Orthostatic Hypotension
The definition of orthostatic hypotension
When someone stood up from sitting or lying down, the body must work to adapt to change that position. It is especially important for the body to push the blood upward and supplies the brain with oxygen. If the body fails to do this with pretty, blood pressure fell / fall, and that person may feel dizzy or even fainting. Orthostatic hypotension is a term used to describe the fall in blood pressure when a person stands up (orthostatic = upright posture, hypo = less + tension = pressure).
Adequate blood supply to the organs of the body depends on three factors:
1. strong enough heart to pump,
2. arteries and veins that are able to constrict or narrow, and
3. enough blood and fluid in the vessels.
When the body change position, diversity of actions occur that involve all parts of the cardiovascular system and autonomic nervous system (autonomic nervous system) that help regulate their function.
Autonomic nervous system can be considered of the body, regulate body processes that we take as a given. There is a balance between the sympathetic system (adrenergic nerves), which speed up various things, and the parasympathetic system (cholinergic nerves) that slows down many things. These names are based on the type of chemicals used to send signals to nerve endings.
* Adrenaline (of the sympathetic nervous system) allows the body to respond to stress. Imagine seeing a bear in the woods; throb faster your heart, your palms sweaty, your eyes dilate, and your hairs stand on end.
* Acetylcholine is a chemical that is anti-adrenaline and engage the parasympathetic nervous system.
Both these systems are in balance, and still need to respond to changes in the body that occur regularly throughout the day.
* When the body moves to a standing position, monitors pressure (baroreceptor cells) located in the carotid arteries and aorta feel the subtle fall in blood pressure due to gravity, which causes blood flow to the legs.
* Almost immediately, sympathetic system is stimulated, causing increased heart rate, heart muscle to contract or squeeze more powerful, and the blood vessels constrict or narrow.
* All of these actions serve to increase blood pressure so that a sufficient amount of blood can still be pumped to the brain and other organs.
* Without these changes, gravity will cause the blood still on Baian the bottom of the body and away from the brain, causing symptoms of dizziness or even fainting.
Orthostatic hypotension is not a disease or complaint from an individual: it is an abnormal change in blood pressure and heart rate associated with the disease.
Causes of orthostatic hypotension
Orthostatic hypotension has many potential causes, some affect only one part of the system that supplies blood to the brain, and others affect two or three.
Loss of fluid in the blood vessels are the most common reason for developing symptoms of orthostatic hypotension. The liquid may be water or blood depending on the cause.
* Dehydration occurs when fluid intake can not match the amount of fluid lost by the body. Vomiting, diarrhea, fever, and diseases associated with heat (for example, heat exhaustion or heat stroke) is common causes someone to lose a significant amount of fluid. Diuretics or water pills used to control high blood pressure is also another cause of the reduced amount of fluid in the body.
* Blood loss and other causes of anemia reduces the number of red blood cells that transports oxygen in the bloodstream, and this may lead to symptoms of orthostatic hypotension. Bleeding may arise from a single large event or may occur slowly over a period of time. With a slow bleeding, the body may be able to compensate, replace the lost volume of red blood cells with water in the bloodstream. However, a moment later loss of blood oxygen-carrying capacity will cause the symptoms to develop. In addition to dizziness, giddiness, there may be weakness, shortness of breath, or chest pain.
* Medications that affect the autonomic nervous system may also cause orthostatic hypotension.
* Drug-Obar Beta blockers such as metoprolol (Inderal) blocking the beta-adrenergic receptors in the body, preventing the heart becomes more rapid, preventing the heart contracting with great force, and raise the blood vessels. All three of these effects affect the body's ability to react to the change-perubahn position. Besides high blood pressure and heart disease, these medications are also used for headache control and prevention of terror.
