Editing CUA: Neurogenic Lower Urinary Tract Dysfunction (2019) (section)

== Autonomic Dysreflexia ==

=== Causes ===
*'''<span style="color:#ff0000">Typically occurs in patients with an injury at level T6 or above'''
* '''<span style="color:#ff0000">Caused by an exaggerated sympathetic nervous system response triggered by either a noxious or non-noxious stimulus originating below the level of the SCI'''

=== Diagnosis and Evaluation ===
*'''<span style="color:#ff0000">Signs and Symptoms (5):'''
*# '''<span style="color:#ff0000">Acute onset hypertension'''
*# '''<span style="color:#ff0000">Reflex bradycardia'''
*# '''<span style="color:#ff0000">Sweating'''
*# '''<span style="color:#ff0000">Headache'''
*# '''<span style="color:#ff0000">Flushing above the level of the spinal cord lesion'''
** '''If BP is > 120 mmHg and patient is symptomatic, presumed autonomic dysreflexia is present'''
***'''The normal BP in para and quadriplegics is low, usually 90-110 mmHg systolic. Elevation with autonomic dysreflexia symptoms classically begin with a 20 mmHg rise above baseline, well within normal range for a neurologic intact individual.'''

=== Management ===
* '''<span style="color:#ff0000">An emergency in patients who have had a spinal cord injury'''
* '''<span style="color:#ff0000">Initial therapy should focus on the removal of inciting factors (e.g. emptying of the bladder and removal of all urodynamic catheters in an SCI patient experiencing autonomic dysreflexia during UDS)'''
* '''<span style="color:#ff0000">If symptoms persist and systolic pressure remains'''
**'''<span style="color:#ff0000">< 150 mmHg, then evaluation for and treatment of fecal impaction, the second most common cause of AD after the bladder, is recommended.'''
** '''<span style="color:#ff0000">> 150 mmHg after bladder emptying and catheter removal, then use of a rapid-onset, short-acting antihypertensive is recommended while the cause of AD is investigated.'''
*** '''<span style="color:#ff0000">Nitroglycerin'''
****'''<span style="color:#ff0000">First-line drugs in the outpatient setting'''
*****'''<span style="color:#ff0000">Nitropaste 2% (preferred)'''
******'''<span style="color:#ff0000">Applied 0.5-1 inch above the level of the lesion (vasoconstriction occurs below the level of the lesion and may interfere with the drugs absorption)'''  
******'''<span style="color:#ff0000">Preferred due to its ability to be wiped free if rebound hypotension occurs''' 
*****'''Nitroglycerin 0.4 mg sublingually'''
**** '''<span style="color:#ff0000">Must make sure the patient has not used a PDE-5 inhibitor for erectile dysfunction in the past 24 hours,</span>''' due to concern for rebound hypotension.
***** If a sildenafil agent has been used within 24 hours, Captopril 25 mg chewed or given sublingually becomes the drug of choice.
*** Nifedipine 
****Used to be recommended as primary treatment or prophylactic agent for AD
****Because of several adverse, rebound hypotensive crisis resulting in stroke or MI after its use, the Joint commission for treatment of High Blood Pressure and National Spinal Cord Injury committees have discouraged its use and it has been banned for treatment or prevention of autonomic dysreflexia in some hospitals
* '''If the blood pressure remains elevated and does not respond to oral therapy I.V. hydralazine is an option'''
**Patient will require hospital admission with further monitoring as BP may be quite labile after use of I.V. hydralazine with both hypotension and/or rebound hypertension
* '''In the outpatient setting, when autonomic dysreflexia is triggered and successfully treated, patient should be monitored for resumption of hypertension for a minimum of two hours'''. 
**If AD recurs, hospitalization with monitoring for 24 hours is recommended, if not, the patient can be discharged from the outpatient setting.

=== Prevention ===

*'''Recommendations to prevent autonomic dysreflexia preceding cystoscopy or urodynamic evaluations'''
**Terazosin 5 mg the night before the exam
**Prazosin 1 mg the night before the exam
**Tamsulosin 0.8 mg the night before the exam
**At the time of the exam place Nitropaste 2% .5 inch (if not on sildenafil)
**Captopril 25 mg sublingually 10-15 minutes prior to exam.
* Recent data suggests that intravesical injection of onabotulintoxinA decreases the frequency and severity of AD episodes.