What are the blood pressure recommendations for patients with subarachnoid hemorrhage?

Blood Pressure Management in Subarachnoid Hemorrhage

For patients with aneurysmal subarachnoid hemorrhage (aSAH), blood pressure should be maintained below 160 mmHg systolic before aneurysm securing, and then increased to a mean arterial pressure >90 mmHg after aneurysm treatment to prevent delayed cerebral ischemia. 1, 2

Pre-Aneurysm Securing Phase

• Frequent blood pressure monitoring and control with short-acting medications is recommended to avoid severe hypotension, hypertension, and BP variability in patients with unsecured aneurysms 1
• Systolic blood pressure should be maintained below 160 mmHg to reduce rebleeding risk, though evidence for this specific threshold is limited 1
• Arterial line monitoring is strongly recommended over non-invasive cuff monitoring due to the need for precise, continuous monitoring 2
• Avoid sudden, profound reduction of BP as excessive BP reduction may compromise cerebral perfusion and induce ischemia 1
• Gradual reduction of BP is recommended when patients are severely hypertensive (>180–200 mmHg) 1
• Strict avoidance of hypotension (mean arterial pressure <65 mmHg) is essential to prevent cerebral ischemia 1, 2

Post-Aneurysm Securing Phase

• After aneurysm securing, blood pressure management goals shift dramatically to prevent delayed cerebral ischemia 2
• Maintain mean arterial pressure >90 mmHg to prevent delayed cerebral ischemia 2
• Induced hypertension may be required to treat symptomatic vasospasm after aneurysm securing 2, 3
• Continuous arterial monitoring remains essential during induced hypertension to maintain precise BP targets according to neurological response 2

Special Considerations

• For patients on anticoagulants, emergency anticoagulation reversal with appropriate reversal agents should be performed to prevent rebleeding 1
• Increased BP variability has been associated with worse outcomes in aSAH 1, 4
• Deviation from personalized blood pressure targets at which cerebral autoregulation is best preserved is associated with worse functional outcomes 4
• Initial systolic blood pressure ≥220 mmHg may indicate poor outcomes in patients with subarachnoid hemorrhage 5

Monitoring Recommendations

• Arterial line monitoring is preferred over non-invasive cuff monitoring for precise, continuous BP monitoring 2, 3
• Close neurological examination while lowering BP is necessary to detect early signs of cerebral ischemia 1
• Transcranial Doppler is reasonable to monitor for the development of arterial vasospasm 1
• Perfusion imaging with CT or MRI can be useful to identify regions of potential brain ischemia 1

Common Pitfalls to Avoid

• Avoid rapid BP fluctuations, which are associated with increased rebleeding risk 1, 2
• Avoid excessively aggressive BP lowering (>70 mmHg reduction in 1 hour) as it may compromise cerebral perfusion 2
• Antihypertensive treatment may reduce rebleeding risk but could increase cerebral infarction risk if BP is lowered too aggressively 6
• Routine use of antifibrinolytic therapy is not recommended as it does not improve functional outcomes 1

Algorithm for BP Management in aSAH

1. Before aneurysm securing:

   • Maintain systolic BP <160 mmHg using titratable short-acting agents 1
   • Use arterial line for continuous monitoring 2
   • Avoid hypotension (MAP <65 mmHg) 1, 2

2. After aneurysm securing:

   • Maintain MAP >90 mmHg 2
   • Consider induced hypertension for symptomatic vasospasm 2, 3
   • Continue close monitoring for delayed cerebral ischemia (days 4-14) 2, 3

3. For patients with EVD:

   • Coordinate EVD management with BP control as changes in one will affect the other 3
   • Monitor cerebral perfusion pressure (target 50-70 mmHg) 3