Autonomic Dysreflexia
This material published in cooperation with the Paralyzed Veterans of America, Spinal Cord Injury Education and Training Foundation.
- DEFINITION:
- Autonomic dysreflexia (or hyperreflexia) is a complication which occurs in people with spinal cord injuries at or above the level of T6 (or rarely as low as T8). In other words, it can occur in all quadriplegics and in paraplegics who have loss of sensation at or above the lower rib cage. It apparently does not occur in any condition other than spinal cord injury (SCI), therefore most physicians have never heard of it. For a detailed description of the neuropathology see one of the references in the bibliography.
When Does Dysreflexia Begin?
The first episode of dysreflexia usually occurs within four to six months after SCI, but may be as early as two months or as late as 10-12 years. Unfortunately, with the short hospital stays these days, many individuals will be discharged from the hospital before the first episode. Even if they were told about dysreflexia in the hospital, they may not remember what they were told and don't recognize the symptoms.
How Often Does Dysreflexia Occur?
The frequency varies widely, from several times a day to once in several years. Some individuals seem to be very sensitive and every minor stimulus triggers dysreflexia. Others may only have dysreflexia with a major stimulus such as a markedly over filled bladder. Since the first episode can occur many years after the onset of SCI, everyone with an injury at or above T-6 must be considered at risk, even if they have not yet had dysreflexia.
SYMPTOMS:
Symptoms may vary considerably from one individual to another, from one episode to another and from moment to moment during the same episode. The symptoms may start off mild and gradually become more intense, or they may become very severe within the first one or two minutes.
- Mild Dysreflexia:
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- Sweating. The first sign is usually profuse sweating on the face and neck - that is, above the level of the injury.
- Mild Increase in Blood Pressure (Up to 140/90). Since the typical resting blood pressure (BP) for a quadriplegic is 90/60 (which is low normal), even a BP of 120/80 could suggest dysreflexia. Until the blood pressure reaches higher levels, the situation is not urgent, but it is important to try to identify and eliminate the cause before this happens.
- Severe Dysreflexia - A Medical Emergency !
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- Hypertension. When the BP reaches 200/100 or higher, it should be considered an emergency because the sudden change from very low to very high blood pressure can lead to convulsions, stroke, hemorrhage or even death. The BP can rise quickly during an episode of dysreflexia, so it is important to check the BP frequently, at least every 5-10 minutes until the cause has been found and eliminated.
- Pounding Headache. The headache is due to the sudden elevation of blood pressure; however, the severity of the headache is not necessarily related to the severity of the hypertension. Therefore, headache is not a reliable indicator of when the BP is dangerously high. A headache associated with normal blood pressure is not due to dysreflexia.
- Heart Rate Changes. The heart rate can either be very slow (bradycardia) or very fast (tachycardia) during an episode, so heart rate alone does not help to make the diagnosis.
- Flushing (Reddening) of the Face and Neck (above the level of SCI) associated with pale, cold skin on the trunk and extremities (below the SCI).
- Less Common symptoms include nasal congestion, anxiety, nausea, blurred vision, difficulty breathing, increased spasticity, chest pain and "goose bumps." However, these symptoms alone do not suggest dysreflexia.
TREATMENT:
- Eliminate the Cause ! ! !
- The most effective management is to identify and eliminate the cause as quickly as possible. This will usually result in immediate lowering of the blood pressure and a fairly prompt end to the sweating (see details below). No medication is indicated.
- Medication:
- If the BP is near 200, and the cause is not obvious, it is advisable to give medication to lower the BP to less dangerous levels while continuing to look for the cause of the dysreflexia. The most frequently used medication is Procardia (Nifedipine) 10 mg. by mouth. It should lower the blood pressure, but will not stop the sweating. If the BP remains high, Procardia can be repeated in 30-60 minutes.
