PEDS Module 4: Altered Immune System

Fever (38.4°C/101.2°F) after chemo

Fever in a neutropenic patient is a medical emergency — even small infections can become fatal due to lack of immune response.

Sore throat

Possible site of infection (bacterial/viral) — port of entry for infection.

Recent chemotherapy (2 days ago)

Nadir (lowest point of neutrophil count) usually occurs 7–14 days after chemo — April is now extremely immunocompromised.

Unresponsive to acetaminophen

Suggests ongoing infection or systemic inflammatory response not controlled by simple antipyretics.

CVAD in place

Central lines are common sources of bloodstream infections in immunosuppressed patients.

Isolates from friends, refuses visitors

Indicates depression, anxiety, and social withdrawal common in children with chronic illness.

Home schooling, missing school

Disruption in normal development; can affect emotional and social skills.

Mother stays home full time

Shows family is under financial and emotional stress due to caregiving burden.

Leukemia (ALL)

Cyclophosphamide

Alkylating agent; cross-links DNA strands to prevent cell replication and cause cell death (especially in rapidly dividing cells like cancer)

Monitor CBC (especially WBC, platelets); assess for infection, bleeding, hydration status; prevent hemorrhagic cystitis (encourage fluids, monitor urine).

Leukemia (ALL)

Methotrexate

Antimetabolite; inhibits folic acid metabolism which inhibits DNA synthesis and cell replication

Monitor CBC, renal function, liver enzymes; ensure leucovorin rescue if needed; monitor for mucositis, nephrotoxicity, hepatotoxicity.

Leukemia (ALL)

Cytarabine

Antimetabolite; inhibits DNA polymerase and DNA synthesis during S-phase

Monitor for bone marrow suppression, assess for signs of infection/bleeding, monitor liver and kidney function.

Prevention of Opportunistic Infections (Pneumocystis jirovecii pneumonia)

Sulfamethoxazole-Trimethoprim (Bactrim)

Inhibits bacterial synthesis of folic acid → bacteriostatic effect

Assess for rash (Steven-Johnson Syndrome risk), monitor CBC for bone marrow suppression, ensure hydration to prevent crystalluria/kidney damage.

GI protection from stress ulcers (chemo/steroid use)

Ranitidine

Histamine H2-receptor antagonist; inhibits gastric acid secretion by blocking H2 receptors in the stomach

Monitor for GI bleeding symptoms, assess renal function (dose adjustment in renal impairment), monitor for mental status changes in children.

Constipation prevention (due to chemo, immobility)

Docusate Sodium

Stool softener; lowers surface tension of stool, allowing water and fat to penetrate and soften feces

Monitor for bowel movement regularity, assess for abdominal distension, encourage fluid intake.

Nausea prevention/treatment (due to chemo)

Ondansetron (Zofran)

Selective 5-HT3 receptor antagonist; blocks serotonin receptors in the CNS and GI tract to prevent nausea and vomiting

Monitor for QT prolongation (obtain baseline EKG if needed), assess for effectiveness, monitor for headache and constipation.

Fever control, comfort

Acetaminophen (Tylenol)

Inhibits prostaglandin synthesis in the CNS (pain/fever reduction, minimal anti-inflammatory action)

Monitor for liver toxicity (especially if taking multiple meds), avoid overdose, assess temperature and pain levels.

Fever (100.8°F oral)

Fever is a critical early sign of sepsis in neutropenic patients.

Pulse 112 bpm

Tachycardia is an early sign of systemic infection or hypovolemia.

Respiration 24 bpm

Mildly elevated; may represent early metabolic compensation (acidosis or sepsis).

BP 102/66

Lower side of normal → risk for hypotension with septic shock.

O2 sat 96%

Adequate, but must monitor closely if sepsis progresses (oxygenation may decline).

Pale skin, cool extremities

Poor perfusion → could be early sign of shock.

Cap refill 3–4 seconds

Delayed perfusion; normal is <2 seconds.

Lethargy, drowsiness

Neurological changes can occur in early sepsis or from anemia.

Soft, non-tender abdomen

GI function currently intact (important because sepsis can cause ileus).

CVAD intact

Important because central line infection could be source of fever.

