Emergency Medical Minute

Contributor: Aaron Lessen, MD
Educational Pearls:
 
Benign Paroxysmal Positional Vertigo (BPPV)
Common inner ear condition that can cause dizziness

Diagnosis of BPPV can help to avoid admissions and extra imaging

Three categories: positional, horizontal, and anterior

Positional is the most common 

Dizziness is not a positive indicator, a torsional nystagmus must be induced

Dix's hallpike maneuver is done to diagnose and an epley maneuver is then used for treatment 

Horizontal 

Usually determined to be the case if the vertigo seems positional and the dix hallpike does not work. A supine roll test would then be done to help diagnose.

Instead of a rotational nystagmus, a one-sided horizontal nystagmus is expected in order to determine a positive indicator

Down-beating nystagmus is determined to be geotropic and is treated by a barbeque roll maneuver. While upbeating nystagmus is apogeotropic and is treated by Gufoni maneuver.

Anterior is more rare

Most cases require neuro consults

Determined by attempting to induce a down-beating nystagmus, which is a more concerning nystagmus.

Treatment is tilting their head back up in a similar way

Inducing the nystagmus is not sided and is more central

 
References
Kim DY, et al. Evaluation and management of blunt cerebrovascular injury: A practice management guideline from the Eastern Association for the Surgery of Trauma. J Trauma Acute Care Surg. 2020.

Biffl WL, et al. Screening for and treatment of blunt cerebrovascular injuries: Western Trauma Association critical decisions algorithm. J Trauma. 2009.

Brommeland T, et al. Best practice guidelines for blunt cerebrovascular injury. Scand J Trauma Resusc Emerg Med. 2018.

Harper PR, et al. Routine CTA screening identifies blunt cerebrovascular injuries missed by clinical risk factors. Trauma Surg Acute Care Open. 2022.

 
Summarized by Sam Pahl | Edited by Sam Pahl & Ahmed Abdel-Hafiz, NREMT-P
 
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Contributor: Aaron Lessen, MD
Educational Pearls:
Big question in cardiac arrest: is the rhythm shockable?

Shockable: ventricular fibrillation (VF) and pulseless ventricular tachycardia

Non-shockable: asystole and pulseless electrical activity (PEA)

Rhythm classification is typically based on ECG, but echocardiography can directly visualize myocardial fibrillation

Occult VF: a rhythm that appears non-shockable on ECG but demonstrates VF on echocardiography

A 2025 multicenter prospective study looked at 811 patients with out-of-hospital cardiac arrest

5.3% had occult VF detected by echocardiography

Of the patients with occult VF: 

81.4% had PEA on ECG

18.6% had asystole on ECG

Patients with occult VF were less likely to receive defibrillation because their ECG suggested a nonshockable rhythm

Clinical takeaway: echocardiography during cardiac arrest may reveal a potentially shockable rhythm hiding behind an apparently nonshockable ECG

This identifies a subset of cardiac arrest patients who would otherwise be managed as PEA or asystole based on ECG

 
References
Gaspari R, Adhikari S, Gleeson T, Kapoor M, Lindsay R, Noble V, Nomura JT, Weekes A, Theodoro D. Occult Ventricular Fibrillation Visualized by Echocardiogram During Cardiac Arrest: A Retrospective Observational Study From the Real-Time Evaluation and Assessment for Sonography-Outcomes Network (REASON). J Am Coll Emerg Physicians Open. 2025 Jan 13;6(1):100028. doi: 10.1016/j.acepjo.2024.100028. PMID: 40012664; PMCID: PMC11853361.

 
Summarized by Meg Joyce, MS3 | Edited by Meg Joyce & Ahmed Abdel-Hafiz, NREMT-P
 
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Contributor: Taylor Lynch, MD
Educational Pearls: 
CPR is an important life-saving measure designed for anyone to perform.

Chest compressions works by two mechanisms: 

Cardiac pump: Direct squeezing of the heart

Thoracic pump: Increasing intrathoracic pressure, causing increased blood flow

Proper hand placement per current AHA guidelines: 

Hands are placed in the center of the chest, on the lower half of the sternum

A recent study challenged this approach, using TEE during chest compressions to visualize the cardiac structures being compressed.

They found that when hands were placed ~1cm to the left of the sternum, this compressed the left ventricular outflow tract, potentially restricting forward blood flow.

