Can a Diabetic Coma Be Diagnosed?
Diabetic coma results from hyperosmolar conditions. Neurological changes begin above levels of 320-330 mg/dL.
Diabetic coma can occur due to either a hyperosmolar hyperglycemic state (HHS) or being in diabetic ketoacidosis (DKA). Both involve a hyperosmolar state, but in HHS, glucose levels can exceed 1,000. In DKA, they are usually lower.
Identifying HHS vs. DKA as the Cause of Diabetic Coma: Blood pH
pH via arterial blood gas assessment will distinguish between HHS vs. DKA, as DKA is an acidosis due to excess ketoacids (ketones) in the blood. Blood gases from an arterial blood sample is used to determine the pH.
The diabetic lack of insulin prevents glucose from entering cells, invoking a compensatory, alternate method for manufacturing glucose for energy that produces ketones as a by-product.
HHS, Alternately, Is a Non-Ketotic Hyperosmolar State
Determination of electrolytes levels is important to identify life-threatening conditions that the hyperosmolar state produces in HHS and DKA. Excess excretion by the kidneys loses water in compensation to correct it. This makes the concentration of some solutes in the blood even higher at the expense of others. Testing of the following are indicated:
● Serum and urine ketones (present or absent)
● Serum sodium, potassium, chloride, bicarbonate, and other electrolytes
ECG/EKG: acidosis or hyperosmolar states resulting in electrolyte abnormalities severely impact cardiovascular status, necessitating an electrocardiogram to determine whether cardiac support is indicated.
Since infection can convert a well-controlled diabetic into an hyperglycemic state, so diagnostic tests for infection, such as bacterial cultures, blood counts, and chest X-rays, are indicated.
Identifying between HHS and DKA as the cause of coma and diagnosing the types of electrolyte disturbances allow for a rational approach to rapid treatment, which is necessary to avoid death.