You have just been dispatched to the home of a 40-year-old male, who is complaining of a sudden onset of a severe headache, blurred vision and diaphoresis. Upon arrival, you find the patient lying on the couch. His initial blood pressure is 220/140 and his heart rate is 125 bpm. As you continue to assess the patient, you notice a wheelchair in the corner. The patient verifies that it is his chair, reporting that he suffered a spinal cord injury approximately eight months ago. His level of injury is T-6. How does this new information change your plan of care?
While his initial complaints may be a cardiac event, a migraine headache or even a stroke, the pre-existing spinal cord injury should refocus your areas of concern and initial care of this patient. The patient may be experiencing the medical emergency known as autonomic dysreflexia. Simple interventions may easily correct some of his presenting symptoms and prevent further injury to the patient.
Autonomic dysreflexia is an exaggerated response of the nervous system, which may include an increase in blood pressure. It occurs in response to a noxious stimuli arising from a source below the level of a spinal cord injury and may occur after spinal shock resolves. The normal sympathetic response to a painful stimulus is not balanced, because descending impulses are blocked by the spinal cord injury (SCI).1
The most common cause of noxious stimuli is distension of the hollow viscera, such as the urinary bladder or bowel. These account for approximately 80% of autonomic dysreflexia cases.1 The SCI patient often has an indwelling urinary catheter, and simple kinks in the tubing or plugs in the catheter can trigger autonomic dysreflexia. Thus, when caring for a SCI patient, always ensure catheter patency (by making sure the catheter is not kinked or pulled too tight, and that it is actually draining urine). For those patients who self-catheterize, it may be appropriate to have the patient catheterize himself at home, prior to transport. After assuring catheter patency, or a decompressed bladder, assess for signs of a urinary tract infection, such as dark, cloudy urine or sediment in the catheter tubing.
Careful physical exam of the SCI patient is imperative during this crisis. Correction of any noxious stimulus will often reduce both the blood pressure and headache without pharmaceutical intervention. Other causative agents usually not considered in medical emergencies include tight clothing, ingrown toenails and constipation.2 Occasionally, the cause may not be readily found. In those instances, your care is focused on blood pressure control, which should be monitored every 3–5 minutes. Assisting the patient to a sitting position may help lower the blood pressure through lower-extremity vascular pooling. Loosening all restrictive garments (shirts, belts, slacks, straps and even shoes) may also reduce the stimulus.
Notifying the receiving facility is imperative, as pharmaceutical interventions may possibly veer from standard protocol. While your current EMS protocol may not include nifedipine, there is still research indicating its use. Nifedipine 10 mg orally (instruct the patient to bite the capsule, then swallow it) can be used for blood pressure readings of 180 mmHg systolic.1,3 Additional medications that may be used in the prehospital phase of care include nitroglycerin sublingual (1/150) or topical paste (1/2 inch), clonidine 0.1–0.2 mg p.o., and hydralazine 10–20 mg IM/IV.4 Upon arrival at the hospital, the patient may be given sodium nitroprusside in an attempt to reduce the blood pressure to 90–100 mmHg systolic.1
Once the symptoms are resolved, have patients and their family members try to determine the causative factors involved in this episode. They should also receive extensive education about early recognition and treatment of A.D. Finally, encourage the patient to carry some type of medic alert identification. It is estimated that approximately 85% of spinal cord injury patients at level T-6 will suffer at least one episode of autonomic dysreflexia. Knowledgeable, educated patients and healthcare providers will be able to treat this medical emergency quickly and efficiently, while minimizing the associated risks.