Contributor: Taylor Lynch, MD

Educational Pearls:

Dilutional Hyponatremia:

• Occurs when there is an excess of free water relative to sodium in the body.
• Causes a falsely low sodium concentration without a true change in total body sodium.

Commonly seen in DKA:

• Hyperglycemia raises plasma osmolality.
• Water shifts from the intracellular to extracellular space.
• This dilutes serum sodium, creating apparent hyponatremia.

Corrected sodium calculation:

Use tools like MDCALC, or apply this formula:

• Add 1.6 mEq/L to the measured sodium for every 100 mg/dL increase in glucose above 100.

Clinical relevance:

• Considering corrected sodium in DKA is crucial, as the lab value may not be reflective of actual sodium depletion.
• True severe hyponatremia can lead to complications like seizures
  • May require treatment with hypertonic saline.

References:

1. Fulop M. Acid–base problems in diabetic ketoacidosis. Am J Med Sci. 2008;336(4):274-276. doi:10.1097/MAJ.0b013e318180f478
2. Palmer BF, Clegg DJ. Electrolyte and Acid–Base Disturbances in Patients with Diabetes Mellitus. N Engl J Med. 2015;373(6):548-559. doi:10.1056/NEJMra1503102
3. Spasovski G, Vanholder R, Allolio B, et al. Diagnosis and management of hyponatremia: a review. JAMA. 2014;312(24):2640–2650. doi:10.1001/jama.2014.13773

Summarized by Ashley Lyons, OMS3 | Edited by Ashley Lyons & Jorge Chalit, OMS4

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Contributors:

Col. (Dr.) Stacy Shackelford Dr. Sean Keenan Paramedic Alan Moreland Dr. Chris Tems Kara Napolitano

From military-inspired trauma protocols to behavioral health alternatives and cardiac resuscitation, EMS is evolving fast. Our Medical Minutes from EMSAC highlight the growing need for prehospital providers to think critically, act quickly, and adapt to new approaches in trauma, crisis response, and patient advocacy.

Educational Pearls:

What was covered & recorded at EMSAC 2024 by EMM?

Col. (Dr.) Stacy Shackelford, U.S. Air Force trauma surgeon and Director of the Joint Trauma System, emphasized the critical importance of early hemorrhage control and timely transfusions in prehospital trauma care. She highlighted military studies showing that interventions within 30 minutes can dramatically increase survival, underscoring the value of rapid response and frontline readiness.

Dr. Sean Keenan, retired Army emergency physician and EMS doctor, introduced the concept of prolonged field care—managing critically injured patients in environments where evacuation is delayed. He discussed how this model, developed in the military, is now being taught to civilian EMS providers in rural areas.

Paramedic Alan Moreland from Denver’s STAR Program (Support Team Assisted Response) explained how alternative response teams, pairing paramedics with clinical social workers, are reshaping how we respond to behavioral health emergencies, reducing reliance on police or ambulance transport and focusing on trauma-informed care.

Dr. Chris Tems, an emergency physician working with ECMO (extracorporeal membrane oxygenation), shared data on using ECMO for refractory cardiac arrest. With a survival rate of 87.5% in select emergency department cases, he highlighted ECMO’s growing role in cardiac resuscitation for patients not responding to CPR.

Kara Napolitano, of the Laboratory to Combat Human Trafficking, outlined the role EMS plays in recognizing human trafficking. She offered key indicators to look for and encouraged providers to stay alert to the signs of exploitation, emphasizing EMS’s role in early intervention.

