[Therapy of hypertensive crises]

Hypertensive crisis is defined as an extreme elevation of arterial blood pressure, with diastolic pressure > 120 mm Hg, and represents an imminent risk to the patient. In such cases, a rapid orientating diagnosis and adequate antihypertensive treatment to avoid sequelae are needed, sometimes even before diagnostic tests are completed. Hypertensive emergencies and hypertensive urgencies can be distinguished. If the critical increase in blood pressure is associated with end-organ damage such as encephalopathy, acute left heart failure and pulmonary edema, angina pectoris, myocardial infarction or dissecting aortic aneurysm, a hypertensive emergency is present, that is an acute threat to the patient's life. A hypertensive emergency requires effective lowering of blood pressure within minutes, but not necessarily to normal range. The choice of suitable antihypertensive agents depends on clinical symptoms, contraindications, duration of pressure elevation and underlying conditions, prior cardiovascular, cerebrovascular and renal disorders. The risk of imminent end-organ damage must be weighed against the risk of rapid blood pressure lowering. In hypertensive urgencies without end-organ complications, blood pressure can be lowered more slowly over several hours, often with oral agents to avoid detrimental fall in blood pressure. The drugs of choice are mainly urapidil i.v. and nitroglycerine.