USMLE Prep - Medical Reference Library

Syncope — ED Risk Stratification

System: Emergency Medicine • Reviewed: Aug 31, 2025 • Step 1Step 2Step 3

Synopsis:

Obtain ECG and orthostatic vitals on all; identify high-risk features for admission; avoid routine head CT in uncomplicated syncope; tailor workup to suspected cause.

Key Points

  • Stabilize ABCs; begin targeted evaluation without delaying life-saving therapy.
  • Use system-specific risk tools to guide testing and disposition.
  • Order high-yield tests first; escalate imaging when indicated.
  • Start evidence-based initial therapy and reassess frequently.

Algorithm

  1. Primary survey and vitals; IV access and monitors.
  2. Focused history/physical; identify red flags and likely etiologies.
  3. Order system-appropriate labs and imaging (see Investigations).
  4. Initiate guideline-based empiric therapy (see Pharmacology).
  5. Reassess response; arrange consultation and definitive management.

Clinical Synopsis & Reasoning

For Syncope Ed Risk Stratification, frame the differential by acuity and pathophysiology, then align diagnostics to the leading hypotheses. Prioritize stabilization while obtaining high‑yield studies such as CBC/BMP (Baseline labs), CXR/targeted imaging (Common ED complaints), Troponin/EKG (chest pain) (ACS rule-out). Incorporate bedside imaging and targeted labs to define severity and identify complications; synthesize results with clinical trajectory to refine the working diagnosis and disposition needs.


Treatment Strategy & Disposition

Initiate disease‑directed therapy alongside supportive care, titrating to objective response. Pharmacologic options commonly include Analgesics, Antiemetics. Use validated frameworks (e.g., Examples of High-Risk Findings) to guide escalation and site of care. Address precipitating factors, de‑escalate empiric therapies with data, and arrange follow‑up for monitoring and risk‑factor modification; admit patients with instability, high risk of deterioration, or needs for close monitoring.


Epidemiology / Risk Factors

  • Varies by presentation; age/comorbidities matter

Investigations

TestRole / RationaleTypical FindingsNotes
CBC/BMPBaseline labsAbnormalities
CXR/targeted imagingCommon ED complaintsFindings vary
Troponin/EKG (chest pain)ACS rule-outMI changesUse risk tools

Examples of High-Risk Findings

FindingConcern
Abnormal ECG (ischemia, AV block)Arrhythmia/ischemia
Exertional syncopeCardiogenic cause
Systolic BP <90 mmHgShock/bleeding
New CHF symptomsStructural disease

Pharmacology

MedicationMechanismOnsetRole in TherapyLimitations
Fluids (IV)Volume expansionMinutesOrthostatic/vasovagalFluid overload; ED use
Treat underlying arrhythmiaVariesMinutesAgent-specificAgent risks; ED use

Prognosis / Complications

  • Outcomes tied to emergency and timeliness of care

Patient Education / Counseling

  • Explain red flags and when to seek emergent care.
  • Reinforce medication adherence and follow-up plan.

Notes

Routine labs and imaging have low yield in uncomplicated syncope. Consider pregnancy test in women of childbearing potential.


References

  1. ACEP Clinical Policy: Syncope — Link
  2. ACC/AHA/HRS Syncope Guideline — Link