OVERVIEW
Hyperkalemia is a condition in which the serum potassium (K+) concentration is higher than 5.5 mmol/L.
Common symptoms include muscle weakness, palpitations, and in severe cases, cardiac arrest.
Common causes include excessive intake of potassium into the body, decreased renal excretion of potassium, and intracellular potassium entering the blood.
Depending on the potassium level, general treatment, drug treatment, dialysis treatment, etc. can be chosen.
What is hyperkalemia?
Definition
Hyperkalemia is defined as a condition in which the concentration of serum potassium ions (referred to as blood potassium) is higher than 5.5 mmol/L. The normal concentration of blood potassium is 3.0 mmol/L.
The normal concentration of potassium is 3.5-5.5 mmol/L. Potassium is the main substance in the cell.
Potassium ions are the major intracellular cations, and under normal conditions, most of the potassium is distributed within the cells, with blood potassium accounting for only a small fraction of all potassium ions in the body.
Classification
Classification according to the degree of elevated blood potassium
Blood potassium concentration >6.5 mmol/L is generally considered to be severe hyperkalemia.
Classification according to etiology
Nephrogenic hyperkalemia: renal dysfunction is the most common cause of hyperkalemia.
Non-nephrogenic hyperkalemia: non-renal causes of hyperkalemia, such as input of large amounts of stored blood, overtreatment of hyperkalemia, and crush syndrome.
Pseudohyperkalemia: common causes are hemolysis and thrombocytosis.
Morbidity
Hyperkalemia rarely occurs in normal subjects and is most commonly seen in those with acute kidney injury, chronic kidney disease, and those taking drugs that inhibit renal excretion of potassium.
The percentage of hyperkalemia in outpatients over 18 years of age with comorbid chronic kidney disease, heart failure, diabetes mellitus, and hypertension was 22.89%, 12.54%, 7.11%, and 6.51%, in that order.
Questions you may be concerned about
What are the dangers of hyperkalemia?
Hyperkalemia is mainly harmful to the heart and skeletal muscle, including:
Effects on the heart: the main danger of hyperkalemia is that it causes cardiac arrhythmias such as sinus bradycardia, sinus arrest, ventricular tachycardia, and ventricular fibrillation.
Effects on skeletal muscle: Muscle weakness can be seen in hyperkalemia, patients have weakness of limbs, walking effort etc.
If you find hyperkalemia, you should go to the hospital for treatment in time.
Can hyperkalemia be regulated by diet?
Hyperkalemia can be regulated by diet.
Choose low-potassium diet, such as pumpkin, winter melon and other vegetables, and reduce potassium-rich foods, such as mushrooms, kelp, beans, bananas and oranges.
Choose the right kind of salt. Some salts have added potassium salt, try to avoid it.
Vegetables can be soaked, cooked and eaten to remove some of the potassium and phosphorus from the food.
Eat small and frequent meals to prevent a fasting state.
If the situation is serious, hospital treatment is recommended.
Is too much potassium harmful?
Too much potassium supplementation leads to hyperkalemia, which weakens neuromuscular stress, and in early stages, patients may experience numbness of the limbs, extreme fatigue, and muscle aches and pains. It can also be harmful to the person by depressing the heart muscle, which can cause arrhythmia, etc.
Generally speaking, patients with hypokalemia who take oral potassium supplementation as prescribed by the doctor are usually less likely to have too much potassium supplementation. However, if potassium-preserving diuretics, such as spironolactone, are used at the same time, the blood potassium may be too high.
Therefore, potassium supplementation requires regular observation of the blood potassium level.
Causes
Causes
Common causes of hyperkalemia include excessive intake of potassium into the body, decreased potassium excretion by the kidneys, intracellular potassium entering the bloodstream, etc. Pseudohyperkalemia may also occur for other reasons.
Excessive intake of potassium
Taking potassium-containing drugs by mouth or injecting potassium-containing fluids intravenously too much and too fast.
High-potassium diet, such as consuming large quantities of potassium-rich foods such as bananas.
Massive input of blood from long-term stock or radiation-irradiated blood, etc.
