Oncologic Emergencies and Misc. Supportive Care Flashcards
Which drugs have shown a higher risk of bleeding in cancer patients? Which type of cancer?
DOACs (apixaban, rivaroxaban, edoxaban, dabigatran)
-GI (esophageal, colon, gastric)
-Genitourinary cancer (bladder, prostate, cervical, kidney)
Which DOAC is likely to fail in patients who had parts of their stomach cut out or using enteral feeding
resection of the colon: apixaban
enteral feeding: Rivaroxaban
absorption is mainly in the stomach
What happens in patients with Tumor Lysis Syndrome (TLS)?
killing of many cancer cells -> release of intracellular content:
-potassium -> arrhythmia
-phosphate (from DNA) -> precipitate with calcium (Ca2+ and PO4 go low, crystals form causing AKI)
-uric acid -> crystallizes in the urine causing AKI
AKI and arrhythmia
Which labs to check in patients with TLS?
-high SCr: from crystallization of uric acid or PO4 (with calcium)
-Hypophosphatemia
-Hypocalcemia -> risk for arrhytmia
-high potassium (hyperkalemia) -> risk for arryhtmia
When is a patient at higher risk for TLS?
-chemosensitive cancer (rapidly growing)
-first cycle
-
Which types of cancer have the highest risk for TLS?
-leukemia and lymphoma
-small cell lung cancer
-germ cell tumor
(rapidly growing and chemosensitive)
-1st cycle
-large number of tumor cells (WBC >50.000, ALL > 100.000)
Which drug is used to treat hyperuricemia (uric acid)?
-Allopurinol 300 mg PO with hydration
(Xanthine inhibitor)
-Rasburicase
Oxidizes uric acid to more soluble metabolites
expensive, only used if they need to
Which drugs are used to manage electrolyte disorders caused by TLS?
-loop diuretics
-sodium polystyrene (Kayexalete) or Lokelma
-insulin/dextrose, albumin
Which enzyme converts purines into uric acid, potentially causing crystallization and AKI?
Xanthine
blocked by Allopurinol
(also metabolizes 6-MP)
How does cancer cause hypercalcemia?
-release cytokines -> increase osteoclast activity -> Ca2+ goes into the blood (hypercalcemia)
-secretion of PTH-like peptides (more calcium reabsorption at the kidney)
symptoms of hypercalcemia:
-N/V, AMS, constipation, dehydration
What is calcium bound to and how does it affect the lab values?
-to albumin
-there is free and bound calcium
need to calculate the corrected calcium:
[(4 - pts albumin) x 0.8] + serum Ca
!!!!
What calcium level is considered mild hypercalcemia?
-mild hypercalcemia: corrected Ca2+: <12 mg/dl
Know equation!!
How to treat hypercalcemia
-start with fluids for several hours (bc they are dehydrated)
-give bisphosphonate after hydration
-for severe hyperkalemia: add calcitonin (decreases Ca2+)
What is the role of bisphosphonates in cancer therapy?
-used to treat hypercalcemia (reduces bone breakdown and Ca2+ release into the blood)
-used to treat metastasis in the bone, the cancer increases osteoclast activity to create space in the bone