WBC 0.2 (Normal 4.5–11.0)

Critically low → Severe neutropenia → No immune defense against infection

Worsening (previous 0.3)

Hgb 7.4 (Normal 12–16)

Severe anemia → Risk for hypoxia, tachycardia, fatigue

Worsening (previous 8.2)

Platelets 54 (Normal 150–450)

Severe thrombocytopenia → High risk of spontaneous bleeding

Worsening (previous 61)

Neutrophil % 1% (Normal 42–72%)

Profound neutropenia → Extremely high risk of overwhelming infection

Worsening (previous 0%)

Bands 0% (Normal 3–5%)

No immature neutrophils → No "left shift", no reserve to fight infection

Stable

Sodium 130 (Normal 135–145)

Hyponatremia → Risk of seizures, confusion, cerebral edema

Stable (previous 129)

Potassium 3.5 (Normal 3.5–5.0)

Low-normal; needs monitoring → Electrolyte balance critical for heart function

Improving (previous 3.3)

Glucose 70 (Normal 70–110)

Low-normal → Watch for hypoglycemia during illness/infection

Slightly worsening (previous 82)

BUN 26 (Normal 7–25)

Elevated → Possible dehydration or renal stress

Worsening (previous 17)

Creatinine 1.4 (Normal 0.6–1.2)

Elevated creatinine → Early acute kidney injury risk (especially with sepsis)

Worsening (previous 1.1)

Magnesium 1.9 (Normal 1.6–2.0)

Normal; important for cardiac stability

Stable (previous 2.0)

Ionized Calcium 1.05 (Normal 1.05–1.46)

Low-normal → Need monitoring, risk of tetany if drops

Worsening (previous 1.11)

Amylase 29 (Normal 25–125)

Normal → No pancreatitis

Stable

Lipase 27 (Normal 3–73)

Normal → No pancreatitis

Improving (previous 39)

Lactate 1.8 (Normal 0.5–2.2)

High-normal → Early concern for sepsis if trending up

Slightly worsening (previous 1.7)

PT/INR 0.9 (Normal 0.9–1.1)

Normal clotting function

Stable

Albumin 3.5 (Normal 3.5–5.5)

Low-normal → Watch for decreased oncotic pressure (fluid shifts/edema)

Worsening (previous 3.9)

Total Bilirubin 1.0 (Normal 0.1–1.0)

High-normal → Monitor for liver dysfunction

Worsening (previous 0.9)

ALT 22 (Normal 8–20)

Mildly elevated → Monitor for liver stress

Worsening (previous 20)

AST 29 (Normal 8–20)

Mildly elevated → Early sign of hepatocellular injury

Worsening (previous 21)

Alkaline Phosphatase 75 (Normal male 38–126; female 70–230)

Normal → No cholestasis

Stable

Specific Gravity 1.042 (Normal 1.015–1.030)

Elevated → Dehydration likely. Body conserving water; hypovolemia risk.

All other UA findings

Normal → No evidence of infection, hematuria, or proteinuria.

Creatinine

0.6–1.2 mg/dL

Creatinine 1.4 → Early kidney injury likely due to sepsis, dehydration, nephrotoxic drugs

Strict I&O, ensure IV fluids running, daily labs, monitor BP, assess for decreased urine output, notify provider if worsening.

WBC 0.2

Profound neutropenia (< 0.5) → critical risk of infection.

Hgb 7.4

Severe anemia → reduced oxygen delivery to tissues; may cause fatigue, tachycardia.

Platelets 54

Thrombocytopenia → high risk of spontaneous bleeding.

Neutrophils 1%

No functional immune system to fight infection.

Sodium 130

Hyponatremia; can cause neurological symptoms (seizures, confusion).

Potassium 3.5

Low normal; monitor for cardiac arrhythmias.

BUN 26 / Creatinine 1.4

Rising → Early acute kidney injury, possibly from sepsis or dehydration.

Creatinine 1.4

Rising → signals kidney injury or poor perfusion secondary to sepsis.

Neutropenic precautions

Prevent infection

No new infections acquired

Blood cultures

Identify pathogen

Guide appropriate antibiotic

IV fluids

Restore perfusion

Normalize BP, prevent kidney failure

Ceftriaxone, Vancomycin

Empiric broad coverage antibiotics

Control infection early

Acetaminophen

Manage fever

Reduce metabolic demand and comfort

Septic Shock

Tachycardia, Hypotension, Decreased urine, Mental status changes

Rapid fluids, O2, vasopressors, notify provider immediately

Anxiety, isolation

Active listening, emotional support, arrange video calls with friends, involve child life specialist

Infection prevention

Strict handwashing, avoiding sick contacts, monitoring for fevers

Medication adherence

Complete antibiotics, chemo follow-ups

Signs/Symptoms education

Teach parents about early signs of infection, dehydration, sepsis