Management: Start Subcutaneous Insulin
In a 70-year-old woman 2 days post-ischemic stroke with random blood glucose of 12–13 mmol/L (216–234 mg/dL), you should initiate subcutaneous insulin therapy targeting a glucose range of 140–180 mg/dL (7.8–10 mmol/L), not simply observe. 1, 2
Why Insulin Therapy is Indicated
The American Heart Association/American Stroke Association guidelines explicitly recommend treating hyperglycemia when blood glucose persistently exceeds 180 mg/dL (10 mmol/L), with a target range of 140–180 mg/dL for critically ill stroke patients. 3, 1
This patient's glucose of 12–13 mmol/L (216–234 mg/dL) clearly exceeds the 180 mg/dL threshold, making observation alone inappropriate. 2
Persistent hyperglycemia above 200 mg/dL during the first 24 hours independently predicts infarct expansion, hemorrhagic transformation, increased brain edema, and worse functional outcomes. 2, 4
Why NOT tPA
tPA is absolutely contraindicated at 2 days post-stroke, as the therapeutic window for intravenous thrombolysis is 4.5 hours from symptom onset. 1
This patient is well beyond any reperfusion therapy window, making option C completely inappropriate. 1
Specific Insulin Regimen
For a stable stroke unit patient (not ICU-level critically ill), subcutaneous basal-bolus insulin is preferred over intravenous infusion: 1, 4
Start with a total daily dose of approximately 0.3 units/kg (roughly 18–21 units for a 70 kg patient). 4
Divide as 50% long-acting basal insulin once daily and 50% rapid-acting insulin before meals with correction doses. 4
Reserve continuous IV insulin infusion only for critically ill patients or those with severe hyperglycemia >200 mg/dL requiring rapid control. 1
Critical Monitoring Requirements
Before and during insulin therapy, you must: 2, 4
Confirm persistent hyperglycemia by measuring blood glucose every 6 hours for the first 24–48 hours (don't treat based on a single reading). 1
Check serum potassium before and during insulin treatment to prevent hypokalemia. 2, 4
Avoid glucose levels below 80 mg/dL (4.4 mmol/L), as hypoglycemia causes additional neuronal injury and may be more immediately dangerous than moderate hyperglycemia. 2, 4
Evidence Against Tight Control
Do NOT target normoglycemia (<140 mg/dL), as meta-analyses demonstrate that tight glucose control increases severe hypoglycemia rates and mortality without improving neurological outcomes. 3, 1
The GIST-UK trial, the only large randomized study of aggressive insulin therapy in acute stroke, showed no benefit on clinical outcomes and was stopped early. 1
Common Pitfalls to Avoid
Never use sliding-scale insulin alone as the single regimen, as it results in undesirable glucose fluctuations and increased hospital complications. 4
Don't delay treatment thinking this is just stress hyperglycemia—at 2 days post-stroke, you're still within the critical window where glucose control impacts outcomes. 2
Avoid sulfonylureas (especially chlorpropamide and glyburide) in this elderly patient due to prolonged half-life and escalating hypoglycemia risk. 4