Autonomic Dysreflexia
Key Points
- Autonomic dysreflexia is a medical emergency in patients with spinal cord injury above T6.
- Common triggers include bladder distension, bowel impaction/constipation, and restrictive clothing.
- Typical findings include severe headache, hypertension, bradycardia, flushing, and profuse sweating.
- Immediate management is trigger removal plus upright positioning while preserving safe body alignment.
Pathophysiology
Autonomic dysreflexia is an exaggerated autonomic reflex response that occurs when noxious stimuli below the level of a high spinal cord injury trigger uncontrolled sympathetic discharge. Because descending inhibitory signals are disrupted, severe hypertension and systemic instability can develop rapidly.
Bladder and bowel distension are common provoking stimuli, but external compression from tight clothing can also precipitate episodes.
Classification
- Bladder-triggered episode: Urinary retention or urinary-system irritation.
- Bowel-triggered episode: Constipation or impaction.
- External-triggered episode: Restrictive garments or other noxious peripheral stimuli.
Nursing Assessment
NCLEX Focus
In SCI above T6 with sudden severe headache and hypertension, treat as autonomic dysreflexia until proven otherwise.
- Assess for severe headache, hypertension, bradycardia, flushing, and diaphoresis.
- Assess recent bowel/bladder function and evaluate for retention or impaction.
- Assess for restrictive clothing or external triggers.
- Reassess neurologic and cardiopulmonary status continuously during the event.
Nursing Interventions
- Remove triggers immediately: loosen restrictive clothing and relieve bowel/bladder distension.
- Elevate the head of bed while maintaining correct alignment.
- Continue close blood-pressure and heart-rate monitoring until stabilization.
- Implement prevention plan: frequent GI/GU assessment, bowel/bladder training, skin protection, ROM activity, and DVT-prevention support.
- Reinforce bladder maintenance to reduce urinary infection risk, including regular emptying and prevention-focused hydration habits.
Hypertensive Emergency Risk
Delayed recognition and trigger removal can cause severe complications, including stroke and end-organ injury.
Pharmacology
| Drug Class | Examples | Key Nursing Considerations |
|---|---|---|
| Antihypertensives (acute episode context) | Protocol-dependent | Use after immediate trigger-removal actions if severe hypertension persists. |
Clinical Judgment Application
Clinical Scenario
A patient with chronic SCI above T6 develops sudden severe headache, flushing, BP surge, and bradycardia.
- Recognize Cues: Classic autonomic dysreflexia pattern.
- Analyze Cues: Likely noxious trigger below lesion level with uncontrolled sympathetic response.
- Prioritize Hypotheses: Immediate cardiovascular risk from severe hypertension.
- Generate Solutions: Sit patient up, remove triggers, and check bowel/bladder status urgently.
- Take Action: Perform trigger-directed interventions and continuous hemodynamic reassessment.
- Evaluate Outcomes: Blood pressure and symptoms improve after trigger resolution.
Related Concepts
- spinal-cord-injury - Underlying lesion context for autonomic dysreflexia risk.
- nursing-care-priorities-for-neuromuscular-impairment - Respiratory and skin-risk prevention in severe neurologic disability.
- bladder-assessment - Retention recognition and bladder-trigger prevention.
Self-Check
- Why is autonomic dysreflexia most associated with lesions above T6?
- Which action comes first when autonomic dysreflexia is suspected?
- Which recurrent triggers should be monitored in daily prevention planning?