How to choose kidney dialysis for patients with chronic kidney disease? Explain in detail the advantages and disadvantages of peritoneal dialysis and hemodialysis and the timing of kidney transplantation

1. Who needs “Kidney dialysis”

The main function of the kidney is to remove excess water and waste, balance electrolytes, regulate blood pressure, recycle nutrients and secrete erythropoietin, so the kidney is a silent but important organ. When the kidneys lose their function when they are sick, they cannot remove excess water and metabolic waste. At this time, the accumulated toxins will cause harm to the body, and further dialysis treatment, commonly known as kidney dialysis, or even kidney replacement is required to maintain life.

The timing of the use of kidney dialysis can be mainly divided into two types, acute and chronic kidney diseases. “Acute” kidney disease may be due to relative ischemia of the organ caused by insufficient blood perfusion in the system , or kidney damage caused by hormones produced by bacterial infection, or nephrotoxic drugs, etc., resulting in a sharp decline in kidney function. The above situation may require urgent dialysis treatment to help the patient pass the time of renal impairment and correct the cause of acute kidney injury at the same time.

The symptoms of “chronic” kidney disease may not be obvious in the early stage. At this time, it can be controlled by drugs and does not require dialysis. However, when the disease progresses to end stage renal disease (ESRD, end stage renal disease; or ESKD, end stage kidney disease), the kidney function is almost completely lost , and dialysis treatment is necessary at this time.

Therefore, for patients with kidney failure who need dialysis, dialysis can not only improve the quality of life, but also a necessary means to save the patient’s life.

About the disease:chronic kidney disease

Next, we’ll talk a little bit about chronic kidney disease (CKD, chronic kidney disease).

Regarding chronic kidney disease, in addition to changes in the “value” of the test, there will also be “symptoms” of the disease. For the convenience of communication in medicine, the creatinine value measured in the blood will be converted into the glomerular filtration rate (eGFR). When there is evidence of kidney damage (such as proteinuria) and the glomerular If the filtration rate (eGFR) is less than 60ml/min/1.73m2 for more than three months, it can be called chronic kidney disease. According to glomerular filtration rate (eGFR), chronic kidney disease can be divided into five stages. [1]

Although the symptoms of the first and second stages of chronic kidney disease are not yet obvious, it is necessary to actively search for the cause, prevent it and avoid entering a more serious stage. Once the patient enters the third stage, he will start to show symptoms ; in the fourth stage, he will start to carefully evaluate the possibility of dialysis; in the fifth stage , the eGFR is less than 15 ml/min/1.73m2, and the kidneys are close to failure. At this time, renal replacement therapy (RRT, renal replacement therapy), that is, dialysis treatment must be used to maintain life.

Symptoms caused by kidney failure can be collectively referred to as “uremia or uremic syndrome”. The manifestations are as follows:

1. Cardiopulmonary system: Because the kidneys cannot remove water, the body’s fluid volume is overloaded, which will increase the chances of high blood pressure and chronic heart failure. In the long run, it is easy to cause pericardium or hydropleural effusion, and even develop complications such as pericarditis, pulmonary edema, or even systemic edema.

2. Malnutrition: The kidneys are like a sophisticated filtration system that retains nutrients and removes waste. Therefore, once the function of the kidneys declines, nutrients may be lost, resulting in malnutrition.

3. Symptoms of disturbance of consciousness and itching: Excessive accumulation of waste containing nitrogen will affect the operation of the central nervous system and cause disturbance of consciousness. At the same time, patients may also experience severe itching due to the accumulation of uremic toxins and calcium and phosphorus deposits on the skin.

4. Nausea and vomiting: The waste accumulated in the blood will also stimulate the gastrointestinal mucosa, causing symptoms such as nausea and vomiting. These symptoms are often difficult to control with medication. Some people even manifest themselves with persistent hiccups.

5. Electrolyte imbalance: The kidney is very important for the regulation of the pH value in the blood. Its main function is to eliminate hydrogen ions (acidic substances) in the body and recycle bicarbonate (alkaline substances) to achieve acid-base balance . Kidney problems can cause metabolic acidemia and affect systemic organ functions. At the same time, the kidney is the organ that mainly eliminates potassium ions in the human body to maintain a stable blood potassium concentration. After renal failure, patients may develop symptoms of hyperkalemia, resulting in severe arrhythmia and death.

