Inappropriate initial antimicrobial therapy for hematological malignancies patients with Gram-negative bloodstream infections

Background Inappropriate initial antimicrobial therapy (IIAT) may increase the mortality rate of hematological malignancies (HMs) patients with Gram-negative bacteria bloodstream infections (GN-BSI). The aim of this study is to determine whether IIAT affects the prognosis in this patient population and recommend the appropriate antibiotic regimen to minimize IIAT. Methods We reviewed a retrospective cohort study of 361 HM patients with neutropenic fever from GN-BSI. The patients' clinical characteristics and the results of the drug sensitivity test in vitro were analyzed. Results IIAT rate was 21.3% in HM patients with neutropenic fever caused by GN-BSI. There was a significant difference in 7-day mortality rate between patients treated with appropriate antibiotics and those with IIAT (7.7% vs 29.9%, p < 0.01). Multivariate analysis confirmed that IIAT was an independent risk factors for early mortality [4.860 (1.541-15.323)]. Drug sensitivity data of GN-bacteria suggested that carbapenems monotherapy or beta-lactamase inhibitors (BLBLI) combined with amikacin as the initial therapy can effectively reduce the IIAT rate. In the stratified antibiogram based on prior antimicrobial exposure, our results showed that BLBLI monotherapy could be initially used as an empirical treatment in patients without prior antimicrobial exposure. In those who had received prior antimicrobial exposure, BLBLI (especially piperacillin-tazobactam) combined with amikacin is recommended. Conclusions IIAT was a critical factor contributing to the mortality of HM patients with neutropenic fever from GN-BSI.