Metabolic Emergencies : Cancer

Metabolic Emergencies : Cancer 150 150 Tony Guo
Metabolic Emergencies
Syndrome of Inappropriate Antidiuretic Hormone (SIADH)
  • Tumor cells can produce abnormal or sustained production of antidiuretic hormone (ADH).
  • Many chemotherapy agents may also contribute to ectopic ADH production or potentiate ADH effects
  • Water retention and hyponatremia (hypotonic hyponatremia).
  • Weight gain without edema, weakness, anorexia, nausea, vomiting, personality changes, seizures, oliguria, decrease in reflexes, and coma
  • Treat underlying malignancy.
  • Take measures to correct sodium-water imbalance, including fluid restriction, oral salt tablets or isotonic (0.9%) saline administration, and IV 3% sodium chloride solution (severe cases).
  • Furosemide (Lasix) used in initial phases.
  • Monitor sodium level because correcting SIADH rapidly may result in seizures or death.
Hypercalcemia
  • Occurs in metastatic disease of bone or multiple myeloma, or when a parathyroid hormone–like substance is secreted by cancer cells.
  • Immobility and dehydration can contribute to or exacerbate hypercalcemia.
  • Serum calcium in excess of 12 mg/dL (3 mmol/L) often produces symptoms.
  • Apathy, depression, fatigue, muscle weakness, ECG changes, polyuria and nocturia, anorexia, nausea, and vomiting.
  • High calcium elevations can be life threatening.
  • Chronic hypercalcemia can result in nephrocalcinosis and irreversible renal failure.
  • Treat primary disease.
  • Hydration (3 L/day) and bisphosphonate therapy.
  • Diuretics (particularly loop diuretics) used to prevent heart failure or edema.
  • Infusion of bisphosphonate zoledronate (Zometa) or pamidronate (Aredia)
Tumor Lysis Syndrome (TLS)
  • Metabolic complication characterized by rapid release of intracellular components in response to chemotherapy and radiation therapy (less commonly).
  • Massive cell destruction releases intracellular components (potassium, phosphate, DNA, RNA) that are metabolized to uric acid by liver.
  • Hallmark signs: hyperuricemia, hyperphosphatemia, hyperkalemia, hypocalcemia.
  • Weakness, muscle cramps, diarrhea, nausea, and vomiting.
  • Occurs within first 24 to 48 hr. after initiation of chemotherapy.
  • May persist for about 5 to 7 days.
  • Metabolic abnormalities and concentrated uric acid (which crystallizes in distal tubules of kidneys) can lead to acute kidney injury.
  • Identify patients at risk.
  • Increase urine production using hydration therapy.
  • Decrease uric acid concentrations using allopurinol.
  • Use IV sodium bicarbonate to counter effects of acidic properties that are released

Leave a Reply

Your email address will not be published.