What is "Autonomic Dysreflexia?"

Autonomic dysreflexia is a syndrome
characterized by abrupt onset of excessively high blood pressure
caused by uncontrolled sympathetic nervous system discharge in
persons with spinal cord injury. Persons at risk for this problem
generally have injury levels above T-6. True autonomic
dysreflexia is potentially life-threatening and is considered a
medical emergency.

What are signs and symptoms of Autonomic
Dysreflexia?

• Hypertension (blood pressure greater than
  200/100)

• Pounding headache (secondary to hypertension/vasodilatation)

• Flushed (reddened) face (secondary to vasodilatation)

• Red blotches on the skin above
  level of spinal injury (secondary to vasodilatation)

• Sweating above level of spinal
  injury (secondary to vasodilatation)

• Nasal stuffiness (secondary to vasodilatation)

• Nausea (secondary to vagal
  parasympathetic stimulation)

• Bradycardia – slow pulse <60 beats per
  minute – (secondary to vagal parasympathetic stimulation)

• Piloerection ("goose bumps") below
  level of spinal injury

• Cold, clammy skin below level of
  spinal injury

What sort of things can precipitate this syndrome?

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 bladder wall
  • Urinary tract infection
  • Urinary retention
  • Blocked catheter
  • 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)

• Skin-related Disorders
  • Any direct irritant below the
    level of injury (eg. – prolonged pressure by
    object in shoe or chair, cut, bruise, abrasion)
  • Pressure sores (decubitus ulcer)
  • Ingrown toenails
  • Burns (eg. – sunburn, burns from
    using hot water)
  • Tight or restrictive clothing or
    pressure to skin from sitting on wrinkled
    clothing
• Sexual Activity
  • Over stimulation
    during sexual
    activity [stimuli to the pelvic region which
    would ordinarily be painful if sensation were
    present]
  • Menstrual cramps

• Labor and delivery

• Other
  • Heterotopic ossification
    ("Myositis ossificans",
    "Heterotopic bone")
  • Acute abdominal conditions
    (gastric ulcer, colitis, peritonitis)
  • Skeletal fractures

What can be done to manage an episode of autonomic
dysreflexia?

Principle #1 is to 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 digital
stimulation.

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.

What medical interventions are possible when removal of
noxious stimuli doesn’t end an episode of autonomic dysreflexia?

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:

• Immediate/emergent
  • Procardia – 10 mg. p.o./sublingual
  • Nitroglycerine – 1/150 sublingual
    or 1/2 inch Nitropaste topically
  • 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.

How can autonomic dysreflexia be prevented?

• Frequent pressure relief in bed/chair
• Avoidance of sun burn/scalds (avoid
  overexposure, use of #15 or greater sunscreen, watch
  water temperatures)
• Faithful adherence to bowel program (no
  longer than 3 days between bowel evacuations)
• Keep catheters clean and remain faithful
  to intermittent catheterization schedule
• 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 autonomic dysreflexia.