Neutropenic Fever or Febrile Neutropenia

Homepage: EMNote.org ■ 🚩Membership: https://tinyurl.com/joinemnote 🚩ACLS Lecture: https://tinyurl.com/emnoteacls Neutropenic Fever: Overview Neutropenia is defined as an absolute neutrophil count (ANC) below 1500 cells per microliter. Severe neutropenia occurs when ANC is below 500 cells per microliter; profound neutropenia is below 100 cells per microliter. Fever is defined as a single oral temperature above 101°F (38.3°C) or sustained temperature above 100.4°F (38.0°C) for at least one hour. Most cases of neutropenic fever are labeled as fever of unknown origin due to unidentified infectious causes. Neutropenic fever is a medical emergency due to compromised immune function. Etiology and Risk Factors Chemotherapy-induced myelosuppression is a common cause of neutropenic fever. Congenital neutropenia is suspected in adults with severe neutropenia (ANC below 500 cells/µL) and somatic findings. Medications, including antibiotics, anti-inflammatory drugs, and psychotropics, can cause neutropenia. Nutritional deficiencies such as vitamin B12, folate, or copper deficiency contribute to neutropenia. High-risk groups include older patients, those with comorbidities, and individuals with hematologic cancers like leukemia. Symptoms and Clinical Presentation Fever is often the only reliable symptom in neutropenic patients. Additional symptoms may include abdominal pain, mucositis, and perirectal pain. Complications like severe sepsis or septic shock may present with extreme pain, confusion, or shortness of breath. Signs of septic shock include increased heart rate, decreased urination, and shivering. Reduced or absent signs of infection are common due to low neutrophil counts. Diagnosis and Evaluation Diagnosis involves evaluating fever duration, symptoms, and potential infection sites. Laboratory tests include complete blood count (CBC), differential white cell count, and cultures (blood, urine, stool). Imaging studies like chest X-rays or CT scans may be required based on clinical presentation. Galactomannan and 1,3-beta-D-glucan tests help diagnose fungal infections. Procalcitonin testing may assist in detecting bacteremia in sepsis cases. Risk Assessment The MASCC Risk Index identifies risk levels in chemotherapy-induced neutropenia. A MASCC score ≥ 21 points indicates low risk; ≤ 20 points indicates high risk. The Clinical Index of Stable Febrile Neutropenia (CISNE) is another tool for risk stratification. High-risk patients are more likely to develop complications like severe sepsis or septic shock. Risk assessment guides treatment decisions and antibiotic selection. Treatment and Management Immediate evaluation includes risk assessment, blood cultures, and broad-spectrum empiric antibiotics. Low-risk patients typically receive oral antibiotics; high-risk patients require intravenous therapy. IDSA recommends antipseudomonal beta-lactam agents like cefepime or piperacillin/tazobactam for high-risk patients. Vancomycin is added if catheter-related infections, skin infections, or pneumonia are suspected. Empiric antifungal therapy is considered after 4–7 days of persistent fever and suspicion of fungal infection. Prevention Strategies Limit exposure to opportunistic pathogens through hygiene, food safety, and avoiding contact with infected individuals. Hospitalized patients require standard precautions, including hand hygiene and protective equipment. Avoid procedures that cause skin breaks, such as rectal thermometers or enemas. Preventive therapy with colony-stimulating factors (e.g., G-CSFs) is recommended for high-risk patients. Routine monitoring of skin, mucous membranes, and other entry points helps prevent infections.