Podcast #280: Isolated Aphasia in Stroke

Author: Aaron Lessen, M.D.

Educational Pearls

  • Patients with an ischemic stroke from occlusion of the left middle cerebral artery often present with aphasia in addition to other neurological deficits.
  • A recent study looked at patients presenting with suspected stroke. Of the 700 patients recruited, 3% had isolated aphasia on exam.  On follow-up, none of the 3% had evidence of stroke on imaging. Underlying causes of the isolated aphasia in these patients included syncope, infections, seizures were the underlying cause.  

References: Gabriel Casella, Rafael H. Llinas, Elisabeth B. Marsh, Isolated aphasia in the emergency department: The likelihood of ischemia is low, Clinical Neurology and Neurosurgery, Volume 163, 2017, Pages 24-26, ISSN 0303-8467, https://doi.org/10.1016/j.clineuro.2017.10.013.

Podcast #268: Poiseuille’s Law

Author:  Dave Rosenberg, M.D.

Educational Pearls

  • Poiseuille’s Law addresses the flow of a fluid through a tube.
  • Many common ED presentations involve alterations in flow: asthma, MI, ischemic stroke, etc.
  • According to the law, flow increases with the 4th power of the radius. That is to say, doubling the radius of the tube will increase the flow by 16x.
  • Therefore, in situations that require re-opening of an anatomic tube (artery, airway), small changes in the size of the opening will result in dramatic effects.

References: https://www.openanesthesia.org/poiseuilles_law_iv_fluids/

Podcast #266: MI in Young Patients

Author: John Winkler, M.D.

Educational Pearls

  • Some risk factors for MI in the young are history of CAD, stimulant drug use, coronary spasm and diabetes.
  • In those with diffuse ST elevations on EKG, think pericarditis. Troponin will also be elevated.

References: Egred M, Viswanathan G, Davis GK Myocardial infarction in young adults Postgraduate Medical Journal 2005;81:741-745

Podcast #264: Witnessed Cardiac Arrest

Author: Aaron Lessen, M.D.

Educational Pearls

  • For patients with in-hospital cardiac arrest, intubation in the 1st 15 minutes of resuscitation was associated with worse outcomes (mortality, neurologic outcome). This is likely due to cessation of high-quality CPR and defibrillation during the intubation sequence.
  • In those with an in-hospital, shockable, cardiac arrest, administration of epinephrine before the 2nd defibrillatory shock was associated with worse outcome. This was likely due to the cessation of high-quality CPR.
  • For in-hospital cardiac arrest, resuscitation should focus on high-quality CPR.

References: Andersen LW, Granfeldt A, Callaway CW, Bradley SM, Soar J, Nolan JP, Kurth T, Donnino MW, for the American Heart Association’s Get With The Guidelines?Resuscitation Investigators. Association Between Tracheal Intubation During Adult In-Hospital Cardiac Arrest and Survival. JAMA. 2017;317(5):494?506. doi:10.1001/jama.2016.20165

Podcast #259: Transient Ischemic Attacks

Author: Peter Bakes, M.D.

Educational Pearls

  • A TIA is defined as focal neurological deficit that resolves within 24 hours and has negative imaging. The etiology is a transient thrombus, embolus, or narrowing of a branch of a cerebral artery.
  • Screening tests are generally negative and low-yield. MRI and vascular imaging are usually done to look for reversible causes.
  • Patients presenting with TIA are usually admitted because of a higher risk for stroke. However, there are some patients that are low-risk and do not require admission. Risk can be assessed using the “ABCD” mnemonic: Age>60, BP (history of HTN), Clinical presentation (area of deficit), Diabetes/Duration of symptoms. See reference link for scoring sheet.
  • Patients with a low enough score may be eligible for outpatient follow-up.

References: http://www.stroke.org/sites/default/files/resources/tia-abcd2-tool.pdf?docID

Podcast #249: Detecting Pulses

Author:  Jared Scott, M.D.

Educational Pearls

  • Overall, medical providers are bad at detecting pulses.
  • However, only 2% of patients do not have a detectable DP pulse.
  • In one study, for patients with limb claudication, there was only about 50% agreement on the presence of a DP pulse.

References: Brearley et al. Peripheral pulse palpation: an unreliable physical sign. Annals of the Royal College of Surgeons of England. 1992

Podcast #246: Patent Foramen Ovale

Author: Jared Scott, M.D.

Educational Pearls

  • The foramen ovale (FO) connects the left and right atria to allow oxygenated blood to bypass the developing lungs, it usually closes at birth but for some it remains patent (PFO).
  • A PFO allows clots to cross from the venous to arterial circulation, increasing the likelihood of stroke.
  • PFO is present in 25% of general population, present in 50% of those with stroke of unknown cause, and very common those with stroke under 50 years old.
  • Treat with anticoagulation or surgical correction.

References: http://www.heart.org/HEARTORG/Conditions/More/CardiovascularConditionsofChildhood/Patent-Foramen-Ovale-PFO_UCM_469590_Article.jsp#.WarsZZN95E

Podcast #239: GERD vs. MI

Author: Dave Rosenberg, M.D.

Educational Pearls

  • MI and GERD can present similarly. For example, 47% with angina report increased belching with an anginal attack, and 20% of people with an MI describe symptoms  of indigestion that are relieved by antacids.
  • Overall, GERD is more common in those with CAD, so don’t be “reassured” by GERD symptoms in the setting of chest pain.

References: http://www.mdedge.com/ecardiologynews/article/82215/cad-atherosclerosis/gerd-may-boost-risk-mi

Podcast #227: CPR-Induced Consciousness

Author: Nick Hatch, M.D.

Educational Pearls

  • CPR-induced consciousness is a phenomenon that occurs when someone who was previously unconscious and is undergoing CPR regains consciousness and makes purposeful movements.
  • Studies have shown that this phenomenon is increasing, likely because of increased quality of CPR.
  • Many people use a sedative such as ketamine  to keep patients unconscious to reduce the psychologic trauma of CPR.
  • 39% of people who survive CPR with good neurologic details remember the process of CPR.

References:

Joshua Pound, P. Richard Verbeek, and Sheldon Cheske. CPR Induced Consciousness During Out-of-Hospital Cardiac Arrest: A Case Report on an Emerging Phenomenon. 2017. Prehospital Emergency Care Vol. 21.

Podcast #224: Troponin

Author: Sam Killian, M.D.

Educational Pearls

  • Not every troponin elevation is an MI.
  • Trop elevates in about an hour in ACS and stays elevated for days.
  • Non-MI conditions that cause elevated troponin: Critical illness (sepsis), increased cardiac demand, right heart strain, LV dysfunction, hypotension, pressor use, acute PE, SAH, chronic renal failure, CHF, aortic dissection, and peri/myocarditis.
  • Elevated troponin in settings other than MI is correlated with increased mortality.

References: Korff S, Katus HA, Giannitsis E. Differential diagnosis of elevated troponins. Heart. 2006;92(7):987-993. doi:10.1136/hrt.2005.071282.