Diabetic ketoacidosis

Definition

An anion gap acidosis caused by an accumulation of ketone bodies secondary to severe insulin deficiency

Severe insulin deficiency causes the body to be unable to process glucose for energy, so instead relies on increased fatty acid metabolism, resulting in an accumulation of ketone bodies
Hyperglycemia creates an osmotic diuresis which causes dehydration
Insulin deficiency also causes a potassium shift from intra- to extracellular space, combined with the diuresis causes total body potassium depletion

History
- Thirst/polyuria
- Nausea/vomiting/abdominal pain
- Weakness/malaise
- Change in mental status
Exam
- Altered mental status
- Kussmaul respiration
- Fever
- Acetone on breath

Fluid resuscitation (most important)
- Aggressive fluid resuscitation is the best treatment for hyperglycemia
- Usually require 6-10L in first 24 hours
Insulin therapy treats the ketoacidosis, so don't stop until anion gap resolves
- 0.1-0.2 units/kg/h (6-10 U/kg/h on average)
- Titrate based on anion gap and hyperglycemia
Potassium supplementation: patients lose about 5mEq/kg when in DKA
- If initial K <3.3, must replace potassium before starting insulin
- Supplement to keep K between 4-5
Sodium bicarb: consider adding when pH<6.8 or in respiratory failure
Treat the underlying cause
Change to subcutaneous insulin when glucose < 15, anion gap resolved (x12+ hours), and patient willing to eat
- Calculate total daily dose from IV rate x 24h, then give that dose as detemir/glargine twice daily (new TDD is twice the IV TDD)
- Overlap with insulin running at half current rae for 6-8 hours after basal insulin

IV fluids:
- NS at 500-1000 mL/h for 2 h
- 1/2 NS at 250-500 mL/h until glucose <13.8 mmol/L
- D5w-1/2 NS at 150-250 mL/h until resolution of DKA, targetting gluoce of 11.1 mmol/L
Potassium
- K > 5.5: check serum K every 2 hours
- K 4-5.5: add 20 mmol KCL/L
- K 3-4: add 40 mmol KCl/L
- K <=3: give 10-20 mmol KCl hourly until serum K over 3, then add 40 KCl mmol/L
Insulin
- Insulin aspart hourly
  - Loading dose 0.3 units/kg SC once, followed by
  - 0.1 units/kg SC q1h until glucose <13.8, then
  - 0.05 units/kg SC q1h until resolution of DKA
- Insulin aspart every 2 hours
  - Loading dose 0.3 units/kg SC once, followed one hour later by
  - 0.2 units SC q2h until glucose <13.8, then
  - 0.1 units SC q2h until resolution of DKA
- IV regular insulin
  - Bolus 0.1 units/kg IV once, followed by
  - Continuous infusion of 0.1 units/kg/h until glucose <13.8, then
  - Continuous infusion of 0.05 units/kg/h until resolution of DKA
Laboratory
- Admission: CBC, complete metabolic panel, venous pH, serum beta-hydroxybutyrate
- BMP, venous pH, phosphorus, and beta-hydroxybutyrate every 2 horus x2 then every 4 hours until resolution of DKA
- Point-of-care glucose fingerstick every 1-2 hours