Insulin therapy is important for resolution of diabetic ketoacidosis.
Insulin therapy may include a mixture of bolus intravenous doses and continuous infusion.
Initial intravenous bolus: 0.1 units per kg regular insulin
Initial intravenous infusion: 0.05 to 0.1 units per kg per hour regular insulin (max 15 units per hour)
If the patient is hyperglycemic and if the serum glucose does not fall by at least 10% in the first hour, then give 0.14 units per kg as IV bolus and continue infusion.
Serum glucose concentrations should be monitored at least hourly.
If the serum potassium concentration is low (< 3.3 mmol/L), then starting insulin therapy may be associated with worsening hypokalemia.
Once the blood glucose reaches 200-225 mg/dL then reduce regular insulin intravenous infusion to 0.01 to 0.05 U per kg per hour.
The target glucose concentration is in the range between 150 to 200 mg/dL until the ketoacidosis has resolved.
Endpoint of therapy:
(1) anion gap < 12 mmol/L (exception: end-stage renal disease)
(2) serum bicarbonate > 18 mmol/L
(3) glycemic control reasonable
(4) the patients feel better and tolerates oral diet.
A long-acting insulin is often started to prevent relapse of the ketoacidosis after the infusion is stopped.
Once the insulin infusion is stopped then the patient should be monitored for relapse of the ketoacidosis.
If the patient is being treated with an SGLT2 inhibitor, then the drug should be discontinued and not restarted until after recovery from the acute illness.
Challenges:
(1) high-level insulin resistance
(2) persistent acidosis
Complications:
(1) hypoglycemia
(2) hypokalemia
