Hypertension is a significant issue with stroke for two reasons. Firstly, hypertension is the most important cause of stroke in our community and treatment of hypertension prior to stroke can be expected to reduce the patientís risk of stroke, and as such one should always consider that.
But in the setting of secondary hypertension, that is in post stroke, as in this scenario, treatment of hypertension can be a little tricky at times. Often patients will have a markedly elevated blood pressure following stroke due to the activation of the sympathetic and cortisol based mechanisms such that their blood pressure will often be elevated in the region of 170-200mm systolic.
As youíll be well aware, the brain has autoregulation and as such during this time, interfering with this autoregulation with aggressive blood pressure lowering may lead to actually increased risk of recurrent infarction and extension of the infarct that has already happened.
As such, when you are called to manage or asked to manage hypertension after stroke, once you consider that the blood pressure is 180 systolic itís certainly probably safe and certainly donít need acute management.
Blood pressures from 180 to just over 200 may need some cautious management with gradual blood pressure lowering agents. Whereas blood pressures beyond 220mmH certainly need to be acutely lowered, but again very cautiously, only lowering the blood pressure by perhaps 10-15% in the initial phase and not more than 25% over the next few days.
In terms of choice of medication for those without severe hypertension it has been well shown that ACE inhibitors plus diuretics as well as angiotensin receptor blockers are very safe medications for this indication.
For those with accelerated hypertension, that is blood pressure more than 220mm systolic and/or patients who have complications in their hypertension (such as headache, impaired consciousness or falling renal function), then perhaps a more aggressive strategy is warranted, but cautious lowering of blood pressure with an intravenous agent such as a nitrate or perhaps an intravenous dose of beta blocker may be effective.
Itís important to remember that treating hypertension is a lifelong experience rather than necessarily something that should be done in the first few days.