as everyone knows
Potassium is one of the most abundant chemical elements in human body.
Play a very important role
One of the most important functions.
Is to maintain the excitability of neuromuscular.
And normal function of myocardial cells.
When hypokalemia occurs, the excitability of neuromuscular decreases, from weakness of limbs to paralysis of lower limbs. If the respiratory muscles are involved, it will lead to dyspnea; When it affects gastrointestinal smooth muscle, it can cause paralytic intestinal obstruction. Hypokalemia is more harmful to the heart. When the blood potassium is lower than 2.0 mmol/L, it may cause serious arrhythmia and even cardiac arrest, which is a critical state that needs urgent treatment.
Causes of hypokalemia
The causes of hypokalemia are generally as follows: insufficient intake, excessive excretion and abnormal distribution. Let's take a closer look at them.
1 Hypokalemia caused by insufficient intake
Food is rich in potassium, and hypokalemia caused by insufficient potassium intake rarely occurs in clinic. Unless you can't eat because of coma, digestive tract diseases, or major gastrointestinal surgery, if you don't supplement potassium in time when intravenous nutrition is high, or the amount of potassium supplement is insufficient, it will cause hypokalemia for a long time.
2 Excessive excretion leads to hypokalemia.
This mainly includes gastrointestinal potassium loss and renal potassium loss.
Gastrointestinal potassium loss is a common cause. Digestive fluids (such as saliva, gastric juice, intestinal juice, pancreatic juice, etc.). ) is rich in potassium. If vomiting and diarrhea are repeated, too much potassium will be lost with gastrointestinal fluid, which will also cause hypokalemia. Patients with these medical histories should routinely detect electrolytes (including blood potassium, sodium and chlorine) to find hypokalemia in time, so as to avoid serious consequences. Sweating generally does not cause hypokalemia, but in the case of heavy sweating such as strenuous exercise and high temperature work, it may also cause hypokalemia if only water is supplemented without electrolyte.
Renal potassium deficiency is the most common cause of hypokalemia. The characteristics of kidney potassium excretion are "eat more and discharge more, eat less and discharge less, and discharge if you don't eat". When the potassium intake from food exceeds the human body's needs, the urinary potassium excretion will increase; When eating potassium ion is insufficient, urinary potassium excretion will automatically decrease; But even if you don't eat or drink, there will be a certain amount of urinary potassium excretion, so fasting for more than 2 weeks will cause hypokalemia.
Clinically, the causes of renal potassium loss are as follows.
Parts-1
The most common cause of renal potassium loss is diuretics, such as furosemide, torasemide, hydrochlorothiazide and indapamide. These drugs are often used for detumescence treatment of heart failure, ascites due to cirrhosis, nephrotic syndrome and other diseases. Diuretics are also commonly used for hypertension. Many compound antihypertensive drugs (such as perindopril, indapamide, losartan/valsartan/irbesartan hydrochlorothiazide tablets, Kefute).
It can be seen that non-professional patients should not use drugs without authorization, and should consult professional doctors for drug adjustment.
the second part
Hypertension with hypokalemia is not only caused by drugs, but also the possibility of endocrine hypertension should be carefully examined. Adrenal gland can produce a hormone called aldosterone, which plays the role of "preserving sodium and expelling potassium" on distal renal tubules, thus regulating blood pressure and water-sodium balance. If adrenal hyperplasia or adenoma spontaneously secretes too much aldosterone, too much sodium accumulates in the body, leading to hypertension, and too much potassium is lost through the kidney, causing hypokalemia. This disease is called "primary aldosteronism". If this disease is found, hypertension can be cured or significantly relieved by removing the diseased adrenal gland or adding targeted drugs.
the third part
In addition to the diuretics mentioned above, there are many drugs that can cause hypokalemia.
Abnormal distribution causes hypokalemia.
98% of potassium ions in human body exist in cells, while extracellular potassium accounts for only 2%, and blood potassium accounts for only 0.3% of total potassium. The intracellular potassium ion concentration (about 140 mmol/L) is 35 times that of the extracellular potassium ion concentration (about 4.0 mmol/L). This concentration difference is maintained by the continuous operation of the "sodium and potassium pump" on the cell membrane. This pump is responsible for transporting intracellular sodium to the outside of the cell and extracellular potassium to the inside of the cell. If the function of this pump is slightly strengthened, it will have a significant impact on blood potassium.