Decreased renal potassium excretion
Decreased renal potassium excretion can be related to diseases or long-term use of specific drugs, etc.
Disease
Acute kidney injury with oliguric phase, chronic renal failure, renal tubular acidosis, hypoadrenocorticism, etc.
Hyporeninemic hypoaldosteronism.
Systemic lupus erythematosus.
Post renal transplantation.
Azotemia.
Long-term medications
Potassium retention diuretics: e.g. spironolactone, aminopterin, amiloride.
Angiotensin-converting enzyme inhibitors: e.g. captopril, enalapril, and other purinergic drugs.
Angiotensin II receptor antagonists: such as chlorosartan, olmesartan and other sartans.
Non-steroidal anti-inflammatory drugs: e.g. aspirin, acetaminophen, etc.
Intracellular potassium entering the blood
Severe hemolysis, massive burns, crush syndrome, rhabdomyolysis, gastrointestinal bleeding, tumor lysis syndrome, and other disorders that can lead to tissue damage and blood cell destruction.
Hypoxia.
Acidosis.
Beta-blockers (e.g., propranolol, metoprolol, etc.), cardiac glycosides (e.g., digoxin, etc.).
Familial hyperkalemic paralysis: also known as hyperkalemic periodic paralysis, an autosomal dominant disorder that develops when intracellular potassium ions migrate outward into the bloodstream, resulting in hyperkalemia.
The use of intravenous fluids such as mannitol and hypertonic glucose saline leads to intracellular dehydration and increased outward migration of potassium.
Pseudohyperkalemia
Pseudohyperkalemia is a condition in which the serum potassium concentration is elevated while the actual plasma potassium is not elevated.
Acidosis due to prolonged upper arm compression (several minutes) and intermittent fist clenching during blood collection.
Extravascular hemolysis.
Leukocytosis: elevated blood potassium can occur after specimen placement when the white blood cell count is >500 x 109/L.
Thrombocytosis: hyperkalemia can be caused by a platelet count >600 x 109/L.
Pathogenesis
Adults require 3 to 4 grams of potassium per day, mainly from dietary sources; fruits, vegetables, and meats are rich in potassium; a normal diet is sufficient to meet the body’s normal requirements for potassium.
Under normal circumstances, potassium ions ingested into the body are mainly excreted through the kidneys, in which hormones are involved, and potassium can also be excreted through sweating and colonic excretion.
Hyperkalemia may occur once there is an abnormality in the intake, excretion, and transport of potassium ions.
Potassium ions play an important role in the body in maintaining cell metabolism, neuromuscular stress and normal function of the heart muscle, regulating osmotic pressure and acid-base balance, etc. Therefore, symptoms related to neuromuscular and cardiac disorders may occur when hyperkalemia occurs.
Symptoms
Main symptoms
Neuromuscular symptoms
Muscle weakness may be accompanied by mild tremor and sensory abnormalities.
Muscle symptoms often appear in the limbs and may gradually progress to the trunk muscles and even affect the respiratory muscles.
Central nervous system symptoms such as slowness of movement and drowsiness may occur.
Cardiac symptoms
Hyperkalemia can lead to cardiac arrhythmias, with palpitations as the main symptom.
In severe cases, cardiac arrest may occur, which is characterized by sudden onset of loss of consciousness and cessation of breathing and heartbeat.
Other symptoms
In severe cases, symptoms such as pale skin, clammy cold and bruising may occur.
Consultation
Department of Medicine
Nephrology
If you have chronic kidney disease and experience symptoms such as muscle weakness, abnormal sensation, slowed movement, or panic attacks, you should consult a nephrologist promptly.
Cardiovascular Medicine
If you are taking diuretics or antihypertensive drugs for a long period of time and experience the above symptoms, it is recommended that you consult a physician promptly.
Emergency Medicine
If you experience symptoms such as difficulty in breathing, drowsiness, loss of consciousness, etc., it is recommended that you go to the Emergency Department or call the 120 emergency number immediately.
Preparation for medical treatment
Preparation for medical consultation: registration, preparation of documents, common problems
Tips for medical treatment
It is recommended to be accompanied by someone to prevent falls and injuries, and to use a wheelchair if necessary.
