Exam 2 - Oncologic Emergencies Part 1 Flashcards
List the metabolic oncologic emergencies? (3)
hypercalcemia of malignancy, syndrome of inappropriate antidiuretic hormone (SIADH), tumor lysis syndrome (TLS)
List the hematologic metabolic emergencies? (2)
febrile neutropenia, hyperviscosity syndrome
List the structural oncologic emergencies? (3)
spinal cord compression, pericardial effusion, superior vena cava syndrome (SVCS)
Describe the incidence of hypercalcemia of malignancy?
occurs approximately in 30% of cancer patients, more common in stage IV
Define hypercalcemia?
corrected calcium level of >/=10.5 mg/dL
Define mild hypercalcemia?
10.5-11.9
Define moderate hypercalcemia?
12-13.9
Define severe hypercalcemia?
14+
What is the formula for corrected calcium?
0.8 x (4 - albumin) + serum calcium
List the clinical manifestations of hypercalcemia of malignancy?
renal, GI, neurologic, cardiac
Describe the humoral mechanism of hypercalcemia?
increased parathyroid hormone-related peptide (PTHrP) causes increased renal tubular reabsorption of calcium which increases phosphorus excretion; hypercalcemia and hypophosphatemia
Which cancers have higher rates of humoral mechanism of hypercalcemia?
squamous cell carcinomas
Describe the bone invasion mechanism of hypercalcemia?
local osteolytic activity that leads to secretion of calcium
Which cancers have higher rates of bone invasion of hypercalcemia?
multiple myelomas, metastatic breast cancer
Describe the rare causes mechanism of hypercalcemia?
increased calcitriol production or ectopic PTH production
Which cancers have higher rates of rare causes of hypercalcemia?
Hodgin’s lymphoma and patients with Hx of head/neck irradiation and chronic lithium therapy
What is used for increasing calcium secretion when treating hypercalcemia of malignancy?
IV fluids; normal saline 1-2 L bolus followed by 200-500 mL/hr
What can be added on to increase calcium secretion when treating hypercalcemia of malignancy?
furosemide 20-40 mg for those with volume overload
List drugs used for reducing bone resorption when treating hypercalcemia of malignancy? (4)
pamidronate, zoledronate, denosumab, calcitonin
What is the MOA of bisphosphonates?
inhibits osteoclast activity
What is the MOA of denosumab?
binds to RANKL to inhibit interaction with RANK and prevent osteoclast formation
What is the MOA of calcitonin?
directly inhibits osteoclastic bone resorption and increases excretion of calcium, phosphate, sodium, magnesium, and potassium
What is the dosing for pamidronate with a corrected calcium of 12-13.5 mg/dL?
60-90 mg IV over 2-24 hrs
What is the dosing for pamidronate with a corrected calcium of >13.5 mg/dL?
90 mg IV over 2-24 hrs
What are the AEs of pamidronate?
bone fractures, musculoskeletal pain, flu-like symptoms, osteonecrosis of the jaw
What is the dosing for zoledronic acid with a corrected calcium of 12+ mg/dL?
4 mg IV qw
What are the AEs of zoledronic acid?
hypophosphatemia/calcemia/magnesemia/kalemia, nausea, anemia, infusion site reactions
What is the dosing for denosumab?
120 mg SC qw
What are the AEs of denosumab?
bone fractures, musculoskeletal pain, osteonecrosis of the jaw, increased infection risk, hypophosphatemia/calcemia, HA
Which medication can be used in renal impairment when treating hypercalcemia of malignancy?
denosumab
What is the dosing for calcitonin?
4-8 U/kg IM/SC q12 hrs
What are the AEs of calcitonin?
hypocalcemia, facial flushing
What is a clinical pearl for calcitonin?
limit therapy to 24-48 hrs due to tachyphylaxis
What are other interventions for treating hypercalcemia of malignancy? (2)
glucocorticoids, dialysis
Define tumor lysis syndrome (TLS)?
a condition caused by a number of cancer cells lysing in a short period of time and contents of these cells being released into the peripheral bloodstream
Describe the incidence of tumor lysis syndrome?
more common in non-solid tumors, highest risk in patients with elevated baseline uric acid/nephropathy/hypotension/LV dysfunction
Explain the Cairo-Bishop definition for laboratory tumor lysis syndrome?
2 or more of the following abnormalities within 3 days before or 7 days after initiation of treatment: hyperkalemia (6+ mEq/L), hyperuricemia (8+ mEq/L), hyperphosphatemia (4.5+ mg/dL), hypocalcemia (7 mg/dL or less); or 25% increase/decrease for all, respectively
Explain the Cairo-Bishop definition for clinical tumor lysis syndrome?
presence of laboratory tumor lysis plus at least one of the following: acute kidney injury, seizures/neuromuscular irritability, cardiac arrhythmia
What is used for the treatment of tumor lysis syndrome? (3)
laboratory monitoring q4-6 hrs, fluids (normal saline 150-300 mL/hr), uric acid lowering medications
What is treatment for low risk tumor lysis syndrome patients?
monitoring
