The significance of maintaining relatively stable arterial blood pressure, including the following aspects: 1, blood pressure is stable to ensure effective blood supply and oxygen supply to brain tissue, a drop in blood pressure will lead to a drop in blood supply and oxygen supply to brain tissue, causing dizziness, nausea, vomiting and other symptoms, which can lead to cerebral infarction in severe cases, stable blood pressure can also increase tissue perfusion, improve peripheral blood circulation, and improve terminal hypoxia. 2, the kidney requirements for blood pressure are also relatively high, relatively stable blood pressure, can maintain effective renal blood flow, conducive to urine excretion, to prevent water and sodium retention.3, stable blood pressure, especially diastolic blood pressure, can increase coronary artery blood supply, if the coronary artery perfusion pressure is insufficient, will also cause the corresponding myocardial cells ischemia, hypoxia, in serious cases, can lead to angina pectoris, or the occurrence of myocardial infarction. In the case of relative or absolute insufficiency of blood volume, it is more important to maintain the stability of arterial blood pressure, which should be actively expanded and rehydrated, and if necessary, intravenous application of antihypertensive drugs to prevent the emergence of shock.