Autonomic dysreflexia (AD) is a condition that can occur in
anyone who has a spinal cord injury at or above the T6 level. It
is related to disconnection's between the body below the injury
and the control mechanisms for blood pressure and heart
function. It causes the blood pressure to rise to potentially
Autonomic dysreflexia can be caused by a number of things. The most common causes
are a full bladder, bladder infection, severe constipation, or
pressure sores. Anything that would normally cause pain or
discomfort below the level of the spinal cord injury can trigger dysreflexia.
Autonomic dysreflexia can occur during medical tests or procedures and
need to be watched for.
The symptoms that occur with
Autonomic dysreflexia are directly related to the
types of responses that happen in the sympathetic and
parasympathetic nervous systems. Symptoms such as a pounding
headache, spots before the eyes, or blurred vision are the
direct result of the high blood pressure that occurs when blood
vessels below the injury constrict. The body responds by
dilating blood vessels above the injury, causing flushing of the
skin, sweating, and occasionally goosebumps. Some patients
describe nasal stuffiness and will feel very anxious.
Autonomic dysreflexia can cause a stroke if not treated.
The treatment for
Autonomic dysreflexia involves removing the reason for the
stimulation. One of the first things a patient can do is to sit
up. This naturally decreases blood pressure. If there is a
catheter in place, it should be checked to be certain that there
is not a kink in the tubing. If there is not a catheter in
place, the patient should be catheterized. The bowels should be
checked to be certain there is no stool in the rectum. If the
symptoms are caused by skin breakdown, the patient should get to
an emergency department as soon as possible.
The primary risk of
Autonomic dysreflexia is stroke. It is a potentially
life-threatening condition. If
Autonomic dysreflexia is left untreated, the body's
attempt to control blood pressure will severely decrease the
heart rate. This, combined with uncontrolled high blood
pressure, can be fatal. For this reason, it is very important to
treat this condition as soon as possible. The most important
thing patients can do to prevent
Autonomic dysreflexia from occurring is to take
good care of themselves. Patients should monitor bladder output
and should maintain a regular bowel program which fully empties
the bowels. They should also do regular skin checks to prevent
pressure sores from occurring.
Signs & Symptoms
Pounding headache (caused by the elevation in blood pressure)
Sweating above the level of injury
Blotching of the Skin
Hypertension (blood pressure greater than 200/100)
Flushed (reddened) face
Red blotches on the skin above level of spinal injury
Sweating above level of spinal injury
Slow pulse (< 60 beats per minute)
Cold, clammy skin below level of spinal injury
There can be many stimuli that cause autonomic dysreflexia.
Anything that would have been painful, uncomfortable, or
physically irritating before the injury may cause autonomic
dysreflexia after the injury.
The most common cause seems to be overfilling of the bladder.
This could be due to a blockage in the urinary drainage device,
bladder infection (cystitis), inadequate bladder emptying,
bladder spasms, or possibly stones in the bladder.
The second most common cause is a bowel that is full of stool or
gas. Any stimulus to the rectum, such as digital stimulation,
can trigger a reaction, leading to autonomic dysreflexia.
Other causes include skin irritations, wounds, pressure sores,
burns, broken bones, pregnancy, ingrown toenails, appendicitis,
and other medical complications.
In general, noxious stimuli (irritants, things which would
ordinarily cause pain) to areas of body below the level of
spinal injury. Things to consider include:
Bladder (most common) - from overstretch or irritation of
Urinary tract infection
Overfilled collection bag
Non-compliance with intermittent catheterization program
Bowel - over distention or irritation
Constipation / impaction
Distention during bowel program (digital stimulation)
Hemorrhoids or anal fissures
Infection or irritation (eg. appendicitis)
Any direct irritant below the level of injury (eg. - prolonged
pressure by object in shoe or chair, cut, bruise, abrasion)
Pressure sores (decubitus ulcer)
Burns (eg. - sunburn, burns from using hot water)
Tight or restrictive clothing or pressure to skin from sitting
on wrinkled clothing
Over stimulation during sexual activity [stimuli to the pelvic
region which would ordinarily be painful if sensation were
Labor and delivery
Heterotopic ossification ("Myositis ossificans", "Heterotopic
Acute abdominal conditions (gastric ulcer, colitis, peritonitis)
Treatment must be initiated quickly to prevent complications.
