Serum calcium is tightly regulated by various factors which act in a coordinated manner to keep calcium levels in the normal range. A simple mnemonic for recalling both the causes and treatment of hypercalcemia is “BLACK-RHINOS”
Hypercalcemia Memory Aid. The Black Rhino (Created by OpenAI DALLE2)
The causes of hypercalcemia (RHINOS)
- R Renal insufficiency (secondary and tertiary hyperparathyroidism)
- H Hyperparathyroidism (primary hyperparathyroidism either sporadic or part of MEN syndrome)
- I Immobilisation and iatrogenic (overdosage of calcium, vitamin D, thiazide diuretic exposure)
- N Neoplasms (bone metastasis, primary bone cancer and paraneoplastic syndromes. Due to the production of cytokines and PTHrp etc)
- O Other endocrinopathies (thyrotoxicosis and Addison’s disease)
- S Sarcoidosis and other granulomatous conditions
The treatment of hypercalcemia (BLACK)
An excellent way of remembering the treatment options for hypercalcemia requires the recollection of the mnemonic “BLACK RHINO”.
- B : Bisphosphonates
- L : Liquids (referring to normal saline)
- A : Aquaretics (medications that induce fluid loss e.g. Furosemide)
- C : Calcitonin
- K : OsteoKlast inhibitors (Denosumab)
A collection of other highly effective hormone (endocrinology) mnemonics to help you remember essential clinical pearls can be found here.