An individual with a spinal cord injury at or above T6 presents with an acute onset of signs and symptoms of autonomic dysreflexia.
- Recognize the signs and symptoms of autonomic dysreflexia, including:
- Elevated blood pressure.
- Pounding headache.
- Bradycardia (may be a relative slowing so that the
heart rate is still within the normal range).
- Profuse sweating above the level of the lesion,
especially in the face, neck, and shoulders, or possibly below the level of
the lesion.
- Piloerection or goose bumps above or possibly below the
level of the lesion.
- Cardiac arrhythmias, atrial fibrillation, premature
ventricular contractions, and atrioventricular conduction abnormalities.
- Flushing of the skin above the level of the lesion,
especially in the face, neck, and shoulders, or possibly below the level of
lesion.
- Blurred vision.
- Appearance of spots in the patient's visual fields.
- Nasal congestion.
- Feelings of apprehension or anxiety over an impending
physical problem.
- Minimal or no symptoms, despite a significantly elevated blood pressure (silent autonomic dysreflexia).
(Scientific evidence-None; Grade of recommendation-Expert consensus; Strength of panel opinion-Strong)
An individual may have one or more of these signs and symptoms when experiencing an episode of autonomic dysreflexia. Symptoms may be minimal or even absent, despite an elevated blood pressure.
Health-care providers should be aware that the varying cognitive and verbal communication abilities of adults, children, and adolescents can cause the symptoms of autonomic dysreflexia to be absent, subtle, vague, or expressed imperfectly. Because of the varying cognitive and verbal communication abilities of individuals as they progress through infancy, childhood, and adolescence, symptoms of autonomic dysreflexia may not be expressed or may be communicated in a less articulate manner compared to a cognitively intact adult with spinal cord injury. For instance, preschool-aged children, even though they are verbal, may present with vague complaints; they are not able to accurately articulate that they are experiencing a pounding headache-a cardinal feature of autonomic dysreflexia.
- Check the individual's blood pressure.
- A sudden, significant increase in both the systolic and
diastolic blood pressure above their usual levels, frequently associated with
bradycardia. An individual with spinal cord injury above T6 often has a normal
systolic blood pressure in the 90-110 mm Hg range. Therefore, a blood pressure
of 20 mm to 40 mm Hg above baseline may be a sign of autonomic dysreflexia.
- Systolic blood pressure elevations more than 15-20 mm
Hg above baseline in adolescents with spinal cord injury or more than 15 mm Hg
above baseline in children with spinal cord injury may be a sign of autonomic
dysreflexia.
(Scientific evidence-III/V; Grade of recommendation-C; Strength of panel opinion-Strong)
Elevated blood pressures can be life-threatening and need immediate investigation and treatment. For children and adolescents, age and body size are determinants of normal blood pressures, with increasing blood pressures advancing with age and approximating adult norms in older teenagers. Similar to adults with spinal cord injury, children and adolescents with cervical and upper thoracic spinal cord injury would be expected to have lower baseline blood pressures compared to the general population. Therefore, it is important to determine and document baseline blood pressures on an annual basis or as needed, as the child or adolescent with spinal cord injury ages. For the purposes of these guidelines, the panel agreed that systolic blood pressures at or above 150 mm Hg in adults, 120 mm Hg in children under 5 years old, 130 mm Hg in children 6-12 years old, and 140 mm Hg in adolescents is when pharmacological agents should be considered.
Be calm and maintain a reassuring environment in the presence of the child's parents/caregiver when obtaining blood pressures. Any anxiety associated with obtaining blood pressures in children and adolescents may make it difficult to obtain accurate measurements both for baseline determinations as well as during an episode of autonomic dysreflexia. Teaching parents how to obtain blood pressures or having school nurses obtain baseline blood pressures may be beneficial. It is important that all health-care professionals remain calm and maintain a relaxing atmosphere.
Use appropriately sized blood pressure cuffs when measuring blood pressure in children and adolescents. The width of the blood pressure cuff should be approximately 40 percent of the arm circumference, measured midway between the olecranon and the acromion. The cuff bladder will cover 80 to 100 percent of the circumference of the arm. A blood pressure cuff that is too small may result in an overestimation of the individual's blood pressure. In contrast, a blood pressure cuff that is too large may result in an underestimation of the blood pressure, which is less than the error of overestimation with a cuff that is too small. If an appropriately sized blood pressure cuff is not available, interpretation of the blood pressure is complicated. However, it is important for the health-care professional or caregiver to remember that small blood pressure cuffs tend to overestimate and large cuffs tend to underestimate the true blood pressure.
