CPHON Neutropenia and Infection Management 2 — Questions and Answers

Question 1: Which prophylactic medication is routinely given to pediatric oncology patients receiving intensive chemotherapy to prevent Pneumocystis jirovecii pneumonia (PJP)?

Trimethoprim-sulfamethoxazole (TMP-SMX / co-trimoxazole) (Correct answer)
Vancomycin
Metronidazole
Fluconazole

Correct answer: Trimethoprim-sulfamethoxazole (TMP-SMX / co-trimoxazole)

TMP-SMX is the first-line prophylactic agent for PJP in immunocompromised pediatric oncology patients. It is typically given 2–3 days per week. Alternatives for sulfa-allergic patients include dapsone, atovaquone, or monthly inhaled pentamidine.

Pneumocystis jirovecii (formerly carinii) pneumonia (PJP) is an opportunistic fungal infection that can cause life-threatening pneumonia in immunocompromised hosts. Standard prophylaxis with TMP-SMX (trimethoprim-sulfamethoxazole) administered 2–3 consecutive days per week (or alternative dosing schedules) provides >95% protection. PJP prophylaxis is indicated during intensive chemotherapy for leukemia/lymphoma, during and after HSCT, and in patients on prolonged high-dose corticosteroids. If TMP-SMX is contraindicated (sulfa allergy, bone marrow suppression), alternatives are: dapsone (oral, daily/weekly), atovaquone (suspension, daily), or aerosolized pentamidine (monthly, for older children). PJP presents with non-productive cough, fever, and hypoxemia with bilateral interstitial infiltrates; treatment is high-dose TMP-SMX IV.

Question 2: A neutropenic pediatric oncology patient develops a new fever on day 5 of broad-spectrum antibiotics without an identified source. The nurse should anticipate the provider will order:

Addition of empiric antifungal therapy due to risk of invasive fungal infection (Correct answer)
Stopping all antibiotics as the fever is likely drug-related
Adding a third antibiotic covering only gram-positive organisms
Continuing current antibiotics without change for 7 more days

Correct answer: Addition of empiric antifungal therapy due to risk of invasive fungal infection

Persistent fever after 4–7 days of broad-spectrum antibacterials in a neutropenic patient raises concern for invasive fungal infection (Aspergillus, Candida). Empiric antifungal therapy (amphotericin B or an azole/echinocandin) is a standard guideline recommendation in this scenario.

IDSA and MASCC/ESMO guidelines recommend that neutropenic patients who remain febrile after 4–7 days of appropriate antibacterial therapy without a documented bacterial source be evaluated for invasive fungal infection and considered for empiric antifungal therapy. Invasive mold infections (Aspergillus) and invasive candidiasis are increasingly prevalent after prolonged broad-spectrum antibiotic therapy, which selects for fungal colonization. High-resolution CT of the chest is obtained to look for mold-related pulmonary infiltrates (halo sign). Empiric options include amphotericin B (conventional or lipid formulations), caspofungin (echinocandin), micafungin, or voriconazole. Duration continues until neutrophil recovery and resolution of infection.

Question 3: Which sign or symptom in a neutropenic patient indicates possible Clostridium difficile (C. diff) colitis and requires contact precautions?

Profuse, watery, foul-smelling diarrhea (≥3 loose stools in 24 hours) after antibiotic exposure (Correct answer)
Blood-streaked stools without diarrhea
Constipation and abdominal cramping
Bilious vomiting with absent bowel sounds

Correct answer: Profuse, watery, foul-smelling diarrhea (≥3 loose stools in 24 hours) after antibiotic exposure

C. difficile produces toxin-mediated colitis in patients whose gut flora has been disrupted by antibiotics. It presents with profuse watery, foul-smelling diarrhea and is highly contagious via spore transmission, requiring contact precautions and specific hygiene measures.

Clostridium difficile (C. diff) colitis occurs when broad-spectrum antibiotic therapy disrupts the normal gut microbiome, allowing C. diff spores to germinate and produce toxins A and B, which damage the colonic epithelium. Classic presentation: ≥3 loose/watery stools per 24 hours with a characteristic foul odor, abdominal cramping, and low-grade fever — typically 1–10 days after antibiotic initiation. Diagnosis by GDH antigen + toxin EIA or nucleic acid amplification test on liquid stool. Management includes: (1) Contact precautions (gown and gloves); (2) Hand washing with soap and water (NOT alcohol gel — spores resist alcohol); (3) Treatment with oral vancomycin or fidaxomicin (not metronidazole as first-line per current guidelines for severe disease); (4) Consider stopping the precipitating antibiotic if clinically safe.

Question 4: A child with a bone tumor on high-dose chemotherapy has an ANC of 85/µL. The parents report the child has been playing outdoors, and a neighbor child visited who had a mild runny nose. Which nursing education point is most important?

