From the Guidelines
In patients with subarachnoid hemorrhage, blood pressure should be gradually reduced when severely hypertensive (>180-200 mmHg), while avoiding hypotension (mean arterial pressure <65 mmHg) and closely monitoring neurological examination. This approach is based on the most recent guideline from the American Heart Association/American Stroke Association, published in 2023 1. The goal is to balance the risk of rebleeding with the risk of cerebral ischemia due to excessive blood pressure lowering.
Key considerations in managing blood pressure after a subarachnoid hemorrhage include:
- Maintaining systolic blood pressure below 140-160 mmHg until the aneurysm is secured to reduce the risk of rebleeding
- Using short-acting continuous-infusion intravenous agents such as nicardipine, labetalol, or clevidipine, which have a reliable dose-response relationship and favorable safety profile
- Avoiding sodium nitroprusside due to its potential to raise intracranial pressure and cause toxicity with prolonged infusion, as noted in previous guidelines 1
- Individualizing blood pressure management based on the patient's neurological status, comorbidities, and timing relative to aneurysm treatment
It is crucial to avoid excessive blood pressure lowering, as it may compromise cerebral perfusion in patients with elevated intracranial pressure, while also being mindful of the risk of rebleeding associated with high blood pressure, particularly systolic blood pressure >160 mmHg 1.
From the Research
Subarachnoid Bleed Blood Pressure Management
- The management of blood pressure in patients with subarachnoid hemorrhage (SAH) is crucial to prevent rebleeding and improve clinical outcomes 2, 3.
- Studies have shown that intensive blood pressure management can lower the risk of early rebleeding in SAH patients 2.
- The use of antihypertensive agents such as nicardipine and labetalol has been found to be effective and safe in controlling blood pressure in SAH patients 4, 5.
- The target blood pressure range for SAH patients is generally considered to be between 140-160 mmHg, although this may vary depending on individual patient factors 2, 3.
- Avoiding large degrees of blood pressure variability is also important to improve clinical outcomes in aneurysmal SAH 3.
- Elevated blood pressure is common in patients with acute SAH, and antihypertensive therapy is often administered selectively in emergency department patients with SAH 6.
Blood Pressure Targets
- A study found that SAH patients with systolic blood pressure (SBP) ≥ 160 mmHg are at increased risk of rebleeding and neurologic decline 6.
- Another study suggested that acute lowering of SBP to a range of 140-160 mmHg decreases the risk of rebleeding while also maintaining cerebral perfusion pressure (CPP) after aneurysmal rupture 3.
- However, one study found that ED SBP within the target range (SBP ≤ 140 mmHg) does not negate the risk of early rebleeding, and other treatment options should also be explored 2.
Treatment Options
- Nicardipine infusion has been found to be a safe and moderately effective treatment for blood pressure control in patients with SAH 5.
- Labetalol has also been found to be effective and safe in controlling blood pressure in SAH patients, although it may take longer to reach goal blood pressure compared to nicardipine 4.
- Treatment with a short-acting antihypertensive agent allows for rapid titration of blood pressure and reduces blood pressure variability 3.