CAUSES OF DYSREFLEXIA:
- Urinary - The most common cause is increased pressure in the bladder due to overfilling or bladder spasms. It may also be caused by inserting or irrigating a catheter, and urological procedures such as cystoscopy, urodynamics, etc.
- Bowel - The second most common cause is rectal distention due to constipation, inserting a supposi-tory, gas, "bloating," doing a rectal exam, digital stimulation for bowel movement, impaction, enema, etc.
- Skin - Anything below the level of the SCI that would be painful (if it could be felt) can trigger dysreflexia, including pressure sores, staying too long in one position, ingrown toenails, burns, etc.
- Less Common causes are tight clothing or shoes, tight leg bag straps, broken bones, ejaculation, uterine contractions associated with menstrual cramps, labor or delivery and excessive heat or cold.
- Strategy for Finding the Cause:
- Check the most likely causes first. The following sequence is suggested:
- Bladder - Be sure the bladder is not over-distended (too full) or having bladder spasms. If there is any doubt, it is better to catheterize to assure that the bladder is empty.
- Skin - Change patient's position to relieve skin pressure. Check for tight clothing.
- Rectum - Check for impaction.
- How Will You Know When the Cause Has Been Removed?
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- Sweating - The sweating will become less profuse or stop. However, in order to recognize this change, it is necessary to wipe off the sweat frequently to see if it comes back.
- Blood Pressure - There will usually be an imme- diate lowering of the BP. However, if it was very high, it may take an hour or more to return com- pletely to the usual resting BP.
CAUTION !
Autonomic dysreflexia is a potentially fatal condition when it is not correctly diagnosed and treated. Since most physicians have had little or no experience with people with spinal cord injuries, it is not surprising that the diagnosis is often missed. Therefore, it is essential for every person with SCI to know how to recognize and treat the condition. Even when an individual with SCI knows exactly what needs to be done, it may be difficult to convince Emergency Room personnel or physicians who are not familiar with SCI that the situation is urgent. For this reason a credit card-sized "Medical Alert" card has been developed by the Arkansas Spinal Cord Commission and is available from any Case Manager.
RECOMMENDATIONS:
Anyone who has a spinal cord injury at or above the level of T-6 should:
- Understand the signs, symptoms, causes and treatment of dysreflexia.
- Have equipment for taking blood pressure available and know how to use it.
- Keep a few tablets of Procardia on hand for emergencies (prescription needed).
- Keep a "Medical Alert" card handy at all times, especially when away from home.
- Be sure that all of their regular physicians have information about dysreflexia.
BIBLIOGRAPHY:
- "Autonomic Hyperreflexia Revisited." B.Y. Lee, M.G. Karmakar, B.L. Herz, R.A. Sturgill. Journal of Spinal Cord Medicine 18(2):75-87. 1995.
- "Autonomic Dysreflexia: A Potentially Fatal Complication of Somatic Stress in Quadriplegics." S. Givre, H.A. Freed. Journal of Emergency Medicine Vol. 7, pg. 461-463. 1989.
- "Autonomic Dysreflexia: A Survey of Current Treatment." R.L. Braddom, J.F. Rocco. American Journal of Physical Medicine & Rehabilitation Vol. 70, pg. 234-241. 1991.
- "Incidence and Clinical Features of Autonomic Dysreflexia in Patients with Spinal Cord Injury." R. Lindan, E. Joiner, A.A. Freehafer, C. Hazel. Paraplegia Vol. 18, pg. 285-292. 1980.
Anyone who is interested in more complete information about this condition may request any of the above articles from the Education and Research Center of the Arkansas Spinal Cord Commission.
- Developed by:
- Shirley McCluer, M.D., Medical Director of Arkansas Spinal Cord Commission.
- Date:
- October 3, 1995.
- Published by:
- The Arkansas Spinal Cord Commission, 1501 North University, Suite 470, Little Rock, AR 72207.
- Phone:
- (501) 296-1788 (voice) / 296-1794 (tdd)
For additional information, please see the following resources:
