View source for Autonomic dysreflexia

==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)===
*[[urinary retention|Bladder distension]] ~80%
*Bowel distension, [[fecal impaction]] ~15%
*[[decubitus ulcers|Pressure ulcers]]

==Clinical Features==
''Possible to be asymptomatic''

*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)

===Unopposed PSNS above lesion===
*[[blurred vision|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 DDX}}

==Evaluation==

==Management==
''Hypertension should abate once offending agent corrected (normal = SBP 90-110 mmHg)''
#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
#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==
*[[Spinal Trauma (Main)]]

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

[[Category:Neurology]]