Hypertensive Crisis

If a patient has a systolic blood pressure >179 mmHg or a diastolic blood pressure >109 mmHg, that patient is having a hypertensive crisis.  If one of these lood pressure values are present in the absence of end-organ damage, this crisis is defined as a "hypertensive urgency".  However, as soon as end-organ damage occurs, the crisis is defined as a "hypertensive emergency". 

This definition is important.  If only an urgency, the blood pressure must be lowered over 24-48 hours.  If it is an emergency, the blood pressure must be lowered immediately with IV medications, but not to normal blood pressure levels.

So what is considered end-organ damage?  Pulmonary edema, renal failure, encephalopathy (often manifesting as headache or confusion), heart attack, aortic dissection, and acute vision changes can be classified as end-organ damage.

Reduce the diastolic blood pressure over 30-60 minutes to a level around 110 mmHg, but no lower than 10-15% of the highest DBP.  That is the general rule-of-thumb unless the patient has a dissection.  In the case of dissection, the SBP should be <120.