Blood Pressure Management in the Neuro Intensive Care

UnitHarold C. McGrade , M.D.

Department of Neurocritical Care

Ochsner Medical Center

Outline

• Acute Ischemic Stroke

• IV thrombolysis

• IA mechanical thrombectomy

• Carotid Endarterectomy

• Intracerebral hemorrhage

• Subarachnoid hemorrhage

Acute Ischemic Stroke

• AHA/ASA guidelines: no treatment of blood pressure in first 24 hrs unless over 222/120 mmHg

• After the first 24 hours, reduction of BP by 15% of presentation BP is probably safe

• Before IV thrombolysis, BP should be less then 180/110 mmHg and this pressure should be maintained for the duration of the infusion

• After IV tpa administered, the BP should be kept below 180/105 for the next 24 hours

Autoregulation

• The maintenance of cerebral blood flow in the setting of fluctuations in systemic blood pressure

• This is controlled by changes in intracranial lumen size from feedback from afferent baroreceptors in the carotid artery and Aorta

• Measured through various techniques: TCD, perfusion studies, PET

• No consistent agreed upon value or technique has been recognized

Collateral flow and penumbra

• An infarct is divided into two regions:

• infarct core (irreversible ischemia)

• infarct penumbra ( salvageable tissue)

• As long as a cerebral artery is occluded, penumbra will eventually disappear as the core enlarges

• Collateral flow can delay this process

• Aggressive blood pressure reduction in a setting where autoregulation is disturbed can accelerate core enlargement

The evidence?

• There is no lack of studies in the stroke literature looking at the effects of treatment, or lack thereof, of blood pressure

• All of these studies share the following:

• all stroke populations where included suggesting the effect of blood pressure treatment is consistent across stroke subgroups

• the timing of treatment occurred up to 30 hrs out from the onset of stroke, only a few randomized patients within 7 hours

• the endpoints were vague and could have been influenced by many factors, i.e mortality, disability, or functional status)

Recommendations

• Elevated blood pressure in the first 24 hours with the exception after IV thrombolysis should not be treated

• If another condition is present where guidelines of practice are better established in regards to hemodynamic management, then that condition dictates the blood pressure

• IV titratable gtts are probably safer and avoid large BP swings which occur with prn injections

• It is reasonable to begin gradually lowering the BP by 15% of admission value after 24 hrs

Intracerebral hemorrhage

•• Considerations

•• 1.) Untreated blood pressure leads to hematoma expansion in

the acute setting (pro BP lowering)

•• 2.) There is a perihematomal region of edema that is from

ischemia ( con BP lowering)

Intracranial hematoma expansion

• Occurs in 35-40% of ICH patients within the first 24 hours

• Peak time of hematoma expansion is within the first 4 hours

• Death and disability are substantially increased in ICH patients that have hematoma expansion

• Pilot safety studies looking at blood pressure modification and it’s effect on hematoma expansion and safety were started ( ATACH and INTERACT)

• Both studies compared a guideline treatment arm, SBP< 180mmHg to intensive treatment, SBP < 160 or140mmHg

INTERACT and INTERACT 2

• Enrolled within 6 hours of onset of ICH

• Two groups were compared

• Guideline management, SBP <180mmHg

• Intensive management, SBP< 140mmHg

• Time to target BP was 1 hour and sustained for 24 hrs

• Results

• no difference in mortality or major disability

• ordinal analysis of mRS showed better functional outcome in intensive treatment group

ATACH and ATACH 2

• Treatment with iv Cardene within 4.5 hrs of symptoms

• Two groups

• Intensive group ( SBP 110-139mmHg )

• Standard group ( SBP 140-179mmHg )

• Results

• no difference in mortality or major disability between groups

• average SBP at 2 hrs was 129mmHg in intensive group and 140mm/hg in standard group

• Nonsignificant decrease in hematoma expansion but substantial more renal events in treatment group, p = 0.002

Subarachnoid Hemorrhage

• All data on this subject are from case reports or retrospective reviews

• Review of three published guideline statements

• AHA/ASA: SBP< 160mmHg

• Neurocritical Care society: < 160mmHg, MAP < 110mmHg

• European Stroke Organization: SBP< 180mmHg

• Problems with existing literature: Hypertension causes rebleed or rebleed causes hypertension

• Problems with aggressive blood pressure lowering: vasoparalysis, ICP

Questions?

Title and Content Layout with List

• Click to edit Master text styles

• Second level• Third level

• Fourth level

• Fifth level

Title and Content Layout with Chart

0

1

2

3

4

5

6

Category 1 Category 2 Category 3 Category 4

Series 1 Series 2 Series 3

Two Content Layout with Table

Class Group A Group B

Class 1 82 85

Class 2 76 88

Class 3 84 90

• First bullet point here

• Second bullet point here

• Third bullet point here

Two Content Layout with SmartArt

• First bullet point here

• Second bullet point here

• Third bullet point here

Group A

• Task 1• Task 2

Group B

• Task 1• Task 2

Group C

• Task 1• Task 2