Data collection and Definitions
Sex, age, underlying diseases, presence of diabetes mellitus, length of
hospitalization, clinical laboratory values ( white blood cell counts,
absolute neutrophil and platelet counts, and hemoglobin levels) at the
same time or within 24h of BC, neutropenia duration prior to obtaining
any BC, disease status, strains of pathogenic bacteria and resistance to
antibiotics, and antibiotic therapy type(s) were extracted from the
charts. Prior antimicrobial exposure was defined as the presence of any
previous history of antibiotics for over 48 hours within 1 month. We
used the definitions proposed by Kameda et al. to define definite or
probable BSI.[26] Briefly, ”definite BSI” was defined as the
isolation of at least one BC of a bacterial or fungal pathogen other
than common skin contaminants. For common skin contaminants such as
diphtheroids, Bacillus spp., Propionibacterium spp., coagulase-negative
Staphylococci, viridans streptococci, Aerococcus spp., and Micrococcus
spp., detection in two or more separate blood cultures is required for a
definite BSI diagnosis. [27 28] Neutropenia and profound neutropenia
were defined as an absolute neutrophil count (ANC) of <500
cells/mm3 and <100 cells/mm3, respectively.[29] MDR
bacteria were defined as those that were resistant to three or more
classes of antibiotics.[30] Acute respiratory failure and acute
renal failure have been described by Tang et al.[31] Antibiotic
exposure was defined as any antimicrobial therapy lasting more than 48h
in the previous month.[32]Inappropriate initial antimicrobial
therapy (IIAT) refers to antibiotic regimens prescribed and administered
during the first 72h after suspecting BSI, and is not active against the
pathogen identified by culture and in vitro susceptibility testing.[31
33]