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Episode 926: Supraventricular Tachycardia

Emergency Medical Minute

Release Date: 10/21/2024

Episode 936: Etomidate vs. Ketamine for Rapid Sequence Intubation show art Episode 936: Etomidate vs. Ketamine for Rapid Sequence Intubation

Emergency Medical Minute

Contributor: Ricky Dhaliwal MD Educational Pearls:  Etomidate was previously the drug of choice for rapid sequence intubation (RSI) However, it carries a risk of adrenal insufficiency as an adverse effect through inhibition of mitochondrial 11-β-hydroxylase activity A recent meta-analysis analyzing etomidate as an induction agent showed the following: 11 randomized-controlled trials with 2704 patients Number needed to harm is 31; i.e. for every 31 patients that receive etomidate for induction, there is one death The probability of any mortality increase was 98.1% ...

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Emergency Medical Minute

Contributor: Aaron Lessen MD Educational Pearls: Pregnant patients at high risk of cardiac arrest, in cardiac arrest, or in extremis require special care A useful mnemonic to recall the appropriate management of critically ill pregnant patients is TOLDD T: Tilt the patient to the left lateral decubitus position This position relieves pressure exerted from the uterus onto the inferior vena cava, which reduces cardiac preload If the patient is receiving CPR, an assistant should displace the uterus manually from the IVC towards the patient’s left side O: Administer high-flow...

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Episode 934: Subendocardial Ischemia show art Episode 934: Subendocardial Ischemia

Emergency Medical Minute

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Emergency Medical Minute

Contributor: Alec Coston MD Educational Pearls: Causes of seizures in a fairly well-appearing child with diarrhea: Electrolyte abnormalities: hypocalcemia, hyponatremia Also hyperkalemia which causes arrhythmias and syncope - can appear like seizures Hypoglycemia If the child has diarrhea and appears very sick, differential diagnosis may include: Hemolytic uremic syndrome (HUS): simultaneous occurrence of microangiopathic hemolytic anemia, thrombocytopenia, and acute kidney injury Typically caused by Shiga-like toxin producing Escherichia coli (also known as EHEC, or...

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Episode 932: Induction Agent Hypotension show art Episode 932: Induction Agent Hypotension

Emergency Medical Minute

Contributor: Aaron Lessen MD Educational Pearls: Induction agent selection during rapid sequence intubation involves accounting for hemodynamic stability in the post-intubation setting Many emergency departments use ketamine or etomidate A recent study sought to explore the rates of post-induction hypotension of ketamine compared with propofol Single center retrospective cohort study of patients between 2018-2021 Ketamine and propofol were both significantly associated with post-induction hypotension Ketamine adjusted odds ratio = 4.50 Propofol adjusted odds ratio = 4.88 50%...

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Episode 931: Naloxone in Cardiac Arrest show art Episode 931: Naloxone in Cardiac Arrest

Emergency Medical Minute

Contributor: Aaron Lessen MD Educational Pearls: Can opioids cause cardiac arrest? Opioids can cause respiratory suppression and the subsequent low oxygen levels can lead to arrhythmias and eventually cardiac arrest. In 2023, 17% of out-of-hospital cardiac arrests (OHCA) were attributable to opioids. Given that this is a rising cause of cardiac arrest, should we just treat all cardiac arrest with naloxone (Narcan)? Naloxone is correlated with an increased chance of return of spontaneous circulation (ROSC) Additionally, a wide variety of individuals can be exposed to opioids and...

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Emergency Medical Minute

Contributor: Aaron Lessen MD Educational Pearls: A study evaluated the patient-care impact and financial costs of holding patients in the ED, a nationwide issue Prospective, observational study of acute stroke management Conducted at a large urban, comprehensive stroke center The study evaluated patients in multiple categories:  admitted to med/surg admitted to med/surg but held in the ED admitted to the ICU Admitted to ICU but held in the ED Examined the amount of time nurses and providers spent with each patient This was analyzed in conjunction with the...

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Emergency Medical Minute

Contributor: Aaron Lessen MD Educational Pearls: Aortic injury occurs in 1.5-2% of patients who sustain blunt thoracic trauma Majority are caused by automobile collisions or motorcycle accidents Due to sudden deceleration mechanism accidents Clinical manifestations Signs of hypovolemic shock including tachycardia and hypotension, though not always present Patients may have altered mental status Imaging Widened mediastinum on chest x-ray, though not highly sensitive CT is more sensitive and specific, and signs of thoracic injury include an intimal flap, aortic wall...