Preparation Checklist
Symptom list
Pay special attention to the time of onset of symptoms, special symptoms, etc.
Are there any symptoms such as muscle tremors, sensory abnormalities, etc.?
Is the urine output normal?
How long have these symptoms been present?
Medical History Checklist
Have you recently eaten large quantities of certain foods, such as bananas?
Are there any chronic medical conditions, such as kidney disease, high blood pressure, systemic lupus erythematosus, etc.?
Any long-term use of certain medications?
Is there a family history of similar illnesses?
Checklist
Test results in the past 6 months, which can be brought to the doctor’s office
Blood biochemistry
Electrocardiogram
Medication list
Medication used in the last 3 months, if available in boxes or packages, bring with you to the doctor’s office
Beta-blockers: propranolol, metoprolol
Angiotensin-converting enzyme inhibitors: captopril, enalapril
Angiotensin II receptor antagonists: chlorosartan, olmesartan
Diuretics: spironolactone, furosemide
Diagnosis
Diagnosis is based on
medical history
Presence of renal disease.
High intake of potassium-rich foods or medications.
Prolonged use of spironolactone, aminopterin, and drugs such as angiotensin-converting enzyme inhibitors and nonsteroidal anti-inflammatory drugs.
Clinical manifestations
Symptoms
Symptoms such as muscle weakness, abnormal sensation, and palpitations may occur.
Physical signs
Arrhythmia may be detected by pulse palpation and cardiac auscultation.
When blood pressure is measured, blood pressure is elevated in the early stages and may decrease in the later stages.
Tendon reflexes are diminished or absent.
Laboratory Tests
Blood Electrolyte Tests
Primarily, serum potassium, sodium, and calcium ion concentrations are measured.
The diagnosis of hyperkalemia can be confirmed by serum potassium ion concentration >5.5 mmol/L.
Blood routine
Red blood cell count, white blood cell count, platelet count and other indicators can help determine whether there is hemolysis, leukocytosis, thrombocytosis and other conditions.
Kidney function
Blood creatinine and urea nitrogen may be elevated when renal function is impaired.
Urine routine
Urine pH, urine creatinine, etc. assist in the detection of primary diseases.
Electrocardiogram
Hyperkalemia mainly threatens the heart. Electrocardiogram (ECG) can clarify the abnormal electrical activity of the heart, and help the doctor to determine the degree of elevated potassium in the blood, and assist in confirming the diagnosis.
When the blood potassium is >6 mmol/L, the base of the T wave of ECG is narrow and hyperacute.
When blood potassium is 7-9 mmol/L, PR interval is prolonged, P wave disappears, QRS wave cluster becomes wider, R wave becomes lower, S wave becomes deeper, and ST segment fuses with T wave.
When blood potassium is >9 mmol/L, sinusoidal wave may appear, QRS wave cluster is prolonged, and T wave is hyperacute.
Differential diagnosis
Hyperkalemia with electrocardiographic changes is more acute and can be diagnosed clearly by blood electrolyte tests. Generally, there is no need to differentiate it from other diseases, and the focus is on clarifying the cause of the disease through examination.
Treatment
The principle of treatment for hyperkalemia is to rapidly reduce the blood potassium level and protect the heart. According to the degree of elevation of blood potassium, general treatment, drug treatment and dialysis treatment should be chosen.
General treatment
Discontinue all potassium-containing drugs and fluids (including blood).
Stop high potassium diet.
Choose a high-sugar, high-fat diet or use intravenous nutrition to ensure adequate calories and reduce potassium release from the body.
For severe hyperkalemia, cardiac monitoring, regular measurement of blood potassium concentration, etc. are also needed.
Medication
Drugs can be chosen to antagonize the effect of potassium on the heart and to promote potassium excretion.
Drugs that antagonize the cardiac inhibitory effect of potassium
Such as sodium lactate or sodium bicarbonate solution, calcium, hypertonic saline, glucose and insulin, selective β2 agonists (e.g. salbutamol).
