Definition
Diabetic coma is a severe form of metabolic derailment in patients with diabetes mellitus. Diabetic coma is accompanied by unconsciousness in about 10% of cases, and about 70% of patients are awake but with limited consciousness. The change in consciousness is therefore a frequent complication of this diabetic emergency and therefore gives the name to this type of metabolic derailment.
The diabetic coma exists in two subforms. One is the ketoacidotic diabetic coma, the other the hyperosmolar diabetic coma. The ketoacidotic coma is more common in type 1 diabetics, the hyperosmolar coma more common in type 2 diabetics.
Causes of diabetic coma
The underlying mechanism is different in the two forms of diabetic coma. What they have in common, however, is that they are triggered by a lack of insulin and promoted by infections, because the body’s insulin requirements change during infections.
- Ketoacidotic coma: An absolute lack of insulin, the hormone that metabolizes blood sugar, results in elevated blood sugar levels (>300mg/dl).
In addition, the lack of insulin stimulates fat metabolism and breaks down the body’s fatty acids. Degradation products are so-called ketone bodies, which lead to hyperacidity (acidosis) of the blood and give this form of diabetic coma its name. The ketoacidotic coma is very often the first manifestation of diabetes mellitus type 1 in young patients who are in a state of absolute insulin deficiency for the first time.
- Hyperosmolar coma: Here there is a relative lack of insulin.
The insulin available to the body is not sufficient to adequately lower the blood sugar level, which can reach values above 1000mg/dl. The osmolarity of the blood (number of particles that lead to the flow of fluid into the blood vessels) is increased by the sugar molecules, which gives this form of diabetic coma its name. Water flows into the blood vessels (quasi to dilute the blood sugar level) and thus leads to dehydration (dehydration). The presence of “residual” insulin prevents the metabolism of fatty acids and prevents the formation of ketone bodies and hyperacidity. The most frequent causes of hyperosmolar coma in type 2 diabetics are treatment with diuretics (“water tablets”) and dietary errors.
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