Acute stroke /ICH/SAH/ Blood pressure is 210 /120 !
You are called in to control the BP . . . What will you do ?
Basics
Neurogenic HT is adrenergic dependent /stress related .It is often volume independent .Nitroglycerin worsens adrenergic hypertension by reflex tachycardia even though it may drop the initial BP .Sustained reduction won’t happen with NTG .Further , nitroglycerine is known to elevate the intra cranial pressure and worsen the stroke laden cortical / brain-stem ischemia
Best drugs
- Alpha methyl dopa
- Metoprolol
- Labetalol
Not best ( Worst ? )
- Nitroglycerine ( I guess most would disagree with this ! how dare you call NTG useless for controlling HT )*
- Calcium blocker (It is still useful for spasm prevention in SAH)
- Diuretics
* IV NTG is useful in some of these patients for a instant effect. However , It has a huge risk of raising intra- cranial pressure .
Final message
Control of neurgenic HT requires correction of the primary trigger namely the neural insult .The second best option is to stop the effects neural signal outflow .Adrenergic blockers are the best way to do it . All other drugs like calcium/Nitric oxide /diuretics are non specific and only provide a transient relief and may in fact aggravate sympathetic mediated hypertension.There is no harm in giving calcium blockers but it should always be accompanied by beta blockers to bring aggressive control .
Finally , controlling hypertension in stroke is to be done with frequent confabulations ! with neurologists , as blood pressure lowering modalities has a competing interest with brain perfusion !
Dr.S.Venkatesan MD 