What are the initial steps in the assessment of a patient with hypernatraemia in primary care?

Initial assessment of a patient presenting with hypernatraemia in primary care involves:

• Confirming the diagnosis by repeating serum sodium measurement to exclude rapid changes that may require urgent intervention.
• Assessing the patient's volume status clinically (signs of hypovolaemia, euvolaemia, or hypervolaemia) to guide management.
• Identifying and treating any underlying acute illness that may contribute to hypernatraemia.
• Reviewing current medications that may contribute to hypernatraemia and stopping them if appropriate, with specialist input if necessary.
• Considering the need for urgent referral or hospital admission if the patient is symptomatic, has severe hypernatraemia, or signs of hypovolaemia.

Initial management steps include:

• For hypovolaemic hypernatraemia, cautious volume resuscitation with isotonic saline (0.9% sodium chloride) to restore extracellular volume.
• For euvolaemic or hypervolaemic states, management depends on the underlying cause and may require specialist input.
• Monitoring plasma sodium frequently during correction to avoid rapid changes, aiming for a reduction in plasma sodium of less than 12 mmol/L per 24 hours.
• In children, if intravenous fluids are required, replace fluid deficit slowly over approximately 48 hours using isotonic solutions, with frequent monitoring of plasma sodium.

Patients with severe symptoms, rapid onset, or significant electrolyte disturbance should be referred urgently to secondary care for specialist management.

Oral rehydration therapy may be considered in mild cases without shock or severe symptoms, especially in children, using low-osmolarity oral rehydration solutions.

Overall, primary care management focuses on assessment, stabilisation, treating underlying causes, cautious correction of sodium, and timely referral when indicated.

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