Oncological Emergencies in Pediatrics

Oncological Emergencies

• Can have various presentations and may be the first presentation of underlying malignancy
• Accurately assessing and recognizing these emergencies is crucial for prevention and management
• The most common etiologies for pediatric oncologic emergencies are:
  • Metabolic
  • Hematologic
  • Space occupying Lesion “Pressure”
  • Infectious & Inflammatory

Tumor Lysis Syndrome (TLS)

• Rapid breakdown of malignant cells, releasing large amounts of Nucleic acid, phosphorus, and potassium into circulation
• Can occur:
  • After chemotherapy, particularly in highly sensitive tumors
  • Spontaneously, especially in rapidly growing tumors like Burkitt lymphoma
• Complications:
  • Hyperkalemia due to release of intracellular potassium
  • Hypocalcemia as a result of calcium joining with phosphate and precipitating
  • Urate nephropathy due to accumulation of DNA breakdown byproduct
  • Ca-Phos nephropathy due to precipitation
• Lab Investigations (Cairo and Bishop classification):
  • 2 or more of the following within 3 days before or 7 days after initiation of chemotherapy:
    • Uric acid > 8 mg/dl
    • Potassium > 6 mmol/dl
    • Phosphorus > 6.5 mg/dl (more than 10 = nephropathy)
    • Corrected calcium < 7 mg/dl
    • Ionized calcium < 1.12 mg/dl
• Symptoms:
  • Acute kidney injury
  • Cardiac arrhythmia
  • Seizures and tetany
  • Paresthesias and laryngeospasm
  • Sudden death
• Risk Factors:
  • Large tumor burden and hyperleukocytosis
  • Rapidly growing malignancies
  • Intravascular volume depletion
  • Renal insufficiency
• Management:
  • Admit to PICU
  • Establish good venous access (CVC)
  • Lab monitoring
  • Consult nephrology services
  • Treat electrolyte imbalance
  • Hydration with IV fluids
  • Allopurinol and Rasburicase for hyperuricemia
  • Calcium gluconate, Sodium Bicarbonate, Insulin & Glucose, and Salbutamol for hyperkalemia
  • Avoid oral phosphate and use oral phosphate binder for hyperphosphatemia

Hypernatremia, Hyponatremia, and Hypercalcemia

• Hypernatremia:
  • Etiology: dehydration, sodium load
  • Manifestation: seizures, lethargy
  • Treatment: hydration, electrolyte replacement
• Hyponatremia:
  • Etiology: SIADH, fluids, sodium loss
  • Manifestation: seizures, lethargy
  • Treatment: restrict free water, replace sodium
• Hypercalcemia:
  • Etiology: bone resorption, ectopic parathormone, vitamin D, prostaglandins
  • Manifestation: anorexia, nausea, polyuria, prolonged PR, shortened QT interval
  • Treatment: hydration, furosemide diuresis, corticosteroids, calcitonin, bisphosphonates

Hematological Emergencies

• Hyperleukocytosis:
  • Defined as peripheral WBC > 100,000 cells/UL
  • Present at initial presentation of: ALL, AML, CML
  • Pathophysiology: leukostasis, tissue injury
  • Manifestations: hypoxia, tachypnea, CNS manifestations
  • Management: hydration, chemotherapy, blood transfusion, leukapheresis, exchange transfusion
• Neutropenia:
  • Defined as absolute neutrophil counts < 0.5 × 109/L
  • Associated with increased risk of infection
  • Management: GM-CSF
• Graft vs Host Disease:
  • Defined as hostile immune reaction made by graft against the body
  • Etiology: immunosuppression, non-irradiated blood products, bone marrow transplantation
  • Manifestations: dermatitis, diarrhea, hepatitis
  • Management: corticosteroid, cyclosporine, tarcolimus, antithymocyte globulin
• Disseminated Intravascular Coagulation (DIC):
  • Defined as abnormal excessive formation of fibrin and thrombin in blood
  • Etiology: sepsis, hypotension, tumor factors
  • Manifestations: shock, hemorrhage
  • Management: FFP, platelets, cryoprecipitate, TTT of underlying cause
• Hemorrhagic Cystitis:
  • Defined as hematuria resulting from inflammation of the bladder
  • Etiology: chemotherapy (cyclophosphamide and ifosfamide)
  • Primary Prophylaxis: hyperhydration, continuous bladder irrigation, administration of Mesna
• Extravasation:
  • Defined as leakage of chemotherapy products from blood to nearby tissue
  • Management: stop injection, aspirate residual drug, antidote, avoid applying pressure to site of swelling

Space Occupying Lesions

• Superior vena cava syndrome (SVC syndrome):
  • Etiology: large masses, compression of great vessels
  • Manifestations: swelling of face and neck, prominence of neck and chest veins, cyanosis or plethora, stridor, dyspnea, neck hyperextension, chest pain, sudden respiratory arrest
  • Management: continuous cardio-respiratory monitoring, give oxygen, adequate hydration, spontaneous breathing, avoid general anesthesia, empiric treatment may be necessary
• Spinal Cord Compression:
  • Etiology: metastasis to vertebra and extramedullary space
  • Manifestations:
    • Back pain
    • Cord above T10 symptoms
    • Conus Medullaris (T10 - L2)
    • Cauda Equina Syndrome (L2 - all way below)
  • Investigations: MRI or CT
  • Treatment: combination of analgesia, corticosteroids, radiation therapy, and surgery (decompressive laminectomy)
• Increased ICP:
  • Etiology: primary or metastatic brain tumor
  • Manifestations:
    • Headache
    • Projectile vomiting
    • Blurring of vision and Papilledema
    • Seizure
    • Confusion and coma
    • Hypertension and bradycardia
    • Hydrocephalus
    • Cranial nerve III& V palsies
  • TTT: CT or MRI, Phenytoin and corticosteroids, ventriculostomy tube, radiotherapy and chemotherapy

This quiz covers the presentations, etiologies, and management of oncological emergencies in pediatric patients. It includes topics such as metabolic, hematologic, and space-occupying lesions, as well as tumor lysis syndrome.