Avoid close contact with anyone who is ill; this level of neutropenia (ANC <100) constitutes profound immunosuppression and any viral exposure carries serious risk (Correct answer)
Outdoor play is fine but should be limited to 30 minutes daily
The child's neutropenia is mild and routine precautions are sufficient
Only fever above 39°C warrants a call to the oncology team at this ANC level

Correct answer: Avoid close contact with anyone who is ill; this level of neutropenia (ANC <100) constitutes profound immunosuppression and any viral exposure carries serious risk

ANC <100 is profound neutropenia. Even a mildly ill contact represents significant infection risk — common respiratory viruses can cause severe, disseminated infections in the profoundly neutropenic child. Families must understand that any fever (≥38.3°C) is an emergency.

Profound neutropenia (ANC <100/µL) represents near-complete absence of neutrophil-mediated immune defense. At this level, infections that the intact immune system handles easily — including common respiratory viruses (RSV, influenza, rhinovirus, coronavirus), herpes viruses, and ubiquitous environmental fungi — can cause life-threatening disseminated disease. Family education must include: (1) Avoid all individuals who are ill or recently exposed to illness; (2) Avoid crowded public places; (3) Strict hand hygiene for all household members; (4) Fever ≥38.3°C (single) or ≥38.0°C (sustained) = call the oncology center immediately regardless of time of day; (5) Do NOT give acetaminophen or ibuprofen without calling first, as these mask fever; (6) Go to the oncology ER (not a walk-in clinic) if the child develops fever.

Question 5: Which finding on physical examination of a neutropenic patient should prompt the nurse to suspect invasive pulmonary aspergillosis?

New onset pleuritic chest pain, non-productive cough, and hemoptysis in a patient with prolonged neutropenia (Correct answer)
Frothy pink sputum and bilateral dependent rales
Vesicular lesions on the torso following a dermatomal pattern
Profuse watery diarrhea and abdominal cramping

Correct answer: New onset pleuritic chest pain, non-productive cough, and hemoptysis in a patient with prolonged neutropenia

Invasive pulmonary aspergillosis (IPA) in neutropenic patients characteristically presents with pleuritic chest pain, dry cough, and hemoptysis — due to angio-invasive hyphae causing pulmonary infarction. The 'halo sign' on CT is pathognomonic.

Aspergillus species are angio-invasive molds — their hyphae penetrate blood vessel walls, causing thrombosis and pulmonary infarction. This vascular invasion is the basis for the classic symptoms of IPA: pleuritic chest pain (infarction of pleural tissue), dry/non-productive cough, and hemoptysis (erosion into pulmonary vessels). Classic CT finding: the 'halo sign' — a nodule surrounded by a halo of ground-glass opacity representing hemorrhagic infarction — is highly suggestive but not specific. Galactomannan antigen in serum or BAL fluid supports the diagnosis. Treatment: voriconazole is first-line; isavuconazole and liposomal amphotericin B are alternatives. Neutrophil recovery is the most critical factor in survival.

Question 6: G-CSF (filgrastim) is prescribed to a child after myelosuppressive chemotherapy. What is the expected therapeutic outcome the nurse should monitor for?

Rising absolute neutrophil count (ANC) indicating neutrophil recovery (Correct answer)
Decreasing absolute neutrophil count indicating drug effect
Rising platelet count above 100,000/µL
Normalization of hemoglobin within 48 hours

Correct answer: Rising absolute neutrophil count (ANC) indicating neutrophil recovery

G-CSF stimulates the proliferation and accelerated release of neutrophil precursors from bone marrow, resulting in a rising ANC. The nurse monitors daily CBC with differential to assess for neutrophil recovery and document when the nadir occurs and reverses.

Granulocyte colony-stimulating factor (G-CSF, filgrastim, pegfilgrastim) works by binding to specific receptors on neutrophil precursors in the bone marrow, stimulating their proliferation, differentiation, and release into the peripheral blood. The therapeutic goal is to shorten the duration of post-chemotherapy neutropenia (the nadir period) and reduce the risk and duration of febrile neutropenia. The nurse monitors: (1) Daily CBC with differential — ANC is the primary parameter; (2) Common side effects: bone pain (from marrow expansion — managed with non-opioid analgesics), mild splenomegaly, headache, and transient leukocytosis; (3) Signs of splenic rupture (rare but serious — sudden left-sided abdominal/shoulder pain); (4) ANC typically begins rising 2–3 days after G-CSF initiation.

CPHON Neutropenia and Infection Management 2

Which prophylactic medication is routinely given to pediatric oncology patients receiving intensive chemotherapy to prevent Pneumocystis jirovecii pneumonia (PJP)?