Remain in a sitting position, but do a pressure release
immediately. You may transfer yourself to bed, but always keep
your head elevated.
Since a full bladder is the most common cause, check the urinary
drainage system. If you have a Foley or suprapubic catheter,
check the following:
Is your drainage full?
Is there a kink in the tubing?
Is the drainage bag at a higher level than your bladder?
Is the catheter plugged?
After correcting an obvious problem, and if your catheter is not
draining within 2-3 minutes, your catheter must be changed
immediately. If you do not have a Foley or suprapubic catheter,
perform a catheterization and empty your bladder.
If your bladder has not triggered the episode of autonomic
dysreflexia, the cause may be your Bowel. Perform a digital
stimulation and empty your bowel. If you are performing a
digital stimulation when the symptoms first appear, stop the
procedure and resume after the symptoms subside.
If your bladder or bowel are not the cause, check to see if:
You have a pressure sore
You have an ingrown toenail
You have a fractured bone.
Identify and remove the offending stimulus whenever possible.
Often, this alone is successful in allowing the syndrome to
subside without need for pharmacological intervention. It is
also good for the person with the symptoms to be sitting up with
frequent blood pressure checks until the episode has resolved.
[In hospital-based settings or in high-risk individuals /
persons who have recurrent episodes, consideration should be
given having atropine at the bedside]
Suspected cause = bladder? Check catheter - remove kinks if
found, empty urinary collection bag, irrigate catheter. If
catheter is not draining, replace it immediately. If an
intermittent catheterization program is in place, a straight
catheterization should be performed immediately with (slow
drainage to prevent bladder spasms).
Suspected cause = bowel? If episode happens during digital
stimulation, stop stimulation until symptoms and signs subside.
Consider use of a prescribed anesthetic ointment to suppress the
noxious stimulus. If the issue is impacted stool, disimpact. If
it occurs while doing a bowel program in bed, try commode-based
bowel evacuation. Consider use of abdominal massage instead of
Suspected cause = skin? Loosen clothing. Check for source of
potential offending stimulus - check for pressure sores, toenail
problems, soles of the feet.
If symptoms persist despite interventions such as the foregoing,
notify a physician.
Medications are generally used only if the offending
trigger/stimulus cannot be identified and removed - or when an
episode persists even after removal of the suspected cause.
Potentially useful agents include:
Procardia - 10 mg. p.o./sublingual
Nitroglycerine - 1/150 sublingual or 1/2 inch Nitropaste
Clonidine - 0.1 to 0.2 mg. p.o.
Hydralazine - 10 to 20 mg. IM/IV
Chronic (recurrent episode prevention)
Prazosin ("Minipress") - 0.5 to 1.0 mg. daily
Clonidine ("Catapres") - 0.2 mg. p.o. b.i.d.
The following are precautions you can take which may prevent
Frequent pressure relief in bed/chair
Avoidance of sun burn/scalds (avoid overexposure, use of #15 or
greater sunscreen, watch water temperatures)
Maintain a regular bowel program.
Well balanced diet and adequate fluid intake
Compliance with medications
Persons at risk and those close to them should be educated in
the causes, signs and symptoms, first aid, and prevention of
If you have an indwelling catheter:
Keep the tubing free of kinks
Keep the drainage bags empty
Check daily for grits (deposits) inside of the catheter.
If you are on an intermittent catheterization program,
catheterize yourself as often as necessary to prevent
If you have spontaneous voiding, make sure you have an adequate
Carry an intermittent catheter kit when you are away from home.
Perform routine skin assessments.
If you are unable to find the stimulus causing autonomic
dysreflexia, or your attempts to receive the stimulus fail, you
need to obtain emergency medical treatment. Since all physicians
are not familiar with autonomic dysreflexia (hyperreflexia) and
its treatment, you should carry a card with you that describes
the condition and the treatment required.
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