You have a new patient!
A 58-year-old female is brought into the emergency department (ED) by her family for dizziness and fatigue that started today. She has a history of hypertension for which she takes a calcium channel blocker and end-stage renal disease (ESRD) and has been on dialysis for the last four years. She did miss her dialysis session today due to her symptoms, with her last session four days ago.
At triage, her vital signs are as follows: BP 170/90 mmHg, HR 30/min, RR of 18/min, temperature 37.1 degrees Celsius, SpO2 of 98% on room air. She appears fatigued but is able to answer questions appropriately and has no obvious focal neurologic deficits.
Triage EKG is below
What do you need to know?
Hyperkalemia is one of the most important electrolyte abnormalities you will encounter in the emergency department (ED), given the potential for cardiac arrest in these patients. It refers to when the serum potassium (K) is greater than 5.5mEq/L. In all patients suspected of hyperkalemia, it is essential to place them on a cardiac monitor, obtain IV access, and perform an EKG due to the significant role potassium plays in the cardiac cycle. These patients may have non-specific symptoms, such as weakness and fatigue, and thus can make it hard to discern the diagnosis up front. Patients with a high pretest probability, such as those who miss dialysis or have had prior episodes of hyperkalemia, are usually treated for hyperkalemia before lab results are available due to the potential life-threatening nature of the condition. Potassium is stored in the body’s cells. It can be excreted during cellular damage, such as in rhabdomyolysis, or during certain physiologic states to balance the body’s pH when the serum becomes acidotic (e.g., DKA) [1,2]. Potassium is then excreted from the body by the kidneys/urinary system, so in patients whose kidney function has declined, such as ESRD, or in patients with an obstruction (bladder stone, enlarged prostate), potassium must be excreted through dialysis or by removal.
Medical History
Patients with hyperkalemia often present with non-specific symptoms, such as fatigue, muscle weakness, and cramps, which can often lead to a delay in the diagnosis and can be detrimental, even fatal to the patient. Elevations of potassium in a patient’s serum can be caused when there is a disruption in the storage or excretion mechanisms in the body and can cause cardiac arrhythmias, such as premature beats (PVCs), irregular beats (atrial fibrillation) or cardiac arrest (ventricular fibrillation) due to the role of potassium in regulating the cardiac membrane potential [1-5]. Since an underlying elevation in potassium can cause these non-specific symptoms, it is imperative to do a thorough history, keying in on a history of kidney issues, dialysis appointments, and urinary symptoms.
Physical Examination
The most crucial physical exam components in patients with hyperkalemia are the cardiac and skin exam, especially in patients who may not be able to give you much information, as a thorough skin exam can elicit an AV fistula/graft or tunnel catheter, which would clue you into the patient being on dialysis. If the patient does not have a history of ESRD on dialysis, the cardiac exam could be another clue, elucidating irregular rhythms or bradycardia and prompting you to get further evaluation with an EKG.
Alternative & Differential Diagnoses
Given that hyperkalemia can cause a myriad of non-specific symptoms, patients can sometimes have a long list of differential diagnoses. Outside of the cardiac complications, hyperkalemia can cause muscle cramping, fatigue, or feeling weak. Unless you have a high index of suspicion, these symptoms can be attributed to muscle strains or viral illnesses, which in patients who are otherwise healthy or have a good history of these may be more likely than hyperkalemia [5].
Acing Diagnostic Testing
One of the most important tests for patients suspected of having hyperkalemia is the EKG, given how quickly this bedside test can be performed and the wealth of information that can be obtained, especially regarding electrolytes [4,5]. The classic EKG finding in patients with hyperkalemia is peaked T waves. However, hyperkalemia can mimic many EKG changes, and other findings suggest hyperkalemia are a widened QRS, flattened P waves, and heart blocks [3,4,5]. The EKG may follow a step-wise pattern of peaked T waves, followed by progressively lengthening QRS. However, generally, they do not always follow this pattern, so it is important to have a high index of suspicion when you see these changes. The next step is usually laboratory testing with a basic metabolic panel to confirm hyperkalemia. It can also indicate the patient’s electrolyte levels, provide insight into their acid-base balance, and suggest other potential diagnoses. You may also get other testing depending on the cause of the hyperkalemia, such as CT or US imaging, if urinary tract obstruction is the suspected cause. However, in general, imaging is not needed to make the diagnosis.
Risk Stratification
Most of the patients with hyperkalemia are going to be chronic kidney disease or dialysis patients, which are inherently at higher risk given their underlying disease process as well as the fact that the kidneys process and excrete potassium in the body. Specifically, anuric patients within this group are going to be at higher risk for complications, given that the only way to excrete potassium is through dialysis, putting them at risk for the potentially fatal complications of hyperkalemia [1,2].
