Electrolyte Conditions, Signs, Causes and differentials

Question 1

What are the signs of hypercalcemia?

Answer 1

Nephrogenic diabetes insipidus - Polyuria and Polydipsia

Muscle weakness

Hyporeflexia

Abdominal signs - cramping, anorexia, nausea and vomiting (neuron dysregulation in the ANS, and issues with smooth muscle contraction)

Arrythmias (calcium in serum affecting myocyte AP)

Dehydration

Mood change - anxiety,lethargy, cognitive disruption and depression (causes by calcium dysregulating neurotransmitter release)

Kidney stones and renal colic

Increased osteolysis and fracture incidence

Question 2

What is the commonest cause of hypercalcaemia?

Answer 2

Malignancy- e.g. non small cell lung anger as a paraneoplastic syndrome due to PTH secretion from the tumour

Common malignant causes:
Squamous cell lung cancer
Breast cancer
Multiple myeloma
Cholangiocarcinoma

(>2.6 mmol/L is hypercalcaemia)