Antimicrobial Stewardship on Patients with Neutropenia: A Narrative Review Commissioned by Microorganisms

Examining the effect of direct-from-blood bacterial testing on antibiotic administration and clinical outcomes: a protocol and statistical analysis plan for a pragmatic randomised trial

INTRODUCTION

Patients with suspected bacterial infection frequently receive empiric, broad-spectrum antibiotics prior to pathogen identification due to the time required for bacteria to grow in culture. Direct-from-blood diagnostics identifying the presence or absence of bacteria and/or resistance genes from whole blood samples within hours of collection could enable earlier antibiotic optimisation for patients suspected to have bacterial infections. However, few randomised trials have evaluated the effect of using direct-from-blood bacterial testing on antibiotic administration and clinical outcomes. This manuscript describes the protocol and statistical analysis plan for a randomised trial designed to evaluate the effect of blood cultures plus direct-from-blood bacterial testing results compared with blood culture results alone on antibiotic administration and clinical outcomes.

METHODS AND ANALYSIS

We are conducting a prospective, single-centre, parallel-group, non-blinded, pragmatic, randomised trial. The trial will enrol 500 adult patients presenting to the emergency department at Vanderbilt University Medical Center with suspected bacterial infection who have been initiated on empiric intravenous vancomycin. Eligible patients are randomised 1:1 to receive Food and Drug Administration-approved direct-from-blood bacterial testing in addition to blood cultures or blood cultures alone. The primary outcome is the time to the last dose of intravenous vancomycin within 14 days of randomisation. The secondary outcome is the time to the last dose of systemic antipseudomonal beta-lactam antibiotics within 14 days of randomisation. Additional outcomes include highest stage of acute kidney injury, lowest platelet count and receipt of kidney replacement therapy within 14 days of randomisation, as well as hospital-free days, intensive care unit-free-days and all-cause, in-hospital mortality within 28 days of randomisation. Enrolment began on 13 December 2023.

ETHICS AND DISSEMINATION

The trial involves human participants and was approved by the Vanderbilt University Medical Center institutional review board with a waiver of informed consent (IRB#231229). Results will be submitted in a peer-reviewed journal and presented at scientific conferences.

TRIAL REGISTRATION NUMBER

NCT06069206.

Use of Granulocyte Transfusions in the Management of Severe Infections Among Children with Neutropenia

Background/Objectives: Infections remain the leading cause of mortality among neutropenic patients with haematologic malignancies, making effective infection management crucial. Achieving a sufficient neutrophil count is essential for the elimination of pathogens. Granulocyte concentrate (GC) can be a treatment option for neutropenic patients with severe infections. This study aimed to evaluate the efficacy, safety, and impact on survival of GC transfusions in neutropenic children with severe infections treated over the past 13 years in a single centre. Methods: The retrospective study analysed clinical data from 60 children (median age 9.5 years) who received GC transfusions at our centre. Granulocytes were collected by apheresis from donors stimulated with granulocyte colony-stimulating factor. The majority of the patients (70%) were diagnosed with acute leukaemia. The main indications for GC were severe pneumonia (45%) and bacterial sepsis (38.33%). Results: The patients received 1 to 29 GC transfusions for 1 to 70 days, with a median time of administration of 3 days. Neutrophil counts increased to >1000/µL within a median of 5 days. GCs were well tolerated by most patients. One patient presented symptoms of anaphylaxis, the other acute lung injury related to transfusions, and alloimmunisation was reported in one patient. Of the patients analysed, 78.33% survived the infection that justified GC administration. We did not observe significant differences in survival depending on the aetiology of the infection. Conclusions: Based on our research, GC appears to be a beneficiary for neutropenic children with severe infections and reduces infection mortality rates. However, further well-designed randomised trials are needed to define its role in this setting.

Implementing an Antimicrobial Stewardship Program in an Oncology Center in Lima, Peru: A Model for Low- and Middle-Income Countries

Our center launched the first antimicrobial stewardship program in Peru. From 2016 to 2023, the proportion of antimicrobial prescriptions audited increased from 60% to 95%, and 65% to 95% of recommendations were accepted. Vancomycin and meropenem use dropped by 95% and 84%, respectively. The proportion of recommendations for surgical prophylaxis exceeded 90%.

Antimicrobial De-Escalation in Critically Ill Patients

Antimicrobial de-escalation (ADE) is defined as the discontinuation of one or more antimicrobials in empirical therapy, or the replacement of a broad-spectrum antimicrobial with a narrower-spectrum antimicrobial. The aim of this review is to provide an overview of the available literature on the effectiveness and safety of ADE in critically ill patients, with a focus on special conditions such as anti-fungal therapy and high-risk categories. Although it is widely considered a safe strategy for antimicrobial stewardship (AMS), to date, there has been no assessment of the effect of de-escalation on the development of resistance. Conversely, some authors suggest that prolonged antibiotic treatment may be a side effect of de-escalation, especially in high-risk categories such as neutropenic critically ill patients and intra-abdominal infections (IAIs). Moreover, microbiological documentation is crucial for increasing ADE rates in critically ill patients with infections, and efforts should be focused on exploring new diagnostic tools to accelerate pathogen identification. For these reasons, ADE can be safely used in patients with infections, as confirmed by high-quality and reliable microbiological samplings, although further studies are warranted to clarify its applicability in selected populations.