Hyperparathyroid Crisis

A parathyroid crisis is abrupt, severe decompensation from PTH-driven hypercalcemia. The excess calcium disrupts brain function, renal perfusion, gastrointestinal motility, and cardiac conduction; vomiting and calcium-induced polyuria then remove intravascular volume and further reduce renal calcium clearance. This creates a self-reinforcing deterioration rather than an isolated laboratory abnormality. For a Canadian NP, the immediate decision is disposition. Corrected total calcium above approximately 3.5 mmol/L or ionized calcium above approximately 2.5 mmol/L, particularly with confusion, dehydration, renal impairment, vomiting, or ECG changes, warrants emergency management regardless of cause. Canadian NP authority is set by provincial or territorial regulation, but this presentation exceeds outpatient management: arrange emergency transfer, begin assessment and supportive measures within local protocols, and involve endocrinology and endocrine surgery. Fluids and calcium-lowering drugs are a bridge; removing the pathological parathyroid source is the cure for primary hyperparathyroidism.