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