Autonomic Dysreflexia: Procedure Safety Cards

If your spinal cord injury is at or above the T6 level, certain medical procedures can set off autonomic dysreflexia (AD) — a sudden, dangerous spike in blood pressure triggered by something the body senses below your injury. The triggers are usually predictable: a full bladder, a catheter change, bowel work, surgery, sexual activity, or labor. That predictability is good news. When your care team knows AD is a risk before they start, they can prevent it, watch for it, and treat it fast.

This page gives you short, printable "cards" — one for each procedure that commonly triggers AD. Print the ones you need and hand them to the clinician, dentist, anesthesiologist, or labor nurse before they begin. For the full picture of what AD is and how it's treated, read our main guide: Autonomic Dysreflexia.

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Autonomic dysreflexia is a medical emergency. A blood pressure that keeps climbing can cause seizure, stroke, or death within minutes. If symptoms don't settle quickly when the trigger is removed, it needs emergency treatment. This page is information to share with your team, not medical advice or a substitute for their judgment.

Shared principles: what every team should know

These basics apply to all of the cards below. The procedure-specific cards add the details that matter for each setting.

Who is at risk. AD is a risk for people with SCI at or above T6. Risk is higher with complete injuries and higher levels. Some people with injuries as low as T7–T10 also report symptoms, so when in doubt, treat the person as at-risk.

Why it happens. A trigger below the level of injury — most often a full or irritated bladder or bowel — sends a signal the brain can't fully calm. Blood pressure rises sharply. The most common single trigger is the bladder.

The universal prevention basics:

Empty the bladder first. Drain the bladder (or check that a catheter is flowing and unkinked) before and during the procedure. Avoid letting it fill.
Know the person's baseline blood pressure. For many people with SCI above T6, a normal resting systolic pressure runs low — often around 90–110 mm Hg. A reading that looks "normal" (like 120/80) can actually be a dangerous rise for them.
Use topical anesthetic where it helps. For bladder and bowel procedures, lidocaine jelly applied before instrumentation can reduce stimulation.
Have a plan and medications ready before starting, not after symptoms appear.

The universal response if AD starts:

Stop the procedure and sit the person upright (this lets blood pool and lowers pressure).
Loosen anything tight — clothing, straps, abdominal binders, leg bags, compression.
Check the blood pressure right away and recheck every few minutes.
Hunt for the trigger, bladder first, then bowel, then skin. Drain or unblock the catheter; check for impaction; remove anything pressing on the skin.
Treat the high blood pressure with a fast-acting, short-duration medication if it stays elevated while the cause is being found.

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When it's an emergency — and a medication caution. Call for emergency help if blood pressure stays high after the trigger is removed, if symptoms don't ease, or if there's a severe headache, chest pain, vision change, confusion, or seizure. Guideline sources warn against giving nifedipine by the sublingual (under-the-tongue) route, because it can drop blood pressure too fast and too far. See the full treatment protocol in our main AD guide.

What to tell any team, in one breath: "I have a spinal cord injury at [your level]. I'm at risk for autonomic dysreflexia — a sudden dangerous rise in blood pressure. Please keep my bladder empty, monitor my blood pressure closely, and stop and sit me up if it spikes or I get a pounding headache."

Card 1 — Urodynamics & cystoscopy

Bladder studies are among the most reliable AD triggers because they stretch and stimulate the bladder directly. Cystoscopy tends to provoke larger blood-pressure rises than urodynamics.

Typical triggers: filling the bladder during urodynamics; the scope and bladder distension during cystoscopy; a full or irritated bladder.
Prevent before/during: use lidocaine jelly before instrumentation; keep filling volumes and pressures as low as the study allows; drain the bladder promptly afterward; don't over-fill.
Tell the clinician: "I'm at risk for AD. Please monitor my blood pressure throughout, fill slowly, and stop and drain if it rises."
Monitoring (BP): check blood pressure before starting and frequently during the study — many sources advise at least every couple of minutes for at-risk patients.
Warning signs: pounding headache, sweating or flushing above the injury, goosebumps, nasal stuffiness, a sudden rise in blood pressure.

