Authors: Fallah-tafti, Aerfan, Kaur, Elizabeth, Riar, Akashpreet, Salem, Fares, Rahimi, Zohal, and Walker, Annagail

Cardiology Interest Group, American University of the Caribbean School of Medicine, Cupecoy, Sint Maarten

Introduction: Potassium is one of the most critically important intracellular cations in maintenance and function of the human body. In addition to being the most abundant cation in intracellular fluid, potassium plays a key role in neuronal function, blood pressure, cardiac function, muscle function, and cellular metabolism. (1) Due to its importance in regulation and normal function of critical bodily functions, the human body is especially sensitive to disruptions in potassium levels. Symptomatic potassium level imbalance, along with comorbidities requires urgent treatment, and must not be missed in clinical evaluation. Hypokalemia occurs in up to 21% of hospitalized patients, and up to 2-3% of outpatients (4), while hyperkalemia occurs in up to 10% of hospitalized patients and up to 1% of outpatients (5). Classification of hyperkalemia is made on the basis of blood serum level exceeding 5.5 mEq/L, while classification of hypokalemia is made on the basis of blood serum level less than 3.5 mEq/L.(2) (3) Potassium levels in the blood can be altered as a result of disease, differing consumption, and interactions with medications, particularly in patients with chronic disease. (2) Medications in patients with chronic disease, such as angiotensin converting enzyme inhibitors (ACE inhibitors), diuretics, angiotensin receptor blockers (ARBs) can potentiate hyperkalemia or hypokalemia.

Case Presentation: We present the case of a 72 year old male patient who presents to the emergency room with complaints of fatigue and palpitations. He has a history of chronic hypertension, hyperlipidemia, and type 2 diabetes mellitus. His current medications are 40mg daily atorvastatin and twice daily 500mg metformin. He was prescribed an ACE inhibitor 6 months prior to admission. He was subsequently diagnosed with hyperkalemia.

Initial ECG:

Discussion: This case illustrates the importance of identifying potassium imbalances in patients with chronic conditions, as well as the importance of follow up evaluations. As potassium imbalance is a common electrolyte imbalance with significant health risk, a primary objective for physicians must be to determine potassium electrolyte imbalance through analysis of patients history, labs, and EKG findings. In addition, post visit follow up is essential for early diagnosis of electrolyte imbalance before it becomes symptomatic.

1: Stone MS, Martyn L, Weaver CM. Potassium Intake, Bioavailability, Hypertension, and Glucose Control. Nutrients. 2016;8(7):444. Published 2016 Jul 22. doi:10.3390/nu8070444

2: Viera AJ, Wouk N. Potassium Disorders: Hypokalemia and Hyperkalemia. Am Fam Physician. 2015;92(6):487-495.

3: Lehnhardt A, Kemper MJ. Pathogenesis, diagnosis and management of hyperkalemia. Pediatr Nephrol. 2011;26(3):377-384. doi:10.1007/s00467-010-1699-3

4: Paice BJ, Paterson KR, Onyanga-Omara F, Donnelly T, Gray JM, Lawson DH. Record linkage study of hypokalaemia in hospitalized patients. Postgrad Med J. 1986;62(725):187–191.

5: Shemer J, Modan M, Ezra D, Cabili S. Incidence of hyperkalemia in hospitalized patients. Isr J Med Sci. 1983;19(7):659–661.