Should I start an insulin drip for a patient with type 1 diabetes (T1D) on Lantus (insulin glargine) 8 units, who has been administered stress steroids, and is experiencing a stroke?

Management of Hyperglycemia in Type 1 Diabetes During Acute Stroke

For a 65-year-old with type 1 diabetes presenting with acute stroke on Lantus 8 units and stress steroids, you should initiate an insulin drip if blood glucose is persistently >180 mg/dL, targeting 140-180 mg/dL, while maintaining frequent glucose monitoring to avoid hypoglycemia. 1

Critical Decision Points

When to Start an Insulin Drip

Initiate intravenous insulin therapy when:

• Blood glucose persistently exceeds 180 mg/dL 1
• The patient has type 1 diabetes (absolute insulin requirement) 1, 2
• Stress steroids are administered (significantly increases insulin resistance) 1
• The patient is critically ill or in the acute stroke phase 1, 3

The American Heart Association/American Stroke Association guidelines specifically recommend insulin therapy be initiated for persistent hyperglycemia starting at a threshold of 180 mg/dL, with a target glucose range of 140-180 mg/dL for critically ill patients 1. This is particularly important in your patient given the combination of type 1 diabetes, acute stroke, and steroid administration.

Why Lantus Alone is Insufficient

Lantus 8 units as monotherapy is dangerously inadequate for this patient because:

• Type 1 diabetes requires both basal AND prandial insulin coverage—approximately 50% of daily insulin should be basal and 50% prandial 2
• Using only long-acting insulin fails to control postprandial glucose excursions, leading to persistent hyperglycemia 2
• Typical total daily insulin requirements for type 1 diabetes range from 0.4-1.0 units/kg/day, meaning an 8-unit basal dose alone is grossly insufficient 2
• Stress steroids dramatically increase insulin requirements beyond baseline 1
• Patients with type 1 diabetes are at high risk for diabetic ketoacidosis without adequate prandial insulin coverage 2

Specific Protocol Recommendations

Implement the following approach:

1. Check current blood glucose immediately 1

2. If glucose >180 mg/dL, start IV insulin infusion:

   • Use regular insulin at 1 unit/mL concentration 1
   • Prime tubing with 20 mL waste volume 1
   • Initial infusion rate typically 0.5 units/hour, adjusted to maintain glucose 140-180 mg/dL 1, 4
   • Monitor blood glucose every 1-2 hours initially 1

3. Continue basal insulin (Lantus) at reduced dose:

   • Do NOT stop the Lantus entirely—this patient has type 1 diabetes and requires continuous basal insulin to prevent ketoacidosis 2, 4
   • Consider reducing the Lantus dose while on IV insulin to avoid stacking 1

4. Monitor for hypoglycemia aggressively:

   • Check glucose levels every 1-2 hours during IV insulin therapy 1
   • Avoid glucose <80 mg/dL 3
   • The risk of symptomatic hypoglycemia is significantly increased with intensive insulin therapy (number needed to harm = 9) 5

Critical Pitfalls to Avoid

Common errors that worsen outcomes:

• Never use sliding-scale insulin alone as the sole regimen for glucose management in this setting 6
• Never stop basal insulin completely in a patient with type 1 diabetes, even when starting an IV drip—this risks diabetic ketoacidosis 2, 4
• Avoid aggressive glucose targets <140 mg/dL in acute stroke, as this increases hypoglycemia risk without proven benefit 1, 5
• Do not delay IV insulin if glucose remains >180 mg/dL despite subcutaneous adjustments—earlier intervention may be more effective 1
• Monitor potassium closely when administering IV insulin, as insulin stimulates potassium movement into cells and can cause life-threatening hypokalemia 4

Evidence Regarding Tight Glycemic Control in Stroke

The evidence shows no benefit to aggressive glucose lowering but significant harm from hypoglycemia:

• The GIST-UK trial showed no improvement in mortality or functional outcomes with intensive insulin therapy targeting euglycemia in acute stroke 1, 5
• A Cochrane review of 11 RCTs (1583 participants) found no difference in death, dependency, or neurological deficit with intensive insulin therapy, but a 14.6-fold increased risk of symptomatic hypoglycemia 5
• The SHINE trial is still being analyzed but will provide definitive data on optimal glucose targets (80-130 mg/dL vs. standard care) 1
• Meta-analyses revealed increased rates of severe hypoglycemia and mortality in tightly controlled cohorts compared to moderate control 1

Therefore, the consensus recommendation is to target 140-180 mg/dL rather than normoglycemia 1.

Special Considerations for This Patient

Type 1 diabetes with stress steroids creates unique challenges:

• Intravenous insulin is preferred for type 1 diabetes patients who are hemodynamically unstable or critically ill 1
• Stress steroids significantly increase insulin resistance, often requiring 2-3 times the usual insulin dose 1
• Frequent glucose monitoring is mandatory—every 1-2 hours initially 1
• Transition to subcutaneous basal-bolus regimen only after stabilization, resolution of peripheral edema, and when off vasopressors 1

Monitor for hypokalemia aggressively as IV insulin administration has rapid onset and can cause respiratory paralysis, ventricular arrhythmia, and death if potassium drops precipitously 4.