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Three Part Question

In [older adult patients presenting to the emergency department with syncope], are [abnormal orthostatic vital signs] efficacious in the [diagnosis or exclusion of life-threatening events]?

Clinical Scenario

A 67-year-old female with a history of diabetes and hypertension, on metformin and an ACE-inhibitor, presents to the emergency department (ED) following an episode of syncope while walking into her bathroom. She had preceding lightheadedness, but no other symptoms. She has a blood pressure of 158/87 with a heart rate of 78, unremarkable ECG, and her blood glucose is 84 mg/dL. As part of her diagnostic evaluation, you consider whether orthostatic vital signs will help to rule out any life-threatening causes of her syncope?

Search Strategy

Medline 1966-04/20 using PubMed, Cochrane Library (2020), and Embase
[(exp syncope) AND (exp hypotension, orthostatic OR exp orthostatic vital signs[title]) AND (exp emergency service)]. LIMIT to English language.

Search Outcome

17 studies were identified; two studies addressed the clinical question including one meta-analysis.

Relevant Paper(s)

Author, date and country	Patient group	Study type (level of evidence)	Outcomes	Key results	Study Weaknesses
White J, et al. Dec 2018 United States	1,974 patients >60 years of age with a complaint of syncope or near syncope.	Prospective cohort study	Rate of 30-day serious events	No difference in 30-day outcome event rates when comparing those with abnormal to those with normal orthostatic vital signs.	Not all patients presenting with syncope received orthostatic vital signs; method of orthostatic measurement was not standardized; across test sites.
Schaffer J, et al. Dec 2015 United States	4 studies of ED patients (n=1974) in whom orthostatic vital signs were measured	Meta-analysis	Diagnostic utility of orthostatic vital signs as a test for orthostatic syncope; diagnostic utility of orthostatic vital signs to diagnose or exclude life-threatening causes of syncope in ED patients .	Orthostatic hypotension is common in ED patients with syncope (89%), orthostatic vital signs perform poorly when determining if orthostatic hypotension is the cause of a patient’s syncope.	The study population was relatively young, with a low prevalence of heart disease. Recruitment of patients is inexplicit, and it is unclear if a significant number of eligible patients were not screened. Timing of evaluation is unclear and could bias the results if prior interventions affected the vital signs or if orthostatic hypotension resolved spontaneously. It is not reported how the final cause of syncope was determined, if there were clear criteria, or who made the diagnosis.

Comment(s)

Orthostatic vital signs (OVS) are blood pressure and heart rate measured in lying and sitting positions, on immediate standing, and after 3 minutes of upright posture. These are traditionally performed in the evaluation of syncope and frequently requested by ED consultants or admitting teams to evaluate for orthostatic hypotension. Orthostatic hypotension is defined as a drop in systolic BP of >20 mm Hg or diastolic BP of >10 mm Hg with assumption of an upright posture. The 2017 ACC/AHA/HRS Guideline for the Evaluation and Management of Patients with Syncope recommends performing OVS on all patients presenting with syncope, but provides no references with data supporting this recommendation. These studies offered no consensus or standardized method for measuring OVS which serves to limit their reliability and comparison.

Clinical Bottom Line

In older adults presenting to the ED with syncope, abnormal orthostatic vital signs are not effective for confirming a diagnosis of orthostatic hypotension or at excluding life threatening events.

References

1. White JL, Hollander JE, Chang AM, Nishijima DK, Lin AL, Su E, Weiss RE, Yagapen AN, Malveau SE, Adler DH, Bastani A, Baugh CW, Caterino JM, Clark CL, Diercks DB, Nicks BA, Shah MN, Stiffler KA, Storro Orthostatic vital signs do not predict 30-day serious outcomes in older emergency department patients with syncope: A multicenter observational study. Am J Emerg Med 2019 Dec;37(12):2215-2223.
2. Schaffer JT, Keim SM, Hunter BR, Kirschner JM, De Lorenzo RA. Do Orthostatic Vital Signs Have Utility in the Evaluation of Syncope? J Emerg Med 2018 Dec;55(6):780-787