Hyperkalemia

Definition/Description[edit | edit source]

Membrane potential ions (id).jpg

Potassium is an important nutrient and electrolyte, it helps muscles work, including those involved in breathing and keeping the heart beating. But too much potassium in our system, known as hyperkalemia, can cause serious health problems. And people with kidney disease are more prone to developing hyperkalemia.[1]

Hyperkalemia is defined as a serum or plasma potassium level above the upper limits of normal, usually greater than 5.0 mEq/L to 5.5 mEq/L. While mild hyperkalemia is usually asymptomatic, high levels of potassium may cause life-threatening cardiac arrhythmias, muscle weakness or paralysis. Symptoms usually develop at levels higher levels, 6.5 mEq/L to 7 mEq/[2]

Image 1: Illustration of the way that differences in ion concentration on opposite sides of a cell membrane produce a voltage difference. Potassium is usually an intracellular cation.

For patients with mild transient hyperkalemia, the prognosis is excellent if the inciting cause is addressed and treated. Sudden onset, extreme hyperkalemia can cause cardiac arrhythmias that can be lethal in up to two-thirds of cases if not rapidly treated. Hyperkalemia is an independent risk factor for death in hospitalized patients.[2]

Etiology[edit | edit source]

Often a report of high blood potassium isn't true hyperkalemia. Instead, it may be caused by the rupture of blood cells in the blood sample during or shortly after the blood draw. The ruptured cells leak their potassium into the sample. This falsely raises the amount of potassium in the blood sample, even though the potassium level in your body is actually normal. When this is suspected, a repeat blood sample is done.

Dialysis.jpg

The most common cause of genuinely hyperkalemia is related to the kidneys, eg:

Other causes of hyperkalemia include:

Image 2: Dialysis for Chronic Kidney Disease.

Epidemiology[edit | edit source]

Hyperkalemia is unusual in the general population, reported in less than 5% of the population, worldwide.

  • Affects up to 10% of all hospitalized patients, most cases in hospitalized patients are due to medications and renal insufficiency.
  • Diabetes, malignancy, extremes of age, and acidosis are other important causes in inpatients.
  • Hyperkalemia is rare in children but may occur in up to 50% of premature infants.
  • Hyperkalemia is more commonly reported in men than women perhaps due to increased muscle mass and higher rates of rhabdomyolysis and increased prevalence of neuromuscular disease.

Today there is a risk that empirical use of ACE inhibitors may cause hyperkalemia, which can be of concern in high risk populations eg diabetics, those with heart failure, and peripheral vascular disease[2].

Characteristics/Clinical Presentation[edit | edit source]

Hyperkalemia most commonly occurs in patients with chronic renal failure and is also correlated with diabetes. [4] [5]

Image 3: ECG is monitored in patients with hyperkalemia:

Signs and Symptoms

  1. muscular weakness
  2. flaccid paralysis
  3. ileus
  4. ECG changes[4]
  5. nausea
  6. slow, weak or irregular pulse
  7. sudden collapse (heart rate too slow or stops)[6]
  8. paraestesias
  9. fatigue
  10. palpitations

Potassium is regulated through excretion via the renal system. When this system's function declines, the extracellular potassium concentration increases and can lead to membrane excitability.  Some signs and symptoms listed above are a result of the impaired nerve conduction and muscle contraction dysfunction.  Muscular dysfunction includes the cardiac system and can lead to life threatening ventricular arrhythmias.  Electrocardiogram (ECG) dysfunction is more common in patients with acute hyperkalemia.[7]

Diagnostic Tests/Lab Tests/Lab Values[edit | edit source]

Initial diagnosis is initiated with patient history, medication review, and physical examination. 

Laboratory tests include:

  1. serum electrolytes (especially potassium and glucose [7])
  2. creatinine
  3. blood urea nitrogen (BUN)
  4. spot urine test (potassium, creatinine, and osmoles)
  5. transtubular potassium gradient (assessment of renal potassium handling)
  6. trial of oral fludrocortisone (Florinef)[4]

Patients will likely not present with symptoms of hyperkalemia until potassium levels have exceeded 7 mmol/L.  However, immediate medical attention is required when potassium level exceed 6.5 mmol/L or exceed 6.0 mmol/L with ECG changes consistent with hyperkalemia.[7]

  Systemic Involvement  [edit | edit source]

Table 5-10 Clinical Features of Various Electrolyte Imbalances[8]

Potassium Imbalance (hyperkalemia) System Dysfunction
Cardiovascular tachycardia and later bradycardia, ECG changes, cardiac arrest (with levels .7.0 mEq/L)
GI nausea, diarrhea, abdominal cramps
Musculoskeletal muscle weakness, flaccid paralysis
Genitourinary oliguria, anuria
Central nervous system areflexia progressing to weakness, numbness, tingling, and flaccid paralysis
Acid-base balance metabolic acidosis

Treatment[edit | edit source]

The urgency with which hyperkalemia should be managed depends on how rapidly the condition developed, the absolute serum potassium level, the degree of symptoms, and the cause.[2]

  • The presence of ECG changes, a rapid rise of serum potassium, indications of decreased kidney function, or significant acidosis require immediate medical treatment for hyperkalemia. 
  • Although ECG changes are common indicators for severe hyperkalemia, the patient may still have life threatening hyperkalemia even if ECG readings are normal. 
  • The intent of immediate medical intervention is to stabilize the myocardium to prevent arrhythmias. 

