What is autonomic dysreflexia?

Spinal cord injuries Levels have been quite common in recent centuries. It is seen more frequently in young men, and is usually the result of traffic accidents, although it varies greatly depending on the region of the world where it is analyzed.

Unfortunately, these injuries are quite delicate and the way they affect people will be determined by the region where they occurred.

A neck injury, where there is a high probability of quadriplegic, is not the same as an injury to your lumbar spine.

Autonomic dysreflexia is a frequent complication of spinal cord injuries originating above T6 (the sixth thoracic or dorsal vertebra, almost in the middle of your spine).

According to large studies, it is possible to say that between 50 and 90% of people suffering from this type of lesion (which varies according to the geographical area) will suffer from autonomic dysreflexia syndrome.

It is a complete syndrome characterized by several classic symptoms, where arterial hypertension stands out. In this case

there may be a 20% increase in basal systolic pressure (about 20-40mmHg above, in a normal or previously healthy person).

This increase in blood pressure is caused by nociceptive stimulation generated under the lesion, i.e.

any painful stimulus below T6 or D6. This will increase reflex sympathetic activity, which is uncontrolled in these patients, giving rise to an abrupt response that can be fatal.


How Does Autonomic dysreflexia Happen?


There is something called spinal/medullary shock, a complication that occurs just after the injury. It is characterized by transient depression of the reflexes below the lesion, with flaccid paralysis, involving absolutely all systems.

Depending on the magnitude of the lesion, this picture can extend up to weeks. Normally, it is reversed in a few months.

Let’s look at it this way. After the injury, its sympathetic system (the one in charge of important functions such as maintaining blood pressure, heart rate, part of the peristalsis, secretion of hormones, etc.) is turned off.

In other words, it will no longer transmit the impulse needed to perform the above-mentioned functions. The most important thing is that there is a predominance of the vagal system (part of the system opposite to the sympathetic one), which will cause hypotension and decrease the heart rate.

To counteract this, your body increases frequency and tension through general reflex responses that are mediated by other receptors and mechanisms.

However, when you begin to regain your “medullary automatism” (the ability to keep the sympathetic and parasympathetic system active) is when the problems begin.

Your body now reacts abnormally to painful stimuli, to which it previously reacted accordingly. In this case, any pain below the injury will greatly increase your heart rate and blood pressure. It is a chain reaction that will lead to the release of many hormones such as dopamine, norepinephrine, and epinephrine.

The only thing that stops us from dying instantly with such abrupt and dysregulated elevations is our brain. We can use special mechanisms to try to counteract the effect of this hormonal shock, although it is not always enough.


Autonomic dysreflexia Symptoms


Increased blood pressure and heart rate are not the only symptoms. Remember that this is a complete syndrome with a large release of hormones, so we can expect many important symptoms among which stand out:



-Nasal Obstruction

-Redness of the skin


The noxious stimuli that can trigger this response are not always related to what we mean by “painful stimuli”. It is possible that it is only bladder or rectal distension due to the accumulation of excretions that have not been released by the patient’s current condition. Even so, the range is quite open and can range from ejaculation (a non-pathological condition) to sepsis (a fatal generalized infection).


Autonomic dysreflexia Treatment


In terms of therapeutic management, the first measure, if you are lying down, is that you immediately sit with your legs in decline so that blood accumulates in the distal region of the lower limbs. In this way, blood pressure can be lowered in the rest of the body.

In addition, you should apply any secondary measures you have available to relax and soften the pressure on your body. For example, take off tight clothing, get out of hot places, don’t make any major movements, etc.

Another important point is to look for the trigger to eliminate it. For example, it may be a distension in the bladder or rectum, so it’s best to find a way to empty it (catheter or enema). Normally this is the most frequent cause, and the symptoms will be maintained until the stimulus ceases, so it is important to attack it quickly.

The symptom that we must treat without a doubt is hypertension. It is best to use antihypertensives that have a rapid effect when the systolic pressure exceeds 150 mmHg. In addition, although the cause has been determined and corrected, if the pressure does not decrease within 60 seconds of reaching 150 mmHg systolic pressure, hypertensive treatment must be maintained (or started).


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