Management of Hyperglycaemia in Acute Ischaemic Stroke
In this 72-year-old patient with acute ischaemic stroke and a blood glucose of 12.2 mmol/L, you should target a glucose range of 6.0–10.0 mmol/L using subcutaneous correctional insulin (sliding scale) while she remains nil by mouth, avoiding aggressive glucose lowering that could worsen neurological outcomes. 1
Immediate Glycaemic Target and Rationale
- The UK JBDS Inpatient Care group recommends a target blood glucose range of 6.0–10.0 mmol/L for hospitalized patients with hyperglycaemia, with an acceptable range of 4.0–12.0 mmol/L 1
- Her current glucose of 12.2 mmol/L is only marginally above the acceptable upper limit and does not require aggressive intervention 1
- In acute ischaemic stroke, rapid or intensive glucose lowering has NOT shown additional benefit and may increase hypoglycaemia risk, which can worsen neurological outcomes 1
- Hyperglycaemia in acute stroke is associated with poor outcomes, but the optimal glucose-lowering strategy remains uncertain, and hypoglycaemia must be avoided 1, 2
Specific Treatment Approach While Nil by Mouth
Hold metformin immediately – she is nil by mouth and metformin is contraindicated in acute illness with potential renal compromise and nil oral intake 1
Initiate subcutaneous correctional insulin (sliding scale):
- Despite guidelines discouraging sliding scale insulin as monotherapy, it is appropriate for patients with mild stress hyperglycaemia who are nil by mouth and have uncertain nutritional status 1
- Use a conservative sliding scale protocol targeting glucose <11.1 mmol/L rather than aggressive normalization 1
- Monitor capillary blood glucose every 4-6 hours initially 1
Avoid basal-bolus insulin at this stage because:
- Her glucose is only mildly elevated (12.2 mmol/L) 1
- She has an HbA1c of 56 mmol/mol (7.3%), indicating reasonable baseline control 1
- Her nutritional status is uncertain pending swallow assessment 1
- Risk of hypoglycaemia outweighs benefits of tight control in acute stroke 1, 2
Monitoring and Adjustment Strategy
- Check capillary blood glucose every 4-6 hours while nil by mouth 1
- Monitor for signs of hypoglycaemia (confusion, sweating, tremor) which may be masked by stroke symptoms 1
- Once swallow assessment is completed and oral intake resumes, reassess the insulin regimen 1
- Avoid glucose levels <4.0 mmol/L as this increases hypoglycaemia risk and may worsen stroke outcomes 1
Transition Plan After Swallow Assessment
If swallow assessment is safe and oral intake resumes:
- Restart metformin 1g twice daily with meals, provided renal function is stable (her creatinine is 88 μmol/L, which is acceptable) 1
- Continue correctional insulin coverage for glucose >11.1 mmol/L 1
- Consider adding basal insulin (0.1-0.2 units/kg/day) only if glucose consistently exceeds 11.1 mmol/L despite metformin 1, 3
If prolonged nil by mouth status (>48-72 hours):
- Transition to basal insulin at low dose (0.1 units/kg/day = approximately 6-7 units daily for her weight) 1, 3
- Continue correctional insulin for glucose excursions 1
- Ensure adequate IV fluid glucose content to prevent hypoglycaemia 1
Critical Pitfalls to Avoid
- Do not aggressively lower glucose to <6.0 mmol/L – this has not shown benefit in acute stroke and increases hypoglycaemia risk 1, 2
- Do not continue metformin while nil by mouth – risk of lactic acidosis in acute illness 1
- Do not use complex basal-bolus regimens in a patient with mild hyperglycaemia and uncertain nutritional status 1
- Do not ignore the stroke context – glucose management in acute ischaemic stroke requires a more conservative approach than general inpatient hyperglycaemia 1, 2