- If a pregnant woman with a spinal cord injury at T6 or above presents with signs and symptoms of autonomic dysreflexia, consider referral to an obstetric health-care provider under the following circumstances:
- Determination of choice of antihypertensive medication.
- Persistent hypertension after resolution of the acute
autonomic dysreflexia episode.
- Persistent symptoms of autonomic dysreflexia despite
acute care measures.
- Life-threatening autonomic dysreflexia.
- Autonomic dysreflexia episode occurring in the third
trimester of pregnancy.
- Hypotension requiring pharmacological treatment.
- First episode of autonomic dysreflexia during the
pregnancy.
- Presence of vaginal bleeding or suspicion of labor.
- Decisions to be made about long-term medication use.
- Unclear about the causes, signs, and symptoms, despite
a normal blood pressure.
(Scientific evidence-None; Grade of recommendation- Expert consensus; Strength of panel opinion-Strong)
Care of pregnant women with autonomic dysreflexia should take into account that, due to compression of the vena cava, hypotension may occur if the woman is in supine position. A lateral tilt or upright position facilitates resolution of the hypotension and improves uterine flow.
- If signs or symptoms of autonomic dysreflexia are present, but the blood pressure is not elevated and the cause has not been identified, refer the individual to an appropriate consultant depending on symptoms.
(Scientific evidence-None; Grade of recommendation-Expert consensus; Strength of panel opinion-Strong)
Other medical problems may be causing the signs and symptoms of autonomic dysreflexia.
- If the blood pressure is elevated, immediately sit the person up if the individual is supine.
(Scientific evidence-III/V; Grade of recommendation-C; Strength of panel opinion-Strong)
Performing this maneuver may allow a pooling of blood in the lower extremities and may reduce the blood pressure. If possible, in addition to sitting the person up, lower their legs as well.
- Loosen any clothing or constrictive devices.
(Scientific evidence-III/V; Grade of recommendation-C; Strength of panel opinion-Strong)
Performing this maneuver may allow a pooling of blood in the abdomen and lower extremities and may reduce the blood pressure.
- Monitor the blood pressure and pulse frequently.
(Scientific evidence-III/V; Grade of recommendation-C; Strength of panel opinion-Strong)
Blood pressures have the potential of fluctuating quickly during an autonomic dysreflexia episode. Therefore, pressures need to be monitored every few minutes (every 2 to 5 minutes is commonly cited), until the individual is stabilized. Individuals with spinal cord injury usually have impaired autonomic regulation, and therefore blood pressures can rapidly fluctuate.
- Quickly survey the individual for the instigating causes, beginning with the urinary system.
(Scientific evidence-III/V; Grade of recommendation-C; Strength of panel opinion-Strong)
The most common cause of autonomic dysreflexia is bladder distension.
- If an indwelling urinary catheter is not in place, catheterize the individual.
(Scientific evidence-None; Grade of recommendation-Expert consensus; Strength of panel opinion-Strong)
The most common cause of autonomic dysreflexia is bladder distension.
- Prior to inserting the catheter, instill 2 percent lidocaine jelly (if immediately available) into the urethra and wait 2 minutes, if possible.
(Scientific evidence-None; Grade of recommendation-Expert consensus; Strength of panel opinion-Strong)
Catheterization can exacerbate autonomic dysreflexia. The use of lidocaine jelly may decrease the sensory input and relax the sphincter to facilitate catheterization. The peak effect of lidocaine jelly is between 2-5 minutes. Exercise clinical judgment regarding elevated blood pressure; immediate catheterization may be necessary.
- If the individual has an indwelling urinary catheter, check the system along its entire length for kinks, folds, constrictions, or
obstructions and for correct placement. If a problem is found, correct it
immediately.
(Scientific evidence-None; Grade of recommendation-Expert consensus; Strength of panel opinion-Strong)
- If the catheter appears to be blocked, gently irrigate the bladder with a small amount (10-15 cc) of fluid, such as normal saline at body temperature. Irrigation should be limited to 5-10 ml for children under 2
years of age and to 10-15 ml in older children and adolescents. Avoid manually compressing or tapping on the bladder.