* Sildenafil (Viagra), vardenafil (Levitra) and tadalafil (Cialis) expand the blood vessels, and this class of drugs may cause orthostatic hypotension. The effect can be magnified if taken with nitrates, be used medications to treat angina [for example, nitroglycerin (Nitrostat, Nitroquick, Nitrolingual, Nitro-Dur, Minitran, Nitro-Bid, and others), isosorbide mononitrate (Imdur, Ismo, Monoket )], alcohol, or narcotic pain medications.
* Other medications used to control high blood pressure may be a potential cause of orthostatic hypotension, even if taken as prescribed.
* Orthostatic hypotension is a side effect of many psychiatric drugs, including tricyclic antidepressants [amitriptyline (Endep, Elavil), nortriptyline (Pamelor, Aventyl), phenothiazines (Thorazine, Mellaril, Compazine), and MAO inhibitors (Nardil, Parnate)
Vasovagal episode is a condition that may occur when a stimulus causes an excessive activation of the parasympathetic system, slowing the heart rate and raise / dilate blood vessels. Symptoms of dizziness or fainting then occurs which is caused by decreased blood pressure and reduced blood flow to the brain. The stimulus may be the pain of injuries such as broken bones, or there may be psychological triggers, such as a medical student who was looking at the first operation. Vagus nerve which causes this response may also in some cases triggered by urination (micturition syncope) or by pressing hard time defecating.
Patients with diabetes may develop peripheral neuropathy that may affect the nerves of the autonomic nervous system, and as a result, may develop orthostatic hypotension. Likewise, patients with poorly controlled diabetes have the potential to become too dehydrated (lack of fluids).
Some patients may develop post-prandial lightheadedness, which means that these symptoms occur after a heavy meal (a lot). In this case, the body dilate blood vessels to the stomach and intestines to aid digestion, leaving less blood available to flow to the brain.
Addison's disease, or adrenal insufficiency, may also be associated with the body's inability to compensate for changes in position.
There is a diversity of causes of heart disease may cause orthostatic hypotension. Abnormalities of electrical conduction system, including pulse, heart rate is too slow or too fast (cardiac arrhythmia) may cause changes in blood pressure. Patients with heart valve diseases, heart failure, and heart attacks may all have orthostatic hypotension.
Diseases of the nervous system may also cause orthostatic hypotension. Examples include Parkinsonism, amyloidosis, and Shy-Drager Syndrome (or multiple system atrophy).
Postural orthostatic tachycardia syndrome describes the feelings of dizziness, nausea, fatigue, and weakness associated with an increased heart rate (greater than 120 beats per minute) that began within 10 minutes of heads-up tilt table test. Often seen in women younger between the ages of 12 and 50 years, and there may be a relationship with chronic fatigue syndrome.
Risk factors for orthostatic hypotension
Orthostatic hypotension is most common in the elderly. "Hardening of the arteries" or atherosclerosis that develops as we age to make blood vessels more difficult to adapt quickly when needed. Likewise, many of the diseases associated with orthostatic hypotension is progressive, with symptoms worsen with age.
Pregnancy associated with orthostatic hypotension. As the pregnancy progresses, the volume of the circulatory system and blood pressure tends to swell to fall. This may lead to dizziness when standing quickly. Blood pressure levels returned to normal after birth.
Excessive sweating is caused by physical exertion and heat exposure on the risk factors and potential causes of dehydration and symptoms of orthostatic hypotension. Patients who have other risk factors for developing orthostatic hypotension had an increased risk if they become dehydrated even with the light.
Chronic use of alcohol and drug abuse are also risk factors for developing symptoms of hypotension orhostatik.
Symptoms of orthostatic hypotension
When the brain is not getting enough blood supply, he began to drop its function.
Symptoms include:
* Dizziness,
* Confusion,
* Nausea, and
* Fainted.
There may also be a weakness, blurred vision, and tremble
These symptoms may disappear quickly when the body is slowly adjusting to a standing position, but in some cases the patient must sit or lie down quickly to prevent fainting.
