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 clinical status, including symptoms and signs of dehydration or hypovolaemia, neurological symptoms (such as drowsiness, convulsions), and any acute illness that may contribute to hypernatraemia.
• Reviewing medications that may contribute to hypernatraemia and stopping any non-essential drugs if appropriate.
• Evaluating fluid status carefully to determine if the patient is hypovolaemic, euvolaemic, or hypervolaemic, as this guides management.

Initial management steps include:

• Treating any underlying acute illness that may be causing or contributing to hypernatraemia.
• For hypovolaemic patients, cautiously restoring extracellular volume with isotonic fluids such as 0.9% sodium chloride.
• Replacing water deficit slowly to avoid rapid correction; the plasma sodium should not fall faster than 12 mmol/L in 24 hours.
• Monitoring plasma sodium and other electrolytes frequently during treatment, especially in the first 24 hours.
• Considering referral or urgent specialist advice if the patient is symptomatic, has severe hypernatraemia, or if the cause is unclear.

In children, oral rehydration with low-osmolarity oral rehydration solutions is preferred unless intravenous therapy is indicated, and intravenous fluids should be isotonic with slow correction of sodium levels under expert guidance.

Hospital admission is warranted if the patient is acutely unwell, symptomatic, or has severe hypernatraemia.

These steps ensure safe and effective initial management of hypernatraemia in primary care.

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