Tumor Lysis Syndrome Flashcards
What is tumor lysis syndrome (TLS)?
TLS is a metabolic derangement caused by the rapid lysis of tumor cells, leading to the release of intracellular contents (e.g., potassium, phosphate, nucleic acids) into the circulation.
What types of malignancies are at high risk for tumor lysis syndrome?
Malignancies with a high cell turnover or bulky disease, such as aggressive lymphomas (e.g., diffuse large B-cell lymphoma) and leukemias, especially after chemotherapy or spontaneously.
What are the key risk factors for developing tumor lysis syndrome?
High tumor burden, rapid cell turnover, initiation of combination chemotherapy or immunotherapy, and inadequate prophylaxis (e.g., fluids, xanthine oxidase inhibitors).
What are the key electrolyte abnormalities seen in tumor lysis syndrome?
Hyperphosphatemia, hyperkalemia, hyperuricemia, and hypocalcemia (due to calcium-phosphate precipitation).
What are the severe manifestations of tumor lysis syndrome?
Acute kidney injury (due to uric acid and calcium-phosphate deposition), cardiac arrhythmias (due to hyperkalemia), and seizures (due to hypocalcemia).
What ECG changes are associated with hyperkalemia in tumor lysis syndrome?
Progression from peaked T waves, Widened QRS complexes, to ventricular fibrillation, then asystole.
What are the main prophylactic measures for tumor lysis syndrome?
Intravenous fluids for hydration, xanthine oxidase inhibitors (e.g., allopurinol or febuxostat), and monitoring of electrolytes.
What is the first-line treatment for established tumor lysis syndrome?
Aggressive intravenous fluids, electrolyte correction, and administration of rasburicase to rapidly lower uric acid levels.
Why is rasburicase preferred over allopurinol in managing tumor lysis syndrome?
Rasburicase breaks down existing uric acid into a more water-soluble product, while allopurinol only prevents the formation of new uric acid.
What are the life-threatening complications of tumor lysis syndrome?
Acute kidney injury, severe cardiac arrhythmias, seizures, and metabolic acidosis.
What is the hallmark of tumor lysis syndrome on laboratory tests?
Elevated potassium, phosphate, and uric acid levels with decreased calcium.
What drugs are contraindicated in patients with glucose-6-phosphate dehydrogenase (G6PD) deficiency when treating tumor lysis syndrome?
Rasburicase is contraindicated due to the risk of methemoglobinemia.