6. Endocrine disorders: mainly manifested as anemia caused by erythropoietin (EPO) deficiency and bone lesions caused by vitamin D deficiency. With the progress of time, the secondary hyperparathyroidism induced by calcium and phosphorus imbalance will gradually appear.

Health care indications for kidney dialysis

Since the importance of kidney dialysis was discussed in the previous section, the current payment standards for kidney dialysis in Taiwan’s health insurance are listed below: they can be divided into absolute indications and relative indications for public reference.

1. Absolute indications: glomerular filtration rate <5 ml/min/1.73m2 or serum creatinine ≥10 mg/dl.

2. Relative indications: It can be divided into diabetic patients and non-diabetic patients.

a. If you are a diabetic patient, because you are prone to uremic complications, you need to start receiving dialysis treatment earlier. Therefore, patients with glomerular filtration rate ≦15 ml/min/1.73m2, or serum creatinine ≧6 mg/dl accompanied by any kind of complications are indications for dialysis.

b. For non-diabetic patients, those with glomerular filtration rate ≦10 ml/min/1.73m2 or serum creatinine>8 mg/dl, and those with any kind of complications are indications for dialysis.

2. How to do “kidney dialysis”

medical treatement

Patients receiving dialysis therapy need not only receive dialysis regularly, but also supplement nutrients that cannot be synthesized due to “dialysis loss” or renal failure . Therefore, the following introduces the common drug treatments for patients:

1. Folic acid, B group: Vitamins can be divided into fat-soluble and water-soluble. Kidney dialysis patients tend to lose “water-soluble” vitamins . Even if they can be supplemented in their diet, some of them will be lost after dialysis. Therefore, after “kidney dialysis”, it is necessary to supplement water-soluble vitamins such as folic acid and group B in the dose prescribed by the doctor. In addition, folic acid and group B are coenzymes needed for hematopoiesis, and are also helpful for renal anemia.

2. Phosphorus binders: Phosphorus binders can be taken when the phosphorus concentration in the blood is too high. It can combine with phosphorus in the intestinal tract, reducing the absorption of phosphorus in the gastrointestinal tract.

3. Vitamin D: Vitamin D is a fat-soluble vitamin that can be synthesized by the human body through diet or skin exposure to sunlight . However, it needs to be activated by the kidneys to exert its function of regulating blood calcium. Kidney dialysis patients must use active vitamin D (Calcitriol) as appropriate, which is often used to treat hyperparathyroidism.

4. Erythropoietin (EPO): The cortical cells of the kidney secrete erythropoietin, which can promote the continuous differentiation of red blood cell precursor cells into mature red blood cells. Therefore, patients with renal failure must inject EPO in a timely manner to prevent anemia and increase physical strength and activity .

5. Iron and stool softeners: Iron is the raw material for hematopoiesis, and patients with renal failure often lack it due to dietary restrictions. Moderate supplementation can improve anemia. About 10% of the potassium ions in the body are excreted from the gastrointestinal tract. It is very important for patients with renal failure to keep the gastrointestinal tract unblocked to maintain the potassium excretion function.

Because the kidneys lose their ability to filter and remove waste, external forces must be used to remove the accumulated toxins and water that the kidneys are unable to remove. common can be divided into “peritoneal dialysis” or “hemodialysis”Two kinds.

Hemodialysis → “wash blood”

Patients undergoing hemodialysis must go to specialized medical institutions for dialysis treatment, which needs to be performed 2-3 times a week, and takes about 4-5 hours each time. It should be noted that “vascular access” needs to be established before hemodialysis treatment. Hemodialysis uses vascular access to drain blood out of the body and enter the artificial kidney. The dialysis machine is powered by a pump to drive the blood flow and then enters the artificial kidney (dialyzer) with a dialysis membrane for dialysis. At the same time, it diffuses with the dialysate to exchange substances. . During the process, anticoagulants are injected to prevent blood clotting, and the clean blood after treatment is returned to the body through vascular access .

