What is the next step for a patient on insulin (intravenous insulin) gtt (glucose titration) at 0.1 units/kg/hr with severe hyperglycemia (blood glucose > 600)?

Immediate Management of Severe Hyperglycemia on Insulin Infusion

If your patient's blood glucose has not decreased by at least 50 mg/dL in the first hour on insulin infusion at 0.1 units/kg/hr, you should verify adequate hydration status and then double the insulin infusion rate hourly until achieving a steady glucose decline of 50-75 mg/dL per hour. 1

Assessment and Initial Actions

Verify Current Management

• Confirm adequate fluid resuscitation is ongoing - this is critical as dehydration impairs insulin effectiveness 1
• Check that potassium is >3.3 mEq/L before continuing or escalating insulin (if <3.3 mEq/L, hold insulin and replace potassium first) 1
• Ensure the patient received an initial IV bolus of 0.15 U/kg regular insulin when the infusion was started 1

Determine the Underlying Crisis Type

With glucose >600 mg/dL, assess for:

• Hyperosmolar hyperglycemic state (HHS): pH ≥7.3, bicarbonate ≥15 mEq/L, effective serum osmolality ≥320 mOsm/kg 1
• Diabetic ketoacidosis (DKA): pH <7.3, bicarbonate <15 mEq/L, positive ketones 1
• Calculate effective serum osmolality: 2[measured Na (mEq/L)] + glucose (mg/dL)/18 1

Insulin Dose Escalation Protocol

If Glucose Has Not Fallen Adequately

The standard 0.1 units/kg/hr dose should decrease plasma glucose by 50-75 mg/dL in the first hour 1

If this target is not met:

1. Verify hydration status is acceptable 1
2. Double the insulin infusion rate 1
3. Repeat this doubling every hour until steady glucose decline of 50-75 mg/dL per hour is achieved 1

Target Glucose Levels During Treatment

• Continue aggressive insulin infusion until glucose reaches 250 mg/dL (for DKA) or 300 mg/dL (for HHS) 1
• At these thresholds, decrease insulin to 0.05-0.1 units/kg/hr and add dextrose 5-10% to IV fluids 1

Critical Monitoring Requirements

Frequent Laboratory Assessment

• Draw blood every 2-4 hours for serum electrolytes, glucose, BUN, creatinine, osmolality, and venous pH 1
• Venous pH is adequate for monitoring (typically 0.03 units lower than arterial pH); repeat arterial blood gases are generally unnecessary 1

Fluid Management

• Maintain IV fluid rate at approximately 1.5 times 24-hour maintenance requirements to achieve smooth rehydration 1
• Decrease osmolality by no more than 3 mOsm/kg/hr to avoid cerebral edema 1
• Once renal function is confirmed and potassium known, include 20-40 mEq/L potassium in fluids (2/3 KCl or potassium-acetate and 1/3 KPO₄) 1

Common Pitfalls to Avoid

Do not continue the same insulin dose if glucose is not falling appropriately - clinical inertia is a major barrier to achieving glycemic control 2

Do not rely on urine or serum ketone measurements by nitroprusside method to assess response to therapy in DKA, as β-hydroxybutyrate (the predominant ketone) is not measured and conversion to acetoacetate during treatment may falsely suggest worsening ketosis 1

Do not allow glucose to fall too rapidly - the goal is 50-75 mg/dL per hour, not faster, to prevent complications 1