Recorded by: Steven Fujaros, Brian Parga, & Ahmed Abdel-Hafiz Summarized by: Steven Fujaros

Contributor: Jorge Chalit-Hernandez, OMS4

Educational Pearls:

• What is the toxic dose of acetaminophen?
  • 7.5 grams, in an adult. The safe daily limit is 4 grams in an adult with a normally functioning liver.
  • This is equivalent to fifteen 500mg pills.
• What are the symptoms of acetaminophen toxicity?
  • First 24 hours, symptoms are non-specific e.g. nausea, vomiting, lack of appetite. Can also be asymptomatic.
  • 24-72 hours, hepatotoxicity occurs (causing yellow skin, pruritus, abdominal pain, bleeding, and confusion)
  • Fulminant liver failure at 72-96 hours
  • Liver function tests (LFTs) peak at 72-96 hours.
• When would you give activated charcoal?
  • Within 4 hours of ingestion.
  • The risk of activated charcoal is that it can be very dangerous if aspirated so use with caution with a poorly mentating patient
• When would you give N-acetylcysteine (NAC)?
  • The peak absorption of acetaminophen occurs at about 4 hours with acute ingestions
  • Use the Rumack–Matthew nomogram to plot the serum level of acetaminophen versus the time since ingestion to see if you are above the treatment line.
  • If the ingestion time is unknown then just give it.
• How do you dose NAC?
  • 3 bag system: First, a 150 mg/kg bolus is administered IV over 15-60 minutes (Bag 1), then a 50 mg/kg drip is administered over 4 hours (Bag 2), then a 100 mg/kg drip is administered over the following 16 hours (Bag 3).
    • This is the Prescott Protocol that requires three bag of IV fluids
  • 2 bag system: There is a simplified protocol that only requires 2 bags, 200mg/kg IV over 4 hours (Bag 1) followed by 100mg/kg over 16 hours (Bag 2)
    • Less risk of anaphylactoid reactions with a 2-bag system due to the high rate of IV NAC given in the 3 bag system.
• What are the endpoints for stopping NAC?
  • If the INR is

Contributor: Aaron Lessen, MD

Educational Pearls:

• Many trauma patients are placed on oxygen via non-rebreather
• A large, multicenter, controlled trial evaluated the outcomes of oxygen administration in trauma patients
• Patients were randomized to two groups
  • 1. 8-hour restrictive oxygen strategy: only receiving oxygen when the patient’s saturation dropped below 94% 2. 8-hour liberal oxygen strategy: 12-15 liters of oxygen per minute or fraction of inspired oxygen of 0.6-1.0
• The study evaluated rates of death or major respiratory complications at 30 days
• There was no statistical difference between the two groups
  • Therefore, there is no clear benefit to administering liberal amounts of oxygen to trauma patients, but there is also no clear harm
• Ultimately, trauma patients do not need to be on oxygen via non-rebreather unless they are hypoxic or short of breath

References

1. Arleth T, Baekgaard J, Siersma V, et al. Early Restrictive vs Liberal Oxygen for Trauma Patients: The TRAUMOX2 Randomized Clinical Trial. JAMA. 2025;333(6):479-489. doi:10.1001/jama.2024.25786

Summarized by Meg Joyce, MS2 | Edited by Meg Joyce & Jorge Chalit, OMS4

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Contributor: Aaron Lessen, MD

Educational Pearls:

• Prehospital seizures are typically managed with intramuscular midazolam (Versed)
• Seizures theoretically involve the NMDA pathway, and ketamine is a potent NMDA antagonist
• A recent retrospective cohort study analyzed a Florida EMS protocol that uses ketamine in seizures refractory to midazolam
  • One group received two doses of midazolam for seizure control
  • The other group received a dose of midazolam followed by a dose of ketamine
• After matching, 82% of the midazolam-only group patients had resolution of convulsions prior to ED arrival
  • 94.4% of patients in the midazolam + ketamine group experienced resolution
  • Absolute difference between groups was 12.4% (95% CI 3.1% to 21.7%)
• Limitations to the study include its prehospital setting and limited long-term follow-up

References

1. Zitek T, Scheppke KA, Antevy P, et al. Midazolam and Ketamine for Convulsive Status Epilepticus in the Out-of-Hospital Setting. Ann Emerg Med. 2025;85(4):305-312. doi:10.1016/j.annemergmed.2024.11.002

Summarized & Edited by Jorge Chalit, OMS4

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Contributor: Alec Coston, MD

Educational Pearls:

For patients presenting to the emergency room with hypertension, clinicians should determine if it is isolated and uncomplicated, or involves comorbidities with more complex underlying pathophysiology. 

