Diabetic ketoacidosis:
In DKA, the following therapeutic principles are recommended:
- Initial volume administration of 1 l of isotonic solution (e.g., 0.9% NaCl) within the first hour to stabilize the circulation. Subsequently, fluids and electrolytesshould be administered depending on concomitant diseases, age, height, and weight (administration of 6 l / 24 h may be required [Haak 2018]).
In patients with known heart failure, there is a risk of pulmonary edema due to too rapid infusion rate. Here, therefore, infusion should be slow (Herold 2020).
Hypokalemia must be compensated for prior to insulin treatment, as potassium shifts it intracellularly, posing a risk of hypoglycemic ventricular fibrillation (Herold 2020).
- Substitution of potassium at a pH of > 7.1:
- for potassium > 4 - 5 mmol /l substitution of 10 - 15 mmol / l
- for potassium 3 - 4 mmol / l substitution of 15 - 20 mmol / l
- for potassium < 3 mmol / l substitution of 20 - 25 mmol / l (Herold 2020)
A maximum of 40 mmol of potassium chloride should be infused per 1,000 ml of NaCl 0.9% at a time (Haak 2018). Contraindication to potassium administration is anuria (Herold 2020).
If hypokalemia of < 3 mmol / l occurs during insulin therapy, insulin administration should be interrupted if necessary (Herold 2020).
The target serum potassium should be > 3.5 mmol / l (Kasper 2015).
- Administration of insulin via perfuser.
Insulin may act poorly in exsiccosis, so primary volume administration is required to achieve a good effect of insulin (Reitgruber 2021).
In shock, patients should be treated with normal insulin only; the duration of action is 20-40 min, and the half-life is <10 min (Herold 2020).
Blood glucose concentration should be reduced by 50 mg / dl / h (2.8 mmol / l), but not lower than 250 mg / dl during the first 24 h to avoid cerebral edema and retinal damage (Herold 2020).
From a blood glucose concentration of 300 mg / dl (16.7 mmol / l), an infusion with 10% glucose should run in parallel to avoid too rapid a drop in blood glucose (Haak 2018) and to avoid lipolysis with an increase in free fatty acids (Herold 2020).
"Low-dose" insulin therapy is recommended in most patients, i.e.:
- initial bolus of 0.10 - 0.15 IU / kg bw i. v. and subsequently about 5 IU normal insulin / h i. v. via the dosing pump (Herold 2020).
If blood glucose does not drop within 2 h, the patient requires higher doses of insulin due to insulin resistance. To break the resistance, the insulin dose should be doubled. In rare cases, an even higher amount of insulin may be needed beyond that (Herold 2020).
Bicarbonate should only be given from a pH- value < 7.0 and only until corrected to pH 7.1 (Haak 2018), since lipolysis is inhibited under insulin therapy anyway. The dosage should be only 25% of the calculated requirement to avoid hypokalemia (Herold 2020). Too high a dose of bicarbonate also increases the risk of cerebral edema (Kasper 2015).
Sodium is substituted as part of infusion therapy (Herold 2020).
Phosphate is usually within the normal range. If the value is < 0.5 mmol / l, substitution of about 50 mmol / 24 h may be recommended. However, phosphate is contraindicated in renal insufficiency (Herold 2020).
Magnesium deficiency may occur during treatment of DKA, requiring appropriate substitution (Kasper 2015).
- Specific therapy such as antibiotics, etc.
- Research into the causes of coma (Haak 2018).
The complication rate can be reduced by:
- low-dose insulin therapy
- Slow compensation of metabolic derailments (Herold 2020).
Hyperosmolar hyperglycemic syndrome:
Treatment differs from the above in that initially no insulin is given. Volume replacement with 0.9% saline alone results in a decrease in blood glucose levels.
Although there is hypernatremia due to exsiccosis, there is real sodium loss. Provided urine output is normal and there is only moderate hypernatremia of < 150 mmol / l, rehydration should be with 0.9% NaCl or Ringer's solution. If there is marked hypernatremia of > 150 mmol / l or if there is marked hyperosmolality, the use of semi-isotonic saline or hypoosmolar whole electrolyte solution (Herold 2020) is recommended.
The sodium concentration should not fall faster than 180 mg / dl (10 mmol / l) within 24 h (Haak 2018).
The substitution of potassium is the same as in DKA (see above).
Blood glucose should not drop more than 90 mg / dl (5 mmol / l) per hour.
If the BG does not drop further with i. v. administration of the fluid alone or there is ketonemia of > 18 mg / dl (1 mmol / l), insulin infusion of 0.05 IU / kg / h should be started (Haak 2018).
Kasper (2015) previously recommends an insulin bolus of 0.1 IU / kg bw.
The CNS needs some time to normalize the water shifts triggered by the coma. Therefore, the patient may remain unconscious despite normalization of blood glucose, electrolytes, pH and volume balance. This disturbance usually disappears with a delay (Herold 2020).
The diet should start with a light diet. A small amount of normal insulin s. c. should be injected before each meal. Subsequently, a readjustment of the DM is necessary (Herold 2020).