ITE Diabetic Ketoacidosis and HHS 2 — Questions and Answers
Question 1: A patient with DKA has a serum potassium of 5.8 mEq/L on presentation. When should potassium supplementation be initiated?
- Immediately with insulin infusion
- When potassium falls below 5.5 mEq/L (Correct answer)
- When potassium falls below 3.5 mEq/L
- Only after anion gap closes
Correct answer: When potassium falls below 5.5 mEq/L
Potassium supplementation should be added to IV fluids when serum K+ falls below 5.5 mEq/L to prevent hypokalemia from insulin-driven cellular uptake.
Question 2: Which of the following best explains the mechanism of anion gap metabolic acidosis in DKA?
- Lactic acid accumulation from tissue hypoperfusion
- Accumulation of beta-hydroxybutyrate and acetoacetate (Correct answer)
- Loss of bicarbonate through the kidneys
- Hyperchloremia from normal saline administration
Correct answer: Accumulation of beta-hydroxybutyrate and acetoacetate
DKA causes anion gap acidosis due to accumulation of ketoacids (beta-hydroxybutyrate and acetoacetate) from unregulated fatty acid oxidation.
Question 3: A 28-year-old with type 1 DM presents with DKA. Blood glucose is 420 mg/dL and beta-hydroxybutyrate is elevated. After 8 hours of treatment, glucose is 180 mg/dL but pH remains 7.15 and anion gap is still elevated. What is the most appropriate next step?
- Increase insulin infusion rate
- Add dextrose to IV fluids and continue insulin (Correct answer)
- Stop insulin and reassess in 2 hours
- Administer sodium bicarbonate
Correct answer: Add dextrose to IV fluids and continue insulin
When glucose falls below 200-250 mg/dL before anion gap closes, dextrose should be added to IV fluids to allow continuation of insulin until ketoacidosis resolves.
Question 4: What is the most common precipitating factor for DKA in patients with established type 1 diabetes?
- New onset diabetes
- Infection or illness
- Insulin omission (Correct answer)
- Myocardial infarction
Correct answer: Insulin omission
Insulin omission (non-adherence) is the most common precipitating cause of DKA in patients with known type 1 diabetes.
Question 5: A patient with HHS has a serum osmolality of 345 mOsm/kg and blood glucose of 1100 mg/dL. Which IV fluid is most appropriate for initial resuscitation?
- 0.45% NaCl (hypotonic saline)
- 0.9% NaCl (isotonic saline) (Correct answer)
- D5W (5% dextrose in water)
- Lactated Ringer's solution
Correct answer: 0.9% NaCl (isotonic saline)
Isotonic normal saline (0.9% NaCl) is used first in HHS to restore circulating volume before transitioning to hypotonic fluids for free water replacement.
Question 6: Which laboratory finding would most strongly suggest HHS rather than DKA in a hyperglycemic patient?
- Serum glucose > 600 mg/dL
- Serum osmolality > 320 mOsm/kg
- Absence of significant ketonemia with pH > 7.3 (Correct answer)
- Blood urea nitrogen > 30 mg/dL
Correct answer: Absence of significant ketonemia with pH > 7.3
The hallmark distinguishing feature of HHS from DKA is the absence of significant ketoacidosis (pH > 7.3, bicarbonate > 18 mEq/L, minimal ketonemia).
Question 7: A patient recovering from DKA develops worsening headache, confusion, and pupillary changes 6 hours into treatment. What is the most likely diagnosis?
- Hypokalemia-induced arrhythmia
- Cerebral edema (Correct answer)
- Hypoglycemia from insulin overdose
- Septic encephalopathy
Correct answer: Cerebral edema
Cerebral edema is a life-threatening complication of DKA treatment, most common in children, caused by rapid fluid shifts and osmotic changes during correction.
ITE Diabetic Ketoacidosis and HHS 2
A patient with DKA has a serum potassium of 5.8 mEq/L on presentation.
When should potassium supplementation be initiated?