Table 5.

Example 7.

Patient: 51 year old male.
Patient Location: Presenting to Emergency Department.
Clinical Notes on Request Form: Acute confusional state.
On risperidone.
Case Details
Plasma
Sodium	108 mmol/L	(136–146)
Potassium	4.1 mmol/L	(3.5–5.5)
Creatinine	80 umol/L	(50–110)
Urea	2.0 mmol/L	(2.7–7.8)
Osmolality	227 mmol/kg	(280–300)
Urine
Sodium	12 mmol/L
Potassium	8 mmol/L
Osmolality	0 mmol/kg
A Suggested Comment: Severe hyponatraemia and a hypo-osmotic plasma with appropriately dilute urine and no evidence of salt wasting. This pattern is in keeping with primary polydipsia with water intoxication. While risperidone is not necessarily the cause of the polydipsia, an alternative atypical antipsychotic may be more effective in improving polydipsic behaviour.