Card 2 — Routine catheter changes

Everyday bladder care can trigger AD — including suprapubic catheter changes, which involve removing and replacing a tube through the bladder wall.

Typical triggers: a full bladder before the change; a blocked, kinked, or crusted catheter; the stretch of insertion or balloon inflation; bladder spasm.
Prevent before/during: drain the bladder before changing the catheter; use lidocaine jelly; work gently and confirm the new catheter is flowing freely before finishing; never leave a catheter kinked or clamped.
Tell the clinician: "A blocked or full bladder can trigger AD for me. Please make sure it's draining and watch my blood pressure."
Monitoring (BP): check blood pressure if you feel symptoms; for people with frequent or severe AD, check before and after the change.
Warning signs: headache or sweating that starts during the change, or no urine flow after insertion (a sign the catheter isn't draining).

Card 3 — Bowel procedures & colonoscopy

The bowel is the second most common AD trigger after the bladder. Rectal exams, disimpaction, scopes, and bowel-prep distension can all set it off.

Typical triggers: rectal stretch and stimulation; digital exam or disimpaction; insufflation and distension during colonoscopy; a full rectum or impaction.
Prevent before/during: empty the bladder first; consider lidocaine jelly to the anal area before rectal work; go gently and pause if blood pressure rises. (Note: evidence on whether topical lidocaine reliably blunts AD during routine bowel care is mixed — it should not replace blood-pressure monitoring or stopping the trigger.)
Tell the clinician: "Bowel and rectal procedures can trigger AD for me. Please monitor my blood pressure and stop if it climbs." For colonoscopy, ask the team to discuss anesthesia/sedation and close BP monitoring in advance.
Monitoring (BP): check before, during, and after; keep monitoring after the procedure, since AD can occur after a colonoscopy.
Warning signs: headache, sweating, flushing, or a blood-pressure rise during rectal stimulation or insufflation.

Card 4 — Dental work

Dental visits can trigger AD through pain, anxiety, and a full bladder during a long appointment — and the dental team may not know to watch for it.

Typical triggers: pain or strong stimulation during a procedure; a bladder that fills during a long visit; anxiety; sometimes the stimulant in local anesthetic.
Prevent before/during: empty the bladder right before the appointment; ask for good local anesthesia/pain control (dental sources advise using the smallest necessary amount of epinephrine in the local anesthetic); plan breaks for longer procedures.
Tell the dentist: "I have an SCI above T6 and can get autonomic dysreflexia — a sudden dangerous blood-pressure spike. Please keep a blood-pressure cuff on me, and stop if I say it's starting or get a pounding headache."
Monitoring (BP): ask the team to keep a blood-pressure cuff on and monitor through the procedure; most people feel AD coming and can signal to stop.
Warning signs: sudden pounding headache, sweating or flushing of the face, anxiety, a spike in blood pressure.

Card 5 — Surgery & anesthesia

Any surgery — even minor — can trigger AD, because pain signals and bladder/bowel distension reach the body during and after the operation. The anesthesiologist is your key ally here.

Typical triggers: surgical stimulation and pain; a full bladder during or after surgery; bowel distension; positioning; pain as anesthesia wears off in recovery.
Prevent before/during: the team keeps the bladder drained (often with a catheter); they choose an anesthetic plan that prevents AD. Anesthesia sources note that spinal or epidural (neuraxial) techniques can block the triggering signals, and general anesthesia is used at a depth sufficient to prevent AD — either with close blood-pressure monitoring throughout.
Tell the anesthesiologist (well before the day if possible): "I have an SCI at [level] and a history of autonomic dysreflexia [note your usual triggers]. Please plan anesthesia to prevent AD, keep my bladder drained, monitor my blood pressure closely, and have fast-acting blood-pressure medication ready."
Monitoring (BP): continuous or close blood-pressure monitoring before, during, and into recovery — AD can appear as anesthesia wears off.
Warning signs: sudden hypertension, slow heart rate, sweating or flushing, headache on waking.

