Sun14November1246PM 40

A 67-year-old man is admitted to the Emergency Department after a sudden collapse, just before which he was complaining of a severe occipital headache. He has a history of hypertension controlled with two oral agents.

On examination, his mean arterial pressure is 140. Pulse is 88 and regular, he has bilateral papilloedema, GCS is reduced at 13. Although he is confused he is moving all 4 limbs. CT head reveals evidence of a large subarachnoid haemorrhage.

Which of the following is the target for cerebral perfusion pressure?

(Please select 1 option)

<60 mmHg

100 mmHg

61-80 mmHg Correct

91-100 mmHg

81-90 mmHg

Explanation

The target is 61-80 mmHg. The most relevant guidelines come from the American Heart Association and American Stroke Association, who recommend a cerebral perfusion pressure of 61-80 mmHg. Perfusion pressures below 60 run the risk of inadequate perfusion and watershed infarction, and pressures >80 mmHg run the risk of extending any area of cerebral haemorrhage.

The other options are either incorrect because they run the risk of expanding any area of neurological impairment related to poor blood supply, or extending the cerebral haemorrhage.

Evidence for the level of blood pressure lowering required is actually remarkably weak, with one main trial, (INTERACT2), looking at aggressive BP lowering, (to less than 140mmHg), vs standard management of blood pressure. This study did not show a significant improvement in hard outcomes, although a secondary measure, (Rankin score), was better in patients with BP between 150 and 200 mmHg systolic who were targeted to the aggressive lowering group.

IV agents are preferred for lowering blood pressure in the acute phase as their dose can be easily titrated.