USMLE Prep - Medical Reference Library

Febrile Neutropenia — Risk Scores, Early Antipseudomonal Coverage, and Disposition

System: Hematology Oncology • Reviewed: Sep 1, 2025 • Step 1Step 2Step 3

Synopsis:

Fever with ANC <500 (or expected to decline) after chemotherapy. Obtain cultures quickly and start an antipseudomonal β‑lactam within 60 minutes; add MRSA coverage only with specific indications. Use MASCC/CISNE for risk and consider outpatient oral therapy for low‑risk patients.

Key Points

  • Use the highest‑yield diagnostic test early; do not let testing delay time‑critical therapy.
  • Set objective targets and reassess frequently.
  • Plan definitive source control or disease‑specific therapy when indicated; document follow‑up and patient education.

Algorithm

  1. Triage and obtain cultures; start antipseudomonal β‑lactam within 60 minutes.
  2. Risk‑stratify (MASCC/CISNE); choose inpatient IV vs outpatient oral regimen.
  3. Add MRSA coverage only when specific indications present; consider antifungals if persistent fever after 4–7 days and neutropenia continues.
  4. Daily reassessment; de‑escalate based on cultures and clinical response; plan growth factor per oncology.

Clinical Synopsis & Reasoning

Fever with ANC <500 (or expected to decline) after chemotherapy. Obtain cultures quickly and start an antipseudomonal β‑lactam within 60 minutes; add MRSA coverage only with specific indications. Use MASCC/CISNE for risk and consider outpatient oral therapy for low‑risk patients.


Treatment Strategy & Disposition

Stabilize ABCs. Initiate guideline‑concordant first‑line therapy with precise dosing and continuous monitoring. Escalate to advanced/procedural interventions based on explicit failure criteria. Define ICU, step‑down, and ward disposition triggers; involve specialty teams early.


Epidemiology / Risk Factors

  • Risk varies by comorbidity and precipitants; see citations for condition‑specific data.

Investigations

TestRole / RationaleTypical FindingsNotes
Blood cultures (peripheral + line) before antibioticsSource IDHigh yieldDo not delay antibiotics
CXR/CT and urinalysisSource searchPneumonia/UTI commonTailor imaging to symptoms
Risk scores (MASCC, CISNE)DispositionLow vs high riskGuides IV vs oral/outpatient

Pharmacology

Medication/InterventionMechanismOnsetRole in TherapyLimitations
Cefepime or Piperacillin‑tazobactam or MeropenemAntipseudomonal β‑lactamMinutesFirst‑line monotherapyAdd vanc only if indicated
Vancomycin (indications only)GlycopeptideMinutesCatheter infection, SSTI, pneumonia, hemodynamic instability, MRSA colonizationAvoid routine use
Levofloxacin + Amoxicillin/clavulanate (low‑risk oral)Oral step‑downHoursFor stable low‑riskAdjust by allergies/local resistance

Prognosis / Complications

  • Outcome depends on timeliness of diagnosis and definitive therapy; monitor for complications.

Patient Education / Counseling

  • Provide red‑flag education, adherence guidance, and explicit return precautions; arrange timely specialty follow‑up.

References

  1. ASCO/IDSA guideline update on febrile neutropenia — Link