Blood pressure reduction does not reduce perihematoma oxygenation: a CT perfusion study

Area of Science:

• Neurology
• Neurosurgery
• Critical Care Medicine

Background:

• Intracerebral hemorrhage (ICH) management involves controversial blood pressure (BP) reduction strategies.
• Concerns exist that BP reduction may compromise perihematoma perfusion and cause secondary brain injury.

Purpose of the Study:

• To investigate whether BP reduction affects oxygenation in the brain tissue surrounding an intracerebral hemorrhage.
• To test the hypothesis that BP reduction leads to decreased perihematoma tissue oxygenation.

Main Methods:

• Randomized controlled trial comparing two systolic BP targets (<150 mmHg vs. <180 mmHg) in acute ICH patients.
• CT perfusion (CTP) imaging used to assess cerebral blood flow (CBF), oxygen extraction fraction (OEF(max)), and oxygen consumption (CMRO2(max)).
• Analysis of perihematoma and contralateral tissue hemodynamics.

Main Results:

• Sixty-five patients were included, with CTP imaging performed a median of 9.8 hours post-onset.
• Perihematoma oxygen extraction fraction (OEF(max)) was elevated, indicating a compensatory response.
• Despite significant BP differences between groups, perihematoma CBF, OEF(max), and CMRO2(max) were not significantly affected by aggressive BP reduction.

Conclusions:

• Early, aggressive BP reduction in ICH patients does not negatively impact perihematoma oxygen delivery.
• These findings support the safety of implementing early, intensive BP management strategies in acute ICH.
• The study provides evidence against concerns of critical reductions in perihematoma perfusion due to BP lowering.