What we have learned about hypotension

[Guest guest]

There have been several posts on the list recently about hypotension and I thought I would share what we have learned about this vexing problem:

Neurally mediated orthostatic hypotension (a drop in blood pressure when standing caused by the nervous system, as opposed to other factors such as dehydration or cardiac problems) occurs when the autonomic nervous system fails to direct the brain to secrete hormones that expand and contract the blood vessels upon change in position. So basically, because of the failure of the autonomic nervous system to work properly, the blood is more susceptible to the effects of gravity. There are several possible treatments for this problem:

External pressure:

Jobst stockings (very tight, custom made stockings) act to exert pressure from the outside and prevent blood from pooling in the legs when standing, thus forcing more blood to go to the upper body, including the vital organs and brain. To work properly the stockings must be put on BEFORE standing up and only worn when up and about.

Exercise in the water is also excellent for people with orthostatic hypotension because the water exerts pressure from the outside and helps to keep blood from pooling in the lower extremities.

Medication:

There are two primary medications to treat hypotension, which are florinef and midodrine (also known as proamatine). These medications act in different ways and are often used together. Florinef acetate is a steroid and acts to increase blood volume by retaining water in the blood stream. In order to work properly it needs to be taken with salt (either Thermotabs buffered salt tablets, or bouillon will work) and lots of water. Florinef is long acting and takes a while to build up in the system, so it's actions are not immediate. Midodrine, by contrast, acts to contract the blood vessels. It is short acting, and generally lasts about 4 hours. Because it's action can increase blood pressure regardless of position, it should not be taken within 4 hours of lying down to avoid blood pressure going too high.

Elevating the head of the bed:

While at first this seems contrary, the reason doctors recommend raising the head of the bed also because of the failure of the autonomic nervous system to secrete chemicals -- this time the chemical that relaxes blood vessels. Many patients find that supine (lying down) blood pressure gets too high, thus increasing the risk of stroke. When the blood pressure becomes elevated, the kidneys work to "fix" the problem, by drawing water out of the blood stream. (This is one reason people with SDS/MSA have to get up so often at night to urinate.) For people with orthostatic hypotension, this means that when they get up in the morning their blood pressure will be even lower, because the kidneys have rid the blood stream of the water that is needed to maintain blood pressure at acceptable levels during the day. Raising the head of the bed helps keep blood pressure from going too high (that gravity thing again) thus also helps maintain higher blood pressure during the day because hydration is better maintained.

Water and food:

Good hydration is important because it helps to increase blood volume. The recommendation is to drink at least 2 liters of water a day, along with liberal consumption of salt. In addition, it's best to consume more frequent small meals rather than less frequent large ones, since the effort of digesting a large amount of food concentrates blood in the digestive system, thus causing blood pressure to fall. In the event that blood pressure gets too high, consuming carbohydrates or sugars can act to reduce it quickly. The rule of thumb is water to increase, carbs/sugar to decrease.

Position:

If a person with orthostatic hypotension feels dizzy or faint, the best thing to do is sit down or lie down quickly. Holding on to something or trying to support the patient in a upright position will not work, and may cause the patient and/or the caregiver to fall. Sometimes the patient can increase blood pressure when standing by raising up on his/her toes and or squatting down -- basically making the muscles act as a pump to force the blood to move out of the legs.

Exercise:

The best exercise is one that is gentle and steady. Exercise in the water is great because of the pressure of the water. Walking is good (assuming the person is steady enough to do it) and biking, because of the "crunched up" position is good too. If balance is a problem, a stationary bike can be used. Avoid becoming overheated, since this dilated blood vessels and causes blood pressure to drop. Avoid stopping exercise abruptly, since when exercising the blood flow to the large muscles is increased and stopping abruptly can also lower blood pressure (even for a healthy person).

Well gang, that's my brain dump. Hope it helps!

Carol & Rob

in sunny and beautiful Lexington, MA