Febrile Neutropenia

Neutropenia in oncology patients often results due to chemotherapy. The lowest neutrophil count is generally seen 5 -10 days after the last chemotherapeutic dose and the risk of developing an infection primarily depends on the severity and duration of neutropenia, comorbidities, use of in-dwelling catheters. 

The absolute neutrophil count (ANC) normal range is 1500 to 8000/mm3 (1.5 to 8.0 × 109/L).  Fever is defined as a temperature of 38.3°C on one occasion or 38.0°C persisting >1 hour.


Definitions
Neutropenia is defined as an absolute neutrophil count <1000/mm3(<1.0 × 109/L)
Severe neutropenia is defined as an absolute neutrophil count <500/mm3 (<0.5 × 109/L) Profound neutropenia is defined as an absolute neutrophil count <100/mm3 (<0.1 × 109/L).

Fever is the most common finding seen with bacterial infections in the neutropenic patient. Common symptoms and signs are often absent in the neutropenic patient because impaired inflammatory response. 



Examination (Head to toe to look of any signs of infection)

Lungs
Skin
Urine
Abdomen
CNS

Oral cavity
Perianal area
Intravascular catheters (Thrombophlebitis, Infective Endocarditis)

Avoid doing a Digital Rectal Examination in neutropenic patients. Id necessary, do only after antibiotic administration. 

Work up

• Blood cultures
• Urinalysis, Urine culture,
• CXR
• Sputum, stool, and wound drainage Gram stains and culture 
• FBC, Renal and Liver function  

Treatment 

Known source - Guided Antibiotics
Unknown source and ill patient - Empiric Broad Spectrum Antibiotics

Gram-positive bacteria currently account for more than half of microbiologically confirmed infections in febrile neutropenic patients. Monotherapy with an appropriate broad-spectrum agent is as effective as dual-agent treatment in most circumstances. Consider adding vancomycin if:

• Hemodynamic instability
• Radiographic pneumonia
• Catheter-related infection
• Skin or soft tissue infection
• Known colonization with a resistant gram-positive organism
• Severe mucositis (recent use of fluoroquinolone prophylaxis)

Discussion with patient's treating oncologist should happen simultaneously about the choice of Antibiotics (unless there are agreed existing protocols) and plan for admission v/s discharge since hospitalization may lead to drug-resistant infections. 

A subgroup of patients with febrile neutropenia may appear well with no signs of infection. They are expected to settle their neutropenia within a week have a low risk of severe infection and can be considered for outpatient care in liaison with the Oncologist.        Ensure early follow up for them prior to discharge. 

Decision Rules to risk stratify Neutropenic Patients

Clinical Index of Stable Febrile Neutropenia 

MASCC Risk Index for Febrile Neutropenia 

Clinical evidence supports the benefits of empiric antibiotics only with ANC ≤500/mm. There is little evidence for empiric antibiotics when the ANC >1000/mm. Abx are continued until the infection has clinically resolved and/or the ANC is >500/mm3 (>0.5 × 109/L).

Posted by:

              

     Lakshay Chanana

     

     ST4 Trainee

     Royal Infirmary of Edinburgh

     Department of Emergency Medicine

     Edinburgh

     Scotland

     @EMDidactic