What are the initial steps in managing diabetic ketoacidosis (DKA)?

Diabetic Ketoacidosis (DKA) Management: Initial Steps

The initial management of diabetic ketoacidosis requires immediate intravenous insulin therapy, aggressive fluid resuscitation with 0.9% NaCl at 15-20 mL/kg/hr, and electrolyte replacement, particularly potassium, once serum levels fall below 5.5 mEq/L. 1

MCQ Questions on Diabetic Ketoacidosis (DKA)

Question 1: What is the recommended initial fluid therapy for a patient with DKA?

A) 5% Dextrose solution at 10 mL/kg/hr B) 0.45% NaCl at 5 mL/kg/hr C) 0.9% NaCl at 15-20 mL/kg/hr D) Lactated Ringer's solution at 8 mL/kg/hr E) 5% Albumin at 2 mL/kg/hr

Correct Answer: C) 0.9% NaCl at 15-20 mL/kg/hr

Initial fluid therapy for DKA should be 0.9% NaCl at 15-20 mL/kg/hr to rapidly correct dehydration and improve tissue perfusion 1.

Question 2: Which of the following is the recommended initial insulin regimen for moderate to severe DKA?

A) Subcutaneous regular insulin 0.3 units/kg every 4 hours B) IV regular insulin bolus of 0.15 units/kg followed by 0.1 units/kg/hr continuous infusion C) IM regular insulin 0.2 units/kg every 2 hours D) Subcutaneous insulin glargine 0.5 units/kg once daily E) IV insulin glargine 0.05 units/kg/hr

Correct Answer: B) IV regular insulin bolus of 0.15 units/kg followed by 0.1 units/kg/hr continuous infusion

Insulin therapy should be initiated with IV regular insulin at 0.1 units/kg/hr after an initial bolus of 0.15 units/kg for moderate to severe cases 1.

Question 3: When should potassium replacement be initiated in DKA management?

A) Immediately upon diagnosis regardless of serum potassium level B) When serum potassium falls below 5.5 mEq/L C) Only when serum potassium falls below 3.0 mEq/L D) After acidosis is fully corrected E) Only if ECG shows signs of hypokalemia

Correct Answer: B) When serum potassium falls below 5.5 mEq/L

Despite total-body potassium depletion, mild to moderate hyperkalemia is common in DKA. Potassium replacement should be initiated when serum levels fall below 5.5 mEq/L, assuming adequate urine output 2.

Question 4: Which laboratory parameter is most useful for monitoring the resolution of DKA?

A) Urine ketones measured by dipstick B) Blood glucose levels C) Serum bicarbonate and venous pH D) Serum osmolality E) White blood cell count

Correct Answer: C) Serum bicarbonate and venous pH

Venous pH and anion gap should be monitored to assess resolution of acidosis, as ketonemia typically takes longer to clear than hyperglycemia 2, 1.

Question 5: What is the appropriate modification to insulin therapy when blood glucose reaches 250 mg/dL in DKA?

A) Stop insulin completely B) Decrease insulin infusion to 0.05-0.1 units/kg/hr and add dextrose to IV fluids C) Increase insulin infusion to 0.2 units/kg/hr D) Switch from IV to subcutaneous insulin immediately E) Maintain the same insulin infusion rate until acidosis resolves

Correct Answer: B) Decrease insulin infusion to 0.05-0.1 units/kg/hr and add dextrose to IV fluids

When plasma glucose reaches 250 mg/dL in DKA, the insulin infusion rate can be decreased to 0.05-0.1 units/kg/hr, and dextrose (5-10%) should be added to IV fluids to prevent hypoglycemia while continuing to treat acidosis 2.

Comprehensive DKA Management Algorithm

1. Initial Assessment and Diagnosis

• Confirm DKA diagnosis: blood glucose >250 mg/dL, arterial pH <7.3, serum bicarbonate <18 mEq/L, and presence of ketones 1
• Obtain arterial blood gases, complete blood count, urinalysis, plasma glucose, BUN, electrolytes, chemistry profile, and creatinine levels STAT 2
• Identify and treat precipitating factors (infection, myocardial infarction, stroke) 2

2. Fluid Resuscitation

• Begin with 0.9% NaCl at 15-20 mL/kg/hr 1
• Adjust subsequent fluid choice based on corrected serum sodium levels 1
• Target fluid replacement of 50% in first 12-24 hours 2

3. Insulin Therapy

• Start IV regular insulin at 0.1 units/kg/hr after initial bolus of 0.15 units/kg 1
• If plasma glucose doesn't fall by 50 mg/dL in first hour, check hydration status; if adequate, double insulin infusion rate hourly until glucose decline of 50-75 mg/hr is achieved 2
• When glucose reaches 250 mg/dL, reduce insulin to 0.05-0.1 units/kg/hr and add 5-10% dextrose to IV fluids 2
• Continue insulin until acidosis resolves (pH >7.3, bicarbonate >18 mEq/L) 1

4. Electrolyte Management

• Monitor potassium levels closely
• Begin potassium replacement when levels fall below 5.5 mEq/L (assuming adequate urine output) 2
• Use 20-30 mEq potassium (2/3 KCl and 1/3 KPO₄) in each liter of infusion fluid 2
• Monitor phosphate and replace if severely depleted 1

5. Monitoring

• Check blood glucose every 1-2 hours until stable 1
• Monitor electrolytes, BUN, creatinine every 2-4 hours 1
• Follow venous pH and anion gap to assess resolution of acidosis 2
• Monitor for complications, especially cerebral edema in children 1

6. Transition to Subcutaneous Insulin

• Begin subcutaneous basal insulin 2-4 hours before stopping IV insulin to prevent rebound hyperglycemia 2
• Consider multidose regimen of short- and intermediate/long-acting insulin 2
• For newly diagnosed patients, initiate at approximately 0.5-1.0 units/kg/day 2

Important Considerations and Pitfalls

• Cerebral edema prevention: Avoid insulin bolus, excessive saline resuscitation, and rapid decrease in effective plasma osmolality, especially in children 3
• Potassium management: In patients with relatively low initial potassium levels, consider delaying insulin and administering potassium first to prevent dangerous hypokalemia 3
• Bicarbonate therapy: Generally not recommended unless pH <6.9 1
• Monitoring ketone resolution: Don't rely on nitroprusside method (urine ketones) as it doesn't measure β-hydroxybutyrate, the predominant ketone in DKA 2
• Special populations: Pregnancy, chronic kidney disease, and patients on SGLT2 inhibitors require special consideration in DKA management 4
• Euglycemic DKA: Be aware that DKA can occur with normal or only slightly elevated blood glucose levels, particularly in patients taking SGLT2 inhibitors 1

By following this structured approach to DKA management with emphasis on fluid resuscitation, insulin therapy, and electrolyte replacement while monitoring for complications, outcomes can be optimized and mortality minimized.