What are the causes of hyperkalemia?

Written by Wei Shi Liang
Intensive Care Unit
Updated on September 05, 2024
00:00
00:00

Hyperkalemia, with blood potassium levels greater than 5.5 mmol/L, commonly occurs due to decreased potassium excretion or abnormal potassium transport within cells, as well as other reasons such as excessive intake. Decreased potassium excretion can commonly be due to renal failure, the use of potassium-sparing diuretics, renal tubular acidosis, and reduced secretion of corticosteroid aldosterone. Abnormal potassium transport includes conditions such as acidosis, rhabdomyolysis, extensive burns, severe trauma, intestinal necrosis, and peritoneal bleeding, among other diseases. Excessive potassium intake can be due to sample hemolysis or an elevation in white blood cells, both of which can lead to hyperkalemia. Therefore, it is crucial to be vigilant in clinical settings and address the condition promptly and appropriately.

Other Voices

doctor image
home-news-image
Written by Wei Shi Liang
Intensive Care Unit
1min 11sec home-news-image

Clinical manifestations of hyperkalemia

The clinical manifestations of hyperkalemia mainly affect the cardiovascular system, often presenting with slowed heart rate and various arrhythmias. When the blood potassium level is between 6.6 and 8.0 mmol/L, a tent-shaped T-wave can be observed. Rapid increases in blood potassium can lead to ventricular tachycardia, and even ventricular fibrillation. A gradual increase in blood potassium can cause conduction blocks, and in severe cases, cardiac arrest. Sudden death in severe hyperkalemia is mainly due to ventricular fibrillation and cardiac arrest. The second aspect is symptoms related to the neuromuscular system. As the concentration of potassium ions in the extracellular fluid increases, the resting membrane potential drops, leading to muscle weakness and even paralysis, typically more pronounced in the lower limbs and extending upward along the trunk. In severe cases, some patients may experience difficulty in swallowing and breathing difficulties. Symptoms involving the central nervous system mainly include restlessness, confusion, and fainting.

doctor image
home-news-image
Written by Tang Zhuo
Endocrinology
1min 28sec home-news-image

Hyperkalemia is seen in which diseases?

When serum potassium levels exceed 5.5 millimoles per liter, it is referred to as hyperkalemia. Elevated serum potassium does not reflect an overall increase in body potassium, but due to limitations in testing methods, the clinical diagnosis of hyperkalemia still relies on combining serum potassium levels with electrocardiogram history. The causes of hyperkalemia are complex and commonly include: First, decreased renal potassium excretion, seen in acute kidney failure or insufficiency in adrenal cortical hormone synthesis and secretion, or long-term use of potassium-sparing diuretics; Second, shifts of potassium from inside the cells, often due to hemolysis, tissue damage, large-scale necrosis of tumors and inflammatory cells, shock, burns, excessive muscle contractions, acidosis, or injection of hypertonic saline or mannitol, which causes dehydration inside cells and leads to potassium leakage, resulting in hyperkalemia; Third, excessive intake of potassium-containing medications, such as high doses of potassium penicillin; Fourth, transfusion of stored blood can lead to hyperkalemia; Fifth, digitalis poisoning can cause hyperkalemia.

doctor image
home-news-image
Written by Chen Li Ping
Endocrinology
58sec home-news-image

How is hyperkalemia treated?

For hyperkalemia, commonly used clinical treatments include firstly diuretics, which increase the excretion of potassium, thus increasing its discharge from the body. Additionally, hypertonic glucose with insulin is used intravenously to facilitate the movement of potassium from outside to inside the cells. Sodium bicarbonate can also be used to correct acidosis, which can likewise reduce blood potassium levels. When hyperkalemia causes ventricular arrhythmias, calcium injections should be administered immediately to counteract the cardiac toxicity of high potassium. If these treatments do not result in significant effects and the condition is critical, emergency hemodialysis or peritoneal dialysis can be performed to lower blood potassium levels. (Medication should be administered under the guidance of a doctor.)

doctor image
home-news-image
Written by Wei Shi Liang
Intensive Care Unit
1min 18sec home-news-image

Common symptoms of hypokalemia and hyperkalemia

The common symptoms of hyperkalemia and hypokalemia, mainly seen in severe cases of high or low potassium, manifest as neurological and muscular symptoms as well as circulatory system symptoms, which are fairly similar in both conditions. If the blood potassium is particularly low, less than 2.0 mmol per liter, it can lead to reduced or absent reflexes. In severe cases, this may progress to paralysis of the respiratory muscles, causing respiratory pump failure. For hyperkalemia, particularly severe cases may also present with swallowing difficulties and respiratory distress. These central nervous system issues can lead to confusion and fainting. Another similar issue is the impact on the circulatory system; severe hypokalemia can cause ventricular tachycardia and even ventricular fibrillation, leading to death. In hyperkalemia, the impact on the cardiovascular system primarily causes malignant tachycardia and can also result in ventricular fibrillation. The main cause of sudden death in hyperkalemia is ventricular fibrillation and cardiac arrest, demonstrating that severe hyperkalemia and hypokalemia similarly cause significant arrhythmic conditions in the heart.

doctor image
home-news-image
Written by Gan Jun
Endocrinology
1min 6sec home-news-image

What are the changes in urine output in hyperkalemia?

When patients experience hyperkalemia, urine output generally decreases, leading to reduced potassium excretion by the kidneys, typically accompanied by abnormal kidney function. Thus, as long as kidney function is normal and daily urine output exceeds 500 milliliters, hyperkalemia is usually rare. Some causes of reduced renal potassium excretion include decreased glomerular filtration rates and reduced potassium secretion by the renal tubules, commonly seen in acute and chronic renal failure, adrenal cortex insufficiency, low renin, low aldosterone blood conditions, renal tubular acidosis, and long-term use of diuretics, especially potassium-sparing diuretics. Additionally, β-adrenergic tissue agents and angiotensin-converting enzyme inhibitors can cause drug-induced hyperkalemia, leading to abnormal kidney function and, consequently, decreased potassium excretion by the kidneys, ultimately resulting in reduced urine output.