Non-ketotic hyperosmolar state

This is where severe hyperglycaemia develops without significant ketosis. It is the metabolic emergency characteristic of uncontrolled NIDDM.

Patients present in middle or later life, often with previously undiagnosed diabetes.

Common precipitating factors:

• Consumption of glucose-rich fluids (e.g. Lucozade)
• Concurrent medication (such as thiazide diuretics or steroids)
• Intercurrent illness

Clinical features:

• Dehydration
• Stupor
• Coma

Impairment of consciousness is directly related to the level of hyperosmolality.

Evidence of underlying illness may be present (e.g. pneumonia or pyelonephritis) and the hyperosmolar state may predispose to:

• CVA
• MI
• Lower limb arterial insufficiency

Treatment:

• Replace fluid with normal saline
• Administer insulin with care (as many patients will be extremely sensitive to it). Start off infusing at a rate of 3U/hr for the first 2-3 hrs, increasing to 6U/hr if glucose is falling too slowly.

Prognosis:

Reported mortality is as high as 20-30%, mainly because of the advanced age of the patients and the frequency of intercurrent illness.

Unlike DKA, non-ketotic hyperglycaemia is not an absolute indication for subsequent insulin therapy, and survivors may do well on diet and oral agents.