In a patient with diabetic ketoacidosis receiving a continuous intravenous insulin infusion who develops hypoglycemia, what immediate management steps should be taken?

Management of Hypoglycemia During Insulin Infusion for DKA

When a DKA patient on insulin infusion develops hypoglycemia, immediately administer intravenous dextrose while continuing the insulin infusion at the same rate—never stop the insulin, as this is the most common error leading to persistent or worsening ketoacidosis. 1, 2

Immediate Actions

Step 1: Administer Dextrose Without Stopping Insulin

• Give 10–25 grams of IV dextrose (20–50 mL of 50% dextrose or equivalent volume of 10% dextrose) as a bolus for symptomatic hypoglycemia or glucose <70 mg/dL. 3
• Continue the insulin infusion at the current rate—do not reduce or stop it, because insulin is required to clear ketones even after glucose normalizes. 1, 2, 4
• Ketonemia takes substantially longer to resolve than hyperglycemia, so insulin must be maintained throughout treatment regardless of glucose levels. 2, 4

Step 2: Switch IV Fluids to Dextrose-Containing Solution

• Immediately change the maintenance IV fluid to 5% dextrose with 0.45–0.75% sodium chloride while keeping the insulin infusion running. 1, 2, 4
• This fluid change should have already occurred when glucose fell to 250 mg/dL; if hypoglycemia develops, it indicates either the dextrose was not added or the insulin rate is too high relative to glucose intake. 1, 2
• Add 20–30 mEq/L potassium to the dextrose-containing fluid to maintain serum potassium 4.0–5.0 mEq/L. 1, 4

Step 3: Target Glucose Range

• Maintain blood glucose between 150–200 mg/dL until complete DKA resolution (pH >7.3, bicarbonate ≥18 mEq/L, anion gap ≤12 mEq/L, glucose <200 mg/dL). 1, 2, 4
• Check bedside glucose every 1–2 hours during the acute phase and every 2–4 hours once stable. 1, 4

Adjusting Insulin and Dextrose

If Hypoglycemia Recurs Despite Dextrose

• Increase the dextrose concentration to 10% or even 20% dextrose in the IV fluid while maintaining the insulin infusion rate. 5
• In severe DKA with persistent acidosis, insulin rates of 4–6 U/hour (or higher) may be required with concurrent high-concentration glucose infusion to prevent hypoglycemia while clearing ketones. 5
• The maximum safe rate of dextrose infusion is approximately 0.5 g/kg/hour; about 95% is retained when infused at 0.8 g/kg/hour. 3

Do Not Reduce Insulin Rate Based on Glucose Alone

• Insulin dose adjustments should be guided by ketone clearance and pH normalization, not by glucose levels. 1, 2
• If acidosis persists despite adequate hydration and glucose control, the insulin infusion rate should be increased (not decreased), with appropriate glucose supplementation to prevent hypoglycemia. 1, 5

Monitoring Requirements

• Check serum potassium every 2–4 hours because insulin drives potassium intracellularly and hypoglycemia treatment with dextrose does not address this shift. 1, 4
• Measure venous pH, bicarbonate, anion gap, electrolytes, BUN, creatinine, and osmolality every 2–4 hours until metabolically stable. 1, 2, 4
• Obtain a repeat blood glucose measurement before each dextrose bolus to confirm hypoglycemia and guide dosing. 3

Common Pitfalls to Avoid

• Never discontinue or reduce the insulin infusion when glucose falls—this is the single most common cause of treatment failure and persistent ketoacidosis. 1, 2, 6
• Never rely on glucose levels alone to guide insulin therapy—DKA resolution requires normalization of pH, bicarbonate, and anion gap, which lag behind glucose correction. 2, 4
• Never stop IV insulin without prior subcutaneous basal insulin overlap (administered 2–4 hours before stopping the drip)—this causes rebound DKA. 1, 4, 6
• Failure to add dextrose when glucose reaches 250 mg/dL is a setup for subsequent hypoglycemia; anticipate this threshold and change fluids proactively. 1, 2

Special Consideration: Euglycemic DKA

• If the patient presented with euglycemic DKA (initial glucose <250 mg/dL), dextrose-containing fluids should have been started from the beginning of insulin therapy. 1, 2
• These patients require 150–200 grams of carbohydrate per day to suppress starvation ketogenesis while insulin clears diabetic ketones. 1