Nonketotic Hyperosmolar Coma - Pathophysiology

Pathophysiology

Nonketotic coma is usually precipitated by an infection, myocardial infarction, stroke or another acute illness. A relative insulin deficiency leads to a serum glucose that is usually higher than 33 mmol/l (600 mg/dl), and a resulting serum osmolarity that is greater than 320 mOsm. This leads to polyuria (excessive urination, an osmotic diuresis), which, in turn, leads to volume depletion and hemoconcentration that causes a further increase in blood glucose level. Ketosis is absent because the presence of some insulin inhibits hormone-sensitive lipase (lipolysis).