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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