In diabetic coma (coma diabeticum; ICD-10-GM E14.01: Unspecified diabetes mellitus, with coma, referred to as derailed), the following two forms can be distinguished:
- Diabetic ketoacidosis (DKA; synonym: ketoacidotic coma; severe metabolic derailment (ketoacidosis) in insulin deficiency) – predominantly in type 1 diabetes mellitus.
- Hyperosmolar nonketotic coma or syndrome (HNKS; synonyms: hyperosmolar diabetic coma; hyperglycemic coma) – typical in diabetes mellitus type 2.
Triggering factors are infections and/or inadequate insulin therapy. In approximately 25% of cases, ketoacidotic coma is the first sign of diabetes mellitus type 1 (manifestation coma). The annual incidence is reported to be 3-5 cases per 1,000 diabetic patients. Course and prognosis:
- In ketoacidotic coma, absolute insulin deficiency leads simultaneously to hyperglycemia (hyperglycemia; glucose: > 250 and < 600 mg/dl) and lipolysis (mobilization of fat reserves), which in turn leads to hypovolemia (blood volume in the body ↓) and metabolic acidosis (metabolic acidosis of the blood) via hyperosmolarity and ketosis.
- In hyperosmolar coma, there is decreased peripheral glucose utilization due to a relative insulin deficiency. At the same time, however, there is also increased glucose release from the liver. Hyperglycemia (hyperglycemia; glucose: > 600 to well over 1,000 mg/dl) leads to osmotic polyuria (caused by blood glucose concentrations above 180 mg/dl (renal threshold), which causes the reabsorption capacity of the tubular system to be exceeded, resulting in glucosuria (increased excretion of glucose in the urine) and thus increased water excretion (polyuria)). This in turn leads to hypovolemia (amount of blood in the body ↓) or severe desiccosis (dehydration).Since small amounts of insulin are still released, however, ketosis does not occur.
If left untreated, diabetic coma is lethal (fatal). The prognosis depends on the severity and duration of the metabolic derailment and the age of the patient. The lethality (mortality relative to the total number of people with the disease) is relatively high at 5-15%, depending on multimorbidity (multiple illnesses).