For uncomplicated and isolated hypertension, first-line treatment is thiazide diuretics. 

How do thiazide diuretics work to treat hypertension?

• Thiazide diuretics work by blocking sodium and chloride resorption in the kidneys.  “Where sodium goes, water follows,” thus promoting diuresis and lowering blood pressure.

Examples of thiazide diuretics and their benefits?

• Hydrochlorothiazide (HCTZ): First-line medication in uncomplicated and chronic hypertensive states. Cheaper and fewer significant adverse effects compared to chlorthalidone.
• HCTZ can be associated with decreased risk of stroke and myocardial infarction.
• However, for more complicated hypertension, especially in the setting of heart failure, Angiotensin Converting Enzyme (ACE) Inhibitors should be considered. 

How do ACE Inhibitors manage blood pressure?

• The body’s kidneys drive the Renin-Angiotensin-Aldosterone-System (RAAS) to regulate blood pressure.
• It is easiest to understand RAAS as being pro-hypertensive as a response to decreased renal perfusion. As renal perfusion decreases, renin is released and activates angiotensin I, which is converted by ACE to Angiotensin II, which causes release of aldosterone.
• ACE Inhibitors prevent the conversion of Angiotensin I to Angiotensin II, thus decreasing the kidneys' production of Angiotensin II and Aldosterone levels.

Why, in the context of heart failure, are ACE Inhibitors preferred?

• In heart failure, especially left-sided or left-ventricular heart failure, a vicious cycle can develop wherein the left ventricle fails to perfuse the kidneys due to over-dilation.
• The kidneys are hypoperfused and activate RAAS to try to retain volume and increase peripheral vasoconstriction, promoting renal perfusion.
• The increase in blood pressure puts further strain on the heart, thereby further decreasing cardiac output. The cycle develops, and extremely elevated blood pressures can develop.
• ACE Inhibitors can directly block this cycle, hence their preference in heart failure.

Big takeaway?

• In uncomplicated hypertensive patients, consider thiazide diuretics. When comorbidities, especially heart failure, are introduced, then consider ACE Inhibitors.

References

1. Carey RM, Moran AE, Whelton PK. Treatment of Hypertension: A Review. JAMA. 2022;328(18):1849-1861. doi:10.1001/jama.2022.19590
2. Fan M, Zhang J, Lee CL, Zhang J, Feng L. Structure and thiazide inhibition mechanism of the human Na-Cl cotransporter. Nature. 2023;614(7949):788-793. doi:10.1038/s41586-023-05718-0
3. Hripcsak G, Suchard MA, Shea S, et al. Comparison of Cardiovascular and Safety Outcomes of Chlorthalidone vs Hydrochlorothiazide to Treat Hypertension. JAMA Internal Medicine. 2020;180(4):542-551. doi:10.1001/jamainternmed.2019.7454
4. Yu D, Li JX, Cheng Y, et al. Comparative efficacy of different antihypertensive drug classes for stroke prevention: A network meta-analysis of randomized controlled trials. PLoS One. 2025;20(2):e0313309. doi:10.1371/journal.pone.0313309

Summarized by Dan Orbidan, OMS2 | Edited by Dan Orbidan & Jorge Chalit, OMS4

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Contributor: Taylor Lynch, MD Educational Pearls:

How do we risk-stratify chest-pain patients?

