What is AD? – and I don’t mean Assistive Device

When someone says “AD” you think of an assistive device used for walking or functional activities. If your patient were to say “I’m having an AD episode” would you know what that means or what you should do? The topic of today is Autonomic Dysreflexia (AD).

So what exactly is AD if it’s not an assistive device? AD is a life-threatening emergency where the systolic and diastolic blood pressure rise in individuals with a spinal cord injury (SCI), usually at the level of T6 and above. AD occurs due to a noxious stimulus present in the body below the level of the lesion. For example, your patient has a T6 ASIA A SCI and has an ingrown toenail. Since this patient is an ASIA A, they cannot feel the ingrown toenail. The sympathetic nervous system gives a signal saying something is wrong and the pain stimuli from the toe is sent up the spinal cord towards the brain. However, there is a road block (think of it as a brick wall) at T6, so the pain transmission is stopped and the input cannot get to the brain for the patient to realize they are feeling pain. Since the sympathetic nervous system is stimulated, this causes the patient to experience high blood pressure, pounding headaches, visual changes, goose bumps, or paleness below the level of the lesion. There are receptors above the level of the lesions, called baroreceptors, that sense the rise in blood pressure and the parasympathetic nervous system is alerted. The brain sends a signal down the spinal cord, but once again, hits the road block at T6, so the effects of the sympathetic nervous system below the lesion cannot be counteracted.


Signs of AD

Above the level of the lesion your patient could experience any or all of the following:

  • HTN (high blood pressure)
  • Flushing
  • Sweating
  • Bradycardia
  • Pupillary constriction
  • Nasal congestion
  • Anxiousness
  • Blurred vision
  • Bi-temporal headache

Below the level of the lesion your patient could experience any or all of the following:

  • Pale, cool skin
  • Piloerection

***The patient could exhibit high blood pressure as their only symptom***

What causes AD

There are many triggers to AD. The most frequent trigger is bladder distention! Any of the below could cause an autonomic dysreflexia episode.

  • Bladder distention
  • Bowel impaction
  • Ingrown toenails
  • Pressure sores
  • Dressing changes
  • Enemas
  • DVT – SCI patients are at a high risk for DVTs to begin with
  • Extreme ROM
  • Orthostatic hypotension
  • Labor
  • Drug reactions
  • UTIs
  • Sexual intercourse
  • Tight clothing/shoes
  • Sunburns
  • Temperature fluctuations
  • Appendicitis
  • Electrical stimulation – use constant voltage instead of constant current and make sure the phase duration is increased.



What to do if your patient experiences AD

An autonomic dysreflexia episode, like stated earlier, is life threatening and immediate action should be taken. The #1 thing you must do is call 911! After 911 has been called, you should get the patient in sitting and remove any abdominal or lower extremity binders/ACE bandages to try to lower their blood pressure. Next, the catheter must be checked for any kinks. If the patient does not have an indwelling catheter, ask them when the last time they cathed. It is also important to ask the patient when their last bowel movement was to make sure they do not have an impacted bowel. The patient will then be taken to the ER and given medication to lower their blood pressure and monitored for at least 2 hours post-attack. It is imperative immediate action is taken when an individual has an AD episode. Though autonomic dysreflexia in itself usually is not fatal, secondary complication, such as heart attack or stroke can occur due to the elevated blood pressure.

***As a medical professional, it is my duty to educate the patient, family/caregiver, and other medical professionals on autonomic dysreflexia so action can be taken when it occurs.***


Vazquez-Morgan, Marie. (2017). Autonomic Dysreflexia. Lecture. LSUHSC – Shreveport, 13 March 2017.


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