What is autonomic dysreflexia?
- over activity of autonomic nervous sys
- massive imbalance in reflex of sympathetic discharge
- unique to spinal cord T5-T6
- is an emergency
Pathophysiology of AD?
- SCI pts are normally hypotensive, but with activation of AD (irritating/painful stimulus below the level of injury)-->
- nerve impulses block by SCI.
- peripheral artery hypertension due to sympathetic surge causing vasoconstriction.
- Impulses cannot reach brain,
- Baroreceptors slow hb, blood vessels dilate above level of injury
- No messages are received below the level of injury, therefore the blood pressure cannot be regulated
Epidemiology of AD
- After spinal shock
- more common if injury traumatic
- Less likely as injury heals (old injuries), but if does manifest may have unusually symptoms.
- Younger age groups report less incidences
- mostly male phenomenon because men are stupid.
- Rare, but can happen as low as T10 (usually pregnant women)
SnSs of AD
- pounding headache
- nasal congestion
- red blotches of the skin above level of SCI
- Brady card
- Hypertension--> ^ 20-40mmHg over baseline (adult), 12-20 adolescent
- Goose pumps below SCI.
- Sweating above
- Flushed red face
- cold, clammy skin below SCI.
Causes of AD after spinal cord injury
- Painful, noxious stimuli below level of injury, usually bladder
- bowel, ie gall stones
- Sexual activity
- Others, i.e. skeletal fractures or internal organ issues.
Complications associated with AD?
- Seizures (gran Mal)
- Cerebral hemorrhage
- retinal hemorrhage
- Cardiac arrest
- If pt had an AD card, LOOK AT IT!!!
Tx for AD?
- must be initiated quickly to prevent complications
- 1) Check BP and elevate head if necessary
- 2) loosen constrictive clothing
- 3) Work to identify the source of stimulus (bladder?)
Medication Tx for AD?
- Check for use of Viagra, Levitra, or Cialis in last 48 hrs.
- Nitrobid. Has short half-life so can be taken off quickly.
- Nitroglycerin, spray has short half life (1-4 mins)
- May use Procardia (has long half-life, difficult to reverse), Clonidine (causes confusion), Hydrazine as last resort.
Big take away points of AD?
- Pts have good education on AD, so listen to them.
- Focus on eliminating the cause/treating BP because...
- ...THERE IS ALWAYS A CAUSE.
- IS A MEDICAL EMERGENCY.