Febrile neutropenia: workup and management
Temperature ≥38.3 °C once, or ≥38.0 °C sustained for 1 h, with ANC under 500/µL or expected to fall under 500 within 48 h. An oncological emergency: broad-spectrum anti-pseudomonal antibiotics within 60 minutes of arrival.
Working diagnosis
Adult · US guidelines
Draft · awaiting physician review
01Orient
What's new in the evidence
- No 2024 ASCO/IDSA update; the 2018 ASCO/IDSA outpatient guideline and NCCN 2026 infection guideline are current
- NCCN 2026 high-risk features: MASCC <21 or CISNE ≥3, inpatient at onset, allogeneic transplant, expected ANC ≤100 for ≥7 days, CrCl <30, grade 3–4 mucositis or uncontrolled cancer
- Stopping empiric antibiotics once afebrile and stable without a documented infection, before count recovery, is supported by trial data (How Long, 2017)
Differential diagnoses
- Bacteremia (gram-negative including Pseudomonas, gram-positive from lines)
- Central line infection
- Pneumonia
- Neutropenic enterocolitis (typhlitis)
- Skin, perianal or mucositis-related infection
- Invasive fungal infection (prolonged neutropenia)
- Viral infection
- Non-infectious: drug fever, transfusion, tumor fever
02Assess
Risk scores and decision tools
- MASCC risk index (≥21 low risk)
- CISNE score for stable outpatients with solid tumors
- Expected duration of neutropenia (>7 days = high risk)
Key history questions
- Chemotherapy regimen and date of last cycle
- Central line, port, recent procedures
- Localizing symptoms: cough, diarrhea, abdominal pain, dysuria, mouth sores, perianal pain
- Prior resistant organisms, recent antibiotics
- G-CSF use, antimicrobial prophylaxis
Examination findings
- Vitals including hypotension
- Line and port sites
- Mouth, skin and perianal inspection (no digital rectal exam)
- Chest, abdomen (right lower quadrant tenderness in typhlitis)
03Investigate
Initial investigations
- CBC with differential
- Blood cultures: one from each line lumen plus one peripheral set
- BMP, LFTs, lactate
- Urinalysis and urine culture
- Chest X-ray
Advanced investigations
- Respiratory viral panel
- C. difficile testing if diarrhea
- CT chest for persistent fever over 3-5 days or high-risk patients (fungal infection)
- CT abdomen if typhlitis suspected
04Treat
Immediate management
- Cefepime 2 g IV every 8 h within 60 minutes (or piperacillin-tazobactam or meropenem per local guidance)
- Sepsis resuscitation if hypotensive
First-line treatment
- Add vancomycin for catheter infection, skin/soft tissue infection, pneumonia, MRSA colonization or hemodynamic instability
- Add anaerobic cover for abdominal or perianal source
- MASCC score ≥21 and stable: consider oral outpatient therapy (ciprofloxacin plus amoxicillin-clavulanate) if local pathway allows
Second-line treatment
- Escalate to a carbapenem for resistant organisms or clinical deterioration
- Empiric antifungal therapy for persistent fever after 4-7 days of antibiotics with expected prolonged neutropenia
- Remove line for S. aureus, Pseudomonas, fungal or tunnel infection
Specialist referrals
- Oncology/hematology team immediately
- Infectious diseases for complex or resistant infection
- ICU for septic shock
05Disposition
Admission criteria
- MASCC score under 21
- Hematological malignancy or expected neutropenia over 7 days
- Hemodynamic instability, organ dysfunction or significant comorbidity
Safe discharge criteria
- MASCC ≥21 low-risk with oncology agreement
- Able to take oral drugs, lives near hospital, has a carer and phone
- Clinically stable after observation
Follow-up timing
- Oncology contact within 24 h if managed as outpatient
Patient instructions
- Return immediately for any fever, rigors or feeling unwell
Monitoring
- Daily CBC with differential
- Daily cultures if fever persists
Clinical pearls and pitfalls
- Do not wait for the CBC result to give antibiotics in a febrile patient after chemotherapy
- Signs of inflammation may be absent without neutrophils
RefGuidelines and landmark evidence
For education only. Typical adult starting points; confirm doses against renal function, allergies, interactions and your institution's protocols. Not a substitute for clinical judgment or senior review.