What are the indications for referral to secondary care in patients with severe hypernatraemia (sodium levels >150 mmol/L)?

Indications for referral to secondary care in patients with severe hypernatraemia (serum sodium >150 mmol/L) include:

• Presence of clinical dehydration or uncertain fluid status requiring expert assessment and management of fluid replacement.
• Need for intravenous fluid therapy with careful monitoring and adjustment of fluid type and rate to avoid rapid changes in serum sodium concentration.
• Worsening or persistent hypernatraemia despite initial fluid replacement efforts.
• Any acute illness contributing to hypernatraemia that requires specialist input.
• Children and young people with hypernatraemic dehydration should receive urgent expert advice on fluid management and frequent plasma sodium monitoring.

In summary, patients with severe hypernatraemia should be referred to secondary care for expert management of fluid therapy, close monitoring of plasma sodium, and treatment of underlying causes to prevent complications from rapid correction or ongoing hypernatraemia.

Key management points in secondary care: Use isotonic fluids (e.g., 0.9% sodium chloride) for fluid deficit replacement and maintenance, replace fluid deficit slowly (typically over 48 hours), and monitor plasma sodium frequently aiming to reduce sodium at a rate of less than 0.5 mmol/L per hour to avoid cerebral oedema or other complications.

These recommendations apply especially to children and young people but are relevant to adults with severe hypernatraemia as well.

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