What is the recommended approach to managing blood pressure in patients with acute ischemic stroke or intracerebral hemorrhage, particularly regarding permissive hypertension?

Blood Pressure Management in Acute Stroke: Permissive Hypertension Approach

In acute ischemic stroke, permissive hypertension should be allowed with no treatment unless systolic blood pressure exceeds 220 mmHg or diastolic blood pressure exceeds 120 mmHg, while in intracerebral hemorrhage, blood pressure should be carefully lowered to a target of 140-160 mmHg systolic to prevent hematoma expansion. 1, 2

Acute Ischemic Stroke BP Management

Non-reperfusion Therapy Patients

• Allow permissive hypertension for first 72 hours after stroke onset 1, 3
• Do not treat BP unless:
  • SBP >220 mmHg or DBP >120 mmHg 1, 2, 4
  • If treatment needed, reduce BP by only 15% during first 24 hours 1, 4
• Rationale: Cerebral autoregulation is impaired in ischemic areas; maintaining systemic BP ensures adequate perfusion to the ischemic penumbra 1, 2
• After 72 hours, if BP remains ≥140/90 mmHg, initiate or reintroduce antihypertensive therapy 1

Reperfusion Therapy Patients

• For patients receiving thrombolysis or mechanical thrombectomy:
  • Lower BP to <185/110 mmHg before treatment initiation 1, 3
  • Maintain BP <180/105 mmHg for at least 24 hours after treatment 1, 3
• Monitoring: Every 15 minutes for 2 hours, then every 30 minutes for 6 hours, then hourly for 16 hours 3

Intracerebral Hemorrhage BP Management

• Immediate BP lowering (within 6 hours of symptom onset) to a systolic target of 140-160 mmHg 1
• Avoid excessive BP drops (>70 mmHg) as this may cause acute renal injury and neurological deterioration 1
• More aggressive BP control is warranted compared to ischemic stroke to prevent hematoma expansion 1, 5

Medication Selection

First-line Agents

• Labetalol: 10-20 mg IV over 1-2 minutes, may repeat or double every 10 minutes to maximum 300 mg; preferred if tachycardia present 3, 2
• Nicardipine: 5 mg/hr IV infusion, titrate by increasing 2.5 mg/hr every 5 minutes to maximum 15 mg/hr; preferred if bradycardia or heart failure present 3, 2

Second-line Agent

• Sodium nitroprusside: Use only for refractory hypertension or DBP >140 mmHg; use with caution due to potential increases in intracranial pressure 3, 2

Pitfalls to Avoid

• Excessive BP lowering: Can compromise cerebral perfusion, especially in the ischemic penumbra, leading to worse outcomes 2, 6
• Rapid BP reduction: Can cause cerebral hypoperfusion; aim for smooth, controlled reduction 3
• Ignoring comorbidities: Different BP targets may be appropriate for patients with concurrent myocardial infarction, heart failure, or aortic dissection 3, 4
• Delayed treatment in ICH: Early BP control (within 6 hours) in ICH is critical to prevent hematoma expansion 1, 5

Long-term BP Management

• For secondary stroke prevention, initiate or restart antihypertensive therapy after neurological stabilization 1
• Target BP <130/80 mmHg for long-term secondary stroke prevention 3
• Preferred agents: Thiazide diuretics, ACE inhibitors, and ARBs; combination therapy shows strong evidence for stroke recurrence reduction 3

By following these guidelines, clinicians can appropriately balance the risks of inadequate cerebral perfusion against the benefits of preventing hemorrhagic transformation or hematoma expansion in acute stroke patients.