In addition to the medications listed in Table 5, total body potassium levels can be lowered through kidney excretion, gastrointestinal (GI) elimination, or dialysis.  Lowering via kidney excretion is achieved by the use of diuretics, while lowering via GI elimination occurs with the use of Kayexalate.  Long term management is focused on addressing the underlying cause, which can be achieved by discontinuing medications or consuming low potassium diets.[4]

Afp20060115p283-f2.gif

Figure 2:  Algorithm for the management of hyperkalemia.[4]

Foods high in potassium can also be implicated in the development of hyperkalemia. 

Table 2. High-potassium foods[7]

(National Kidney foundation, 2010)

- salt substitutes and salt free broth

- yogurt, milk

- molasses

- seaweed

- chocolate

- bran cereal, wheat germ, granola

- vegetables (acorn squash, artichoke, bamboo shoots, beets, broccoli, brussel sprouts, chinese cabbage, carrots, greens (except kale), kohlrabi, mushrooms (canned), parsnips, potatoes, pumpkin, rutabagas, spinach, tomatoes, vegetable juices)

- dried fruit (apricot, dates, figs, raisins, prunes)

- nuts and seeds, (peanut butter)

- dried peas and beans (lima beans, black beans, refried beans, lentils, legumes)

- fruit and juice (apricot, avocado, banana, cantaloupe, grapefruit, honeydew, kiwi fruit, mango, nectarine, orange, papaya, pomegranate, prune)


Physical Therapy Management[edit | edit source]

Hyperkalemia is a disorder that is not managed primarily by a physical therapist, however physical therapists should be aware of signs and symptoms of this disorder and should refer the patient to a medical doctor when indicated.

  • Potassium levels < 3.2 mEq/L or > 5.1 mEq/L are contraindicated for physical therapy intervention due to the potential for arrhythmia and tetany. 
  • When potassium levels are not within the normal range (3.5-5.0 mEq/L) exercise is not effective due to decreased muscle pH and action potentials as well as inhibition of motor neurons. 
  • With a patient who has marginal potassium levels, vital signs (including pulse rhythm) and any signs of dizziness, muscle weakness or cramping, numbness or tingling, and changes in balance should be closely monitored. 

At this time, no research addresses the change in potassium level that occurs with exercise.  However, it is known that patients with hyperkalemia are at risk for ventricular arrhythmias which can result in reduced exercise tolerance.[8]

References[edit | edit source]

see adding references tutorial.

  1. Healthline 5 Things to Know About Hyperkalemia for National Kidney Month Available: https://www.healthline.com/health/high-potassium/hyperkalemia-facts(accessed 18.9.2021)
  2. 2.0 2.1 2.2 2.3 Simon LV, Hashmi MF, Farrell MW. Hyperkalemia. StatPearls [Internet]. 2020 Dec 1.Available:https://www.ncbi.nlm.nih.gov/books/NBK470284/ (accessed 18.9.2021)
  3. Mayo clinic Hyperkalemia Available: https://www.mayoclinic.org/symptoms/hyperkalemia/basics/causes/sym-20050776 (accessed 18.9.2021)
  4. 4.0 4.1 4.2 4.3 4.4 Hollander-Rodriguez JC, Calvert, Jr. JF. Hyperkalemia. American Family Physician 2006; 73(2):283-290. Available from: PubMed. http://www.ncbi.nlm.nih.gov/pubmed/16445274 )22 March 2013)
  5. Tamirisa KP, Aaronson KD, Koelling TM. Spironolactone-induced renal insufficiency and hyperkalemia in patients with heart failure, American Heart J 2004; 148(6):971-978. Available from: Europe Pubmed Central. http://www.sciencedirect.com/science/article/pii/S0002870304007501 (Accessed 4 April 2013)
  6. Dugdale DC, Zieve D. MedlinePlus. [homepage on the Internet]. 2011 [cited 2013 Mar 22]. Available from: U.S. National Library of Medicine, National Institutes of Health Web site: http://www.nlm.nih.gov/medlineplus/ency/article/001179.htm
  7. 7.0 7.1 7.2 7.3 Raymond C, Sood A, Wazny L. Treatment of hyperkalemia in patients with chronic kidney disease--a focus on medications. CANNT Journal [serial on the Internet]. (2010, July), [cited March 22, 2013]; 20(3): 49-54. Available from: CINAHL with Full Text. http://search.ebscohost.com/login.aspx?direct=true&db=c8h&AN=2010782358&site=ehost-live (accessed 22 Mar 2013)
  8. 8.0 8.1 Goodman CC & Fuller KS. In K Falk editor. Pathology: Implications for the Physical Therapist. St. Louis: Saunders Elsevier; 2009. pp.150, 157, 187-189, 480, 558, 927, 1243, 1640-1641