Learning objectives

• Define and describe autonomic dysreflexia
• Recognize signs and symptoms of autonomic dysreflexia
• Manage patients with autonomic dysreflexia

Definition & mechanisms

• Autonomic dysreflexia is a condition that emerges after a spinal cord injury, usually when the damage has occurred above the T6 level
• Dysregulation of the autonomic nervous system leads to an uncoordinated sympathetic response that may result in a potentially life-threatening hypertensive episode when there is a noxious stimulus below the level of the spinal cord injury
• Noxious stimuli consist usually of bladder or bowel distension
• The higher the injury, the greater the severity of the cardiovascular dysfunction
• Significantly increased risk of stroke by 300% to 400%

Signs & symptoms

• Severe headache
• Hypertension
• Piloerection above the level of injury
• Bradycardia
• Facial flushing
• Pallor
• Cold skin
• Sweating in the lower part of the body
• Visual disturbances
• Constricted pupils
• Nasal stuffiness
• Anxiety or feelings of doom
• Nausea and vomiting
• Dizziness

Evaluation

• Identify patients at risk (injury above T6)
• Document baseline blood pressure 
• When severe headache occurs, measure blood pressure
• A systolic blood pressure >150 mmHg or >40 mmHg above baseline is indicative of autonomic dysreflexia

Anesthetic management

Suggested reading

• Allen KJ, Leslie SW. Autonomic Dysreflexia. [Updated 2022 Nov 28]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2022 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK482434/
• Petsas A, Drake J. Perioperative management for patients with a chronic spinal cord injury. BJA Education. 2015;15(3):123-30.