Internal Medicine Diabetic Ketoacidosis Management Questions and Answers — Questions and Answers
Question 1: A 24-year-old female with type 1 diabetes presents to the emergency department with nausea, vomiting, and abdominal pain. Her labs show a blood glucose of 450 mg/dL, pH of 7.15, bicarbonate of 10 mEq/L, and positive serum ketones. Her initial serum potassium is 3.1 mEq/L. After initiating intravenous fluid resuscitation with 0.9% normal saline, what is the most appropriate next step in management?
- Administer intravenous potassium chloride before starting an insulin infusion. (Correct answer)
- Administer a 0.1 unit/kg IV bolus of regular insulin immediately.
- Start a continuous IV insulin infusion at 0.1 units/kg/hour.
- Administer sodium bicarbonate to correct the acidosis.
Correct answer: Administer intravenous potassium chloride before starting an insulin infusion.
In the management of DKA, it is critical to address severe hypokalemia before initiating insulin therapy. Insulin drives potassium into the cells, which can precipitate life-threatening arrhythmias if the initial potassium level is already low. Guidelines recommend holding insulin and repleting potassium if the serum level is less than 3.3 mEq/L. Sodium bicarbonate is generally not recommended unless the pH is life-threateningly low (e.g., <6.9), as the acidosis will correct with fluids and insulin.
Question 2: A 45-year-old male is being treated for moderate Diabetic Ketoacidosis. His initial blood glucose was 520 mg/dL. He has received several hours of IV fluids and a continuous insulin infusion. His current blood glucose is 190 mg/dL, but his anion gap remains elevated at 18 mEq/L and his serum bicarbonate is 14 mEq/L. Which of the following is the most appropriate adjustment to his management?
- Decrease the insulin infusion rate by half.
- Change the intravenous fluids to 0.45% NaCl without dextrose.
- Discontinue the insulin infusion and switch to subcutaneous insulin.
- Add dextrose to the intravenous fluids and continue the insulin infusion. (Correct answer)
Correct answer: Add dextrose to the intravenous fluids and continue the insulin infusion.
The primary goal in DKA management is the closure of the anion gap, which signifies the resolution of ketoacidosis. It is common for the blood glucose to normalize before the anion gap closes. To prevent hypoglycemia while continuing the insulin infusion necessary to resolve the ketosis, dextrose should be added to the IV fluids once the blood glucose falls to around 200-250 mg/dL. Discontinuing or decreasing the insulin infusion prematurely would halt the clearance of ketones and prolong the resolution of DKA.
Question 3: Which of the following sets of criteria best indicates the resolution of Diabetic Ketoacidosis and readiness to transition from an intravenous insulin infusion to a subcutaneous regimen?
- Blood glucose < 250 mg/dL and venous pH > 7.25
- Blood glucose < 180 mg/dL and anion gap < 16 mEq/L
- Blood glucose < 200 mg/dL, serum bicarbonate ≥ 15 mEq/L, and anion gap ≤ 12 mEq/L (Correct answer)
- Urine ketones are negative and serum bicarbonate > 20 mEq/L
Correct answer: Blood glucose < 200 mg/dL, serum bicarbonate ≥ 15 mEq/L, and anion gap ≤ 12 mEq/L
The resolution of DKA is defined by the correction of the metabolic acidosis and ketosis, not just the hyperglycemia. Widely accepted guidelines state that DKA is resolved when the blood glucose is <200-250 mg/dL, the serum bicarbonate is ≥15-18 mEq/L, the venous pH is >7.3, and the anion gap is ≤12 mEq/L. Relying on only one or two parameters, or using less stringent cutoffs, can lead to premature discontinuation of IV insulin and a relapse into ketoacidosis.
Question 4: A 33-year-old patient with type 1 diabetes is admitted with severe DKA. Initial management includes aggressive IV fluid resuscitation and a continuous regular insulin infusion. According to current guidelines, what is the recommended initial rate for the insulin infusion in most adult patients?
- 0.05 units/kg/hour without a bolus
- 0.1 units/kg/hour, with or without an initial bolus (Correct answer)
- 0.2 units/kg/hour without a bolus
- A fixed rate of 20 units/hour until blood glucose is <300 mg/dL
Correct answer: 0.1 units/kg/hour, with or without an initial bolus
The standard and widely recommended initial dose for a continuous intravenous insulin infusion in adult DKA is 0.1 units/kg/hour. An initial IV bolus of 0.1 units/kg is sometimes given, but studies have shown that starting with an infusion of 0.14 units/kg/hr without a bolus is also effective. A lower rate may not be sufficient to suppress ketogenesis, while a higher rate increases the risk of hypoglycemia and hypokalemia without proven benefit. Fixed-rate infusions that are not weight-based are not standard practice.
Question 5: A 58-year-old female is being treated for DKA. After 12 hours of treatment, her anion gap has closed, her pH is 7.32, and her blood glucose is 175 mg/dL. She is awake, alert, and hungry. The decision is made to transition her to subcutaneous insulin. What is the correct procedure to ensure a safe transition?
- Stop the IV insulin infusion and immediately administer the first dose of subcutaneous long-acting insulin.
- Administer the first dose of subcutaneous long-acting insulin and continue the IV insulin infusion for 1-2 hours. (Correct answer)
- Administer the first dose of subcutaneous rapid-acting insulin and stop the IV insulin infusion 30 minutes later.
- Stop the IV insulin infusion for 4 hours, then begin the patient's home subcutaneous insulin regimen.
Correct answer: Administer the first dose of subcutaneous long-acting insulin and continue the IV insulin infusion for 1-2 hours.
To prevent rebound hyperglycemia and the recurrence of ketosis, there must be an overlap between the intravenous insulin and the newly administered subcutaneous basal insulin. Because long-acting insulins like glargine have an onset of action of 1-2 hours, the IV insulin infusion should be continued for this duration after the subcutaneous dose is given. Stopping the IV infusion before the subcutaneous insulin has taken effect will result in a period of insulin deficiency.
Question 6: A 29-year-old male presents with DKA precipitated by an infection. His initial labs include a pH of 6.95, bicarbonate of 6 mEq/L, and potassium of 5.8 mEq/L. He is hemodynamically stable. In addition to IV fluids and insulin, which of the following interventions is most appropriate regarding his severe acidemia?
- Administer 50 mEq of sodium bicarbonate IV over 30 minutes.
- Initiate continuous renal replacement therapy (CRRT).
- Withhold insulin until the pH is > 7.1.
- Routine use of sodium bicarbonate is not recommended. (Correct answer)
Correct answer: Routine use of sodium bicarbonate is not recommended.
The routine use of sodium bicarbonate in DKA is not recommended and is generally reserved for cases of life-threatening hyperkalemia or severe acidemia (pH < 6.9) causing hemodynamic instability. Studies have not shown a benefit in the rate of recovery of acidosis and have suggested potential harm, including paradoxical CNS acidosis, worsened hypokalemia, and hypernatremia. The acidosis will typically resolve with appropriate fluid resuscitation and insulin therapy, which inhibits further ketone production.
Internal Medicine Diabetic Ketoacidosis Management Questions and Answers
A 24-year-old female with type 1 diabetes presents to the emergency department with nausea, vomiting, and abdominal pain.
Her labs show a blood glucose of 450 mg/dL, pH of 7.15, bicarbonate of 10 mEq/L, and positive serum ketones.
Her initial serum potassium is 3.1 mEq/L.
After initiating intravenous fluid resuscitation with 0.9% normal saline, what is the most appropriate next step in management?