Orthostatic dehydration

Introduction Orthostatic hypotension, also known as orthotropy, is due to changes in body position, such as sudden changes from supine position to erect, or low blood pressure caused by insufficient blood supply to the brain. It is generally believed that post-stiction systolic blood pressure drops 20 mm Hg or a diastolic blood pressure drops 10 mm Hg, which is orthostatic hypotension.

Cause

Orthostatic hypotension is divided into two types: sudden and secondary. Sudden multiple due to autonomic dysfunction, caused by dysfunction of orthostatic arteriolar systolic dysfunction. The main performance is low blood pressure when standing upright, but also accompanied by unstable standing, blurred vision, dizziness, weakness, incontinence, etc. In severe cases, syncope may occur. Secondary is more common in spinal cord disease, acute infectious diseases or serious infections (such as lobar pneumonia), endocrine disorders, chronic malnutrition or the use of antihypertensive drugs, sedatives.

an examination

Related inspection

Blood pressure electrocardiogram

Orthostatic hypotension is a common disease in the elderly and children. According to statistics, the orthostatic hypotension of the elderly over 65 years old accounts for about 15%, and the elderly over 75 years old can be as high as 30% to 50%. In the elderly, due to the gradual hardening of the heart and vascular system, the elastic fibers of the large blood vessels are also reduced, and the sympathetic nerves are enhanced, which can increase the systolic blood pressure in the elderly. Long-term high blood pressure not only damages the sensitivity of the baroreceptor (located at the carotid artery), but also affects the compliance of the blood vessels and the ventricles. When the body position suddenly changes or takes antihypertensive drugs, the risk of ischemia increases greatly as the blood pressure suddenly drops.

In addition, the ability of the elderly to withstand hypovolemia is poor, and may be related to ventricular diastolic filling disorders. Therefore, any acute disease caused by excessive water loss, or lack of oral fluid, or after taking antihypertensive drugs and diuretics, as well as patients who usually have less activity and long-term bed rest, can easily cause orthostatic hypotension after standing.

Once orthostatic hypotension occurs, blood pressure in different positions should be measured repeatedly to confirm the diagnosis and symptomatic treatment to avoid adverse effects on the patient due to syncope.

Differential diagnosis

Physiological hypotension usually refers to those who are healthy, except for low blood pressure, the body has no other symptoms, the body organs are not ischemia or hypoxia, and there is no physical impact on the body.

Pathological hypotension can be divided into two categories, primary hypotension and secondary hypotension. Primary hypotension refers to hypotension, which is no cause, or physiological hypotension. Secondary hypotension refers to the decrease in blood pressure caused by organ diseases in the human body. Secondary hypotension is mostly rapid in a short period of time. Major bleeding, severe trauma, infection, allergies, and acute myocardial infarction can cause a sharp drop in blood pressure.

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