Management
As always, following the ABCs of emergent patient management is crucial in deciding how quickly you need to intervene, especially in hyperkalemic patients, where cardiac arrest is a high possibility. Once you have assessed that your patient has a patent airway by speaking to them, their breathing by listening for bilateral breath sounds, and their circulation by ensuring they have a pulse, the next critical step in managing hyperkalemia is the reduction of potassium within the body and serum. This is achieved in two ways: shifting and elimination [2,3,4,5]. One medication we use in hyperkalemia where we have EKG changes attributed to elevations in potassium is Calcium (gluconate or chloride) which the sole purpose of this medication is stabilization of the cardiac membrane to prevent further deterioration into unstable rhythms and is usually given first in the line of medications [2]. Its onset is rapid (15-30 min) with a duration of 30-60 min. Monitor closely as it does not lower potassium but rather protects the heart. Calcium chloride is more concentrated than calcium gluconate, so it requires a central line due to the risk of tissue damage.
Shifting medications will be Insulin and Albuterol, given that these medications work in the cAMP pathway on the cell membranes, causing extracellular potassium to shift intracellularly, thereby transiently decreasing serum potassium. Dextrose is usually given with insulin to prevent the drop in glucose associated with insulin use, and it does not shift/eliminate potassium, but it is still vital. If your patient is able to make urine, giving a dose of Furosemide (or another potassium-depleting diuretic) is useful to help start the process of potassium elimination, as these medications will pull extracellular potassium into the waste product (urine). If your patient is unable to make urine, giving Sodium zirconium cyclosilicate, a potassium binder in your gastrointestinal tract, to help eliminate potassium is another way to help deplete body potassium. If severe enough (e.g., arrhythmias/cardiac arrests, ESRD patients), most patients will need to undergo hemodialysis for definitive treatment/removal of potassium. Listed below are the medications mentioned above, as well as the recommended doses and frequency.
Table: Medications frequently used in hyperkalemia treatment [5,6]
Drug generic Name | Dose | Effect | Duration | Pregnancy | Cautions / Comments |
Calcium gluconate | 1-3gm IV | 15-30min | 30-60min | C, only if clearly needed |
|
Calcium chloride | 1gm IV | 15-30min | 30-60min | C, only if clearly needed | Concentrated Calcium, needs central line |
Albuterol | 15-20mg nebulized | 30min | 2hrs | C |
|
Insulin/Dextrose | 10u Regular insulin IV; 25-50gm of 50% dextrose IV | 30min-45min | 3-6hrs | B (insulin); C (dextrose) | Usually given together, but can be omitted if Glucose >300 |
Furosemide | 40-80mg IV | 15-20min | 2hrs | C |
|
Sodium zirconium cyclosilicate | 10mg TID PO | Can take up to 48hrs |
| Not Assigned | Usually not first line in the ED |
Special Patient Groups
Given its life-threatening nature, hyperkalemia is generally treated the same way in all patient populations, including children and pregnant patients [5]. The above medications are all for adults, but they do have weight-based dosing for pediatric patients that is easily accessible on Broselow tapes found in the Emergency Department. Additional considerations for each group as follows;
Pediatrics
Hyperkalemia in children is often linked to kidney insufficiency, acidosis, and certain genetic conditions affecting potassium balance [7]. Pediatric hyperkalemia treatment includes insulin-glucose therapy, calcium gluconate, and sometimes sodium bicarbonate for acidosis [7]. Dosing is weight-based; careful monitoring is essential to prevent hypoglycemia following insulin administration [7].
Geriatrics
Older adults are prone to hyperkalemia due to decreased renal function and polypharmacy, especially with medications like ACE inhibitors and potassium-sparing diuretics [8]. Geriatric patients require slower dose titration and close monitoring of cardiac function. Reducing or discontinuing potassium-elevating medications may be prioritized before more invasive treatments. Assessing patient’s medication profile carefully to minimize potential interactions and electrolyte disturbances is important.
Pregnant Patients
Hyperkalemia is rare in pregnancy but may occur due to conditions like preeclampsia or excessive potassium supplementation. Treatment is similar to that of the general population but focuses on the safety of both the mother and fetus. Agents like insulin-glucose therapy are used with caution, and glucose and potassium levels are monitored closely to avoid fetal complications.
Caution!
The drugs listed in the table do have specific considerations for pediatric, geriatric, and pregnant patients, as follows:
- Calcium Gluconate and Calcium Chloride:
- Pregnant Patients: Generally considered safe for use when needed (Pregnancy Category C), but only administered if benefits outweigh the risks due to limited data on safety in pregnancy.
- Pediatrics: Dosing is usually adjusted based on weight, and administration must be done with caution due to the risk of tissue necrosis with calcium chloride if extravasation occurs.
- Albuterol:
- Pregnant Patients: Classified as Category C. Used in asthma or bronchospasm, but risks must be considered, as inhaled bronchodilators are typically preferred.