Patients with long-term kidney dialysis need a dialysis vascular access to connect to the dialysis circuit of the dialysis machine. According to the function, it can be divided into two types: temporary and permanent.

1. Temporary: Generally speaking, vascular access is established on the vein. However, the veins of normal human limbs are not suitable for repeated needle insertion, and cannot provide the blood flow required by the dialysis machine. Therefore, arteriovenous anastomosis must be performed surgically to gradually “arterialize” the veins to meet the treatment requirements. need. It takes two to three months after surgery for the vessels to mature and become available for treatment. However, sometimes patients who need urgent dialysis treatment do not have time to “raise blood vessels” and must establish temporary pipelines. Double-caval catheters fall into this category. Usually a vein in the neck or groin is taken because it is close to the central vein so the blood flow is high enough for the dialysis machine to treat. Because it is a temporary dialysis circuit, the indwelling time is about 3-4 weeks . Due to the design of the double-caval catheter, the blood inlet and outlet are very close, and occasionally there is a problem of recirculation, so the efficiency of hemodialysis is slightly lower.

2. Permanent: Unlike temporary vascular access, surgeons use surgical methods to connect arteries directly to veins to form artificial tubes for dialysis. It takes about 4-6 weeks to mature quickly. For the common permanent arterio-venous artificial catheter (AVF, arterio-venous fistula), surgeons usually use the radial artery and cephalic vein of the forearm to establish, or use suitable blood vessels in the patient’s elbow. When the blood vessels are too small, an arterio-venous graft can also be used to bridge the arteries and veins. The advantages of using this type of vascular access are fewer complications and long-term use .

However, after the vascular access is established, it is still necessary to pay attention to whether there is any obstruction. Therefore, before each kidney dialysis, the doctor will check the health status of the tube through auscultation, palpation and other examinations, and even arrange tube ultrasound. If the blocking condition can be detected and dealt with early, the chance of rebuilding can be reduced and the service life can be extended.

Advantages of hemodialysis

Hemodialysis needs to be performed in professional medical institutions by doctors and nurses. Although kidney dialysis equipment is not required at home, general nursing knowledge is also required. Therefore, hemodialysis is more suitable for the elderly with poor self-care ability or the elderly living alone, and it is safer to send it to a medical institution for execution. In addition, hemodialysis is also suitable for some patients with sudden deterioration of renal function, to help patients temporarily overcome the period of renal failure , and to treat the cause at the same time.

Disadvantages of hemodialysis

Because patients do not have equipment at home, patients undergoing hemodialysis are highly dependent on institutions . The risk of blood infection will also increase during the process of drawing blood out and transporting it outside the body for dialysis . Going to the hospital during the current epidemic of infectious diseases is more likely to increase the risk of infection. In addition, hemodialysis patients may experience rapid changes in blood pressure after dialysis, and their blood pressure may drop, so they may experience physical discomfort; some nutrients will also be lost during dialysis, and the patient will also feel tired. Because kidney dialysis is not performed every day, patients need to strictly control their diet on days when they are not undergoing dialysis : the intake of phosphorus in foods including salt, potassium ions, water, etc. must be limited. And because a large amount of body fluid is temporarily removed outside the body during dialysis, it will have adverse effects on the cardiovascular system in the long run [3], and may also accelerate the deterioration of renal function to the stage of anuria.

Peritoneal dialysis → “wash stomach”

Like hemodialysis, a dialysis circuit needs to be surgically established, but the dialysis circuit is permanent and implanted directly in the abdominal cavity. Peritoneal dialysis requires regular injection of dialysis fluid, using the human peritoneum as a natural dialysis membrane to wash out excess water and toxins in the body, and then discharge the peritoneal fluid after a period of time.

The mode of peritoneal dialysis is flexible and changeable, and the common ones can be represented in two ways, one is continuous mobile peritoneal dialysis (CAPD), and the other is automatic peritoneal dialysis (APD). The former needs to change the peritoneal dialysis solution 3 to 4 times a day , and the retention time and volume of each time are determined by the doctor’s prescription. After the peritoneal dialysate is drawn out, new dialysate needs to be poured in. If the operation process is proficient, it will take about 30 minutes on average . Automated peritoneal dialysis is suitable for patients who cannot change peritoneal fluid frequently. After being connected to the fully automatic peritoneal dialysis machine, the machine will automatically change the liquid. Usually, the patient will pick up the machine before going to bed at night . This item is more suitable for patients who need to go to work during the day.