When should I call my doctor for orthostatic hypotension (orthostatic hypotension)
Feeling faint or dizzy is not normal. While the rare episodes that can be explained by the circumstances, such as work or exercise in the heat, may be ignored, the events should be investigated more seing.
If someone is unconscious and unaware, even for short periods of time, is never normal and should be accessible medical care.
Diagnose orthostatic hypotension
The key to diagnosis is the history and physical examination is good. The doctor will want to know the circumstances associated with symptoms of dizziness or fainting, because patients may not have measured their blood pressure and check their pulse rates in the middle of episodes.
The symptoms tend to be transient (temporary) and disappears quickly. If there is concern that the vital signs will change the position of premises, the doctor will measure blood pressure in both the lying and standing position and looking for changes.
According to the American Academy of Neurology, the formal diagnosis of orthostatic hypotension requires a fall of 20mm in systolic blood pressure or a fall of 10mm in diastolic blood pressure within three minutes of standing. Often there is an associated increase in cardiac pulse, especially if dehydration or bleeding is the cause (if the patient is taking beta blockers, heart pulse may not be able to respond with an increase).
Blood tests may be ordered to find the underlying cause. This may include the number of red blood cells or red blood cell count (CBC) to assess for anemia or bleeding. Electrolytes may be checked, especially if it has any history of loss of fluid through vomiting or diarrhea, because of abnormalities of sodium and potassium may be the problem. Kidney function may be accessed (assessed).
If physical examination reveals concerns about the heart, an electrocardiogram (EKG) may be performed to evaluate the electrical conduction and cardiac rhythm. Echocardiogram or ultrasound of the heart may be ordered to evaluate heart valves and assess the functioning of the heart muscle. Stress tests may be considered if there is concern about coronary artery disease.
Heads-up tilt table test may be ordered if the symptoms of orthostatic hypotension constantly over and over but has become difficult to documenting abnormalities in blood pressure readings. During the test, the patient was tied flat on a table, and when the table was gradually tilted to an angle of 70 or 80 degrees, blood pressure readings and heart pulse continuously taken. Patients may be left on the table for more than 10 minutes to find the pending changes seen in postural orthostatic tachycardia syndrome.
For many patients, the diagnosis may be made based on history and physical examination, and no further testing may be required.
Treatment for orthostatic hypotension
The treatment for orthostatic hypotension depends on the underlying diagnosis. If caused is dehydration, so fluid replacement will eliminate the symptoms. If it is caused by the medication, the dosage adjustments or changes to the type of drugs taken may be required.
Compression stockings may be considered to help prevent fluid from gathering in the legs when a person is sitting or lying down. This allows more blood flow available to the brain when the changes in position occur.
The drugs may be useful, again depending on the underlying cause of orthostatic hypotension. For those who are otherwise healthy and have no specific disease to be treated, salt and fluid intake increases may be recommended. Caffeine and nonsteroidal antiinflammatory drugs for example, ibuprofen may also be suggested.
Some patients may be candidates for fludrocortisone (Florinef) to increase the volume of fluid in blood vessels. This medication has side effects are significant, including the levels of magnesium and potassium in the blood decreased, headache, swollen, and gained weight.
What are the complications of orthostatic hypotension
Falling is the most important complication of orthostatic hypotension. Most often, these symptoms are transient (temporary) and lost his own, giving the patient a chance to sit down, but when the fall in blood pressure lead to syncope (fainting) or near-fainting, is a trauma that is supported in the fall cause the most damage.
Preventing Hypotension Orthosatik
Since dehydration is the most common cause of orthostatic hypotension, is important to minimize risk by maintaining adequate fluid. This is especially important if the individual's work or exercise in hot environments. Fluid loss from vomiting, diarrhea, and other diseases associated with fever should be replaced as possible.
Patients who are taking new medications that may affect the autonomic nervous system should be aware of the potential for orthostatic hypotension and report any symptoms to their doctors.
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