[Hyperosmolar hyperglycemic state].

The hyperglycemic hyperosmolar state (HHS) is a serious acute complication of diabetes decompensation, especially in type 2 diabetes (T2DM), and with critical prognosis. Primary characteristics of HHS include extreme hyperglycemia, severe dehydration (with prerenal hyperazotaemia), plasma hyperosmolarity, frequent disorders of consciousness, absent or minimum ketoacidosis (with higher values, only found in combined forms). Both DKA and HHS have a common pathogenetic mechanism, but both states are opposite extreme deviations, and the boundaries between them are not entirely clear. Significant hyperglycemia is at the forefront of HHS, while ketoacidosis dominates in DKA. Various etiopathogenic mechanisms of the onset and development of HHS are discussed, but a clear explanation of the absence of ketoacidosis in HHS is lacking. The most frequent cause of HHS is serious cardiovascular disease, acute stroke, particularly genitourinary and/or respiratory infections, conditions preventing the patient from adequate water intake during osmotic diuresis, the consequences of inappropriate medication therapy, social conditions, and last but not least, it is often the first manifestation especially in type 2 diabetes. The clinical picture is influenced mainly by dehydration, while circulatory changes can lead to heart or circulatory failure and renal insufficiency. HHS is the cause of frequent disturbances of consciousness, and a cerebrovascular event should always be considered. Given the seriousness of HHS prognosis, timely comprehensive and properly guided therapy is of major prognostic significance. HHS treatment (rehydration, insulin therapy, ion substitution) is governed by similar rules as the treatment of diabetic ketoacidosis, but it also varies in many respects. Particular attention should be paid mainly to the control of dehydration. The patient with HHS should always be admitted to the intensive care unit. The most serious complications include cardiovascular complications, acute renal failure, thrombotic events and infectious complications. Given the still high mortality of patients with HHS the research focuses not only on the uncertainties concerning etiopathogenesis, but particularly on establishing safe and effective therapeutic strategies.