From the April 2014 issue of Emergency Medicine Practice, “Syncope: Risk Stratification and Clinical Decision Making.” Reprinted with permission. To access your EMRA member benefit of free online access to all EM Practice, Pediatric EM Practice, and EM Practice Guidelines Update issues, go to www.ebmedicine.net/emra, call 1-800-249-5770, or send e-mail to firstname.lastname@example.org.
- “It didn't even occur to me that a patient with syncope might have a dissection of the thoracic aorta.”
Syncope is generally a benign process. However, one must be proactive in trying to identify life-threatening causes. History, physical examination, and ECG findings are most helpful, but keep your differential large or you may miss the rare life-threatening conditions.
- “I sent the patient home after syncope with a history suggestive for cardiac syncope. There were no abnormalities on physical examination or on the ECG. The patient returned because of an accident with his truck after syncope.”
People with occupations that are high risk for disastrous outcomes include truck drivers, bus drivers, airplane pilots, and heavy equipment operators. In particular, they need counseling about the risks of driving after syncope. Instructions should be provided for paying attention for prodromal symptoms.
- “I sent a patient home with the diagnosis ”˜syncope based on orthostatic hypotension.' After a few days the patient returned with another episode of syncope, and on the monitor a dysrhythmia was seen.”
There may be multiple causes of a syncopal episode, especially in the elderly. Even if a patient had an obvious stressor prior to the syncopal episode, or had orthostatic hypotension, other causes are still possible.
- “I obtained an ECG in a patient with syncope that showed a sinus rhythm with no conduction abnormalities. The patient died of a sudden cardiac arrest the next day.”
A normal ECG has a high negative predictive value, but it does not completely rule out future cardiac events. Obtain an ECG in every patient with syncope (with, perhaps, the exception of syncope in a young person with a clearly identified trigger) to assess rhythm and conduction abnormalities. Assess for evidence of pre-excitation, prolonged corrected QT time (> 500 ms), and Brugada pattern. When checking the patient's medication list, be alert for drugs known to cause prolonged QT syndrome.
- “I did a complete workup in a 48-year-old patient with syncope, including ECG, laboratory tests, and a chest X-ray, before discharging him. A few hours later, he returned with a hemiparesis from a subarachnoid hemorrhage. He didn't mention he had a sharp headache just before the event.”
The most important step in obtaining an accurate diagnosis is the history of present illness. Invest the time to get all the facts from the patient, family, and bystanders. This investment will yield more efficient ED diagnostic workup, more accurate diagnosis, and a higher quality of emergency care.
- “A patient came in after syncope and had another episode in the ED. I think the underlying problem might be a dysrhythmia that we didn't capture on the ECG.”
Continuous ECG monitoring increases the likelihood of capturing an intermittent dysrhythmia. All patients with a possible cardiac cause of syncope should be placed on continuous ECG monitoring in the ED.
- “I ordered a CT of the thorax because the patient complained of dyspnea and hemoptysis after syncope, and I was concerned for a pulmonary embolism. The patient became more dyspneic and tachypneic, and, while being transported to radiology, he arrested.”
If you recognize a potential life-threatening cause in a patient, consider starting aggressive treatment before getting diagnostics.
- “I discharged a patient from the ED after his first episode of syncope. He had a second episode of syncope and didn't go to see a doctor because ”˜it was nothing the last time.'”
Patients who suffer from syncope and are discharged from the ED should seek follow-up with their primary care physician, especially if they are at the extremes of age. It is necessary to explicitly instruct or arrange this for your patients; otherwise, they may assume it is not important. Make sure they understand the importance of seeking attention with additional symptoms or events.
- “After a discussion with the cardiologist, I discharged the 78-year-old syncopal patient. A detailed history did not identify any new worrisome symptoms. Even though he had a coronary artery bypass graft 3 years prior, there were no abnormalities on physical examination and no ECG changes. Two days later the patient returned with a cardiac arrest.”
Factors associated with higher risk for an adverse event after syncope are advanced age, cardiovascular disease, and an abnormal ECG. Patients with these and other risk factors may require admission for observation and further evaluation. Outpatient follow-up may be inadequate when the patient is risk stratified as high-risk.
- “An 85-year-old patient was sent home after syncope based on orthostatic hypotension. A few weeks later she returned to the ED because she sustained a head injury during syncope.”
Take the time to inform your patients about the possible dangers of syncope. Patients should be warned about possible trigger events for syncope, associated signs and symptoms, and the risk of a sudden attack. Particularly in the elderly, instructions should be provided for procedures to decrease the risk of falls, such as using a cane or walker, taking extra time to equilibrate when changing position, and paying attention to symptoms that may precede the syncopal attack.