Autonomic dysreflexia: Difference between revisions

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==Background==
==Background==
*Syndrome of massive imbalanced reflex sympathetic discharge from strong stimulus below level of spinal lesion
*Syndrome of massive imbalanced reflex sympathetic discharge from strong stimulus below level of spinal lesion
*Carotid and aortic baroreceptors result in strong vagal response with bradycardia and vasodilation above level of injury, but cannot inhibit sympathetics below level of injury - HTN remains dysregulated by the CNS
*Carotid and aortic baroreceptors result in strong vagal response with bradycardia and vasodilation above level of injury, but cannot inhibit sympathetics below level of injury - hypertension remains dysregulated by the CNS
*Occurring in patients with spinal cord injury (SCI) above the splanchnic sympathetic outflow (T5-T6)
*Occurring in patients with spinal cord injury (SCI) above the splanchnic sympathetic outflow (T5-T6)
*Splanchnic innervatoin from T5-T9
*Splanchnic innervation from T5-T9
*Lesions below T6 allow descending inhibitory PSNS control to decrease splanchnic tone, preventing HTN
*Lesions below T6 allow descending inhibitory PSNS control to decrease splanchnic tone, preventing hypertension
*Medical emergency given dangerous sequelae of elevated blood pressure
*Medical emergency given dangerous sequelae of elevated blood pressure


==Diagnosis==
===Common triggers (due to strong stimuli below level of injury)===
===History===
*Bladder distension ~80%
*Unopposed PSNS above lesion
*Bowel distension, fecal impaction ~15%
#Burry vision, miosis
*Pressure ulcers
#Headaches
#Anxiety
#Bradycardia associated with rises in BP
#Sweating, flushing
#Nasal congestion
*Unopposed SNS below lesion
#Pale, cool skin
#Piloerection, goose bumps
*Common triggers of autonomic dysreflexia due to strong stimuli below level of injury
**Bladder distension ~80%
**Bowel distension, fecal impaction ~15%
**Pressure ulcers


===Physical===
==Clinical Features==
#A sudden significant rise in systolic and diastolic blood pressures
''Possible to be asymptomatic''
##usually associated with bradycardia,
 
##SBP >140 mm Hg (in a patient with SCI above T6)
===Unopposed PSNS above lesion===
#profuse sweating/flushing above the level of lesion (especially in the face, neck, and shoulders)
*Blurry vision, miosis
#Possible to be asymptomatic
*[[Headaches]]
*[[Anxiety]]
*[[Bradycardia]] associated with rises in BP
*Profuse sweating/flushing (especially in the face, neck, and shoulders)
*Nasal congestion
 
===Unopposed SNS below lesion===
*Pale, cool skin
*Piloerection, goose bumps


==Differential Diagnosis==
==Differential Diagnosis==
{{Hypertension DDX}}
{{Hypertension DDX}}


==Treatment==
==Evaluation==
*HTN should abate once offending agent corrected - normal is SBP 90-110 mmHg
*A sudden significant rise in systolic and diastolic blood pressures
#Check urinary catheter for any blockage or twisting
**Usually associated with bradycardia
#If cath blocked, gently irrigate bladder with NS at body temp
**SBP >140 mm Hg (in a patient with SCI above T6)
#If cath is draining, suspect fecal impaction and check rectum for stool with lidocaine jelly lube - gentle disimpaction to follow
 
#Place in an upright position to allow gravitational pooling of blood to reduce BP
==Management==
#Careful inspection of nonsensate areas to identify the source of painful stimuli  
;hypertension should abate once offending agent corrected (normal = SBP 90-110 mmHg)
##(e.g. catheter, restrictive clothing, leg bag straps, abdominal supports, orthoses)
#Remove offending agent
*BP meds with SBP > 150, use short-acting since offending agent must be corrected; use with caution in CAD
#*Check urinary catheter for any blockage or twisting
**Nifedipine immediate release
#**If cath blocked, gently irrigate bladder with NS at body temp
**NTG paste or sublingual NTG
#**If cath is draining, suspect fecal impaction and check rectum for stool with lidocaine jelly lube - gentle disimpaction to follow
#*Careful inspection of nonsensate areas to identify the source of painful stimuli  
#**e.g. catheter, restrictive clothing, leg bag straps, abdominal supports, orthoses
#Directly lower blood pressure (if #1 fails)
#*Place in an upright position to allow gravitational pooling of blood to reduce BP
#*BP meds if SBP > 150
#**Use short-acting (since offending agent must be corrected); use with caution in CAD
#**[[Nifedipine]] immediate release
#**[[Nitroglycerine]] sublingual
 
==Disposition==
*Admission


==See Also==
==See Also==
[[Spinal Trauma (Main)]]
*[[Spinal Trauma (Main)]]
 
[[Category:Neuro]]


==References==
==References==
*Gunduz H, Binak DF. Autonomic dysreflexia: an important cardiovascular complication in spinal cord injury patients. Cardiol J. 2012;19(2):215-9.
*Gunduz H, Binak DF. Autonomic dysreflexia: an important cardiovascular complication in spinal cord injury patients. Cardiol J. 2012;19(2):215-9.
[[Category:Neurology]]

Revision as of 10:25, 30 July 2016

Background

  • Syndrome of massive imbalanced reflex sympathetic discharge from strong stimulus below level of spinal lesion
  • Carotid and aortic baroreceptors result in strong vagal response with bradycardia and vasodilation above level of injury, but cannot inhibit sympathetics below level of injury - hypertension remains dysregulated by the CNS
  • Occurring in patients with spinal cord injury (SCI) above the splanchnic sympathetic outflow (T5-T6)
  • Splanchnic innervation from T5-T9
  • Lesions below T6 allow descending inhibitory PSNS control to decrease splanchnic tone, preventing hypertension
  • Medical emergency given dangerous sequelae of elevated blood pressure

Common triggers (due to strong stimuli below level of injury)

  • Bladder distension ~80%
  • Bowel distension, fecal impaction ~15%
  • Pressure ulcers

Clinical Features

Possible to be asymptomatic

Unopposed PSNS above lesion

  • Blurry vision, miosis
  • Headaches
  • Anxiety
  • Bradycardia associated with rises in BP
  • Profuse sweating/flushing (especially in the face, neck, and shoulders)
  • Nasal congestion

Unopposed SNS below lesion

  • Pale, cool skin
  • Piloerection, goose bumps

Differential Diagnosis

Hypertension

Evaluation

  • A sudden significant rise in systolic and diastolic blood pressures
    • Usually associated with bradycardia
    • SBP >140 mm Hg (in a patient with SCI above T6)

Management

hypertension should abate once offending agent corrected (normal = SBP 90-110 mmHg)
  1. Remove offending agent
    • Check urinary catheter for any blockage or twisting
      • If cath blocked, gently irrigate bladder with NS at body temp
      • If cath is draining, suspect fecal impaction and check rectum for stool with lidocaine jelly lube - gentle disimpaction to follow
    • Careful inspection of nonsensate areas to identify the source of painful stimuli
      • e.g. catheter, restrictive clothing, leg bag straps, abdominal supports, orthoses
  2. Directly lower blood pressure (if #1 fails)
    • Place in an upright position to allow gravitational pooling of blood to reduce BP
    • BP meds if SBP > 150
      • Use short-acting (since offending agent must be corrected); use with caution in CAD
      • Nifedipine immediate release
      • Nitroglycerine sublingual

Disposition

  • Admission

See Also

References

  • Gunduz H, Binak DF. Autonomic dysreflexia: an important cardiovascular complication in spinal cord injury patients. Cardiol J. 2012;19(2):215-9.
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