Passing Out Made Ridiculously Simple . . . or at Least Somewhat Simpler

Passing Out Made Ridiculously Simple . . . or at Least Somewhat Simpler

Three systematic reviews and one guideline provide practical strategies for hospital- and ED-based clinicians for evaluating syncope.

Syncope accounts for about 5% of emergency department (ED) visits and about 3% of hospital admissions. Although many attempts have been made to guide diagnostic and prognostic evaluation of syncope, few researchers have reviewed the literature systematically to evaluate prognostic factors and clinical decision rules. Four recent publications help fill this gap.

The National Institute for Health and Clinical Excellence (NICE) Guideline for Management of Transient Loss of Consciousness emphasizes the value of history and physical examination findings in predicting uncomplicated faints (e.g., vasovagal episodes) and in distinguishing seizure from syncope. Uncomplicated faints are suggested by three Ps: posture (occurs during prolonged standing or history of similar episodes avoided by lying down), provoking factors (e.g., pain, procedure), and prodrome (e.g., sweating, nausea, warmth). Seizure is suggested by tongue biting, head turning during loss of consciousness, no recollection of abnormal behavior, prolonged limb jerking (lasting minutes), post-event confusion, and prodromal déjà vu. In a recent pooled analysis of data from two studies, tongue biting had a specificity of 96% and a positive likelihood ratio (LR) of 8.6 but poor sensitivity and negative LR for predicting seizure.

In a meta-analysis of data from >43,000 international ED patients who presented with syncope, researchers identified patient features that predicted adverse outcomes (death, hospitalization, interventional procedures due to arrhythmia, ischemia, or valvular disease). The strongest predictors were palpitations (odds ratio, 65), exertional syncope (OR, 17), heart disease (OR, 14), bleeding (OR, 13), supine syncope (OR, 8), and lack of prodrome (OR, 7). Each of these factors, except palpitations, is a well-known predictor of adverse outcomes in syncope. Palpitations have been reported previously to suggest benign or vasovagal syncope. Therefore, clinicians should have a higher degree of suspicion for adverse outcomes when patients report palpitations preceding syncope.

A final meta-analysis (of 12 studies involving 5316 patients) summarizes the most well-studied clinical decision rule for syncope: the San Francisco Syncope Rule (SFSR). The SFSR uses five factors (CHESS predictors; table) to predict serious adverse outcomes at 7 or 30 days in patients presenting to the ED. SFSR was associated with a pooled negative predictive value of 97%, sensitivity of 87%, and negative LR of 0.28. Although heterogeneity between studies was moderate, and other syncope clinical decision rules (e.g., Risk Stratification of Syncope in the Emergency Department [ROSE] rule, Evaluation of Guidelines in Syncope Study [EGSYS] score, Boston Syncope Criteria) have slightly better predictive values in studies involving fewer patients, the SFSR is the most thoroughly studied, and practitioners can use it to identify low-risk patients who can be discharged safely from the ED. Patients with negative SFSR scores had <3% risk for serious outcomes.

Comment: These reviews and guideline of syncope evaluation and management summarize the value of a well-studied clinical decision rule, history and physical exam, diagnostic testing, and risk stratification of patients with syncope or transient loss of consciousness. The NICE guideline also offers recommendations regarding specialist referral and risk assessment. Together, they supply hospital- and ED-based clinicians with practical strategies to differentiate risk in patients with the common, yet sometimes elusive, presenting complaint of syncope.

— Daniel D. Dressler, MD, MSc, SFHM, FACP

Published in Journal Watch Hospital Medicine November 14, 2012

Citation(s):

Cooper PN et al. Synopsis of the national institute for health and clinical excellence guideline for management of transient loss of consciousness. Ann Intern Med 2011 Oct 18; 155:543. (http://annals.org/article.aspx?articleid=474999)

Medline abstract (Free)

Brigo F et al. Value of tongue biting in the differential diagnosis between epileptic seizures and syncope. Seizure 2012 Oct; 21:568. (http://dx.doi.org/10.1016/j.seizure.2012.06.005)

Medline abstract (Free)

D'Ascenzo F et al. Incidence, etiology and predictors of adverse outcomes in 43,315 patients presenting to the Emergency Department with syncope: An international meta-analysis. Int J Cardiol 2011 Dec 22; [e-pub ahead of print]. (http://viajwat.ch/RUj0Nl)

Saccilotto RT et al. San Francisco Syncope Rule to predict short-term serious outcomes: A systematic review. CMAJ 2011 Oct 18; 183:E1116. (http://dx.doi.org/10.1503/cmaj.101326)

Original article (Subscription may be required)
Medline abstract (Free)

Reader Remarks:

Review and add to remarks on this article

Syncope studies
Michael Berard, private practice College Park,Md, 19 Nov 2012 3:20 PM EST
Specialty: Internal Medicine
When will this information actually lead to a change in Standard care in our ERs .there is a huge waste... [more]
Passing Out Syncope made simple
Melodee L Millare, 19 Nov 2012 3:20 PM EST
Specialty: Family Medicine
good very short read on relevant topic - practical information.
syncope studies
Thomas F Kline, MD, 26 Nov 2012 11:50 AM EST
Specialty: Geriatric Medicine
About three quarters of patients I see after trips to ER for syncope with negative but costly American Medicine work... [more]
Practical Suggestion - worth applying!
Abid Ahmed, 13 Dec 2012 10:13 AM EST
Specialty: Internal Medicine
I totally agree with Dr. Thomas point of view concerning orthostatic hypotension as one of the common reason in elderly... [more]
Syncope
Daniel D. Dressler, Emory University School of Medicine, 3 Jan 2013 12:09 PM EST
Specialty: Hospitalist
Really appreciate those valuable remarks on Syncope. Completely agree that every patient deserves orthostatic BP and pulse in the ED.... [more]

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