Introduction
The most effective management of cancer-associated hypercalcaemia is successful treatment of the underlying malignancy.
Until this is achieved, three primary treatment goals include:
- Correcting intravascular volume contraction
- Enhancing renal excretion of calcium
- Inhibiting accelerated bone resorption
Important general supportive measures include the removal of calcium from parenteral feeding solutions, discontinuation of the use of oral calcium supplements and discontinuation of medications that may independently lead to hypercalcaemia e.g. lithium, calcitriol, vitamin D and thiazides. Further measures can include, if possible, an increase in the weight-bearing mobility of the patient and discontinuation of the use of sedative drugs, including analgesic drugs to enhance the patient's mental clarity and promote weight-bearing ambulation.
Many agents are available to treat acute hypercalcaemia including normal saline, furosemide, calcitonin, glucocorticoids, bisphoshonates and gallium nitrate.
Hydration with intravenous normal saline (NaCl 0.9%) is the first step in the acute management of hypercalcaemia. Since most patients suffering from acute hypercalcaemia are volume contracted, the administration of normal saline is important because it expands intracellular volume in addition to increasing renal calcium clearance. The optimal administration rate of normal saline is determined by the severity of hypercalcaemia, the degree of volume contraction, the ability of the patient to tolerate fluid, and the overall clinical status of the patient. Although there are no randomised clinical trials to guide this therapy, in general practice, normal saline is administered at a rate of 200-500 ml/h [11].
Mobilisation: Mobilisation of the patient is important, as it slows down the loss of skeletal calcium associated with immobility.