Among the calcium agents are preparations such as calcium gluconate and calcium chloride, which stabilize myocardial excitability.
For severe hyperkalemia, calcium and insulin are often used for treatment, and insulin is usually combined with glucose intravenously.
Drugs to promote potassium excretion
These drugs include high sodium solutions, potassium-excreting diuretics such as furosemide, etanercept, and hydrochlorothiazide, and cation exchange resins.
Cation exchange resins can be combined with diuretics such as sorbitol to prevent constipation.
Dialysis treatment
Dialysis therapy may be required if general therapy and medication are not effective in reducing blood potassium concentrations, or in those with hyperkalemia associated with renal insufficiency.
Dialysis treatment is the quickest and most effective way to reduce blood potassium. There are two types of dialysis: peritoneal dialysis and hemodialysis, with hemodialysis being faster than peritoneal dialysis.
Dialysis requires a certain amount of preparation time, so most people start medication first.
Prognosis
Cure
Cure depends on the degree of potassium elevation, the rate of progression of the disease, and the patient’s own condition.
If the elevation of potassium is small and there are no other water or electrolyte disorders or acid-base balance disorders, the potassium level can be restored to normal after prompt and effective treatment.
Hazards
The main danger of hyperkalemia is cardiac depression, which may cause life-threatening cardiac arrest in severe cases.
Daily management
Daily management
Diet and medication management
Choosing a low-potassium diet requires a moderate reduction in potassium-rich foods such as mushrooms, kelp, beans, lotus seeds, cabbage, bananas and oranges.
Choose appropriate salt for cooking. Some salts have added potassium salt and need to be avoided as much as possible.
Those undergoing hemodialysis and peritoneal dialysis should also be careful to avoid foods high in phosphorus, such as whole wheat bread, animal offal, dry beans, nuts, milk powder, cheese, egg yolks, and chocolate.
Vegetables can be soaked, cooked and eaten to remove some of the potassium and phosphorus from the food.
Do not drink liquids from canned fruits, meats, vegetables, and other foods.
Discontinue potassium-containing medications and medications that reduce the excretion of potassium ions as prescribed by your doctor.
Eat appropriately, you can eat small meals to prevent a fasting state.
Dialysis Care
Hemodialysis
During hemodialysis, attention should be paid to whether there is any bleeding tendency, such as gums, oral mucosa, nosebleed and so on.
After hemodialysis, attention should be paid to protecting the wound and avoiding infection caused by touching or contacting with water, etc. For those who need long-term dialysis and have an indwelling intravenous catheter, attention should be paid to regular disinfection to prevent infection.
If you have kidney disease and need long-term hemodialysis, you also need to pay attention to water and sodium intake, take medication according to the doctor’s requirements, and record your weight and blood pressure.
Participate in social activities appropriately to reduce inner anxiety and other bad emotions.
Peritoneal Dialysis
On the second day after peritoneal dialysis, you can get up and move around, but you should not overdo it, and after 3 days, you can gradually increase the amount of activity.
Pay attention to fixing and protecting the dialysis catheter to prevent infection. Don’t touch it with hands or pull it, keep the outlet dry when showering, and prohibit tub bath and swimming.
If the catheter has any abnormality, such as difficulty in perfusion, drainage, dislocation, etc., it should be consulted promptly.
Soothing exercises such as walking and jogging can be performed, avoiding strenuous, confrontational and other exercises.
The doctor will determine the daily fluid intake according to the patient’s urine output and the amount of ultrafiltration of peritoneal dialysis, and the patient should follow the doctor’s instructions to control fluid intake.
Follow-up
Follow up with your doctor regularly to monitor your potassium level.
Prevention
People with renal dysfunction or long-term use of potassium-retaining diuretics should avoid prolonged or heavy intake of high-potassium foods and potassium-containing drugs.
Long-term use of potassium-retaining diuretics, angiotensin-converting enzyme inhibitors, non-steroidal anti-inflammatory drugs and other medications should be followed up with follow-up consultations to monitor blood potassium levels, and if necessary, the dosage should be reduced or discontinued according to the doctor’s requirements.
Actively treat diseases that can cause hyperkalemia.