Hand placement ~4cm to the left of the sternum resulted in more effective compression of the left ventricle.

While this is not yet reflected in AHA guidelines, the study presents an interesting finding that may influence how CPR is performed in the future. 

Key takeaway: Always prioritize administering high quality compressions.




References: 
American Heart Association. 2025 American Heart Association Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care. Circulation. 2025;152(23_suppl_1). doi:10.1161/CIR.0000000000001378.

Chu S, Cheng C, Chang C, et al. Transesophageal echocardiography during CPR in patients with out-of-hospital cardiac arrest: the EXECT-CPR randomized clinical trial. JAMA Intern Med. 2026;186(5):557-566. doi:10.1001/jamainternmed.2026.0102.

 
Summarized by Ashley Lyons, OMS4 | Edited by Ashley Lyons & Ahmed Abdel-Hafiz, NREMT-P
 
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Contributor: Meghan Hurley, MD
Educational Pearls:
What is hypokalemia?
Hypokalemia is when the measured blood level of potassium falls below 3.5 mEq/L (normal 3.5 - 5.2 mEq/L). 

Can generally be considered in mild (3.0 - 3.5 mEq/L); moderate (2.5 - 2.9 mEq/L); and severe ( Should be noted that blood levels of potassium can be low while total body potassium is normal due to intracellular shift by certain agents like β-2 agonists (e.g. Albuterol) or insulin. There is no appreciable loss of insulin despite hypokalemia being present in labs. 

What are the most common causes of hypokalemia? 
Medications are a predominant cause; mainly loop and thiazide diuretics. 

Gastrointestinal losses such as prolonged emesis or diarrhea (can occur in the setting of chronic illness and treatment such as chemotherapy patients with emesis). 

Other renal losses (e.g. hyperaldosteronism and renal tubular acidosis).

A fun-fact renal loss: A compound found in some licorice (Glycyrrhizic acid) can inhibit 11-ß-hydroxysteroid dehydrogenase enzyme type 2 and cause mineralocorticoid excess. See a 2023 case study in references for Lethal Arrhythmia Induced by Licorice. 

What is a less common cause of hypokalemia?
Hypokalemic Periodic Paralysis (HypoPP) is a genetic autosomal dominant channelopathy where patients leak potassium at rest causing a flaccid paralysis of muscle. 

Typically impacting legs more than arms, and proximal muscles more than distal muscles. 

Can be triggered carbohydrate rich meals, rest after exercise, febrile illness, and fasting.

Male predominance, typically in early adulthood.

Treatment is avoidance of triggers and supplementation with conservative oral potassium to avoid overcorrection during attacks. 

What are some symptoms and findings associated with hypokalemia? 
Patients may present with generalized weakness and fatigue.

Highly crucial to monitor for EKG changes in the setting of hypokalemia. 

May notice flattening of T wave with the development of a U wave at certain potassium levels. The lower the potassium levels, the more likely a TU fusion can be seen. 

Prolongs QT interval which puts patients at risk for lethal arrhythmias.

 What are treatment considerations for hypokalemia?
At milder levels of hypokalemia that are asymptomatic and a reversible cause is identified, oral repletion via potassium tablets should be considered. Patients may be a candidate to complete their course of treatment in the Emergency Room. 

At higher symptomatic levels with distinct EKG changes, more aggressive repletion (including IV Potassium) should be considered. Patients may be candidates for admission. 

Always monitor and replace magnesium levels as well, as they tend to follow potassium levels as well. 

Consider intracellular shifts as a source of hypokalemia to avoid risk of overcorrection into hyperkalemia. 

Hypokalemia can cause deadly heart rhythms such as ventricular fibrillation and ventricular tachycardia including Torsades Des Pointes that will be refractory to defibrillation. Treatment considerations at this point include:

Consideration of esmolol

Double Sequential Defibrillation

Extracorporeal Membrane Oxygenation (ECMO). 

Key takeaways?
Hypokalemia is most often associated with medication side effects or total volume loss from emesis or diarrhea. Depending on the degree of hypokalemia, different treatment considerations must be made. Monitor patient EKG closely for changes that can progress to lethal arrhythmias.  

