Sodium
Hyponatremia- Serum [Na2+]
<136 mmol/l . - Retention of water, eg in response to decreased blood volume or blood pressure.
- Clinical signs → lethargy, weakness, vomiting, muscle cramping, seizures, wide QRS and ST segment elevation.
- Severe hyponatremia (<110 mmol/l) → give 3% saline over 24 hours.
- mmol Na+ required = 0.2 x body weight (kg) x (normal [Na+] - patients [Na+]).
- Less severe (<120 mmol/l) → correct underlying cause and give 0.9% saline.
Hypernatremia
- Serum [Na+] = >160 mmol/l .
- Free water loss, eg heat exhaustion.
- Shift of water from ICS to ECS → cell dehydration, brain cells especially vulnerable.
- Clinical signs → lethargy, confusion, muscle weakness, seizures and coma.
- Give hypotonic fluid, eg 5% dextrose in water or 0.45% NaCl.
- In cats with longstanding hypernatremia, correct slowly to prevent cerebral edema.
Sources
Publications
Other sources of information
- Haskins S C & Aldrich J (1994) Perioperative supportive care. In: Anaesthesia of the Cat. Eds L W Hall and P M Taylor. Balliere Tindall. pp 289-290. ISBN 0 7020 1665 9.
