Episode 955: Cardiac Effects of COVID-19
Emergency Medical Minute
Contributor: Ricky Dhaliwal, MD Educational Pearls: What factors are considered in a COVID-19 infection? The viral load: Understood as the impact of SARS-CoV-2 viral particles infecting host cell tissue itself (utilizing ACE-2 receptors). Pro-Inflammatory Response: Post-infection, the body's downstream systemic cytokine release (can be both normal or hyperactive, aka “cytokine storm”). What cardiac impacts have been observed with COVID-19? Arrhythmias: The mechanism of COVID-19 infection and arrhythmias is believed to be multifactorial. However, evidence suggests T-cell-mediated...
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Episode 954: Combo Rescue Inhalers - New Guidelines
Emergency Medical Minute
Contributor: Aaron Lessen, MD Educational Pearls: What is a Rescue Inhaler? A rescue inhaler is a medication for people with asthma to quickly reverse the symptoms of an asthma attack. Historically albuterol (Short Acting Beta Agonist (SABA)) monotherapy has been the mainstay rescue inhaler. This is because albuterol works fast and is relatively cheap. \n\n What are Combination Rescue Inhalers? Combination rescue inhalers contain a fast-acting bronchodilator as well as an inhaled corticosteroid (ICS) The steroid helps to reduce some of the chronic airway inflammation that is...
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Episode 953: Penicillin Allergies
Emergency Medical Minute
Contributor: Geoff Hogan MD Educational Pearls: Penicillin allergies are relatively uncommon despite their frequent reports 10% of the population reports a penicillin allergy but only 5% of these cases are clinically significant 90-95% of patients may tolerate a rechallenge after appropriate allergy evaluation Penicillin Allergy Decision Rule (PEN-FAST) on MD Calc Useful tool to assess patients for penicillin allergies Five years or less since reaction = 2 points (even if unknown) Anaphylaxis or angioedema OR Severe cutaneous reaction = 2 points Treatment required for...
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Episode 952: Heart Transplants
Emergency Medical Minute
Contributor: Travis Barlock, MD Educational Pearls: Key clinical considerations when managing heart transplant patients due to their unique pathophysiology 1. Arrhythmias A transplanted heart is denervated, meaning it lacks autonomic nervous system innervation The lack of vagal tone results in an increased resting heart rate Adenosine can be used since it primarily slows conduction through the AV node Atropine is ineffective in treating transplant bradyarrhythmia because its mechanism is to inhibit the vagus nerve - but the heart lacks vagal tone Allograft rejection can...
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Episode 951: Pediatric Febrile Seizures
Emergency Medical Minute
Contributor: Taylor Lynch, MD Educational Pearls: Pediatric febrile seizures are defined as seizures that occur between the ages of six months to five years in the presence of a fever greater than or equal to 38.0 ºC (100.4 ºF). It is the most common pediatric convulsive disorder, with an incidence between 2-5% What are the types of seizures? Simple: Tonic-clonic seizure, duration <15 minutes, only one occurrence in a 24-hour period, ABSENCE of focal features, ABSENCE of Todd’s paralysis Complex: Duration >15 minutes, requires medication to stop the seizing, multiple...
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Episode 950: Ultrasound Pulse Check During Cardiac Arrest
Emergency Medical Minute
Contributor: Aaron Lessen, MD Educational Pearls: Point-of-care ultrasound (POCUS) is used to assess cardiac activity during cardiac arrest and can identify potential reversible causes such as pericardial tamponade Ultrasound could be beneficial in another way during cardiac arrest as well: pulse checks Manual palpation for detecting pulses is imperfect, with false positives and negatives Doppler ultrasound can be used as an adjunct or replacement to manual palpation for improved accuracy Options for Doppler ultrasound of carotid or femoral pulses during cardiac arrest: ...
