Ep 172 Syncope Simplified with David Carr

In this main episode podcast, Dr. David Carr joins Anton to give us his simplified approach to syncope based solely on history, physical and ECG to help guide disposition decisions.  We answer questions such as: What features have the best likelihood ratios to help distinguish syncope from seizure? What key clinical features on history and physical exam can help us distinguish orthostatic and reflex syncope from the more sinister cardiac syncope? What is the best approach to ECG interpretation for the patient who has presents with syncope? Are syncope clinical decision tools any better than physician gestalt? and many more.... Podcast production, sound design & editing by Anton Helman; voice editing by Braedon Paul Written Summary and blog post by Kate Dillon, edited by Anton Helman August, 2022 Cite this podcast as: Helman, A. Carr, D. Syncope Simplified. Emergency Medicine Cases. August, 2022. https://emergencymedicinecases.com/simplifying-syncope. Accessed December 6, 2024 The ED approach to syncope is almost entirely based on a focused but thorough history, cardiac physical exam and ECG rather than laboratory tests and imaging. The first step is distinguishing syncope from seizure. The next step is distinguishing cardiac from non-cardiac syncope. Our ultimate aim is to make safe disposition decisions based on this approach. Distinguishing syncope from seizure based on history The most useful symptoms reported by patient/witness for identifying seizure  * Head turning during event - sensitivity 43%; specificity 97%; LR 14 * Unusual posturing during the event - sensitivity 35%; specificity 97%; LR 13 * Absence of presyncope - sensitivity 77%; specificity 86%; LR 5.6 * History of epilepsy - more likely seizure * Post-ictal state - 96% of patients with seizures * Urinary incontinence - sensitivity  24%; specificity 96%; LR 6.7  *despite this impressive LR, urinary incontinence cannot reliably distinguish syncope from seizure  The most useful findings evaluated by the physician for identifying patients with seizures: * The presence of a cut tongue - sensitivity 45%; specificity 97%; LR 17   * Lateral tongue bite has a 100% specificity for tonic clonic seizure * Patient has no recall of unusual behaviors before the loss of consciousness - sensitivity 53%; specificity 87%; LR 4.0 The most useful symptoms reported by patient or witness for identifying patients with syncope: * Loss of consciousness with prolonged sitting or standing (sensitivity 40%; specificity 98%; LR 20 * Dyspnea before loss of consciousness (sensitivity 24%; specificity 98%; LR 13 * Palpitations before loss of consciousness (sensitivity 34%; specificity 96%; LR 8.3 * Muscle tone (increased tone more likely seizure, decreased tone more likely syncope) * Number of limb jerks - The 10:20 Rule: patients with witnessed <10 myoclonic jerks after sudden loss of consciousness is more like syncope vs >20 myoclonic jerks is more likely seizure   Clinical Pitfall: Even though the +LR for urinary incontinence increases the likelihood of seizure, urinary incontinence cannot reliably distinguish seizure from syncope and should not be relied on to do so. Clinical Pearl: Lateral tongue bite after sudden loss of consciousness has a 100% specificity for tonic clonic seizure. Clinical Pearl: Approximately 90% of people who have a syncopal episode will have myoclonic jerks, the 10:20 Rule to help determine whether syncope or seizure is more likely. If there are <10 jerks it is more likely to be syncope, if you have >20 jerks it is more likely to be a seizure. Distinguishing cardiac syncope from non-cardiac syncope After considering syncope caused by diagnoses that typically present...