Pathogenesis fundamentals and laboratory diagnostics
The development of diabetic coma (also known as hyperglycemic coma) is inextricably linked to the course of diabetes mellitus. The fundamental basis of this condition is always a lack of insulin. It is important to understand that this deficiency can be of two types:
- Absolute deficiency: a physical lack of the hormone in the body.
- Relative deficiency: a condition in which the available amount of insulin is insufficient to cover the sharply increased needs of the body.
The main objective confirmation of diabetic coma is a laboratory blood test. The key laboratory criterion is marked hyperglycemia, where the glucose level exceeds 25–30 mmol/L. These exact figures serve as the dividing line when assessing the severity of the patient's condition.
Triggering factors: insulin deficiency
The first broad group of triggers is associated with situations where an insufficient amount of insulin enters the patient's body. Such situations include:
- Manifestation of diabetes mellitus. Coma can be the first clinical manifestation of the disease when the diagnosis has not yet been established.
- Therapy regimen violations. A banal omission of prescribed insulin injections.
- Alimentary factors. A gross violation of the recommended diet.
- Technical failures. In modern practice, a frequent cause is a hardware issue, such as occlusion of an insulin pump catheter, causing the delivery of the drug to suddenly stop.
Triggering factors: increased insulin demand
The second group of causes is related not to a drop in the baseline insulin level, but to a sharp, surges-like increase in the body's demand for this hormone. Even while maintaining the usual dosing regimen, the patient may lack insulin in the following stress-inducing situations for the body:
- Onset of severe infectious diseases.
- Sustaining extensive, severe trauma.
In these cases, the very same relative deficiency develops, triggering a cascade of reactions leading to hyperglycemic coma.
Classification
The pathogenesis of hyperglycemic states is complex and multifaceted. Depending on which pathogenetic mechanism is predominant in a particular patient, clinical practice distinguishes 3 forms of diabetic coma.
To remember the triggers, use the "Two N's" rule: Deficiency of the hormone (malfunctions, omissions, diet) and Need due to increased demand (trauma, infections).
Class and exam questions
What blood glucose level is considered a criterion for diabetic coma?
The laboratory criterion for this condition is hyperglycemia exceeding 25–30 mmol/L.
Deficiency of which hormone causes hyperglycemic coma?
Coma develops exclusively against the background of absolute or relative insulin deficiency (variants involving glucagon, cortisol, or thyroxine deficiency are incorrect).
Can an insulin pump cause a coma?
Yes, technical failures, such as an occluded insulin pump catheter, lead to a sharp shortage of insulin in the blood.
Why can trauma trigger a coma in a patient with diabetes?
Extensive trauma causes a sharp increase in the body's demand for insulin, leading to its relative deficiency.
What else to study on this topic
- Pathogenetic features of the three forms of diabetic coma
- Symptoms and clinical course of diabetes mellitus manifestation
- The impact of severe infections on carbohydrate metabolism
- Algorithms for preventing insulin pump technical failures
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