What to do for severe hyperglycemia unresponsive to insulin lispro?

Immediate Management of Severe Hyperglycemia Unresponsive to Rapid-Acting Insulin

You need to immediately assess for diabetic ketoacidosis (DKA) by checking capillary ketones and consider emergency department transfer if blood glucose remains persistently >350 mg/dL (19.4 mmol/L) despite repeated insulin lispro doses, as this represents potential insulin resistance, DKA, or another acute precipitating factor requiring IV insulin therapy. 1, 2

Urgent Assessment Required

• Check capillary ketones immediately - if ketones >2 mmol/L with blood glucose >270 mg/dL (15 mmol/L), this patient requires emergency hospital assessment for possible DKA 1
• Assess for precipitating causes including infection, medication changes (especially corticosteroids), insulin pump malfunction if applicable, or other acute stressors that may be driving insulin resistance 2
• Verify insulin administration technique - confirm the insulin was actually injected subcutaneously (not intramuscularly or leaked), the insulin has not expired, and proper storage has been maintained 1

Immediate Actions

• If ketones are elevated (>2 mmol/L) or blood glucose reads "HI" or persistently >360 mg/dL (20 mmol/L): Transfer to emergency department immediately for IV insulin infusion and fluid resuscitation 1, 2
• If no ketones present and patient is stable: Administer an additional correction dose of rapid-acting insulin lispro (calculate based on insulin sensitivity factor, typically 2-4 units if sensitivity factor unknown), but do not stack insulin doses more frequently than every 2-3 hours to avoid delayed hypoglycemia 1, 3

Hospital-Based Management if Transfer Required

• IV insulin infusion should follow validated protocols with predefined adjustments based on glycemic fluctuations, targeting blood glucose 140-180 mg/dL for hospitalized patients 2
• Concurrent fluid resuscitation is essential to address dehydration commonly associated with severe hyperglycemia 2
• When transitioning from IV to subcutaneous insulin, administer subcutaneous basal insulin at 60-80% of the daily IV infusion dose, given 1-2 hours before discontinuing IV insulin to prevent rebound hyperglycemia 2

Critical Pitfalls to Avoid

• Do not continue stacking rapid-acting insulin doses every 30-60 minutes - lispro insulin has a duration of action of approximately 3-5 hours, and repeated dosing can lead to severe delayed hypoglycemia once insulin sensitivity improves 3, 4
• Do not assume the insulin is working slowly - persistent hyperglycemia >350 mg/dL after 90 minutes and adequate insulin dosing suggests either DKA, severe insulin resistance from acute illness/steroids, or technical insulin delivery failure 1
• Do not delay hospital transfer if ketones are present - DKA can be life-threatening and requires immediate medical attention with IV insulin and electrolyte management 1

Follow-Up After Stabilization

• After acute hyperglycemia resolves, implement a basal-bolus insulin regimen rather than relying on correction doses alone, as sliding scale insulin without basal coverage is strongly discouraged 2, 5
• For patients with HbA1c ≥9%, combination therapy approaches are recommended to achieve glycemic control more quickly 2