- Pediatrics and Geriatrics: Pediatric dosing is weight-based, while elderly patients may require lower doses due to sensitivity to stimulants.
- Insulin/Dextrose:
- Pregnancy: Insulin is preferred for managing blood glucose in pregnant women with diabetes, categorized as B for insulin, while dextrose is safe when needed.
- Pediatrics: Used in hyperkalemia or diabetic ketoacidosis with dose adjustments based on age and weight.
- Furosemide:
- Geriatrics: Lower doses are generally recommended due to increased risk of dehydration and electrolyte imbalance.
- Pregnancy: Considered Category C, used only if necessary as it may affect fetal renal development.
- Sodium Zirconium Cyclosilicate:
- Limited data on its use in pediatric and pregnant populations, and generally not a first-line treatment in the emergency department for these groups.
Infographic
When To Admit This Patient
There are very few instances where hyperkalemic patients will be discharged from the ED, given the potential life-threatening arrhythmias. However, ESRD patients who receive dialysis, are back to their baseline and have to follow up/able to make it to their scheduled dialysis sessions will most likely be able to be discharged if a cause for their hyperkalemia is something simple, such as missed dialysis appointments. Ensure clear, specific follow-up arrangements to minimize recurrence risk. Confirm with her dialysis provider for her next sessions. Most other patients will be admitted for monitoring to ensure their potassium levels are normalizing and to identify a cause.
Revisiting Your Patient
As you recall, we had a 58-year-old female with dizziness/fatigue who had missed her dialysis session and was found to be bradycardic and hyperkalemic on her initial workup. She was initially treated with calcium gluconate with improvement in her EKG as well as her symptoms and was able to receive dialysis in the ED. After a brief period of observation after her dialysis sessions and repeat BMP showing normalization of her potassium, she was discharged home with her family to continue her outpatient dialysis schedule.
Author
Chelsea N. Allen, DO
Originally from Adel, GA, USA, graduated college with a degree in biology from Columbus State University in Columbus, GA, USA. Then attended medical school at the Edward Via College of Osteopathic Medicine in Auburn, AL before completing her emergency Medicine residency at the University of Florida, Jacksonville, in Jacksonville, FL, USA. She is currently the Assistant Program Director for the Emergency Medicine program at UF-Jacksonville as well.
Listen to the chapter
References
- Harris AN, Grimm PR, Lee HW, et al. Mechanism of Hyperkalemia-Induced Metabolic Acidosis. Journal of the American Society of Nephrology. 2018;29(5):1411-1425. doi:https://doi.org/10.1681/ASN.2017111163
- Mount D. Potassium balance in acid-base disorders. Accessed: November 14, 2024. https://www.uptodate.com/contents/potassium-balance-in-acid-base-disorders.
- Lindner G, Burdmann EA, Clase CM, et al. Acute hyperkalemia in the emergency department: a summary from a Kidney Disease: Improving Global Outcomes conference. Eur J Emerg Med. 2020;27(5):329-337. doi:10.1097/MEJ.0000000000000691
- Helman, A, Baimel, M, Etchells, E. Emergency Management of Hyperkalemia. Emergency Medicine Cases. September, 2016. Accessed November 14, 2024. https://emergencymedicinecases.com/alcohol-withdrawal-delirium-tremens/
- Wachira BW. Fluids, Electrolytes, and Acid-Base Disorders. In: Cydulka RK, Fitch MT, Joing SA, Wang VJ, Cline DM, Ma O. eds. Tintinalli’s Emergency Medicine Manual, 8e. McGraw-Hill Education; 2017. Accessed November 14, 2024. https://accessemergencymedicine-mhmedical-com.uaeu.idm.oclc.org/content.aspx?bookid=2158§ionid=162269029
- Rafique Z, Peacock F, Armstead T, et al. Hyperkalemia management in the emergency department: An expert panel consensus. J Am Coll Emerg Physicians Open. 2021;2(5):e12572. Published 2021 Oct 1. doi:10.1002/emp2.12572
- Lederer Hyperkalemia. Accessed: November 14, 2024. https://emedicine.medscape.com/article/240903-overview?form=fpf
- Ortiz A, Galán CDA, Carlos Fernández-García J, et al. Consensus document on the management of hyperkalemia. Nefrologia (Engl Ed). 2023;43(6):765-782. doi:10.1016/j.nefroe.2023.12.002
Reviewed and Edited By
Arif Alper Cevik, MD, FEMAT, FIFEM
Prof Cevik is an Emergency Medicine academician at United Arab Emirates University, interested in international emergency medicine, emergency medicine education, medical education, point of care ultrasound and trauma. He is the founder and director of the International Emergency Medicine Education Project – iem-student.org, chair of the International Federation for Emergency Medicine (IFEM) core curriculum and education committee and board member of the Asian Society for Emergency Medicine and Emirati Board of Emergency Medicine.
