General Management

Management revolves around IV fluid rehydration, insulin administration, correction of electrolyte abnormalities and treatment of the underlying cause.

Fluids

There is universal agreement that the most important initial therapeutic intervention in DKA is appropriate fluid replacement followed by insulin administration.

The main aims for fluid replacement are:

• Restoration of circulatory volume
• Clearance of ketones
• Correction of electrolyte imbalance

The typical fluid and electrolyte deficits are shown in the table below. For example, an adult weighing 70 kg presenting with DKA may be up to 7 litres in deficit. This should be replaced as crystalloid. In people with kidney failure or heart failure, as well as the elderly and adolescents, the rate and volume of fluid replacement may need to be modified. The aim of the first few litres of fluid is to correct any hypotension, replenish the intravascular deficit, and counteract the effects of the osmotic diuresis with correction of the electrolyte disturbance.

Insulin

Low dose insulin therapy is effective regardless of the route of administration. Intravenous administration is the preferred route because of the delayed onset of action with subcutaneous insulin.

Intravenous insulin causes a more rapid fall in glucose and ketones than subcutaneous insulin. However, there is no difference in the length of stay, total amount of insulin or hypoglycaemic events in either route of administration.

Current practice is to commence a fixed rate intravenous insulin infusion at 0.1 UNITS/kg. In addition to this if the patients normally uses exogenous basal insulin (i.e. Lantus) this should also be administered as normal.

Potassium

Despite a total body potassium deficit, commonly there is initially hyperkalaemia that will resolve with insulin and volume expansion and the subsequent correction of the acidosis.

In the presence of an adequate urine output (0.5ml/kg/hr) potassium replacement needs to be initiated when the potassium level is below 5.5mmol/L. Expert guidance recommends the following potassium replacement;

Add potassium using pre-prepared bags only as follows:

• >5.5 mmol/l – none
• 3.5-5.5 mmol /l – 20 mmol/500 ml bag (i.e. 40 mmol/l)
• <3.5 mmol/l – senior advice is required, and pharmacy involvement may be needed. The patient MUST be looked after in a high dependency area

Anticipate a fall in potassium and replace, once the first plasma potassium result is known. Measure plasma potassium level (and also pH and bicarbonate) at 60 minutes, 2 hours, and 2 hourly thereafter [1].