CPHON Neutropenia and Infection Management 1 — Questions and Answers

Question 1: A child receiving chemotherapy has an absolute neutrophil count (ANC) of 350/µL and a temperature of 38.3°C. The nurse recognizes this as:

Febrile neutropenia (FN), a medical emergency requiring immediate blood cultures and broad-spectrum IV antibiotics (Correct answer)
A low-grade fever that can be monitored at home
Mild neutropenia that requires only increased oral fluid intake
A reaction to chemotherapy that will resolve spontaneously

Correct answer: Febrile neutropenia (FN), a medical emergency requiring immediate blood cultures and broad-spectrum IV antibiotics

Febrile neutropenia is defined as ANC <500/µL (or <1000 with expected decline to <500) AND temperature ≥38.3°C (once) or ≥38.0°C sustained. It is a medical emergency requiring immediate intervention.

Febrile neutropenia (FN) is one of the most common and life-threatening complications of myelosuppressive chemotherapy. Standard definition: ANC <500/µL (or <1000/µL with expected decline to <500 within 48 hours) AND a single oral temperature ≥38.3°C (101°F) or ≥38.0°C (100.4°F) sustained over 1 hour. Without intact neutrophil-mediated host defense, infections spread rapidly without localizing signs or typical inflammatory response. Initial management must occur within 1 hour and includes: (1) Blood cultures from all central line lumens and periphery; (2) Urinalysis and urine culture; (3) Chest X-ray if respiratory symptoms; (4) Empiric broad-spectrum IV antibiotics (e.g., piperacillin-tazobactam, cefepime, or meropenem) within 60 minutes; (5) Vitals and assessment for signs of sepsis/septic shock.

Question 2: How is the absolute neutrophil count (ANC) calculated from a complete blood count with differential?

ANC = WBC × (% segmented neutrophils + % bands) ÷ 100 (Correct answer)
ANC = WBC × % lymphocytes ÷ 100
ANC = WBC − platelet count
ANC = % neutrophils × hemoglobin

Correct answer: ANC = WBC × (% segmented neutrophils + % bands) ÷ 100

ANC is calculated by multiplying the total WBC count (in cells/µL) by the fraction that are neutrophils (segmented + band forms), representing the absolute number of mature and near-mature neutrophils capable of fighting infection.

The ANC calculation: ANC (cells/µL) = WBC (cells/µL) × (% segs + % bands) / 100. Example: WBC = 2000/µL, 20% segs, 5% bands → ANC = 2000 × (20+5)/100 = 2000 × 0.25 = 500/µL. ANC reflects the absolute number of functional neutrophils (segmented neutrophils = mature, bands = near-mature, both capable of phagocytosis). Immature forms (metamyelocytes, blasts) are NOT included. Risk stratification: ANC 500–1000 = mild neutropenia; 200–500 = moderate; <200 = severe; <100 = profound. In pediatric oncology, 'neutropenic precautions' are typically initiated at ANC <500/µL per institutional protocol.

Question 3: A neutropenic child develops a central line-associated bloodstream infection. Blood cultures grow Pseudomonas aeruginosa. The nurse should anticipate which change in antibiotic therapy?

Addition of a second antipseudomonal agent (aminoglycoside or fluoroquinolone) for synergistic coverage (Correct answer)
Switching to oral amoxicillin for completion of therapy
Discontinuing antibiotics once fever resolves
Adding vancomycin as the primary treatment for Pseudomonas

Correct answer: Addition of a second antipseudomonal agent (aminoglycoside or fluoroquinolone) for synergistic coverage

Pseudomonas aeruginosa bacteremia carries high mortality in neutropenic patients and warrants combination therapy with a beta-lactam plus an aminoglycoside or fluoroquinolone for synergistic killing and reduced resistance emergence.

Pseudomonas aeruginosa is one of the most feared pathogens in febrile neutropenia due to its intrinsic resistance mechanisms, rapid dissemination, and high mortality if untreated. Monotherapy failure rates are higher than for other organisms. Combination therapy using an antipseudomonal beta-lactam (piperacillin-tazobactam, cefepime, or meropenem) plus an aminoglycoside (tobramycin, gentamicin) or a fluoroquinolone (ciprofloxacin) provides synergistic bactericidal activity and may reduce emergence of resistance. Duration of antibiotic therapy for Pseudomonas bacteremia is typically 14 days minimum. Central line removal should be considered but individualized based on clinical response and necessity.