(Scientific evidence-None; Grade of recommendation-Expert consensus; Strength of panel opinion-Strong)
Use of a larger volume or of a cold solution might irritate the bladder and exacerbate autonomic dysreflexia. If a lidocaine solution is readily available, irrigation with it may be beneficial by decreasing sensory input from the bladder. Bladder pressure or tapping may also increase sensory input and exacerbate autonomic dysreflexia. Do not continue to irrigate the bladder if the fluid is not draining.
- If the catheter is draining and the blood pressure remains elevated, proceed to recommendation 18.
(Scientific evidence-None; Grade of recommendation-Expert consensus; Strength of panel opinion--Strong)
- If the catheter is not draining and the blood pressure remains elevated, remove and replace the catheter.
(Scientific evidence-None; Grade of recommendation-Expert consensus; Strength of panel opinion--Strong)
Irrigating and changing the catheter should be done as quickly as possible. Pharmacologic management may become necessary if the blood pressure remains elevated and/or if catheter placement is difficult. Refer to Recommendation 19 and its accompanying rationale for guidance on pharmacologic management.
- Prior to replacing the catheter, instill 2 percent lidocaine jelly (if immediately available) into the urethra and wait 2 minutes, if possible.
(Scientific evidence-None; Grade of recommendation-Expert consensus; Strength of panel opinion-Strong)
Catheterization can exacerbate autonomic dysreflexia. The use of lidocaine jelly may decrease the sensory input and relax the sphincter to facilitate catheterization. The peak effect of lidocaine jelly is between 2-5 minutes. Exercise clinical judgment regarding elevated blood pressure and the use of lidocaine; immediate catheterization may be necessary.
- If difficulties arise in replacing the catheter, consider attempting to pass a coude catheter or consult a urologist.
(Scientific evidence-None; Grade of recommendation-Expert consensus; Strength of panel opinion-Strong)
A coude catheter may be useful if there is an associated bladder neck obstruction.
- Monitor the individual's blood pressure during bladder drainage.
(Scientific evidence-None; Grade of recommendation-Expert consensus; Strength of panel opinion-Strong)
Sudden decompression of a large volume of urine would be expected to normalize blood pressure. However, this may cause hypotension if the individual has already been given pharmacological agents to decrease the blood pressure. (See Recommendation 21.)
- If acute symptoms of autonomic dysreflexia persist, including a sustained elevated blood pressure, suspect fecal impaction.
(Scientific evidence-II/V; Grade of recommendation-B/C; Strength of panel opinion-Strong)
Fecal impaction is the second most common cause of autonomic dysreflexia.
- If the elevated blood pressure is at or above 150 mm Hg systolic, consider pharmacologic management to reduce the systolic blood pressure without causing hypotension prior to checking for fecal impaction.
(Scientific evidence-None; Grade of recommendation-Expert consensus; Strength of panel opinion--Strong)
If the blood pressure remains elevated but is less than 150 mm Hg systolic, proceed to recommendation 22.
(Scientific evidence-V; Grade of recommendation-C; Strength of panel opinion-Strong)
Reviewer opinion varied on whether the next step should be investigating other causes (e.g., fecal impaction) or initiating pharmacologic management. The control of hypertension may need to be addressed prior to digital stimulation or other diagnostic maneuvers, which may exacerbate autonomic dysreflexia. This is true for nonpregnant adults, pregnant women, and children and adolescents, as well.
There are no studies showing the exact point at which blood pressure becomes dangerous. For this recommendation, the guideline panel decided to adopt 150 mm Hg systolic blood pressure as the value at which pharmacological treatment should be considered. An adult with an injury at or above T6 would be expected to have a baseline systolic blood pressure between 90 and 110 mm Hg.
Pharmacological management of autonomic dysreflexia in children and adolescents should be considered prior to checking for fecal impaction if the blood pressure is excessively elevated for the child's or adolescent's age and height. Knowing the child's baseline blood pressure is very important when deciding whether to intervene with antihypertensive medications. Indications for pharmacological intervention may include a systolic blood pressure of 120 mm Hg in infants and younger children (under 5 years old), 130 mm Hg in older children (6-12 years old), and 140 mm Hg in adolescents.
- Use an antihypertensive agent with rapid onset and short duration while the causes are being investigated.