• One option is the HEART score
  • This score predicts a patient’s 6-week risk of a major adverse cardiac event.
    • Ex. Cath procedure, CABG, PCI, death
• H stands for History
  • Ask 1) Was the patient diaphoretic? 2) Did they have nausea and/or vomiting? 3) Did the pain radiate down the right or left arm? 4) Was it exertional?
  • Yes to one = one point. Two or more = two points.
• E stands for EKG
  • One point for left ventricular hypertrophy, t-wave inversions, new bundle-branch blocks.
  • No points for first degree AV block, benign early repolarization, or QT-prolongation
  • Two points for ST-depression
• A stands for Age
  • >65 gets two points
  • 45-64 gets one point
• R stands for Risk factors
  • Hypertension, hyperlipidemia, diabetes, obesity, family history, smoking, previous MI, previous CABG, stroke, peripheral arterial disease
  • 1-2 risk factors get 1 point
  • More than two risk factors gets two points
• T stands for Troponin
  • 1-3x upper limit of normal gets one point
  • >3x upper limit of normal gets two points
• This gives you a score between zero and ten
  • 0-3 points, patients have a ~2% chance of an adverse event
    • These patients likely go home
  • 4-6 points, patients have a ~20% chance of an adverse event
    • These patients get admitted or expedited outpatient stress test/echo
  • 7-10 points, patients have a ~60% chance of an adverse event
    • Admit and call cardiology.
    • These patients likely get catheterized

References

1. Backus BE, Six AJ, Kelder JC, Bosschaert MA, Mast EG, Mosterd A, Veldkamp RF, Wardeh AJ, Tio R, Braam R, Monnink SH, van Tooren R, Mast TP, van den Akker F, Cramer MJ, Poldervaart JM, Hoes AW, Doevendans PA. A prospective validation of the HEART score for chest pain patients at the emergency department. Int J Cardiol. 2013 Oct 3;168(3):2153-8. doi: 10.1016/j.ijcard.2013.01.255. Epub 2013 Mar 7. PMID: 23465250.
2. Laureano-Phillips J, Robinson RD, Aryal S, Blair S, Wilson D, Boyd K, Schrader CD, Zenarosa NR, Wang H. HEART Score Risk Stratification of Low-Risk Chest Pain Patients in the Emergency Department: A Systematic Review and Meta-Analysis. Ann Emerg Med. 2019 Aug;74(2):187-203. doi: 10.1016/j.annemergmed.2018.12.010. Epub 2019 Feb 2. PMID: 30718010.
3. https://www.mdcalc.com/calc/1752/heart-score-major-cardiac-events

Summarized by Jeffrey Olson, MS4 | Edited by Jorge Chalit, OMS4

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Contributor: Aaron Lessen, MD Educational Pearls:

• A prospective study at the Mayo Clinic Rochester was conducted to examine whether patients actively using their phones on initial assessment in the ED was associated with higher discharge rates
• The study included 292 patients, and only about 15% of patients were on their phone
  • The patients on their phone tended to be a younger demographic
• Scribes were trained to record the data during their shifts
• The results did show that patients on their phone have a higher rate of discharge
  • 94% chance of discharge if the patient is on their phone
  • 64% chance of discharge if the patient is not on their phone
• This concept can potentially contribute to improving triage decisions

References

1. Garcia SI, Jacobson A, Moore GP, Frank J, Gifford W, Johnson S, Lazaro-Paulina D, Mullan A, Finch AS. Airway, breathing, cellphone: a new vital sign? Int J Emerg Med. 2024 Nov 22;17(1):177. doi: 10.1186/s12245-024-00769-0. PMID: 39578750; PMCID: PMC11583604.

