Orthostatic hypotension

WikiDoc Resources for Orthostatic hypotension
Articles
Most recent articles on Orthostatic hypotension Most cited articles on Orthostatic hypotension Review articles on Orthostatic hypotension Articles on Orthostatic hypotension in N Eng J Med, Lancet, BMJ
Media
Powerpoint slides on Orthostatic hypotension Images of Orthostatic hypotension Photos of Orthostatic hypotension Podcasts & MP3s on Orthostatic hypotension Videos on Orthostatic hypotension
Evidence Based Medicine
Cochrane Collaboration on Orthostatic hypotension Bandolier on Orthostatic hypotension TRIP on Orthostatic hypotension
Clinical Trials
Ongoing Trials on Orthostatic hypotension at Clinical Trials.gov Trial results on Orthostatic hypotension Clinical Trials on Orthostatic hypotension at Google
Guidelines / Policies / Govt
US National Guidelines Clearinghouse on Orthostatic hypotension NICE Guidance on Orthostatic hypotension NHS PRODIGY Guidance FDA on Orthostatic hypotension CDC on Orthostatic hypotension
Books
Books on Orthostatic hypotension
News
Orthostatic hypotension in the news Be alerted to news on Orthostatic hypotension News trends on Orthostatic hypotension
Commentary
Blogs on Orthostatic hypotension
Definitions
Definitions of Orthostatic hypotension
Patient Resources / Community
Patient resources on Orthostatic hypotension Discussion groups on Orthostatic hypotension Patient Handouts on Orthostatic hypotension Directions to Hospitals Treating Orthostatic hypotension Risk calculators and risk factors for Orthostatic hypotension
Healthcare Provider Resources
Symptoms of Orthostatic hypotension Causes & Risk Factors for Orthostatic hypotension Diagnostic studies for Orthostatic hypotension Treatment of Orthostatic hypotension
Continuing Medical Education (CME)
CME Programs on Orthostatic hypotension
International
Orthostatic hypotension en Espanol Orthostatic hypotension en Francais
Business
Orthostatic hypotension in the Marketplace Patents on Orthostatic hypotension
Experimental / Informatics
List of terms related to Orthostatic hypotension

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1] Associate Editor(s)-in-Chief: Sogand Goudarzi, MD [2]

Synonyms and keywords: Postural hypotension; orthostatic intolerance; head rush; dizzy spell

Overview

Orthostatic hypotension is a sudden fall in blood pressure, typically greater than 20/10 mm Hg, that occurs when a person assumes a more vertical postion such as from sitting to standing or from lying down to sitting or standing , usually after a prolonged period of rest.

Causes

Common Causes

Common causes of orthostatic hypotension may include:

• Medical conditions:
  • Pregnancy
  • Heart problems: Bradycardia, heart valve problems, heart attack and heart failure.
  • Dehydration: Fever, vomiting, severe diarrhea, overuse of diuretics and strenuous exercise can lead to dehydration.
  • Endocrine problems
  • Blood loss
  • Septicemia
  • Aanaphylaxis: reaction include foods, certain medications, insect venoms and latex.
  • Anemia: Lack of nutrients (vitamins B-12, folate)
• Medication:
  • Apomorphine hydrochloride
  • Bromocriptine
  • Cidofovir
  • Entacapone
  • Ethacrynic Acid
  • Fluphenazine
  • Hydrochlorothiazide
  • Iloperidone
  • Loxapine
  • Niacin
  • Pergolide
  • Perphenazine
  • Rasagiline
  • Risperidone
  • Ritonavir
  • Rotigotine
  • Thioridazine hydrochloride
  • Thiothixene,
  • Tiagabine
  • Vincristine sulfate liposome

• Orthostatic hypotension is primarily caused by gravity-induced blood pooling in the lower extremities, which in turn compromises venous return, resulting in decreased cardiac output and subsequently lowering of arterial pressure. For example, if a person changes from a lying position to standing, he or she will lose about 700 ml of blood from the thorax. It can also be noted that although there is a decreased systolic (contracting) blood pressure, there is actually an increased diastolic (resting) blood pressure. However, the overall effect is an insufficient blood perfusion in the upper part of the body.