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Laboring Under Pressure Episode 4: Obstetric Emergency in South Africa with Dr. Meghan Hurley show art Laboring Under Pressure Episode 4: Obstetric Emergency in South Africa with Dr. Meghan Hurley

Emergency Medical Minute

Laboring Under Pressure Episode 4: Obstetric Emergency in South Africa with Dr. Meghan Hurley Contributors: Meghan Hurley MD, Travis Barlock MD, Jeffrey Olson MS3 Show Pearls Map of South Africa Referenced South Africa Geography Lesson There is a big disparity between Cape Town and its neighbor Khayelitsha. Cape Town is the legislative capital and economic hub of South Africa, known for its infrastructure, tourist attractions, and developed urban areas. Khayelitsha Township is a large informal settlement on the outskirts of Cape Town, with limited infrastructure and services compared to...

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Episode 928: Neutropenic Fever show art Episode 928: Neutropenic Fever

Emergency Medical Minute

Contributor: Taylor Lynch, MD Educational Pearls: What is neutropenic fever? Specific type of fever that is seen in cancer patients and other patients with impaired immune systems These patients are highly susceptible to infection Typically occurs 7-10 days after the last chemotherapy dose, this is when the immune system is the weakest It is useful to know the specific type of malignancy. For example, heme malignancies (ALL, AML, etc.) have more intense chemo and are at higher risk of neutropenic fever To qualify as a neutropenic fever, a patient must have one recorded temperature...

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Contributor: Taylor Lynch MD

  • Supraventricular tachycardias (SVTs) arise above the bundle of His

    • The term SVT includes AV nodal reentrant tachycardia (AVNRT), atrioventricular reentrant tachycardia (AVRT), atrial tachycardia, atrial fibrillation, atrial flutter, and multifocal atrial tachycardia 

  • AVNRT is the most common form of SVT

    • Paroxysmal

    • Spontaneous or provoked by exertion, coffee, alcohol, or thyroid disease

    • More common in women (3:1 women:men ratio)

    • HR 160-240

    • Narrow complex with a normal QRS

  • Unstable patients receive synchronized cardioversion at 0.5-1 J/kg

  • Valsalva maneuver is attempted before pharmaceutical interventions

    • Increases vagal tone at the AV node to slow conduction and prolongs its refractory period to normalize the conduction

    • Traditionally, patients are asked to bear down, but this only works in 17% of patients

    • REVERT trial assessed a modified valsalva that worked in 43% of patients

  • Adenosine

    • Slows conduction at the AV node by activating potassium channels and inhibiting calcium influx

    • Extremely uncomfortable for most patients

    • Not commonly used anymore

  • Nondihydropyridine calcium-channel blockers are preferred

    • A 2009 RCT investigated low-infusion CCBs compared with adenosine bolus

    • The study found a conversion rate of 98% in the CCB group vs. adenosine group at 86.5%

    • The main adverse effect of CCB is hypotension, which a slow infusion rate can mitigate

    • Diltiazem dose is 0.25 mg/kg/2min and repeat at 0.35 mg/kg/15 minutes or slow infusion at 2.5 mg/min up to a conversion or 50 mg total

References

  1. 1. Appelboam A, Reuben A, Mann C, et al. Postural modification to the standard Valsalva manoeuvre for emergency treatment of supraventricular tachycardias (REVERT): A randomised controlled trial. Lancet. 2015;386(10005):1747-1753. doi:10.1016/S0140-6736(15)61485-4

  2. Belz MK, Stambler BS, Wood MA, Pherson C, Ellenbogen KA. Effects of enhanced parasympathetic tone on atrioventricular nodal conduction during atrioventricular nodal reentrant tachycardia. Am J Cardiol. 1997;80(7):878-882. doi:10.1016/s0002-9149(97)00539-0

  3. Lim SH, Anantharaman V, Teo WS, Chan YH. Slow infusion of calcium channel blockers compared with intravenous adenosine in the emergency treatment of supraventricular tachycardia. Resuscitation. 2009;80(5):523-528. doi:10.1016/j.resuscitation.2009.01.017

  4. Page RL, Joglar JA, Caldwell MA, et al. 2015 ACC/AHA/HRS Guideline for the Management of Adult Patients With Supraventricular Tachycardia: A Report of the American College of Cardiology/American Heart Association Task Force on Clinical Practice Guidelines and the Heart Rhythm Society [published correction appears in Circulation. 2016 Sep 13;134(11):e234-5. doi: 10.1161/CIR.0000000000000448]. Circulation. 2016;133(14):e506-e574. doi:10.1161/CIR.0000000000000311

Summarized & Edited by Jorge Chalit, OMS3

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