An anion gap acidosis caused by an accumulation of ketone bodies secondary to severe insulin deficiency
Etiology
Missed insulin (most common cause)
Pathophysiology
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
Differential Diagnosis
DKA
Hyperglycemia
Hyperosmolar hyperglycemic state (HHS/HONK)
Epidemiology
Risk Factors
Preexisting diagnosis of T1DM
Clinical Manifestations
History
Thirst/polyuria
Nausea/vomiting/abdominal pain
Weakness/malaise
Change in mental status
Exam
Altered mental status
Kussmaul respiration
Fever
Acetone on breath
Investigations
Glucose q1h
SMA7 and VBG q2-4h
Management
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
Memphis Insulin Protocol
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
