The Use of Intravenous Antibiotics at the Onset of Neutropenia In Patients Receiving Hematopoietic Stem Cell Transplants: A Pre-Emptive Strategy.

Hematopoietic Stem Cell Transplant (HSCT) recipients are at risk for fatal bacterial infections during the engraftment period. Empirical antibiotic(s) at the onset of febrile neutropenia remain the standard of care. HSCT recipients began receiving intravenous once daily ceftriaxone at the onset of neutropenia (neutrophils< 1.0) regardless of fever as part of The Ottawa Hospital Blood and Marrow Outpatient Programme policy from Jan 2009; “pre-emptive” approach. We examined the impact of this policy on HSCT recipient outcomes.

A retrospective “before-after” study was conducted to compare 2 cohorts [Jan 2008 - Dec 2008 (Empiric strategy) vs. Jan 09 - Dec 2009 (Pre-emptive strategy)] of patients receiving HSCT. Baseline characteristics between the groups were compared with 2 sample tests. Categorical variables and continuous variables were compared using Chi-squared and Wilcoxan rank-sum tests respectively.

There were 238 HSCTs performed between Jan 2008 and Dec 2009 with 127 and 111 in the earlier and later cohorts respectively. Baseline characteristics between the cohorts were similar. Infection related mortality at 100 days after HSCT and during the engraftment period was similar with a pre-emptive strategy compared to an empiric strategy (7.2% vs 10.2%; p=0.41 and 3.6% vs 7.1%; p=0.24) respectively. Further, there were no differences in ICU admissions or length of hospital stay. Both microbiologically (MDI) and clinically documented infections (CDI) were reduced (11.7% vs 29.1%; p=0.001 and 18.2% vs33.9%; p=0.007) with the pre-emptive strategy compared with an empiric strategy. Importantly, recipients of autologous HSCT appear to have a lower infection related mortality and reduced infection related ICU admissions during the engraftment period with the pre-emptive strategy compared to an empiric strategy (0% vs 6.8%; p=0.03 and 2.9% vs 12.2% p= 0.04). The need for escalation of antimicrobial treatments, resistance pattern of MDIs and cost of antimicrobial treatment were not different between the two groups.

The use of once daily intravenous ceftriaxone at the onset of neutropenia in patients receiving HSCT is safe and effective particularly in patients receiving autologous HSCT. Further studies are warranted to study the impact of this “pre-emptive” strategy.

No relevant conflicts of interest to declare.