background: Bloodstream infection (BSI) is a life-threatening complication in patients with hematological disorders and therapy-induced neutropenia. The mortality rate is high: 5% in the case of bacteremias associated with Gram-positive cocci (GPC) and 18% in the case of those associated with Gram-negative bacilli (GNB). Although there are established guidelines for the use of empirical therapy, local microbiologic pattern and antibiotic susceptibility should be considered.

Aim: To identify risk factors for mortality in a cohort of hematologic patients with bacteremia.

Materials and methods: A retrospective observational study of adults inpatients with hematologic malignancies and febrile neutropenia who were diagnosed with bacteremia between June 2010 and January 2014. The microorganism isolation was performed using BACTEC 9240 with classical identification and antibiogram disk by diffusion. All statistical analysis were perfomed with Minitab 16 program.

Results: Throughout the study period, 246 febrile neutropenic episodes ocurred in 132 patients. The median age at the fever onset was 30 y (range 14-79 y) and 153 (62%) episodes ocurred in males. The predominant underlying diagnoses were acute lymphoblastic leukemia (n=105 42%), acute myeloid leukemia (n=77 31%) and non-Hodgkin lymphoma (n=37 15%). Sixty-eight (27%) patients had relapse of disease. Bloodstream infection: In 77 episodes (31%) occurring in 56 patients, 1 or more bacterial pathogens was detected in blood cultures. A total 85 isolates were recovered from the cases of BSI. Gram-negative bacteria was detected in 41 of these episodes (53.23%), whereas in 28 (36.36%) only Gram-positive bacteria were found. Klebsiella pneumoniae and Escherichia coli were the most common GNB (46% and 36%), whereas the most common GPB were CoNS and Staphylococcus aureus (46% and 39%). Eight (10%) cases of polymicrobial bacteremia were recovered. In the group of bacteremic patients chemotherapeutic regimen with citarabin (p 0.02) or Hyper-CVAD (p 0.03), hypotension (p 0.00006), need of mechanical ventilation (p 0.0006), mayor bleeding (p 0.01) and elevated liver enzymes (p 0.01) were risk factors associated with mortality (Table 1 [Tab. 1]).

Conclusions: Gram-negative bacteria were the predominantly isolated pathogens in our population. The mortality remains high. Appropriate preventive measures and judicious use of empiric antimicrobial therapy may help to lower the mortality associated with these infections.