Hyperosmolar non-ketotic hyperglycaemia
- Severe hyperglycaemia in the absence of ketosis
- Characteristic of Type 2 diabetes
- Common precipitating factors include;
- Consumption of glucose rich fluids
- Concurrent medication such as thiazide diuretics and steroids
- Intercurent illness
- Endogenous insulin is sufficient to prevent hepatic ketogenesis
Clinical presentation
- Dehydration
- Stupor/coma
- Impairment of consciousness is related to degree of hyperosmolarity
- Hyperosmolar state may predispose to stroke, MI or arterial insufficiency in lower limbs
Biochemical presentation
- Blood glucose is high, often higher than that seen in ketoacidosis
- Na is high
- Potassium levels are often raised but total body potassium can be normal
- Urea high due to dehydration
- Serum osmolality is very high
- Arterial pH is not normally raised
Treatment
- Generally treat similarly to diabetic ketoacidosis, however;
- Patient may be normo- or hypernatraemic therefore hypotonic fluid replacement may be required
- There is increased risk of prothrombotic events therefore prophylactic anticoagulation may be necessary
- Bicarbonate therapy is unnecessary and smaller amounts of potassium are required
- Blood glucose levels are extremely high so restoration of normal levels may take many hours, too quick a reestablishment can lead to effects of osmotic disequilibrium on the CNS