(Scientific evidence-V; Grade of recommendation-C; Strength of panel opinion-Strong)
Nifedipine and nitrates are the most commonly used agents. If nifedipine is used, it should be in the immediate-release form. Bite-and-swallow is the preferred method of administration. Sublingual nifedipine administration may lead to erratic absorption.
Nifedipine should be used with extreme caution in elderly people or in people with coronary artery disease. In individuals without spinal cord injury, immediate-release nifedipine has been reported to cause shunting of the blood away from the heart and reflex tachycardia, and to result in an uncontrollable fall in blood pressure.
A review of the literature from 1966 through December 2000 reveals that there have been no reported adverse effects from the use of nifedipine when used to treat autonomic dysreflexia. Nifedipine has been discussed in the literature as a prophylactic treatment for autonomic dysreflexia. Other drugs that have been used to treat autonomic dysreflexia with severe symptoms include hydralazine, mecamylamine, diazoxide, and phenoxybenzamine. In an appropriately monitored setting, the guideline panel supports the use of an intravenous drip of sodium nitroprusside for rapid titration of blood pressure. If 2 percent nitroglycerin ointment is used, 1 inch may be applied to the skin, above the level of spinal cord injury. There are no studies reporting on the best agent to use.
There is increasing use of sildenafil in those with spinal cord injury. The use of medications containing nitrates is contraindicated when a person has taken sildenafil. Medications containing nitrates are sometimes used for the treatment of acute autonomic dysreflexia. Prior to the use of nitrates, such as nitroglycerin, isosorbide dinitrate, or sodium nitroprusside, a person with spinal cord injury presenting with acute autonomic dysreflexia should be questioned regarding sildenafil. If this agent has been used within the last 24 hours it is recommended that an alternative short-acting, rapid-onset antihypertensive agent be used.
Examples of agents with such characteristics are prazosin and captopril. Both have an onset within thirty minutes, achieve peak serum levels within 1-3 hours, and have elimination rate half-lives of 2-4 hours.
- Monitor the individual for symptomatic hypotension
.
(Scientific evidence-None; Grade of recommendation-Expert consensus; Strength of panel opinion-Strong)
Treat severe (symptomatic) hypotension by laying the individual down and elevating the legs. Additional corrective measures are not usually required. However, if indicated, consider intravenous fluids and adrenergic agonists (i.e., in a monitored setting, intravenous norepinephrine for reversal of severe hypotensive events).
- If fecal impaction is suspected and the elevated blood pressure is less than 150 mm Hg, check the rectum for stool, using the following procedure:
- With a gloved hand, instill a topical anesthetic agent,
such as 2 percent lidocaine jelly, generously into the rectum.
- Wait 2 minutes if possible for sensation in the area to
decrease.
- Then, with a gloved hand, insert a lubricated finger
into the rectum and check for the presence of stool. If present, gently
remove, if possible.
- If autonomic dysreflexia becomes worse, stop the manual evacuation. Instill additional topical anesthetic and recheck the rectum for the presence of stool after approximately 20 minutes.
(Scientific evidence-II/V; Grade of recommendation-B/C; Strength of panel opinion-Strong)
A rectal examination may exacerbate autonomic dysreflexia. Instillation of a local anesthetic agent may decrease the occurrence of autonomic dysreflexia during the exam.
- If the precipitating cause of the autonomic dysreflexia episode has not yet been determined, check for less frequent causes. The individual may need to be admitted to the hospital; see recommendation 25 for considerations.
(Scientific evidence-None; Grade of recommendation-Expert consensus; Strength of panel opinion--Strong)
As the most common causes of autonomic dysreflexia are related to bladder and bowel problems, further assessment may need to include more advance diagnostic procedures. For example, cystoscopies or urodynamic studies may detect urinary system pathology or dysfunction.
Other causes of autonomic dysreflexia need to be investigated appropriate treatment and to resolve the episode.
- Following an episode of autonomic dysreflexia, instruct the individual to monitor symptoms and blood pressure for at least 2 hours after resolution of the episode to make sure that it does not reoccur.
- Educate the individual to seek immediate medical
attention if it reoccurs.
- Monitor inpatients closely for at least 2 hours, as
deemed necessary by the health-care provider.
- Seek the pregnant woman's obstetrical-care provider for evaluation.
