Episode 942: Acute Mountain Sickness and High Altitude Cerebral Edema
Emergency Medical Minute
Contributor: Jorge Chalit-Hernandez, OMS3 Educational Pearls: Acute mountain sickness (AMS) is the term given to what is otherwise colloquially known as altitude sickness High altitude cerebral edema (HACE) is a severe form of AMS marked by encephalopathic changes Symptoms begin at elevations as low as 6500 feet above sea level for people who ascend rapidly May develop more severe symptoms at higher altitudes The pathophysiology involves cerebral vasodilation Occurs in everyone ascending to high altitudes but is more pronounces in those that develop symptoms The reduced...
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Episode 941: Rehydration in Pediatric Gastroenteritis
Emergency Medical Minute
Contributor: Meghan Hurley, MD Educational Pearls: Gastroenteritis clinical diagnoses: Diarrhea with or without vomiting and fever Vomiting in the absence of diarrhea has a large list of differential diagnoses, so the combination of diarrhea and vomiting in a patient is helpful to indicate the gastroenteritis diagnosis Symptom timeline is usually 1-3 days, but can last up to 14 days – diarrhea persists the longest Treatment for mild to moderate dehydration: oral or IV rehydration Begin orally to avoid unnecessary IV in a pediatric patient Administer ODT Ondansetron...
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Episode 940: Laceration Repair Methods
Emergency Medical Minute
Contributor: Aaron Lessen, MD Educational Pearls: If a patient sustains a cut, the provider has several options on how to close the wound. If they choose to suture the wound closed, it involves needles both in the form of injecting numbing medication (lidocaine) as well as with the suture itself. Other techniques are “needleless,” like closing the wound with adhesive strips (Steri-Strips) or skin adhesive (Dermabond). But which method is best? A recent study looked to compare guardian-perceived cosmetic outcomes of pediatric lacerations repaired with absorbable sutures, Dermabond, and...
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Episode 939: Serotonin Syndrome
Emergency Medical Minute
Contributor: Jorge Chalit-Hernandez, OMS3 Educational Pearls: Serotonin syndrome occurs most commonly due to the combination of monoamine oxidase inhibition with concomitant serotonergic medications like SSRIs Examples of unexpected monoamine oxidase inhibitors Linezolid - a last-line antibiotic reserved for patients with true anaphylaxis to penicillins and cephalosporins Methylene blue - not mentioned in the podcast due to its uncommon usage for methemoglobinemia Other medications that can interact with SSRIs to cause serotonin syndrome Dextromethorphan - primarily an...
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Episode 938: AHA Policy on Management of Elevated Blood Pressure (BP) in the Acute Care Setting
Emergency Medical Minute
Contributor: Aaron Lessen, MD Educational Pearls: Many patients present to the ED with elevated BP Many are referred from outpatient surgery centers or present after an elevated measurement at home Persistent questions on the best way to treat these patients The AHA published a scientific statement on the management of elevated BP in the acute care setting Hypertensive emergencies: SBP/DBP >180/110–120 mm Hg with evidence of new or worsening target-organ damage Includes aortic dissection or subarachnoid hemorrhage Require aggressive treatment Asymptomatic...
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Episode 937: Pneumomediastinum
Emergency Medical Minute
Contributor: Megan Hurley MD Educational Pearls: What is the mediastinum? The thoracic cavity is separated into different compartments by membranes The lungs exist in their own pleural cavities, and the mediastinum is everything in between The mediastinum extends from the sternum to the thoracic vertebrae and includes the heart, the aorta, the trachea, the esophagus, the thymus, as well as many lymph nodes and nerves. What is a pneumomediastinum? Air in the mediastinum How can pneumomediastinum be categorized? Traumatic Ex. Stab wound to the trachea Ex. Boerhaave’s...
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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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Episode 935: Pregnancy Extremis - TOLDD
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
Emergency Medical Minute
Contributor: Travis Barlock MD Educational Pearls: What is the ST segment? The ST segment on an ECG represents the interval between the end of ventricular depolarization (QRS) and the beginning of ventricular repolarization (T-wave). It should appear isoelectric (flat) in a normal ECG. What if the ST segment is elevated? This is evidence that there is an injury that goes all the way through the muscular wall of the heart (transmural) This is very concerning for a heart attack (STEMI) but can be occasionally caused by other pathology, such as pericarditis What if the ST...
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Episode 933: Benign Convulsions with Gastroenteritis
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...
info_outlineContributor: Megan Hurley MD
Educational Pearls:
What is the mediastinum?
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The thoracic cavity is separated into different compartments by membranes
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The lungs exist in their own pleural cavities, and the mediastinum is everything in between
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The mediastinum extends from the sternum to the thoracic vertebrae and includes the heart, the aorta, the trachea, the esophagus, the thymus, as well as many lymph nodes and nerves.
What is a pneumomediastinum?
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Air in the mediastinum
How can pneumomediastinum be categorized?
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Traumatic
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Ex. Stab wound to the trachea
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Ex. Boerhaave’s Syndrome of the esophagus, possibly from an endoscopic procedure. This mechanism in particular is a higher risk of infection because not only air but food can accumulate in the mediastinum
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Ex. Intubation with a bougie
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These will likely need surgical repair
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Nontraumatic
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Ex. Forceful inhalation causing microperforations in the trachea. Possibly while inhaling something like drugs
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Ex. Bad asthma for similar reasons
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Ex. Gas forming bacteria
What happens if you use positive pressure ventilation on a patient with a hole in their trachea?
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The positive pressure will force extra air into the mediastinum
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The air will move between the layers of subcutaneous tissue and can track up into the neck and face regions recognized as crepitus on exam
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This can also cause a tension pneumomediastinum in which the air pressure in the compartment constricts the heart, impeding its ability to fill during diastole
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These patients can undergo bronchoscopy because that procedure does not require positive pressure and will not worsen the condition. Endoscopies do require positive pressure so endoscopies are not an option
How is a tension pneumomediastinum treated?
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By inserting a needle into the space from below the xiphoid process to allow the air to escape, similar to a pericardiocentesis
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As a temporizing measure, if the hole is high enough in the trachea, the intubation can be continued by deliberately pushing the endotracheal tube into the right main bronchus, creating a seal, and only ventilating the right lung while the patient heads to surgery. This is called right-mainstemming.
References
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Clancy DJ, Lane AS, Flynn PW, Seppelt IM. Tension pneumomediastinum: A literal form of chest tightness. J Intensive Care Soc. 2017 Feb;18(1):52-56. doi: 10.1177/1751143716662665. Epub 2016 Aug 3. PMID: 28979537; PMCID: PMC5606356.
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Grewal, J., & Gillaspie, E. A. (2024). Pneumomediastinum. Thoracic surgery clinics, 34(4), 309–319. https://doi.org/10.1016/j.thorsurg.2024.06.001
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Underner, M., Perriot, J., & Peiffer, G. (2017). Pneumomédiastin et consommation de cocaïne [Pneumomediastinum and cocaine use]. Presse medicale (Paris, France : 1983), 46(3), 249–262. https://doi.org/10.1016/j.lpm.2017.01.002
Summarized by Jeffrey Olson, MS3 | Edited by Meg Joyce & Jorge Chalit, OMS3
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