What are the indications for referring a patient with secondary hyperparathyroidism to a specialist?

Indications for referring a patient with secondary hyperparathyroidism to a specialist include:

• Development of symptoms of hypercalcaemia such as thirst, frequent or excessive urination, or constipation.
• An adjusted serum calcium concentration that increases to 0.25 mmol/L or more above the normal range, particularly if it reaches or exceeds 2.85 mmol/L.
• Estimated glomerular filtration rate (eGFR) less than 60 mL/min/1.73 m2, indicating impaired kidney function.
• Presence of renal stones or increased risk of renal stones, for example, after urinary biochemical stone risk analysis.
• Osteoporosis confirmed on dual-energy X-ray absorptiometry (DXA) scan or occurrence of vertebral or other fragility fractures.
• Failure of previous parathyroid surgery or recurrence of disease after surgery.
• When the cause of hypercalcaemia is unknown or if primary hyperparathyroidism is suspected but not confirmed in primary care.

Referral should be made to an endocrinologist or a surgeon with expertise in parathyroid disease depending on the clinical context and local pathways. Urgency depends on severity of hypercalcaemia and symptoms, with severe hypercalcaemia (>3.5 mmol/L) or severe symptoms requiring emergency hospital admission for specialist management.

In summary, patients with secondary hyperparathyroidism should be referred to a specialist if they have significant biochemical abnormalities, complications such as renal stones or osteoporosis, symptoms, or if their condition is complex or refractory to initial management in primary care.

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