• Still, the blood pressure does not normally fall very much, because it immediately triggers a vasoconstriction, pressing the blood up into the body again. Therefore, a secondary factor is required that, in turn, cause a fall in blood pressure greater than normal. Such factors include hypovolemia, associated disease states, pharmacotherapy, or, very rarely, safety harnesses.

• Drug side effects

• Apomorphine hydrochloride
• Bromocriptine
• Cidofovir
• Entacapone
• Ethacrynic Acid
• Fluphenazine
• Hydrochlorothiazide
• Iloperidone
• Loxapine
• Niacin
• Pergolide
• Perphenazine
• Rasagiline
• Risperidone
• Ritonavir
• Rotigotine
• Thioridazine hydrochloride
• Thiothixene,
• Tiagabine
• Vincristine sulfate liposome

Hypovolemia

Orthostatic hypotension may be caused by hypovolemia (a decreased amount of blood in the body), resulting from bleeding, the excessive use of diuretics, vasodilators, or other types of drugs, dehydration, or prolonged bed rest. It also occurs in people with anemia ,pregnancy in females and venous varicosities .Certain circulating endogenous vasodilators which causes hyperbardykinism and mastocytosis may also cause postural hypotension.

Diseases

The disorder may be associated with Addison's disease, atherosclerosis (build-up of fatty deposits in the arteries), amyloidosis, alcohol neuropathy, spinal cord disease, multiple sclerosis, multiple cerebral infarcts, Tabes Dorsalis, Syringomyelia, idiopathic orthostatic hypotension, diabetes, carcinoid syndrome, pheochromocytoma, and certain neurological disorders including Shy-Drager syndrome and other forms of dysautonomia. It is also associated with Ehlers-Danlos Syndrome

It is also present in many patients with Parkinson's Disease resulting from sympathetic denervation of the heart or as a side effect of dopaminomimetic therapy. This rarely leads to syncope unless the patient has developed true autonomic failure or has an unrelated cardiac problem.

Medication

Orthostatic hypotension can result from antihypertensive medicines such as diuretics especially furosemide, Lisinopril and Hydrochlorothiazide, Beta Blockers, Calcium channel blockers and ACE Inhibitors,Prazosin and Tamsulosin which is a drug for treatment of Benign prostatic hyperplasia. Nitrates have shown to cause side effects of postural hypotension. It can also be the side effect of certain anti-psychotics such as Clozapine, zotepine, Olanzapine, neuroleptics ,sedative hypnotics and anti-depressants, such as duloxetine, tricyclics or MAOIs. It is also a side effect of the short-term use of marijuana. like Nabilone. Dopamine agonists such as Pramipexole, and ropinirole can cause orthostatic hypotension.

Harnesses

The use of a safety harness can also contribute to orthostatic hypotension in the event of a fall. While a harness may safely rescue its user from a fall, the leg loops of a standard safety or climbing harness further restrict return blood flow from the legs to the heart, contributing to the decrease in blood pressure.

Risk Factors

Common risk factors in the development of orthostatic hypotension include:

• Age (y>65)
• Medications (alpha blockers)
• Disease: Parkinson's disease, diabetes
• Postpartum mothers
• Patients who have been on bedrest.

Natural History

• The symptoms of (disease name) usually develop in the first/ second/ third decade of life, and start with symptoms such as ___.
• The symptoms of (disease name) typically develop ___ years after exposure to ___.
• If left untreated, [#]% of patients with [disease name] may progress to develop [manifestation 1], [manifestation 2], and [manifestation 3].

