Advanced Oncology Certified Nurse Practitioner (AOCNP) Certification Practice Test

Hyperkalemia is a laboratory abnormality that is commonly associated with tumor lysis syndrome (TLS). This condition often occurs after the initiation of treatment for certain malignancies, particularly hematologic cancers like leukemias and lymphomas, where there is a rapid breakdown of tumor cells. As these tumor cells lyse, they release their intracellular contents, which includes potassium, into the bloodstream. This sudden influx of potassium can overwhelm the body's ability to excrete it, leading to hyperkalemia, which is one of the hallmark laboratory findings of TLS. In addition to hyperkalemia, TLS is also characterized by the release of other intracellular substances, leading to metabolic abnormalities such as hyperuricemia and hyperphosphatemia. Hypocalcemia also can occur as a secondary effect due to elevated phosphate levels, but the immediate and direct suggestion of TLS is often indicated by hyperkalemia.