Acute tumor lysis syndrome (ATLS) is a potentially life-threatening metabolic imbalance that occurs as a result of rapid breakdown of a large number of tumor cells.
Rapid tumor cell death, in which intracellular contents are released into the bloodstream, causes metabolic abnormalities including hyperkalemia, hyperphosphatemia, hyperuricemia, and hypocalcemia, as well as acute kidney injury. ATLS can occur spontaneously, but is most often associated with the initiation of chemotherapy within 12 hours to 72 hours. It may appear as late as one week later.
Patients who are at the highest risk are those with large tumor burdens, or existing renal impairment or biochemical abnormalities such as high uric acid, LDH, phosphorous, creatinine, and a decreased pH level. Patients with non-Hodgkin's lymphoma, particularly Burkitt's, ALL, or T-cell Leukemia, are more likely to incur ATLS than any other type of cancers.
Risk factors include:
- Rapid proliferation index and large tumor burden
- An initial white blood count greater than 100,000 and an elevated LDH
- Anyone who receives high dose chemotherapy
Symptoms may include:
- Weakness
- Muscle cramping
- Abdominal pain
- Nausea
- Vomiting
- Diarrhea
- Lethargy
- Parasthesias
Late symptoms may include bradycardia, hypotension, oliguria, anuria, edema, ascites, and flank pain (related to kidney or ureters obstruction). These side effects may cause electrolyte imbalances, which can lead to death if untreated.
Thorough nursing assessments, as well as drawing labs per order (chemistry panels) on a timely basis, are essential. Vigorous IVF (intravenous fluids) hydration with sodium bicarbonate, and the administration of oral Allpurinol or even IV Rasburicase, will help to maintain the alkaline urine pH level of greater than 7.0 (hyperuricemia). Kayexalate may also need to be administered. This drug helps with the hyperkalemia.
If the patient can't take Kayexalate orally, a nasogastric tube may need to be placed. Amphogel will help with hyperphosphatemia, and calcium carbonate or calcium gluconate is used for those who are symptomatic with hypocalcemia. Also note that tetany can be one of the symptoms; there should not be any potassium in the IVF, and patients may require diuretics, in case of anuria or oliguria.
Remember, the goal of medical management is to reestablish normal electrolyte balance.
A cardiac monitor may also be necessary to monitor the heart rate. Accurate monitoring of fluid intake and outtake is essential; therefore, perform frequent lab draws, monitor the urine pH at every void, and weigh the patient twice a day. Remember: adequate oral fluid intake is a must.
Clear communication with the patient and his or her family may help reduce anxiety as well as increase awareness about what side effects to look for. This should be done before therapy is started. As always, the patient and family may be the first to notice any changes, so listen to them. We are their advocates and need to be their support system.