What is Autonomic Dysreflexia?
Autonomic dysreflexia is a serious medical diagnosis that requires immediate treatment. This condition is common in patients with spinal cord injuries, especially when the thoracic nerves of the spine are involved. The overreaction of the autonomic nervous system can stimulate the onset of extreme hypertension, excessive sweating, changes in heart rate, etc. that can lead to devastating complications.
The Autonomic Nervous System harmonizes its subparts, the parasympathetic and sympathetic nervous systems. The parasympathetic nervous system functions to slow down bodily reactions while the sympathetic nervous system does otherwise. The combination of both subparts keeps the body’s functions in balance. When the human body feels threatened, it releases a rush of energy, our body’s natural response to threats.
Anything that can cause discomfort or pain can trigger the body to stimulate an episode of autonomic dysreflexia. The cause can be anything that the body considers bothersome below the level of injury. Due to the damage of the spinal nerves, sensory nerves cannot send a message to the brain effectively. The nerve miscommunication can cause a surge of messages to the brain leading to an excessive burst of nerve activity in the body.
The autonomic nervous system of a patient with autonomic dysreflexia is still intact, but it does not function like it used to. The noxious stimuli can cause exaggerated reflexes because of the sympathetic nervous system and can lead to the narrowing of the blood vessels below the site of injury, causing severe hypertension.
Causes of Autonomic Dysreflexia
Common triggers that can send the nervous system of patients with AD into overdrive are:
- Bladder issues- If the bladder is full, the first thing to check is if a kinked catheter causes bladder discomfort, urinary tract infection, bladder stones, or the catheter bag is full or not appropriately attached.
- Bowel issues– Constipation and other gastrointestinal problems such as stomach ulcers, gallstones, and gastritis can also trigger autonomic dysreflexia. Internal issues like Crohn’s disease, diverticulitis, hemorrhoids, and diarrhea could also be considered harmful irritants.
- Skin breakdown– Issues with the skin cover a wide area. It can be an itch that can’t be scratched, pressure sores, bruises, cuts, ingrown toenails, bone fractures, and burns. Tight clothes, socks, and shoes can also be a problem.
- Other causes include: Temperature changes in the environment, sexual intercourse, pregnancy and delivery, deep vein thrombosis, and anything that irritates can be an issue.
Signs and Symptoms of Autonomic Dysreflexia
- Pounding or severe headache
- There is flushing of skin on the area above the site of the spinal injury
- Profuse sweating
- Changes in vision
- Pale, clammy, and cool on the area below the site of the spinal cord injury
- Nasal stuffiness
How Autonomic Dysreflexia is Diagnosed
Diagnosis of Autonomic Dysreflexia is made through blood pressure assessment. Usually, if multiple symptoms are evident, blood pressure is being measured. Adult patients with spinal injuries from T6 and above have an average systolic BP of 90-110mmHg. When their systolic increases to 20-40mmHg, this could be a problem.
AD can also be suspected in patients with upper neuron motor injuries. An episode of autonomic dysreflexia can occur anytime in patients with a neurologic injury such as multiple sclerosis or stroke. Some neurological injuries are progressive, so the onset of AD is unknown until the patient reaches some point of the disease.
Treatments For Autonomic Dysreflexia
Medications for Autonomic Dysreflexia usually consist of antihypertensive drugs for a short duration and rapid onset of symptoms.
- Nitro paste- For topical application. ½” for patients 13 years old and below and 1” for 14 and above, to be applied every 30 minutes. Wash off the paste if blood pressure is back to normal to avoid hypotension.
- Nifedipine- is given sublingually if the nitro paste is unavailable. It may be administered every 30 minutes if needed. Give 0.25-0.5 mg/kg for patients 13 years old and below and 10mg per dose for 14 yrs old and above.
- Antihypertensives are given through IV. It is usually done in a closed control setting like the ICU since it requires constant monitoring
- Alternative medications used to treat autonomic dysreflexia included: Terazosin, Sildenafil, Captopril, and nitrates.
- The emergency goal treatment for AD is to lower the blood pressure as it occurs and to eliminate the stimulus that triggers it.
- If the patient has a history of spinal cord injury, always assess and monitor the blood pressure.
- If the patient is showing symptoms of AD, let them sit upright immediately with their hips and torso at a 90-degree angle. The sudden change in position from lying to sitting can cause orthostatic hypotension that can lower the patient’s BP.
- Investigate the source of the trigger. Start with the three main causes: bowel, bladder and skin. Check the flow of urine. If the patient has little to no urine output, catheterize if necessary. Then assess for a bowel blockage. Disimpact the bowel to remove stool. Check the skin for breakdown, remove irritants, and make sure clothes are not tight.