Question 4: Which food should be avoided by a neutropenic pediatric oncology patient?

Fresh salad bar items, unpasteurized dairy, raw eggs, and undercooked meats (Correct answer)
Pasteurized milk and cooked vegetables
Packaged crackers and cooked pasta
Commercially canned foods and bottled water

Correct answer: Fresh salad bar items, unpasteurized dairy, raw eggs, and undercooked meats

Neutropenic diet restrictions aim to minimize exposure to pathogens; raw produce (especially salad bars with shared utensils), unpasteurized products, raw eggs, and undercooked meats harbor bacteria and fungi that healthy immune systems handle but neutropenic patients cannot.

The neutropenic diet (also called the low-microbial or low-bacteria diet) is prescribed for patients with ANC <500/µL (or per institutional protocol) to minimize ingestion of potentially harmful microorganisms. Foods to avoid: raw fruits and vegetables that cannot be peeled (salad bar items, sprouts, unwashed berries); unpasteurized dairy products (raw milk, soft cheeses like brie, blue cheese, queso fresco); raw or undercooked meats and seafood (sushi, rare beef, raw oysters); raw eggs (Caesar dressing, hollandaise, cookie dough); well water; foods from bulk bins. Safe foods: cooked fruits and vegetables, pasteurized dairy, fully cooked meats and eggs, commercially packaged foods. Note: some evidence questions the effectiveness of strict low-bacterial diets, but most pediatric oncology centers maintain restrictions during profound neutropenia.

Question 5: A neutropenic child develops perianal pain and redness. The nurse should avoid which common assessment action?

Rectal temperature measurement and rectal examinations (Correct answer)
Oral temperature measurement
Inspection of the perianal area visually
Application of topical barrier cream to protect skin integrity

Correct answer: Rectal temperature measurement and rectal examinations

Rectal temperatures and rectal examinations are absolutely contraindicated in neutropenic patients because the trauma to friable, poorly healing rectal mucosa can introduce bacteria from gut flora into the bloodstream, causing bacteremia.

Neutropenic patients have dramatically reduced ability to combat bacterial invasion. The rectum harbors large quantities of gram-negative bacteria (Escherichia coli, Klebsiella, Pseudomonas) and anaerobes. Inserting any device rectally — thermometer, suppository, enema, or finger for examination — can traumatize the friable, poorly healing mucosal barrier and allow bacteria to enter the bloodstream, causing potentially fatal bacteremia. Rectal temperatures are absolutely contraindicated in neutropenic patients; oral, axillary, or temporal artery temperature measurement should be used instead. Rectal suppositories and enemas are also prohibited. If perianal cellulitis or perirectal abscess is suspected, imaging (CT/MRI) is used to assess, and any procedures are done only under specialist guidance with antibiotic coverage.

Question 6: A child receiving chemotherapy for ALL is exposed to a sibling at home who develops varicella (chickenpox) the next day. The child is not known to be immune. The most important immediate action is:

Notify the oncology team immediately for consideration of varicella-zoster immune globulin (VZIG) administration within 96 hours of exposure (Correct answer)
Give the varicella vaccine immediately
Isolate the child at home for 21 days
Administer prophylactic oral acyclovir without notifying the team

Correct answer: Notify the oncology team immediately for consideration of varicella-zoster immune globulin (VZIG) administration within 96 hours of exposure

Varicella in an immunocompromised child can be fatal. VZIG (VariZIG) must be administered within 96 hours of exposure to prevent or attenuate disease in immunocompromised varicella-susceptible patients. The team must be notified immediately.

Varicella (chickenpox) poses extreme risk of disseminated, life-threatening infection in immunocompromised patients. Primary prevention: The varicella vaccine is a live attenuated vaccine and is CONTRAINDICATED during chemotherapy and for most immunocompromised patients. Post-exposure prophylaxis: VariZIG (varicella-zoster immune globulin) provides passive immunity and must be administered as soon as possible but within 96 hours (4 days) of exposure to modify or prevent disease. If VZIG is unavailable, IVIG may be used. If VZIG cannot be given within 96 hours, prophylactic oral acyclovir (7 days) may be considered. If chickenpox develops despite prophylaxis, high-dose IV acyclovir is initiated immediately. Chemotherapy should be held, and the patient may require hospitalization.

CPHON Neutropenia and Infection Management 1

A child receiving chemotherapy has an absolute neutrophil count (ANC) of 350/µL and a temperature of 38.3°C.
The nurse recognizes this as: