Emergency Medical Minute

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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Contributor; Aaron Lessen, MD
Educational Pearls:
A 2026 survey asked Canadian emergency medicine (EM) physicians about their eating and drinking habits while on shift.

Among 527 respondents, 35% reported that they never or hardly ever ate during shifts, and 37% said the same about drinking water.

Lack of time was the most commonly cited barrier, reported by 91% of respondents.

Lack of available food, personal health goals, perceived mental clarity, and emergency department culture were also commonly identified factors.

Physicians who did not eat or drink on shift often reported that this negatively affected their work.

Years in practice were associated with eating more often while on shift, suggesting that newer physicians may be less likely to eat during shifts.

A 2023 study by Kontrick et al. found that 89% of US-based EM residency programs did not have a dedicated meal break, which may help explain why early-career physicians are less accustomed to eating during clinical shifts.

Studies outside of emergency medicine have also suggested that inadequate food and fluid intake can affect fatigue, mood, attention, and cognitive performance, though direct evidence in emergency department physicians and patient care remains limited.

Future studies could examine whether physician eating and drinking habits during shifts are associated with patient outcomes and broaden the scope of this study to other emergency department providers, nurses, and technicians.

References:
Farquhar, Madeleine et al. "A lot on their plates? Examining the on-shift eating and drinking habits of Canadian emergency medicine physicians." CJEM vol. 28,1 (2026): 64-73. doi:10.1007/s43678-025-01044-8

Kontrick, Amy V et al. "Do emergency medicine residents have access to healthy food options during work hours?." AEM education and training vol. 7,4 e10890. 17 Jul. 2023, doi:10.1002/aet2.10890 

Lemaire, Jane B et al. "Physician nutrition and cognition during work hours: effect of a nutrition based intervention." BMC health services research vol. 10 241. 17 Aug. 2010, doi:10.1186/1472-6963-10-241

Wittbrodt, Matthew T, and Melinda Millard-Stafford. "Dehydration Impairs Cognitive Performance: A Meta-analysis." Medicine and science in sports and exercise vol. 50,11 (2018): 2360-2368. doi:10.1249/MSS.0000000000001682




Summarized by Sam Pahl | Edited by Sam Pahl & Ahmed Abdel-Hafiz, NREMT-P
 
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Contributor; Taylor Lynch, MD
Educational Pearls:
Thoracotomy 

Thoracotomy is used in traumatic cardiac arrest to replace conventional CPR with direct access to the chest.

Goals include identifying and controlling reversible causes of bleeding, prioritizing blood flow to the heart and brain, and performing open cardiac massage.

Trauma categories

Penetrating trauma: Gunshot wounds and stab wounds.

Has a higher chance of survival because the injury may be localized and directly repairable.

Cardiac stab wounds may have the highest survivability because the defect can be visualized, repaired, and treated with blood administration.

Blunt trauma: Motor vehicle collisions and falls from height.

Has a much lower chance of survival.

Western guidelines

EMS must witness the patient lose pulses.

Penetrating trauma: CPR for less than 15 minutes.

Blunt trauma: CPR for less than 10 minutes.

Survival decreases to essentially zero beyond these time limits.

Eastern guidelines

Focus on the presence of signs of life in blunt or penetrating trauma.

Signs of life may include:

Pupillary response.

Measurable blood pressure.

Purposeful movement.

Patient selection

Thoracotomy should only be performed when the patient has a reasonable chance of survival.

It is a highly morbid procedure with significant occupational risks, including needlestick injury.

Appropriate patient selection and timing are essential.

Procedure

Begin on the left side of the chest.

Cross-clamp the aorta to restrict blood flow below the heart and prioritize circulation to the heart and brain.

Identify and repair visible sources of bleeding involving structures such as the heart or lungs.

Perform open cardiac massage as the equivalent of CPR.

ACLS medications may still be administered.

References:
Cothren CC, Moore EE. Emergency department thoracotomy for the critically injured patient: Objectives, indications, and outcomes. World J Emerg Surg. 2006;1:4. Published 2006 Mar 24. doi:10.1186/1749-7922-1-4

Rhee, Peter M. ; Acosta, Jose ; Bridgeman, Amy et al. / Survival after emergency department thoracotomy : Review of published data from the past 25 years. In: Journal of the American College of Surgeons. 2000 ; Vol. 190, No. 3. pp. 288-298.

Nunn, Andrew ; Prakash, Priya ; Inaba, Kenji et al. / Occupational exposure during emergency department thoracotomy : A prospective, multi-institution study. In: Journal of Trauma and Acute Care Surgery. 2018 ; Vol. 85, No. 1. pp. 78-84.

Burlew CC, Moore EE, Moore FA, et al. Western Trauma Association critical decisions in trauma: resuscitative thoracotomy. J Trauma Acute Care Surg. 2012;73(6):1359-1363. doi:10.1097/TA.0b013e318270d2df

Seamon MJ, Haut ER, Van Arendonk K, et al. An evidence-based approach to patient selection for emergency department thoracotomy: A practice management guideline from the Eastern Association for the Surgery of Trauma. J Trauma Acute Care Surg. 2015;79(1):159-173. doi:10.1097/TA.0000000000000648




Summarized by Steven Fujaros NREMT | Edited by Steven Fujaros & Ahmed Abdel-Hafiz, NREMT-P
 
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Contributor: Aaron Lessen, MD
Educational Pearls: 
 
Agitated patients who are intoxicated with methamphetamine pose a unique challenge when selecting a sedative to counter their symptoms. Is there a superior medication?

A recent study compared the efficacy of commonly used medications for methamphetamine-induced agitation in the emergency department.

The study compared IM Droperidol 5mg, IM Olanzapine 10mg, IM Midazolam 5mg, and IM Lorazepam 2mg.

The study concluded that Droperidol, Olanzapine, and Midazolam performed similarly, with a median time to adequate sedation of 15 minutes.

Lorazepam took the longest, with a median time of 30 minutes to achieve adequate sedation.

Patients who received Lorazepam also required rescue medication more frequently after the initial dose.

Key takeaway: Droperidol, Olanzapine, and Midazolam may be more effective than Lorazepam for treating methamphetamine-induced agitation.

 
References:
Martel M, Klein LR, Cole JB, et al. Intramuscular droperidol, olanzapine, midazolam, or lorazepam to treat methamphetamine intoxication in the emergency department. Am J Emerg Med. 2021;49:142-148. doi:10.1016/j.ajem.2021.05.045

 
Summarized by Ashley Lyons, OMS4 | Edited by Ashley Lyons & Ahmed Abdel-Hafiz, NREMT-P
 
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