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Episode 949: Hoover's Sign
Emergency Medical Minute
Contributor: Travis Barlock, MD Educational Pearls: What is Hoover’s sign used to identify? This physical exam maneuver differentiates between organic vs. functional (previously known as psychogenic) leg weakness. Organic causes include disease processes such as stroke, MS, spinal cord compression, guillain-barre, ALS, and sciatica, among others In Functional Neurologic Disorder, the dysfunction is in brain signaling, and treatment relies on more of a psychiatric approach How is Hoover's Sign performed? Place your hand under the heel of the unaffected leg and ask the patient to...
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Episode 948: CYP Inducers and Inhibitors
Emergency Medical Minute
Contributor: Jorge Chalit-Hernandez, OMS3 Educational Pearls: CYP enzymes are responsible for the metabolism of many medications, drugs, and other substances CYP3A4 is responsible for the majority Other common ones include CYP2D6 (antidepressants), CYP2E1 (alcohol), and CYP1A2 (cigarettes) CYP inducers lead to reduced concentrations of a particular medication CYP inhibitors effectively increase concentrations of certain medications in the body Examples of CYP inducers Phenobarbital Rifampin Cigarettes St. John’s Wort Examples of CYP inhibitors -azole...
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Episode 947: Hypercapnia
Emergency Medical Minute
Educational Pearls: Physiologic stimulation of ventilation occurs through changes in levels of: Arterial carbon dioxide (PaCO2) Arterial oxygen (PaO2) Hypercapnia is an elevated level of CO2 in the blood - this primarily drives ventilation Hypoxia is a decreased level of O2 in the body’s tissues - the backup drive for ventilation Patients at risk of hypercapnia should maintain an O2 saturation between 88-92% Normal O2 saturation is 95-100% In patients who chronically retain CO2, their main drive for ventilation becomes hypoxia An audit was performed of SpO2 observations...
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Episode 946: Time to Defibrillation
Emergency Medical Minute
Contributor: Aaron Lessen, MD Educational Pearls: Quick background info Cardiac arrest is when the heart stops pumping blood for any reason. This is different from a heart attack in which the heart is still working but the muscle itself is starting to die. One cause of cardiac arrest is when the electrical signals are very disrupted in the heart and start following chaotic patterns such as Ventricular tachycardia (VTach) and Ventricular fibrillation (VFib) One of the only ways to save a person whose heart is in VFib or VTach is to jolt the heart with electricity and terminate the...
info_outlineContributor: Alicia Oberle, MD
Educational Pearls:
- Nitrous oxide (N2O) can cause a vitamin B12 deficiency in patients after regular use
- N2O is used in procedural sedation but also as a popular recreational drug
- N2O binds and inactivate B12 in the body, therefore decreasing usable supply
- Lack of B12, which is essential for myelinating nerves, can lead to subacute combined degeneration of the spinal cord
- Presentation may include paresthesias, ataxia, gait changes, or bilateral lower extremity motor weakness
- B12 can be normal on labs, as the B12 is present but inactivated
- Treatment is daily B12 injections and oral supplementation
References
Stockton L, Simonsen C, Seago S. Nitrous oxide-induced vitamin B12 deficiency. Proc (Bayl Univ Med Cent). 2017;30(2):171-172. doi:10.1080/08998280.2017.11929571
Samia AM, Nenow J, Price D. Subacute Combined Degeneration Secondary to Nitrous Oxide Abuse: Quantification of Use With Patient Follow-up. Cureus. 2020;12(10):e11041. Published 2020 Oct 19. doi:10.7759/cureus.11041
Edigin E, Ajiboye O, Nathani A. Nitrous Oxide-induced B12 Deficiency Presenting With Myeloneuropathy. Cureus. 2019;11(8):e5331. Published 2019 Aug 6. doi:10.7759/cureus.5331
*Image obtained from Wikimedia author Hansmuller and licensed under Creative Commons Attribution-Share Alike 4.0 International license.
Summarized by John Spartz, MS4 | Edited by Erik Verzemnieks, MD
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