Complications

Common complications of orthostatic hypotension include:

• Moderate low blood pressure:
  • Dizziness
  • Weakness
  • Fainting (increase risk of injury by falling down)
    
• Severely low blood pressure:
  • Heart damage (Heart failur)
  • Brian damage (Stroke)

Prognosis

• Prognosis is generally excellent/good/poor, and the 1/5/10-year mortality/survival rate of patients with [disease name] is approximately [--]%.
• Depending on the extent of the [tumor/disease progression] at the time of diagnosis, the prognosis may vary. However, the prognosis is generally regarded as poor/good/excellent.
• The presence of [characteristic of disease] is associated with a particularly [good/poor] prognosis among patients with [disease/malignancy].
• [Subtype of disease/malignancy] is associated with the most favorable prognosis.
• The prognosis varies with the [characteristic] of tumor; [subtype of disease/malignancy] have the most favorable prognosis.

Diagnosis

History and Symptoms

Symptoms, which generally occur after sudden standing, include dizziness, lightheadedness, headache, blurred or dimmed vision (possibly to the point of momentary blindness), and fainting. They are consequences of insufficient blood pressure and cerebral perfusion(blood supply).

---

---

Diagnostic

• The diagnosis of [disease name] is made when at least [number] of the following [number] diagnostic criteria are met:

• [criterion 1]
• [criterion 2]
• [criterion 3]
• [criterion 4]

Symptoms

• Symptoms of orthostatic hypotension may include the following:

• Generalized weakness,
• Fatigue
• Cognitive slowing
• Leg buckling
• Neck pain
• Localized headache (in the suboccipital, posterior cervical, and shoulder region)

Physical Examination

• Patients with orthostatic hypotension usually appear well, pallor and tiredness.
• Physical examination may be remarkable for:

• [finding 1]
• [finding 2]
• [finding 3]
• [finding 4]
• [finding 5]
• [finding 6]

Treatment

Medical Therapy

There are medications to treat hypotension. In addition, there are many lifestyle advices. Many of them, however, are specific for a certain cause of orthostatic hypotension.

Some drugs that are used in the treatment of orthostatic hypotension include fludrocortisone (Florinef), erythropoietin and midodrine. Pyridostigmine bromide (Mestinon) is now also used to treat orthostatic hypotension.

• Treatment of neurogenic orthostatic hypotension:
• Avoid triggers: large meals, hot bath, prolong standig

Lifestyle Advice

Some suggestions for minimizing the effects include:

• Checking blood pressure regularly with a home monitoring kit. Check when lying flat and when standing as well as when symptoms occur.
• Standing slowly rather than quickly, as the delay can give the blood vessels more time to constrict properly. This can help avoid incidents of syncope (fainting).
• Take a deep breath and flex your abdominal muscles while rising to maintain blood and oxygen in the brain. This, however, may be contraindicated in individuals with Stage 3 hypertension. Usually medical personnel have their patients "dangle" before rising from bed to decrease the likelihood of dizziness / falling due to orthostatic hypotension. The dangling is done by having the patient sit on the side of their bed for about a minute so they do not have the sudden dizziness.
• Maintaining an elevated salt intake, through sodium supplements or electrolyte-enriched drinks. A suggested value is 10 g per day; overuse can lead to hypertension and should be avoided.
• Maintaining a proper fluid intake to prevent the effects of dehydration.
• As eating lowers blood pressure, eat multiple smaller meals rather than fewer larger meals. Take extra care when standing after eating.
• When orthostatic hypotension is caused by hypovolemia due to medications, the disorder may be reversed by adjusting the dosage or by discontinuing the medication.
• When the condition is caused by prolonged bed rest, improvement may occur by sitting up with increasing frequency each day. In some cases, physical counterpressure such as elastic hose or whole-body inflatable suits may be required.

External Links

• John G. Bradley, M.D., and Kathy A. Davis, R.N. Orthostatic Hypotension American Family Physician
• DYNA Dysautonomia Youth Network of America, Inc.

Template:WikiDoc Sources