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Bring your AD details to pre-op. Tell the surgical and anesthesia teams your injury level, your usual AD triggers, your baseline blood pressure, and any medication that has worked for you. The earlier they know, the better they can plan.

Card 6 — Sexual activity

This card is for you and a partner more than a clinician — but it's worth sharing with a fertility specialist if you're using assisted ejaculation methods. Sexual stimulation, orgasm, and ejaculation can all trigger AD in people with SCI at or above T6.

Typical triggers: intense genital or pelvic stimulation; orgasm and ejaculation; a full bladder; medical procedures like vibratory stimulation or electroejaculation used for fertility.
Prevent before/during: empty the bladder beforehand; know your pattern; if you've had AD with sex before, talk to your SCI provider — some people are prescribed a medication to take ahead of time to blunt the blood-pressure rise.
What to do if it starts: stop, sit upright, and check blood pressure if you can. Treat as an emergency if it doesn't settle.
For fertility procedures: vibratory stimulation and electroejaculation are well-known AD triggers — these should be done by a team that monitors blood pressure and is ready to manage AD.
Warning signs: pounding headache (often at or near orgasm), sweating, flushing, goosebumps, a blood-pressure spike.

Card 7 — Pregnancy, labor & delivery

AD is the most serious medical complication of pregnancy after SCI and is most likely to occur during labor. It can be life-threatening, so the plan should be set well before the due date.

Typical triggers: uterine contractions; cervical exams; a full or obstructed bladder; bowel distension; fundal pressure/massage; external pressure during ultrasound; tight clothing.
Prevent before/during: a multidisciplinary plan made in advance; keep the bladder drained; avoid unnecessary pelvic stimulation. ACOG notes that neuraxial (epidural or spinal) anesthesia is the treatment of choice to reduce the risk of AD in labor because it blocks the triggering signals from the pelvis — even when labor is painless. An epidural or spinal catheter may be placed early in labor.
Tell the team (antenatally): "I have an SCI at [level] and am at high risk for autonomic dysreflexia in labor. Please involve an obstetric anesthesiologist before delivery, plan for early neuraxial anesthesia, keep my bladder drained, and monitor my blood pressure closely."
Monitoring (BP): close blood-pressure monitoring during labor and delivery, ideally in a unit able to do intensive monitoring.
Warning signs: a sharp blood-pressure rise with contractions, pounding headache, sweating, flushing.

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AD in labor can be mistaken for pre-eclampsia. Both can cause high blood pressure and headache. A key difference ACOG describes: in AD, the blood-pressure rise tends to come with each contraction and ease between them, and there's no protein in the urine; pre-eclampsia hypertension isn't tied to contractions. Getting this right changes the treatment — make sure your team knows your SCI and AD history.

Sources

Consortium for Spinal Cord Medicine / Paralyzed Veterans of America. Acute Management of Autonomic Dysreflexia (Clinical Practice Guideline); and Evaluation and Management of Autonomic Dysfunctions (2nd ed., 2020).
ACOG Committee Opinion No. 808: Obstetric Management of Patients With Spinal Cord Injuries (2020) — labor risk, neuraxial anesthesia, AD vs. pre-eclampsia.
Autonomic Dysreflexia — StatPearls (NCBI); and PM&R KnowledgeNow (AAPM&R).
Perioperative anesthesia references for chronic SCI; and research on AD during urodynamics vs. cystoscopy.

Information, not medical advice. Autonomic dysreflexia is a medical emergency. Always follow the guidance of your own care team, and seek emergency care for a blood pressure that stays high or symptoms that don't ease.