(Scientific evidence-None; Grade of recommendation-Expert consensus; Strength of panel opinion-Strong)
The hypertension and symptoms may have resolved because of the medication rather than the treatment of the cause. Symptoms managed by pharmacologic treatment may begin to reverse themselves within this time frame.
- Consider admitting the individual to the hospital for monitoring to maintain pharmacologic control of the blood pressure, and to investigate other causes:
- If there is poor response to the treatment specified
above.
- If the cause has not been identified.
- If there is suspicion of an obstetrical complication.
(Scientific evidence-V; Grade of recommendation-C; Strength of panel opinion-Strong)
Because of the loss of sensation, individuals with spinal cord injury can have significant pathology with minimal symptoms. These may include problems such as acute abdominal pathology, long bone fractures, and ingrown toenails. Individuals with spinal cord injury frequently may have a positive urine culture. However, this may not be the precipitating cause for autonomic dysreflexia, and therefore other causes of autonomic dysreflexia should be investigated.
- Document the episode in the individual's medical record, including:
- Presenting signs and symptoms and their course.
- Treatment instituted.
- Recordings of blood pressure and pulse.
- Response to treatment.
Evaluate the effectiveness of the treatment according to the level of outcome criteria reached:
- Cause of the episode has been identified.
- Blood pressure has been restored to normal limits for
the individual (usually 90 to 110 systolic mm Hg for a tetraplegic individual
in the sitting position).
- Pulse rate has been restored to normal limits.
- The individual is comfortable, with no signs or
symptoms of autonomic dysreflexia, of increased intracranial pressure, or of
heart failure.
- An education plan has been completed and included preventive and emergency management guidance.
(Scientific evidence-None; Grade of recommendation--Expert consensus; Strength of panel opinion-Strong)
- Once the individual with spinal cord injury has been stabilized, review the precipitating cause of the autonomic dysreflexia episode with the individual, family members, significant others, and caregivers. This preventive process entails:
- Adjusting the treatment plan to ensure that future
episodes are recognized and treated to prevent a medical crisis or, ideally,
are avoided altogether.
- Discussing autonomic dysreflexia during the
individual's education program, so that he or she will be able to minimize the
risks known to precipitate AD, solve problems, recognize early onset, and
obtain help as quickly as possible.
- Providing the individual with education about the prevention and treatment of autonomic dysreflexia at the time of discharge that can be referred to in an emergency.
(Scientific evidence-None; Grade of recommendation-Expert consensus; Strength of panel opinion-Strong)
Health-care professionals should refer to the consumer guide Autonomic Dysreflexia: What You Should Know
to provide individuals a tool to help guide their own treatment of autonomic dysreflexia. This consumer guide is written in such a way that both adults and children will find it helpful. Please refer to the "Companion Documents" field.
A written guide or alert, such as the wallet card found in the above referenced consumer guide, may help them in communicating with their health-care providers. Such an alert system is especially needed when individuals with concomitant injuries that have resulted in reduced or limited cognition and verbal skills may be hindered in their ability to communicate that they are experiencing autonomic dysreflexia.
A written treatment plan for autonomic dysreflexia prepared for children and adolescents with spinal cord injury should include:
- The child's normal blood pressure, which is updated
annually or more frequently as needed.
- Diagnostic criteria.
- An emergency management plan
Limited cognition and verbal skills hinder the ability of younger children to communicate that they are experiencing autonomic dysreflexia with health-care providers, teachers, and other adults who are responsible for supervising their activities.
In addition to the signs and symptoms seen in adults, infants and children may present with nonspecific symptoms, such as crying, irritability, or somnolence. Parents of young children should consider using some form of medical alert identification as well as ensure that appropriate education is provided to those adults who have significant interactions with and responsibility for their child with spinal cord injuries, such as teachers, school nurses, coaches, and community-based health-care providers.
When a woman with spinal cord injury at T6 and above becomes pregnant, her care should be coordinated by an interdisciplinary team. It is recommended that the team develop a plan regarding management of autonomic dysreflexia.
- Schedule detailed evaluations for individuals with recurrent autonomic dysreflexia.
There may be subtle changes in an individual's medical condition, such as a worsening of detrusor sphincter dyssynergia or an expanding syrinx that is causing recurrent autonomic dysreflexia. Therefore, a detailed medical evaluation is warranted.
