Hypercalcaemia is the commonest life-threatening metabolic disorder associated with cancer. It produces several distressing symptoms, and management of hypercalcaemia alleviates the symptoms. Hypercalcaemia is defined as serum calcium (corrected) greater than 2.6mmol/L 0r 10.5mg/dL.
The incidence varies with the underlying malignancy, being most common in multiple myeloma, breast cancer and squamous cell lung cancer. It can occur even in the absence of bone metastasis.
- Assessment must determine the underlying cause, effectiveness of treatment and impact on quality of life for the patient and their family (refer to the Guideline – Symptom Assessment)
- Symptoms and signs of Hypercalcaemia
- General – dehydration, polydipsia, polyuria, pruritis
- Neurological – fatigue, lethargy, confusion, myopathy, hyporeflexia, seizures, psychosis and coma
- Gastrointestinal – anorexia, nausea, vomiting, weight loss, constipation, and ileus
- Musculoskeletal – muscle, bone pain
- Cardiac – shortened Q-T interval, prolonged P-R interval, wide T waves, ventricular and atrial arrhythmias and bradycardia
- Questions to ask before managing hypercalcaemia
- Is this the first episode and if not, what is the interval since the previous episode?
- What is the problem?
- Can it be reversed?
- What is the goal of care?
- Is the treatment appropriate?
- What are the patient’s/carer’s wishes?
- What effect will the relief of symptoms have on the overall general condition?
- Will active treatment improve the quality of life?
- Investigations (when appropriate)
- Serum urea, electrolytes, albumin, and calcium
- Calculate corrected calcium concentration
- Corrected calcium (mmol/L) = Measured Calcium + ([40 – Serum albumin g/L] x 0.02mmol/L) or
- Corrected calcium (mg/dl) = Measured total serum calcium (mg/dL) + ([4.0-serum albumin g/dL] x 0.8)
- Refer the patient to hospital if treatment of hypercalcaemia is appropriate
- Consider symptom management only, if treatment of hypercalcaemia is not warranted or if the patient has advanced disease with poor prognosis
- Stop any drugs that can contribute to/ worsen hypercalcemia (thiazide diuretics, oral calcium supplements, calcitriol, antacids)
- Urgent treatment is needed, if serum calcium level is 4mmol/L or 16mg/dl and above
- Rehydrate with intravenous fluids 2 – 3L of fluid (0.9% saline)
- Volume and rate depend on clinical and cardiovascular status and concentrations of urea and electrolytes
- After a minimum of 2L of intravenous fluids give bisphosphonate infusion
- Zoledronic acid 4mg in 100ml normal saline IV over 15 minutes
- Dental clearance is mandatory before starting bisphosphonates, except in an emergency or acute setting
- The dosage of bisphosphonates should be adjusted for decreased renal function
- Bisphosphonates can produce flu-like symptoms
- Measure concentrations of urea and electrolytes at daily intervals and give intravenous fluids as necessary
- Normalisation of serum calcium takes 3-5 days
- Do not measure serum calcium for at least 48 hours after rehydration as it may rise transiently immediately after treatment
- Patients with repeated episodes or refractory hypercalcaemia should be referred to the care of the oncologist
- Prevention of recurrent hypercalcaemia
- Oncological treatment as appropriate
- Monitor serum calcium levels and consider continuing bisphosphonates monthly
- Bower, M., Robinson, L., Cox, S. (2015). Endocrine and metabolic complications of advanced cancer. Oxford Textbook of Palliative Medicine (pp. 906-918)
- Falk, S., Reid, C. (2006). Emergencies. ABC of Palliative Care (pp. 40-43)
- Kovacs, C., MacDonald, S.M., Chik, C., Bruera, E. Hypercalcemia of Malignancy in the Palliative Care Patient: A Treatment Strategy. Journal of Pain and Symptom Management. (1995); 10(3): 224-232
- Medscape – Hypocalcemia Differential Diagnoses. Retrieved online from https://emedicine.medscape.com/article/241893-differential on 4 January 2019