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Hypokalemia in Emergency Medicine Treatment & Management

  • Author: David Garth, MD; Chief Editor: Romesh Khardori, MD, PhD, FACP  more...
Updated: Aug 02, 2016

Prehospital Care

Be attentive to the ABCs.

If the patient is severely bradycardic or manifesting cardiac arrhythmias, appropriate pharmacologic therapy or cardiac pacing should be considered.


Emergency Department Care

Emergency department care includes the following:

  • Patients in whom severe hypokalemia is suspected should be placed on a cardiac monitor; establish intravenous access and assess respiratory status.
  • Direct potassium replacement therapy by the symptomatology and the potassium level. Begin therapy after laboratory confirmation of the diagnosis.
  • Patients who have mild or moderate hypokalemia (potassium level of 2.5-3.5 mEq/L) are usually asymptomatic; if these patients have only minor symptoms, they may need only oral potassium replacement therapy. Patients with mild hypokalemia whose underlying cause of hypokalemia can be corrected may not need any potassium replacement, such as those with vomiting successfully treated with antiemetics. If cardiac arrhythmias or significant symptoms are present, then more aggressive therapy is warranted. This treatment is similar to the treatment of severe hypokalemia.
  • If the potassium level is less than 2.5 mEq/L, intravenous potassium should be given. Admission or ED observation is indicated; replacement therapy takes more than a few hours.
  • The serum potassium level is difficult to replenish if the serum magnesium level is also low. Look to replace both.

Patients should be transferred only after any cardiac arrhythmias have been treated and the condition has been stabilized. Depending on the level of hypokalemia, an advanced cardiac life support (ACLS) ambulance should be used to allow continuous cardiac monitoring during transport.



An internist or a nephrologist should be consulted for admission or follow-up care.

Consider psychiatric consultation in laxative abuse, anorexia, or bulimia cases.[10]



Medical Care

Further inpatient care involves continuing intravenous replacement of potassium as needed, cardiac monitoring in severe hypokalemia, and repeating potassium level measurements every 1-3 hours. 

Identify the etiology of the hypokalemia.

Consider switching to potassium-sparing diuretic if diuretic therapy is needed. Take 40 mEq KCI daily for 2-3 days and repeat the potassium level.



Replacing potassium too quickly can cause a rapid rise in the blood potassium level, leading to a relative hyperkalemia with subsequent cardiac complications.

If hypokalemia is not corrected easily with replacement therapy, search for other coexistent metabolic abnormalities (eg, hypomagnesemia). Hypokalemia may be refractory to treatment until hypomagnesemia is corrected.

Hypokalemia can potentiate digitalis toxicity in patients who are taking digoxin.

Contributor Information and Disclosures

David Garth, MD Attending Physician, Department of Emergency Medicine, Mary Washington Hospital

David Garth, MD is a member of the following medical societies: American Academy of Emergency Medicine

Disclosure: Nothing to disclose.

Specialty Editor Board

Francisco Talavera, PharmD, PhD Adjunct Assistant Professor, University of Nebraska Medical Center College of Pharmacy; Editor-in-Chief, Medscape Drug Reference

Disclosure: Received salary from Medscape for employment. for: Medscape.

Howard A Bessen, MD Professor of Medicine, Department of Emergency Medicine, University of California, Los Angeles, David Geffen School of Medicine; Program Director, Harbor-UCLA Medical Center

Howard A Bessen, MD is a member of the following medical societies: American College of Emergency Physicians

Disclosure: Nothing to disclose.

Chief Editor

Romesh Khardori, MD, PhD, FACP Professor of Endocrinology, Director of Training Program, Division of Endocrinology, Diabetes and Metabolism, Strelitz Diabetes and Endocrine Disorders Institute, Department of Internal Medicine, Eastern Virginia Medical School

Romesh Khardori, MD, PhD, FACP is a member of the following medical societies: American Association of Clinical Endocrinologists, American College of Physicians, American Diabetes Association, Endocrine Society

Disclosure: Nothing to disclose.

Additional Contributors

Robin R Hemphill, MD, MPH Associate Professor, Director, Quality and Safety, Department of Emergency Medicine, Emory University School of Medicine

Robin R Hemphill, MD, MPH is a member of the following medical societies: American College of Emergency Physicians, Society for Academic Emergency Medicine

Disclosure: Nothing to disclose.


I would like to thank my wife, Mary. Her patience, love, and reassurance, are my bedrock.

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Prominent U waves after T waves in hypokalemia.
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