Oncologic Emergencies: Tumor Lysis Syndrome
Tumor Lysis Syndrome is a potentially fatal complication associated with radiation or chemotherapy induced cell destruction of large or rapidly growing cancers such as leukemia, lymphoma, and small cell lung cancer. Tumor lysis syndrome also refers to the assemblage of metabolic disturbances that may be evident after initiation of cancer treatment. The release of intracellular contents from the tumor cells leads to electrolyte imbalances – hyperkalemia, hypocalcemia, hyperphosphatemia and hyperuricemia – because the kidneys can no longer excrete large volumes of the released intracellular metabolites.
Manifestations
The following are the presentation of tumor lysis syndrome. These clinical manifestations depend on the extent of the metabolic abnormalities.
GI signs and symptoms:
- Anorexia
- Nausea
- Vomiting
- Abdominal cramps
- Diarrhea
Renal signs and symptoms:
- Flank pain
- Oliguria
- Anuria
- Renal failure
- Acidic urine pH
Neurological signs and symptoms:
- fatigue
- Weakness
- Memory loss
- Altered mental status
- Muscle cramps
- Tetany
- Parethesias (numbness and tingling)
- Seizures
Cardiac signs and symptoms:
- Elevated blood pressure
- Shortened QT complexes
- Widened QRS waves
- Dysrhythmias
- Cardiac arrest
Diagnosis
Tumor lysis syndrome is usually diagnosed through blood chemistry. Electrolyte imbalances identified by the laboratory results would pin point the condition.
Management
Management of tumor lysis syndromeare listed as follows:
- Diuretic therapy with a carbonic anhydrase inhibitor, to alkalinize the urine
- To avoid occurrence of renal failure and to restore electrolyte balance, fluid hydration is initiated 48 hours before and after the initiation of cytotoxic therapy to increase urine volume and eliminate uric acid and electrolytes.
- Allopurinol therapy to inhibit the conversion of nucleic acids to uric acid
- Administration of a cation-exchange resin such as sodium polystyrene sulfonate to treat hyperkalemia by binding and eliminating potassium through the bowel
- Administration of hypertonic dextrose and regular insulin to shift potassium into cells and lower serum potassium levels
- Administration of phosphate-binding gels such as aluminum hydroxide to treat hyperphosphatemia by promoting phosphate excretion in the feces
- Hemodialysis is initiated when patients are unresponsive to the standard approaches for managing uric acid and electrolyte abnormalities
- Identify at-risk patients, including those in whom tumor lysis syndrome may develop up to 1 week after therapy has been completed
- Institute essential preventive measures (fluid hydration and allopurinol as ordered)
- Assess patient for signs and symptoms of electrolyte imbalances
- Assess urine pH to conform alkalization
- Monitor serum electrolyte and uric acid levels for evidence of fluid volume overload secondary to aggressive hydration
- Instruct patient to report symptoms indicating electrolyte disturbances