 
References:
Yannopoulos D, Bartos J, Raveendran G, et al. Advanced reperfusion strategies for patients with out-of-hospital cardiac arrest and refractory ventricular fibrillation (ARREST): a phase 2, single centre, open-label, randomised controlled trial. Lancet. 2020;396(10265):1807-1816. doi:10.1016/S0140-6736(20)32338-2

Cheskes S, Verbeek PR, Drennan IR, et al. Defibrillation Strategies for Refractory Ventricular Fibrillation. New England Journal of Medicine. 2022;387(21):1947-1956. doi:10.1056/NEJMoa2207304

Oswald S, Ravioli S, Schwarz C, Lindner G. Hypokalaemia in the emergency department: aetiology, diagnosis, and management. Swiss Medical Weekly. 2026;156(4):4767-4767. doi:10.57187/4767

Gao Z, Xing H, Zhang J, Chen S, Gao Z. Hypokalemic periodic paralysis: novel perspectives from genetic mutations to clinical management. Gene. 2026;999:150172. doi:10.1016/j.gene.2026.150172

Han EJ, Park JS. Lethal Arrhythmia Induced by Licorice. J Korean Med Sci. 2023;38(12):e107. doi:10.3346/jkms.2023.38.e107

Lee YH, Lee KJ, Min YH, et al. Refractory ventricular fibrillation treated with esmolol. Resuscitation. 2016;107:150-155. doi:10.1016/j.resuscitation.2016.07.243

 
Summarized by Dan Orbidan, OMS3 | Edited by Dan Orbidan & Ahmed Abdel-Hafiz, NREMT-P
 
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Contributor: Meghan Hurley, MD
Educational Pearls:
What is hyperkalemia?
Hyperkalemia is when the measured blood level of potassium reaches above 5.2 - 5.5 mEq/L (normal 3.5 - 5.2 mEq/L). 

What are common causes of hyperkalemia? 
Chronic or acute kidney disease.

Medications that impact the Renin-Angiotensin-Aldosterone-System (RAAS). 

Hypoaldosteronism and primary adrenal insufficiency (Addison's Disease).

What are concerns of hyperkalemia?
The biggest concern with hyperkalemia is the impact on the cardiac conduction system.

At differing levels of hyperkalemia, the patient may initially have peaked T waves, that then progress into a widening of the QRS complex which may eventually lead to a sine wave pattern. 

This increases risk for cardiac arrest with ventricular fibrillation, PEA, and asystole.

What is the treatment algorithm for hyperkalemia?
Works through a three-tier approach.

First tier treatment is with a calcium agent (calcium gluconate or chloride). 

Thought for the longest time to "stabilize the cardiac membrane/action potential". Recent research shows the true mechanism of action is likely through acting on calcium dependent channels. 

Does not fix underlying hyperkalemia, but buys time for the heart. 

Second tier treatment is inducing intracellular potassium shift.

Can be achieved through agents such as insulin (which may need to be bolused with glucose to prevent hypoglycemia), albuterol, or sodium bicarbonate. 

Third tier is potassium elimination

If the patient is producing urine, loop or thiazide diuretics can be considered. 

Hemodialysis may also be considered based on patient condition. 

Long term (and slowest method of elimination) through fecal excretion. Unlikely to see benefits in emergency management. 

Key Takeaways? 
Hyperkalemia is a condition that can be brought on by primarily renal conditions and medication side effects. Careful attention must be paid to the patient's cardiac status, and urgent cardiac stabilization (though now we may know that calcium doesn't truly "stabilize" the cardiac membrane) must be performed to prevent deadly arrhythmias. Definitive management involves addressing the offending agent, offloading potassium, and stabilizing the patient long term.  

References:
Geldermann N, Dzimiera J, Fischer H, Christ M. Acute hyperkalaemia in emergency care: evidence-based approaches. Emerg Med J. 2026;43(5):305-311. doi:10.1136/emermed-2025-215469

Piktel JS, Wan X, Kouk S, Laurita KR, Wilson LD. Beneficial Effect of Calcium Treatment for Hyperkalemia is Not Due to "Membrane Stabilization." Crit Care Med. 2024;52(10):1499-1508. doi:10.1097/CCM.0000000000006376

Hunter RW, Bailey MA. Hyperkalemia: pathophysiology, risk factors and consequences. Nephrol Dial Transplant. 2019;34(Suppl 3):iii2-iii11. doi:10.1093/ndt/gfz206

 
Summarized by Dan Orbidan, OMS3 | Edited by Dan Orbidan & Ahmed Abdel-Hafiz, NREMT-P
 
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