Hyperosmolar hyperglycaemic state (HHS)/Hyperosmolar non-ketotic coma (HONK)
Marked hyperglycaemia and dehydration NOT accompanied by significant ketosis or acidosis. Mainly occurs in the middle aged and elderly with type 2 diabetes. Less common than DKA. Mortality is occur in about 30% of cases. Characterised by a relative rather that absolute insulin deficiency.
Initial presentation of type 2; infection (most common precipitating event – usually bacterial); myocardial infarction; stroke; trauma; corticosteroid therapy; antihypertensive drugs; high carbohydrate diet; burns; drugs that affect carbohydrate metabolism (eg corticosteroids).
Usually present after several days of infection. Clinically, similar to ketoacidosis, but not as severe, evolves over a period of several days to weeks and with absence of ketotic breath and vomiting; polyuria, thirst, dehydration, uraemia, hypotension and gradual clouding of consciousness are common. Focal seizures can occur due to hyponatraemia and hyperosmolarity. Many have a pre-existing renal disease and/or are taking diuretic.
Case report of 74 yr old male presenting with clonic focal motor seizures of the foot as the initial manifestation of HHS.
May be a delay in diagnosis due to insidious onset.
Management is similar to ketoacidosis but less insulin needed as more sensitive (IV rehydration; electrolyte replacement; insulin)
Subcutaneous heparin is often used, due to risk of thromboembolism