Summarized by Meg Joyce, MS2 | Edited by Meg Joyce & Jorge Chalit, OMS4

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Contributor: Travis Barlock MD Educational Pearls

• Frank’s sign is a curious physical exam finding first described in the literature in 1973
  • Bilateral earlobe creases are recognized as a marker of coronary artery disease and cerebrovascular disease
• Some studies have found an increase in all-cause mortality in patients with bilateral diagonal earlobe creases
• The pathophysiology is still not fully understood
  • One 2020 study found histopathological changes associated with diagonal earlobe creases, potentially linking them via a model of hypoxia/reoxygenation

References

1. Elliott WJ, Karrison T. Increased all-cause and cardiac morbidity and mortality associated with the diagonal earlobe crease: a prospective cohort study. Am J Med. 1991;91(3):247-254. doi:10.1016/0002-9343(91)90123-f
2. Nazzal S, Hijazi B, Khalila L, Blum A. Diagonal Earlobe Crease (Frank's Sign): A Predictor of Cerebral Vascular Events. Am J Med. 2017;130(11):1324.e1-1324.e5. doi:10.1016/j.amjmed.2017.03.059
3. Stoyanov GS, Dzhenkov D, Petkova L, Sapundzhiev N, Georgiev S. The Histological Basis of Frank's Sign. Head Neck Pathol. 2021;15(2):402-407. doi:10.1007/s12105-020-01205-4

Summarized & Edited by Jorge Chalit, OMS4

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Contributor: Taylor Lynch, MD Educational Pearls:

The KLM Flight Disaster, also known as the Tenerife Airport Disaster, occurred on 27 March 1977. It involved the collision of two Boeing 747 passenger jets from KLM and Pan Am Airlines, resulting in 583 fatalities. 

What fell through the cracks to cause this incident?

• The captain of the KLM flight believed he had received clearance from air traffic control to take off, when in fact he had not.
• This captain was one of the most senior pilots in the organization, and the culture often saw senior pilots as infallible and not to be questioned.
• The co-pilot, who noticed improper communication resulting from power dynamics, did not assertively speak up. 

What lessons can be taken from the tragedy and applied to healthcare? 

• Aviation and healthcare are both high-stakes industries that require extensive communication for the safety of passengers and patients.
• Within medicine, an inherent hierarchy exists, and it is crucial not to let this hierarchy and perceived power imbalance prevent people from speaking up.
• In healthcare, providers such as nurses, paramedics, and technicians may spend more time with patients and thus may notice warning signs earlier. It is imperative to foster a culture where they can speak up freely and without hesitation if something concerning is caught in a patient. 

When might mistakes happen most often?

• Hanna et al. found that radiological interpretation errors were more likely to occur later in shifts, peaking around the 10-to-12-hour mark.
• Leviatan et al. found that medication prescription errors were more likely to occur by physicians working on 2nd and 3rd consecutive shifts.
• Hendey et al. found medication ordering errors were higher on overnight and post-call shifts.
• Gatz et al. found that surgical procedural complication rates are higher during the last 4 hours of a 12-hour shift.

In Short, Ends of shifts are when mistakes are most likely to occur. 

Overall takeaway?

• In a healthcare team, it is critical to look after each other regardless of years of experience or post-nominal letters, and speak up for patient safety. Making a special note that we may need to do so more towards the end of shifts, where we might not be at our sharpest.   

References

1. Gatz JD, Gingold DB, Lemkin DL, Wilkerson RG. Association of Resident Shift Length with Procedural Complications. Journal of Emergency Medicine. 2021 Aug 1;61(2):189–97.
2. Hanna TN, Lamoureux C, Krupinski EA, Weber S, Johnson JO. Effect of Shift, Schedule, and Volume on Interpretive Accuracy: A Retrospective Analysis of 2.9 Million Radiologic Examinations. Radiology. 2018 Apr;287(1):205–12.
3. Hendey GW, Barth BE, Soliz T. Overnight and postcall errors in medication orders. Acad Emerg Med. 2005 Jul;12(7):629–34.
4. Leviatan I, Oberman B, Zimlichman E, Stein GY. Associations of physicians’ prescribing experience, work hours, and workload with prescription errors. J Am Med Inform Assoc. 2021 Jun 12;28(6):1074–80.

Summarized by Dan Orbidan, OMS2 | Edited by Dan Orbidan & Jorge Chalit, OMS4

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