Spinal Cord Injury and Autonomic Dysreflexia

Medical-Surgical · Neurology·Updated 2026-10-28

What it is

Spinal cord injury interrupts motor, sensory and autonomic pathways below the level of damage. Injury at C3 to C5 threatens the diaphragm, and injury at T6 or above removes brain control of sympathetic outflow below the lesion, causing neurogenic shock early after injury. Later, a noxious stimulus below the injury (most often a distended bladder) triggers uncontrolled reflex vasoconstriction and severe hypertension, called autonomic dysreflexia. The body above the injury responds with bradycardia, flushing and sweating, but inhibitory signals cannot cross the lesion, so the trigger must be found and removed.

What the NCLEX focuses on

Acute injury: keep the spine aligned, open the airway with a jaw thrust, and logroll the client.
Cervical injury: monitor respiratory rate, cough strength, vital capacity and SpO2; a falling vital capacity or weakening cough signals impending respiratory failure.
Spinal shock: temporary flaccid paralysis, absent reflexes and loss of bowel and bladder function below the injury; it ends as reflexes return.
Neurogenic shock: hypotension, bradycardia and warm, dry skin from lost sympathetic tone; treated with fluids, vasopressors and atropine for symptomatic bradycardia.
Autonomic dysreflexia: sudden severe hypertension, pounding headache, bradycardia, flushing and sweating above the injury, pale cool skin below it, nasal congestion and blurred vision.
Triggers: bladder distention or a kinked catheter (most common), fecal impaction, pressure injury, tight clothing and ingrown toenails.
Long-term care: pressure injury prevention, a bowel and bladder program, venous thromboembolism prophylaxis and halo vest safety.

Priority nursing actions

Sit the client upright and lower the legs.
Loosen clothing, abdominal binders and leg bag straps.
Check the bladder: look for a kinked or blocked catheter, or catheterize using an anesthetic lubricant.
Check for fecal impaction using an anesthetic lubricant, then inspect the skin for pressure or injury.
Check blood pressure every 2 to 5 minutes and give the prescribed rapid-acting antihypertensive if systolic pressure stays at 150 mm Hg or higher.
Notify the provider and document the episode, the trigger and the response.

Numbers to know

Value	Finding or target	Why it matters
Injury level for autonomic dysreflexia and neurogenic shock	T6 or above	Sympathetic outflow below the lesion loses brain control
Injury level that threatens breathing	C3 to C5	The phrenic nerve supplies the diaphragm
Blood pressure in autonomic dysreflexia	Systolic 20 to 40 mm Hg above baseline	Baseline is often low, so a normal-looking reading can already be dysreflexia
Antihypertensive threshold	Systolic 150 mm Hg or higher after the trigger is sought	Prevents hypertensive stroke and seizures
Blood pressure checks during an episode	Every 2 to 5 minutes	Pressure falls quickly once the trigger is removed
MAP after acute injury	85 to 90 mm Hg for the first 7 days	Maintains spinal cord perfusion

Common exam traps

Choosing to lay the client flat or raise the legs during autonomic dysreflexia: wrong because sitting upright lowers blood pressure by pooling blood in the legs.
Choosing an antihypertensive before sitting the client up and checking the bladder: wrong because removing the trigger is the definitive treatment.
Choosing to notify the provider and wait for orders: wrong because the nurse acts at once to find and remove the cause.
Choosing hemorrhagic shock for hypotension with a heart rate of 46/min after cervical injury: wrong because hypovolemia causes tachycardia; bradycardia with warm, dry skin is neurogenic shock.

What to teach

Prevent dysreflexia: keep the catheter draining, follow the bowel schedule, check the skin, wear loose clothing and carry an autonomic dysreflexia emergency card.
At a pounding headache or flushing: sit up, loosen clothing, check the bladder and bowel, and call 911 if symptoms do not resolve.
Shift weight in the wheelchair every 15 to 30 minutes and inspect the skin twice daily with a mirror.
Halo vest: keep the wrench taped to the vest, never remove the vest, and perform pin-site care as prescribed.

Try 2 NCLEX-style questions on this topic

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Question 1 · QID 32F65B53

A client with a C7 spinal cord injury suddenly reports a pounding headache. Blood pressure is 208/110 mm Hg, heart rate 52/min; the face is flushed and sweaty while the legs are pale and cool. Which action should the nurse take FIRST?

A. Raise the head of the bed fully upright
B. Administer the prescribed rapid-acting antihypertensive before changing position so the blood pressure begins falling as quickly as possible
C. Place the client supine with the legs elevated to maintain cerebral perfusion while the cause of the blood pressure elevation is investigated
D. Notify the provider immediately and wait for specific treatment orders before repositioning the client or investigating possible triggers

Question 2 · QID EF38DCBB

For each finding in a client with a new cervical spinal cord injury, click to specify the condition it best reflects.

	Spinal shock	Neurogenic shock
Flaccid paralysis with absent reflexes below the injury level
Blood pressure 82/50 mm Hg with heart rate 46/min
Warm, dry extremities despite hypotension
Absent bulbocavernosus reflex in the first days after injury
A temporary state that resolves as reflexes gradually return

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Sources

Harding MM, Kwong J, Hagler D, Reinisch C. Lewis's Medical-Surgical Nursing: Assessment and Management of Clinical Problems. 12th ed. Elsevier; 2023; Chapter: Spinal Cord and Peripheral Nerve Problems.
Consortium for Spinal Cord Medicine. Evaluation and Management of Autonomic Dysreflexia and Other Autonomic Dysfunctions: Preventing the Highest Immediate Risks Following Spinal Cord Injury. Clinical Practice Guideline for Health Care Providers. Paralyzed Veterans of America; 2020.
Walters BC, Hadley MN, Hurlbert RJ, et al. Guidelines for the management of acute cervical spine and spinal cord injuries: 2013 update. Neurosurgery. 2013;60(Suppl 1):82-91.

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