The following situations need our attention.
Parts-1
Insulin can strengthen the function of sodium and potassium pump, make more potassium enter cells, and lead to the decrease of extracellular and serum potassium concentration. Therefore, we should be alert to the occurrence of hypokalemia when intravenous infusion of glucose and insulin.
the second part
Thyroxine can also enhance the function of sodium and potassium pump, and some newly diagnosed hyperthyroidism patients (especially young men in Asia) may suddenly have hypothyroid periodic paralysis. So when you encounter unexplained hypokalemia, especially young male patients, don't forget to check thyroid function.
the third part
Another disease similar to hyperthyroidism and hypokalemic periodic paralysis is familial hypokalemic periodic paralysis, which is more common in Caucasians and has a family genetic history. Patients usually have a young onset age and there is no gender difference. The reason of muscle paralysis is related to the abnormality of ion channels (calcium, sodium and potassium) in skeletal muscle. Paralysis of lower limbs occurs periodically, mostly after fatigue, overeating and strenuous exercise. Because eating too much carbohydrate will promote the release of more insulin and induce hypokalemic paralysis, such patients should avoid overeating, overwork and strenuous exercise.
Treat the cause of the disease
Pay attention to potassium supplementation
The premise of hypokalemia treatment is to find the cause. When encountering hypokalemia, it is impossible to "make up" only by oral or intravenous drip of potassium chloride. Patients should find a professional doctor, carefully understand the medical history, do a detailed physical examination, supplemented by necessary examinations, find the culprit of hypokalemia, and the treatment can be targeted.
No. 1
The principle of potassium supplement is mainly dietary supplement and oral potassium supplement, and animal and plant foods are rich in potassium, in no particular order;
second
Oral potassium chloride is best taken after meals to reduce gastrointestinal irritation;
third place
Severe hypokalemia requires intravenous potassium supplementation, and potassium chloride should never be injected intravenously;
fourth
The dynamic changes of blood potassium should be closely observed in the process of potassium supplementation to avoid overcorrection and hyperkalemia.
Expert business card
Zhao Jiasheng
Tongji hospital affiliated to Tongji University
Deputy Director and Chief Physician of Endocrinology and Metabolism Department
Expert clinic: Tuesday afternoon
Special needs clinic: Monday afternoon
Expertise: He is good at the diagnosis and treatment of various difficult and critical endocrine and metabolic diseases, especially in the diagnosis and treatment of endocrine hypertension, and has accumulated rich clinical experience.
Young member of Endocrinology Branch of Chinese Medical Association, member of Diabetes Professional Committee of Shanghai Medical Association. At present, the key direction is to screen and diagnose primary aldosteronism in patients with refractory hypertension, and to develop adrenal vein blood sampling technology in cooperation with radiation interventional department. He gave a keynote speech on "Differential Diagnosis of Hypercalcemia" at the China-Japan Osteoporosis Forum. He gave a special lecture on diabetes and infection at the Endocrinology Forum of Endocrinology Department of Ruijin Hospital. A lecture on the progress of diagnosis and treatment of polycystic ovary syndrome was given in the national continuing education class held by Putuo District Central Hospital. He was invited by clove garden medical website (www.dxy.cn) twice to be interviewed by experts. Among them, "Differential diagnosis of hypokalemic hypertension syndrome" was one of the top ten micro-interviews in 20 13 clove garden, and then "syndrome of abnormal secretion of antidiuretic hormone" was done. Participated in American Diabetes Annual Meeting (ADA) and European Diabetes Annual Meeting (EASD) for many times; 20 10 was elected as a young member of the Endocrinology Branch of the Chinese Medical Association at the annual national endocrinology conference held in Suzhou. Elected as a member of Diabetes Branch of Shanghai Medical Association for two consecutive years. Completed a bureau-level project of Shanghai Health Bureau, the application value of adrenal venous blood sampling in the diagnosis of primary aldehyde typing, and published 5 papers in recent 3 years, including 2 SCI papers.
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Department of Endocrinology and Metabolism
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