Meta-analytic validation of new 'AUS' febrile neutropenia risk score

Can I go home now? The safety and efficacy of a new UK paediatric febrile neutropenia protocol for risk-stratified early discharge on oral antibiotics

OBJECTIVE

To evaluate a new protocol of risk stratification and early discharge for children with febrile neutropenia (FN).

DESIGN

Prospective service evaluation from 17 April 2020 to 16 April 2021.

SETTING

13 specialist centres in the UK.

PATIENTS

405 children presenting with FN.

INTERVENTION

All children received intravenous antibiotics at presentation. Risk stratification was determined using the Australian-UK-Swiss (AUS) rule and eligibility for homecare assessed using criteria including disease, chemotherapy, presenting features and social factors. Those eligible for homecare could be discharged on oral antibiotics after a period of observation proportional to their risk group.

MAIN OUTCOME MEASURES

Median duration of admission and of intravenous antibiotics, and percentage of patients with positive blood cultures, significant infection, readmission within 7 days of initial presentation, intensive care unit (ICU) admission, death from infection and death from other causes.

RESULTS

13 centres contributed 729 initial presentations of 405 patients. AUS rule scores were positively correlated with positive blood cultures, significant infection, ICU admission and death. 20% of children were eligible for homecare with oral antibiotics, of which 55% were low risk (AUS 0-1). 46% low-risk homecare eligible patients were discharged by 24 hours vs 2% homecare ineligible. Homecare readmission rates were 14% overall and 16% for low-risk cases (similar to a meta-analysis of previous studies). No child eligible for homecare was admitted to ICU or died.

CONCLUSIONS

Use of the AUS rule and homecare criteria allow for safe early outpatient management of children with FN.

Prospective cohort study of the predictive value of inflammatory biomarkers over clinical variables in children and young people with cancer presenting with fever and neutropenia

Introduction Fever during chemotherapy induced neutropenia is a common and potentially life-threatening complication of the treatment of childhood cancer. Predictions of poor outcome could be enhanced by incorporating serum biomarkers of inflammation at presentation and reassessment. Methods A prospective cohort study was conducted of children under 18 years old, being treated for cancer or a cancer-like condition, who presented with fever (≥ 38.0°C) and neutropenia (neutrophil count < 0.5*10 ⁹/L). Clinical features were recorded, along with three experimental inflammatory biomarkers: procalcitonin (PCT), interleukin-6 (IL-6) and interleukin-8 (IL-8). Outcomes included serious medical complications (SMC): any infection related mortality, critical care and organ support, severe sepsis, septic shock, significant microbiologically defined infection, or radiologically confirmed pneumonia. Results Biomarker assessments were undertaken in 43 episodes of fever and neutropenia, from 31 patients aged between four months and 17 years old (median six years): 20 were female and 22 had acute leukaemia. Five episodes of SMC were noted. PCT, IL-6 and IL-8 had poor individual discriminatory ability (C-statistic 0.48 to 0.60) and did not add to the value of clinical risk stratification tools. Insufficient data were collected to formally assess the value of repeated assessments. Conclusions Incorporating serum biomarkers of inflammation at presentation of episodes of fever with neutropenia in childhood does not clearly improve risk stratification. The value of serial assessments requires further investigation.

Procalcitonin and Interleukin-10 May Assist in Early Prediction of Bacteraemia in Children With Cancer and Febrile Neutropenia

Objectives

Febrile neutropenia (FN) causes treatment disruption and unplanned hospitalization in children with cancer. Serum biomarkers are infrequently used to stratify these patients into high or low risk for serious infection. This study investigated plasma abundance of cytokines in children with FN and their ability to predict bacteraemia.

Methods

Thirty-three plasma cytokines, C-reactive protein (CRP) and procalcitonin (PCT) were measured using ELISA assays in samples taken at FN presentation (n = 79) and within 8–24 h (Day 2; n = 31). Optimal thresholds for prediction of bacteraemia were identified and the predictive ability of biomarkers in addition to routinely available clinical variables was assessed.

Results

The median age of included FN episodes was 6.0 years and eight (10%) had a bacteraemia. On presentation, elevated PCT, IL-10 and Mip1-beta were significantly associated with bacteraemia, while CRP, IL-6 and IL-8 were not. The combination of PCT (≥0.425 ng/ml) and IL-10 (≥4.37 pg/ml) had a sensitivity of 100% (95% CI 68.8–100%) and specificity of 89% (95% CI 80.0–95.0%) for prediction of bacteraemia, correctly identifying all eight bacteraemia episodes and classifying 16 FN episodes as high-risk. There was limited additive benefit of incorporating clinical variables to this model. On Day 2, there was an 11-fold increase in PCT in episodes with a bacteraemia which was significantly higher than that observed in the non-bacteraemia episodes.

Conclusion

Elevated PCT and IL-10 accurately identified all bacteraemia episodes in our FN cohort and may enhance the early risk stratification process in this population. Prospective validation and implementation is required to determine the impact on health service utilisation.

Optimising Antimicrobial Selection and Duration in the Treatment of Febrile Neutropenia in Children

Febrile neutropenia (FN) is a frequent complication of cancer treatment in children. Owing to the potential for overwhelming bacterial sepsis, the recognition and management of FN requires rapid implementation of evidenced-based management protocols. Treatment paradigms have progressed from hospitalisation with broad spectrum antibiotics for all patients, through to risk adapted approaches to management. Such risk adapted approaches aim to provide safe care through incorporating antimicrobial stewardship (AMS) principles such as implementation of comprehensive clinical pathways incorporating de-escalation strategies with the imperative to reduce hospital stay and antibiotic exposure where possible in order to improve patient experience, reduce costs and diminish the risk of nosocomial infection. This review summarises the principles of risk stratification in FN, the current key considerations for optimising empiric antimicrobial selection including knowledge of antimicrobial resistance patterns and emerging technologies for rapid diagnosis of specific infections and summarises existing evidence on time to treatment, investigations required and duration of treatment. To aid treating physicians we suggest the key features based on current evidence that should be part of any FN management guideline and highlight areas for future research. The focus is on treatment of bacterial infections although fungal and viral infections are also important in this patient group.