Podcast #303: Lazarus Effect

Author: Dylan Luyten, M.D.

Educational Pearls

  • The Lazarus phenomenon is the delayed return of spontaneous circulation after cessation of CPR.
  • A prospective study in Finland found 5 out of 840 patients where CPR was attempted in the setting of cardiac arrest experienced the Lazarus effect (about 0.6%).
  • 3 of these patients died on scene, and the other 2 died in the hospital at 1.5 and 26 hours respectively.
  • Ultimately, the Lazarus effect is rare, but it does occur and providers and family members should be aware that signs such as gasping or twitching may be seen after cardiac arrest, but the prognosis is still dismal.


Kuisma, M, et al. (September 2017) “Delayed return of spontaneous circulation (the Lazarus phenomenon) after cessation of out-of-hospital cardiopulmonary resuscitation”. Resuscitation. 118: 107-111

Podcast #291: Cincinnati Stroke Scale

Author: Nick Hatch, M.D.

Educational Pearls

  • The Cincinnati Stroke Scale uses 3 measures to screen for ischemic stroke. The measures are: facial asymmetry, speech quality and arm drift.
  • This scale is used commonly in EMS systems as a screening tool.
  • Studies show that having one out of the 3 elements correlates with a 72% chance of having an ischemic stroke, while having all 3 of the elements correlates with an 85% chance. Overall the scale is highly sensitive but not very specific  (92% and 48%, respectively, in one study).
  • The measures focus on anterior circulation function, and often misses posterior circulation strokes.
  • The Cincinnati Stroke Scale is good for EMS, but not necessarily for emergency physicians.

References:  http://onlinelibrary.wiley.com/store/10.1002/9781118783467.app5/asset/app5.pdf?v=1&t=jcf2yn71&s=3c2341ba472c1fcc88003dc0af7eac28691dd980

Podcast #282: EKG Changes in DKA

Author: Dave Rosenberg, M.D.

Educational Pearls

  • EKG changes that can be seen in DKA include ST elevation and peaked T-waves secondary to derangements in K levels.
  • In DKA,  serum K is high, but total body K is low, which can cause said EKG abnormalities.
  • Many things cause ST elevation besides MI, so think beyond STEMI.
  • When someone in in DKA, think about the “Three I’s” for underlying cause: (not taking) insulin, ischemia, infection.

References:  Nageswara Rao Chava. ECG in Diabetic Ketoacidosis. Arch Intern Med. 1984;144(12):2379?2380. doi:10.1001/archinte.1984.00350220101022


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