A 70-year-old woman 2 days after an ischemic stroke has normal labs except a random blood glucose of about 13 mmol/L; should she be observed, started on an insulin infusion, or receive tissue plasminogen activator?

Management of Hyperglycemia in a 70-Year-Old Woman 2 Days Post-Ischemic Stroke

For this patient with a random blood glucose of 12-13 mmol/L (216-234 mg/dL) at 2 days post-stroke, you should initiate subcutaneous insulin therapy targeting a glucose range of 140-180 mg/dL (7.8-10.0 mmol/L), not observation alone, and tPA is absolutely contraindicated as she is well beyond the therapeutic window. 1, 2

Why Insulin Therapy is Indicated

The patient's glucose exceeds the treatment threshold of 180 mg/dL (10 mmol/L). The American Heart Association/American Stroke Association guidelines explicitly recommend initiating insulin therapy when blood glucose persistently exceeds 180 mg/dL, with a target range of 140-180 mg/dL for stroke patients. 1, 2

• Persistent hyperglycemia >200 mg/dL during the first 24 hours independently predicts infarct expansion and worse neurological outcomes. 3
• Hyperglycemia is associated with hemorrhagic transformation, increased brain edema, and poor functional recovery. 3, 4
• At 2 days post-stroke, the patient remains within the critical window where glucose control impacts outcomes, though the urgency is less than in the hyperacute phase. 2

Why Subcutaneous Insulin, Not IV Infusion

For this stable, non-critically ill patient 2 days post-stroke, subcutaneous insulin is the appropriate route, not intravenous infusion. 1, 2, 5

• IV insulin infusion is reserved for critically ill patients in the ICU setting or those with persistent severe hyperglycemia (>200 mg/dL requiring immediate control). 1, 2
• This patient is stable in a stroke unit with normal labs, making her a candidate for subcutaneous protocols. 2, 5
• Subcutaneous basal-bolus regimens can safely maintain glucose levels in the target range without excessive healthcare resources. 2, 4

Specific Insulin Protocol

Start a basal-bolus subcutaneous insulin regimen:

• Total daily dose: 0.3 units/kg/day (approximately 18-21 units for a 70kg patient). 4
• Divide as: 50% basal insulin (long-acting, once daily) + 50% rapid-acting insulin before meals if eating adequately. 4, 5
• Add correction doses of rapid-acting insulin for glucose values above target range. 1, 5
• Avoid sliding-scale insulin alone as it results in undesirable glucose fluctuations and increased complications. 4

Critical Monitoring Requirements

Before and during insulin therapy, implement these safety measures:

• Confirm persistent hyperglycemia by measuring glucose every 6 hours for the first 24-48 hours before starting insulin. 2, 3, 4
• Check serum potassium before and during insulin therapy to prevent hypokalemia. 2, 3
• Monitor for hypoglycemia closely—never allow glucose to fall below 80 mg/dL (4.4 mmol/L) as hypoglycemia causes additional neuronal injury in the ischemic brain. 2, 3, 5
• Continue cardiac telemetry to detect atrial fibrillation, which may emerge post-stroke and require anticoagulation. 2

Why Observation Alone is Inadequate

Simple observation (Option A) is inappropriate because:

• The glucose level of 12-13 mmol/L (216-234 mg/dL) exceeds the 180 mg/dL treatment threshold established by multiple guidelines. 1, 2
• Untreated hyperglycemia during the acute stroke period is associated with worse functional outcomes and increased mortality. 1, 3
• While stress hyperglycemia may resolve spontaneously, at 2 days post-stroke with persistent elevation, active management is warranted. 2, 5

Why tPA is Contraindicated

tPA (Option C) is absolutely contraindicated in this patient:

• She is 2 days (48 hours) post-stroke, far beyond the 4.5-hour therapeutic window for thrombolytic therapy. 2
• Administering tPA at this time point would provide no benefit and carries significant hemorrhagic risk. 2

Avoiding Common Pitfalls

Do not target normoglycemia (<140 mg/dL):

• Meta-analyses demonstrate that tight glucose control increases severe hypoglycemia rates and mortality without improving functional outcomes. 1, 2
• The GIST-UK trial showed no benefit from aggressive insulin therapy in acute stroke. 2, 6
• Hypoglycemia (<60 mg/dL) occurred in 35% of aggressively treated patients in one study, with potential for permanent brain damage. 7, 6

Do not start insulin based on a single glucose reading:

• Confirm sustained elevation with repeat measurements to avoid unnecessary treatment of transient stress hyperglycemia. 2

In elderly patients, be especially cautious:

• Avoid sulfonylureas (particularly chlorpropamide and glyburide) due to prolonged hypoglycemia risk. 4
• Consider a less stringent long-term A1C target of 8% after discharge given age and comorbidities. 4

Evidence Strength

The recommendation for moderate glucose control (140-180 mg/dL) over aggressive normalization is supported by:

• Multiple professional society guidelines (American Heart Association, American Diabetes Association, American Stroke Association). 1, 2, 3
• A Cochrane systematic review of 11 RCTs (1583 participants) showing no benefit from intensive insulin therapy and 14.6-fold increased risk of symptomatic hypoglycemia. 6
• Consistent observational data linking both hyperglycemia and hypoglycemia to poor stroke outcomes. 1, 3