Febrile Neutropenia

Febrile neutropenia is a medical emergency characterized by fever occurring in the presence of neutropenia, most commonly following chemotherapy for malignancy or as a result of bone marrow failure syndromes. It is associated with a high risk of severe bacterial and fungal infections because of impaired host immunity. Prompt recognition, immediate administration of empiric broad-spectrum antibiotics, and close monitoring are essential to reduce morbidity and mortality.

These recommendations apply to patients with:

• Fever and neutropenia resulting from known or suspected malignancy or chemotherapy.

• Fever and neutropenia resulting from bone marrow failure syndromes.

• Fever or evidence of infection in patients receiving chemotherapy or within 6 months after completion of cancer therapy, even if neutropenia is not present.

Epidemiology

Febrile neutropenia is one of the most common oncological emergencies in patients receiving cytotoxic chemotherapy. The risk varies according to the underlying malignancy, chemotherapy regimen, duration of neutropenia, and presence of comorbidities. Patients with hematological malignancies generally have a higher risk than those with solid tumors.

Risk factors

Risk factors include:

• Cytotoxic chemotherapy

• Hematological malignancies

• Bone marrow failure syndromes

• Prolonged neutropenia

• Previous episode of febrile neutropenia

• Advanced age

• Poor nutritional status

• Mucositis

• Central venous catheters

• Recent invasive procedures

Pathophysiology

Neutropenia results in impaired innate immune defense, reducing the body's ability to contain bacterial and fungal infections. Chemotherapy-induced mucosal injury facilitates microbial translocation from the gastrointestinal tract, while impaired inflammatory responses may mask the usual signs of infection. Fever may be the only manifestation of severe infection.

Clinical presentation

Patients may present with fever alone or fever associated with symptoms and signs of infection. The source of infection may not be clinically apparent.

Symptoms

• Fever

• Chills

• Rigors

• Malaise

• Fatigue

• Sore throat

• Cough

• Dysuria

• Abdominal pain

• Diarrhoea

• Vomiting

• Oral pain due to mucositis

Clinical signs

• Fever

• Hypotension

• Tachycardia

• Tachypnoea

• Oral mucositis

• Pharyngitis

• Skin or soft tissue infection

• Catheter-site infection

• Cellulitis

• Signs of sepsis

• Altered mental status in severe infection

Differential diagnosis

• Bacterial sepsis

• Viral infection

• Invasive fungal infection

• Malaria

• Drug fever

• Tumor fever

• Transfusion reaction

• Non-infectious inflammatory disorders

Diagnostic criteria

Febrile neutropenia is diagnosed in patients with fever occurring in the setting of chemotherapy-induced or disease-related neutropenia or in patients receiving recent cancer treatment with suspected infection.

Diagnosis should prompt immediate empiric antimicrobial therapy without waiting for microbiological confirmation.

Investigations

• Full blood picture (FBP)

• Liver function tests (LFT)

• Renal function tests (RFT)

• Serum electrolytes

• Malaria screen

• Urinalysis

• Urine culture

• Blood culture

• Stool culture

• Throat swab

• Chest imaging where respiratory symptoms are present

• Additional investigations according to suspected focus of infection

Management

Febrile neutropenia is an oncological emergency.

Initial management includes:

• Assess airway, breathing, and circulation.

• Assess for sepsis and septic shock.

• Obtain appropriate cultures before antibiotic administration where this does not delay treatment.

• Administer empiric intravenous antibiotics as soon as possible.

• Monitor vital signs, urine output, renal function, and blood counts closely.

• Modify antimicrobial therapy according to culture results and clinical response.

Non-pharmacological treatment

• Prompt hospital admission for most patients.

• Adequate intravenous hydration.

• Isolation and strict infection prevention measures where appropriate.

• Regular monitoring of temperature and vital signs.

• Nutritional support.

• Removal of infected intravascular devices where indicated.

Pharmacological treatment

Supportive treatment

• Appropriate antipyretics.

• Appropriate analgesics.

Initial empiric antibiotic therapy

Patients with no significant beta-lactam allergy

• Piperacillin + Tazobactam (fixed-dose combination) – 4 g piperacillin/0.5 g tazobactam – IV – every 6 hours.

PLUS

• Gentamicin – 3–6 mg/kg – IV – once daily.

Second-line empiric therapy

For deteriorating patients without a history of beta-lactam anaphylaxis:

• Meropenem – 500 mg – IV – every 8 hours.

AND

• Amikacin – 15 mg/kg/dose – IV – in 2–3 divided doses.

OR

• Ciprofloxacin – 200–400 mg – IV – every 12 hours.

AND

• Vancomycin – 15–20 mg/kg/dose – IV – every 8–12 hours.

Patients with definite beta-lactam anaphylaxis

• Ciprofloxacin – 200–400 mg – IV – every 12 hours.

AND

• Metronidazole – 500–750 mg – IV – every 8 hours.

AND

• Amikacin – 15 mg/kg/dose – IV – in 2–3 divided doses.

AND

• Vancomycin – 15–20 mg/kg/dose – IV – every 8–12 hours.

Management according to underlying cause

Culture-negative patients

During the first 48 hours

• If the patient has a single spike of fever and temperature returns to normal within 4 hours, antibiotics may be discontinued.

• If the patient has more than one febrile episode, continue antibiotics for a minimum of 7 afebrile days.

Oral herpes or severe mucositis

• Aciclovir – IV – commence according to institutional protocol.

Suspected Candida infection

• Fluconazole – IV – according to institutional protocol.

Suspected invasive fungal infection

• Amphotericin B – IV – according to institutional protocol.

Diarrhoea and vomiting

• Obtain stool culture.

• Ciprofloxacin – administer according to regimen above.

AND

• Metronidazole – administer according to regimen above.

Skin and soft tissue infection

• Add Vancomycin according to the regimen above.

No identifiable focus but rapid clinical deterioration

• Consider adding Vancomycin.

Persistent fever after 5–7 days

• Perform fungal investigations before initiating empiric antifungal therapy.

• Commence appropriate antifungal treatment based on clinical assessment and investigation results.

Referral

Urgently refer patients with febrile neutropenia to an oncology or internal medicine specialist.

Immediate referral is indicated for patients with:

• Septic shock

• Hemodynamic instability

• Persistent hypotension

• Respiratory distress

• Altered mental status

• Persistent fever despite broad-spectrum antibiotics

• Suspected invasive fungal infection

• Multiorgan dysfunction

Complications

• Severe sepsis

• Septic shock

• Invasive fungal infection

• Acute kidney injury

• Respiratory failure

• Multiorgan dysfunction

• Disseminated intravascular coagulation

• Death

Prognosis

The prognosis depends on the severity and duration of neutropenia, underlying malignancy, timeliness of antibiotic administration, and presence of complications. Early administration of appropriate empiric antibiotics significantly reduces mortality. Persistent neutropenia and invasive fungal infections are associated with poorer outcomes.

Prevention

Preventive measures include risk assessment before chemotherapy, appropriate infection prevention practices, patient education regarding early reporting of fever, and consideration of granulocyte colony-stimulating factor (G-CSF) prophylaxis in patients at high risk of chemotherapy-induced febrile neutropenia according to established oncology guidelines.