Compared with hemodialysis, which requires professionals to operate, peritoneal dialysis patients and their families can learn aseptic techniques and fluid replacement methods by themselves. In addition, there is no need to cooperate with the time of the medical institution, you can arrange the dialysis time and work and rest by yourself , and the time arrangement is more flexible. However, it is still necessary to arrange regular follow-up visits 1-2 times a month.

Advantages of peritoneal dialysis

Peritoneal dialysis is gentler because it does not require large amounts of fluid to be removed from the body, and the patient’s blood pressure does not change too much . In addition, peritoneal dialysis can preserve the remaining renal function. At the same time, there is no need to rely on medical institutions, and the cost is relatively lower than that of hemodialysis. [4]

Disadvantages of peritoneal dialysis

Peritoneal dialysis uses the peritoneum, so it is not suitable for patients who have undergone abdominal surgery , because abdominal surgery may reduce the effective peritoneum or peritoneal adhesions, reducing the feasibility of peritoneal dialysis. Because the dialysate needs a higher osmotic pressure to form a gradient to absorb excess water, glucose is added to the dialysate to form a hypertonic solution. However, although glucose is harmless to the human body, it will be absorbed by the peritoneum. Therefore, for diabetic patients, the use of peritoneal dialysis requires more stringent monitoring of blood sugar changes. In addition, if the aseptic technique is not performed properly, there is a certain chance of causing dangerous bacterial peritonitis. If the patient has severe abdominal pain and turbid discharge in the pipeline, he should seek medical treatment as soon as possible and receive antibiotic treatment.

3. In addition to dialysis treatment

kidney transplant

Kidney transplantation is the only way for patients with end-stage renal disease to completely get rid of dialysis. After kidney transplantation, the patient’s renal function index can return to normal, but because it is an allogeneic transplant, the patient needs to take immunosuppressants for life . At present, the commonly used clinical therapy after transplantation is mainly to use immunosuppressants together with steroids, and then adjust it according to the patient’s tolerance and the response of the transplant.

Although kidney transplantation can be said to be the closest curative treatment, patients have to endure long-term medication, as well as common side effects such as bone marrow suppression, a gap in the immune system caused by low white blood cells, and the annoying side effects of immunosuppressants (hepatotoxicity) , nephrotoxicity, etc.). Moreover, the number of donated kidneys in China is not large, and given the lack of kidney sources, the number of patients with end-stage kidney disease who can receive kidney transplants is not many each year. In addition, although the technology of implantable mechanical artificial kidney is under development in foreign countries , it is a pity that it has not yet been popularized and matured, and related research is still in progress, so there is currently no chance of clinical use.

how to choose

When the public has the opportunity and decides to receive a kidney transplant, they can make good use of Shared Decision Making (SDM, Shared Decision Making): doctors and patients share treatment experience and needs (Share), face problems together and propose various solutions (Decision), After the patient has a comprehensive understanding of the condition and the currently available options, the patient makes the final choice (Making) . Therefore, in the face of chronic kidney disease, you can discuss it with your attending physician in detail before treatment. Do not follow hearsay. Using illegal methods and appliances for treatment will delay the condition.

Four. Conclusion

People with chronic kidney disease in the early stage or end-stage kidney disease who are about to receive dialysis should pay attention to the maintenance of their kidneys and adjust their lifestyle: drink plenty of water without holding back urine, try to eat as light as possible and reduce intake of processed foods, develop moderate exercise habits, Pay attention to the safety of medication and do not take drugs of unknown origin, and regularly return to the clinic for follow-up and treatment to delay the progress of the disease. For high-risk groups of nephropathy, such as: patients with three highs and metabolic syndrome, regular renal function checks can be performed to make immediate adjustments in the early stage of disease and reverse the course of nephropathy. Even if you are really unfortunate enough to enter end-stage renal disease and need kidney dialysis, you can learn about various treatment methods in advance, and discuss with the attending physician to decide the best treatment method.

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