Autonomic dysreflexia

AD:Acute syndrome of massive sympathetic discharge triggered by noxious stimulus in persons with SCI above the level of the sympathetic splanchnic outflow which usually couples with the spinal cord at T6.

Incidence:48% to 83% in tetraplegia and paraplegia

Mostly not in the first 2 months post injury

Cause: Blabber distension(most common)

Pressure sore

Bowel impaction

Ingrow toenails

Tight clothing or shoes

Leg bag strap

UTI

Ueterine contraction during delivery

Invasive procedure:

Bladder catheterization

Rectal stimulation

Cystometrography

ESWL

Pathomechanism:The triggering event produce impulses transmitted to

dorsal column and spinothlalamic tract

Due to the spinal lesion above the sympathetic outflow, inhibitory impulses cannot effectively descend in the sympathetic chain to block the autonomic response

The result is peripheral and splanchnic vasoconstriction and the development of acute hypertension, sweating, and piloerection

Symptoms and signs:With the increase in BP (severe paroxysmal

hypertension), the aortic arch and carotid sinus receptor are stimulated, which can result in reflex bradycardia and vasodilation above the level of the lesion

The vasodilation is manifested as headache, facial flushing, sweating, and nasal congestion

Differential diagnosis:Essential hypertension prior to injury

Pre-eclampsia in pregnant woman

Both are asymptomatic and nonepisodic

Complications:due to severe hypertensionConfusion

Visual disturbance

Loss of consciousness

Encephalopathy

ICH

Seizure

Electrocardiographic change

AF

Acute myocardial failure

Pulmonary edema

Management: The first action:upright sitting Frequently moniter BP and pulse Quick survey of cause and correct:

• Bladder distension• Rectal impaction• Tight clothing

Medication:• Rapid-onset short duration antihypertensive (nitrates, nifedipine, prazosin,

hydralazine, mecamylamine, and IV diazoxide)• 2% nitroglycerine ointment:1 inch skin above the lesion level• Acetaminophen:for headache

Recurrent AD treatment: Ganglionic blocking agent (guanethidine,

mecamylamine, and phenoxybenzamin) Newer alpha-adrenergic receptor blockers

(terazosin) Pudental nerve blocks, posterior rhizotomy, and

cordectomy:obliterate autonomic afferent imput

Prevention:Proper bladder and bowel management and skin

care

Education:Appropriate antihypertensive home medication

can be used in emergency

Teach the patient how to explain to medical personnel