Autonomic dysreflexia (AD) is a sudden medical emergency characterized by an uncontrolled spike in blood pressure. This condition typically affects individuals with a spinal cord injury at the sixth thoracic vertebra (T6) or higher. The brain cannot properly regulate the sympathetic nervous system’s response to a stimulus below the injury level, causing blood pressure to rise rapidly. Immediate action is required to prevent severe complications, including stroke, seizure, and death.
Recognizing the Crisis and Immediate Steps
The onset of Autonomic Dysreflexia (AD) is marked by distinct physical signs. The most common symptom is a severe, pounding headache resulting from sudden hypertension, defined as a blood pressure elevation of 20 to 40 mm Hg above the person’s baseline. Individuals often experience profuse sweating and flushing of the skin above the level of the spinal cord injury, particularly on the face and neck. Other signs include nasal congestion and a feeling of anxiety.
Below the level of injury, the body exhibits signs of vasoconstriction, such as goosebumps, pallor, and cold skin. Once AD is suspected, two immediate actions must be taken to manage the rapidly rising blood pressure. First, immediately sit the individual upright or elevate the head of the bed. This allows gravity to pool blood in the lower extremities, helping to reduce blood pressure.
Simultaneously, loosen or remove any constrictive clothing, such as tight shoes, abdominal binders, or compression stockings. Blood pressure must be checked every two to five minutes to monitor the response to these initial interventions. After these steps, the next crucial phase is to begin a methodical search for the irritant that triggered the reaction.
Systematic Search for the Underlying Cause
The physiological trigger for an AD episode is always an irritating stimulus below the level of the spinal injury, most commonly originating in the bladder or bowel. Since bladder distension or irritation accounts for the majority of AD cases, the urinary system should be checked first. If an indwelling catheter is present, check its entire length for kinks, blockages, or folds that prevent urine drainage.
If the catheter appears blocked, attempt a gentle irrigation with a small amount of sterile water, or replace the catheter. For individuals using intermittent catheterization without a catheter in place, immediate catheterization is necessary to empty the bladder. When performing this procedure, use a generous amount of lubricating jelly containing a local anesthetic, such as 2% lidocaine, to prevent further stimulation.
If addressing the urinary system does not resolve the symptoms, check the bowel for fecal impaction or distension. A rectal examination may be performed to check for stool, but this must be done with extreme caution, as manipulation can intensify the AD episode. Apply an anesthetic lubricant to the rectum a few minutes before attempting any digital stimulation or manual evacuation.
If the bladder and bowel are ruled out, a systematic check of the skin and other systems is required. Inspect the body below the injury level for sources of irritation. These include:
- Pressure sores
- Ingrown toenails
- Burns
- Friction injuries from clothing
Less common triggers include menstrual cramps, sexual activity, acute infection, or changes in environmental temperature.
When to Seek Emergency Medical Treatment
While immediate steps and the systematic search resolve most AD episodes, specific situations require professional medical intervention. Emergency help is needed if the systolic blood pressure remains elevated (typically above 150 mm Hg), or if symptoms do not begin to resolve within 15 to 20 minutes of identifying and removing the trigger. A persistent, unmanaged hypertensive crisis carries risk of stroke or heart attack.
Individuals should call 911 or seek emergency medical services if the cause of the AD cannot be identified quickly or if blood pressure remains high despite corrective efforts. In a medical setting, pharmacological management with fast-acting blood pressure medications is initiated to rapidly decrease hypertension. Medications such as sublingual Nifedipine or Nitroglycerin paste are examples of fast-acting vasodilators that may be administered by a physician or prescribed for emergency use.
These medications lower blood pressure while the search for the trigger continues or when the trigger is known but cannot be immediately corrected. Once the episode is under control, the individual may require continued monitoring for several hours, as AD can recur. The use of any blood pressure medication for AD must be done under the explicit instruction and prescription of a healthcare provider.
Strategies for Preventing Recurrence
Preventing the recurrence of AD relies on meticulous daily health management to avoid common triggers. Strict adherence to scheduled bowel and bladder programs is the most effective preventative measure. This includes maintaining a consistent schedule for intermittent catheterization or ensuring proper function of indwelling catheters to prevent bladder distension, the most frequent cause of AD.
A regular, scheduled bowel regimen, often including dietary fiber and prescribed medication, helps prevent fecal impaction, the second most common trigger. Maintaining skin integrity is also important. This involves performing regular pressure relief maneuvers and conducting thorough daily skin checks to identify and address any pressure injuries or sores immediately.
The affected individual, family members, and all caregivers should receive education on the signs, symptoms, and management protocol for AD. Proactive communication with a healthcare team about any changes in health, such as signs of infection or new sources of irritation, can prevent a mild issue from escalating into a dysreflexic episode.