Autonomic Dysreflexia

Timing: after a T6 or higherr lesion
Loss of supraspinal control of Sympathetic NS
- Sinus Bradycardia – most common arrhythmia following SCI
- Orthostatic and Supine Hypotension – lack of sympathetic tone
- Autonomic Dysreflexia – unchecked visceral stimulation (lesions higher than T6)
  - Sympathetic dysregulation (stimulus in abdomen)
  - Autonomic dysreflexia is defined as an increase in systolic blood pressure of at least 20% associated with a change in heart rate and accompanied by at least one of the following signs (sweating, piloerection, facial flushing), or symptoms (headache, blurred vision, nasal congestion) due to a stimulus such as overdistended bladder or bowel impaction. Guidelines for treatment of autonomic dysreflexia include 1) patient immediately placed in a sitting position if the person is supine. 2) clothing or constrictive devices need to be loosened 3) troubleshoot etiologies for bladder distention or bowel impaction 4) a SBP >150 mmHg may need to be treated with nifedipine or nitrates 5) close monitoring of symptoms, blood pressure, and heart rate for at least 2 hours.
  - Presentation:
    - Bradycardia
    - Hypertension
    - Headache, agitation
  - Mx:
    - Put patient seated
    - Loosen all constrictive clothing
    - Troubleshoot etiologies
      - Bladder distention
      - Bowel impaction
      - Undiagnosed fracture – pathologically weak bones
      - infection
    - SBP >150 – nitrates
    - Monitor vitals at least 2 hours