What is uremia that dialysis patients are concerned about? One article explains it all!

What is uremia

Chronic kidney disease is divided into 5 stages, and the 5th stage is what we call uremia. In the early stages of uremia, many patients do not have particularly obvious symptoms. They may only show unexplained drowsiness, fatigue, edema, dull complexion, loss of appetite, mild nausea, vomiting, low back pain, itchy skin, urine odor on breath, drowsiness, slow reaction and other discomforts, but loss of appetite is the earliest and most common symptom of most uremia patients. Therefore, many patients only discovered renal failure when they went to the gastroenterology department for treatment. Some patients often have very high creatinine but do not feel any discomfort, while some patients will experience nausea and vomiting when the creatinine is two or three hundred. This is actually related to each person's tolerance to toxins.

Function of the kidneys

(1) Produce urine;

(2) Excrete toxins from the body;

(3) Maintain the water, electrolyte, and acid-base balance in the human body;

(4) Endocrine function: ① Secrete erythropoietin to stimulate hematopoiesis; ② Secrete renin, prostaglandins, and kinins to regulate blood pressure through a series of endocrine systems.

Why do we need to choose renal replacement therapy when we reach the uremia stage?

High blood pressure, anemia, acidosis, and calcium-phosphorus metabolism disorders can be corrected by medication, but many toxins in the body cannot be excreted during the uremia stage. Many toxins rely on the kidneys to be excreted. Other organs are soaked in blood with high toxin levels for a long time, causing the above-mentioned symptoms to appear and become more and more serious. At this time, renal replacement therapy is needed.

In addition, there is one situation that must be known, that is, the urine volume of patients with uremia is normal, but the urine of patients with uremia can only excrete water, not toxins, just like pure water, toxins cannot be excreted in urine.

How to assess whether uremia has occurred

First of all, urea nitrogen and creatinine values ​​are only indicators of kidney function that can be monitored under existing medical conditions, but creatinine values ​​are not sensitive and cannot clearly reflect the patient's kidney function.

For example, one kidney is equivalent to 50 people, and both kidneys are equivalent to hiring 100 people to carry garbage every day, but this is actually the workload of 50 people. In principle, these 100 people can take turns to rest. When creatinine increases, it means that there are less than 50 people working. At this time, the remaining 50 people cannot rest and can only continue to work. As the intensity of work increases, there are fewer and fewer people left, and more and more garbage in the body, and creatinine will rise accordingly, but at this time the kidney damage is already quite serious. In other words, when there are less than 15 people, it enters the uremia stage.

Therefore, we cannot simply draw a conclusion based on the results of creatinine and urea nitrogen. We should evaluate the renal function of both kidneys. If the renal function of both kidneys is less than 15 ml/min, the patient has entered the uremia stage. Of course, the prerequisite is that the patient must be diagnosed with chronic kidney disease.

When should dialysis be started?

A creatinine level of 600 or 700 does not necessarily require dialysis. The more important thing is to judge based on one's own symptoms. For example, some people are born roses, while others are cacti. Roses will wither if not properly cared for, but cacti can survive in harsh environments. Different properties determine the most important factor in the patient's dialysis time. This also explains why some people have a creatinine level of more than 1,000 or 2,000 but have not yet entered dialysis, while some people may need dialysis when their creatinine level exceeds 300 or 400.

We have several criteria for judging this: The first is the creatinine level. The traditional view is that if the creatinine is greater than 707 umol/L and the glomerular filtration rate is less than 10 ml/min, dialysis should be initiated. This is because the kidney function itself is already poor, toxins and water cannot be metabolized normally, and the body is at a high level of toxins for a long time, which poses a high risk to the cardiovascular and cerebrovascular system. The second is based on the patient's symptoms. Although some patients do not have very high creatinine, they have severe symptoms such as nausea, vomiting, and edema, and their quality of life is poor. This is obviously an imbalance of toxins and water in the body, and dialysis should also be considered at this time. The third is whether there are complications. If the patient has serious complications such as hyperkalemia, heart failure, and acid-base metabolism imbalance, timely dialysis or even emergency dialysis is required.

Is dialysis addictive?

Entering the dialysis stage means that the kidneys can no longer detoxify, and the only way to replace the kidneys is to choose a method. If toxins remain in the body for a long time, it will cause irreversible damage to many organs. Just like wearing glasses for myopia, this cannot be called dependence, but something that must be done to improve the quality of life and survival time.

Renal replacement therapy (dialysis)

Peritoneal dialysis and hemodialysis: There is no absolute difference between the two methods, each has its own characteristics. When choosing between peritoneal dialysis and hemodialysis, we must first understand the characteristics of the two dialysis methods and choose according to our own physical condition, family situation, and work situation.

Peritoneal dialysis uses the exchange capacity of the peritoneum to remove water and toxins. It is simple, safe, painless, and can be performed at home. In the early stage, a peritoneal dialysis tube is placed in the abdominal cavity through minimally invasive surgery in the hospital. The peritoneal dialysis fluid is infused into the abdominal cavity through this tube and retained for several hours. The old peritoneal dialysis fluid is then drained and new peritoneal dialysis fluid is injected. This cycle is repeated three times a day, and each fluid change takes 20 minutes. Patients can work and move normally during the period of peritoneal dialysis fluid retention. Advantages: (1) The operation is relatively simple and can be performed at home without frequent visits to the hospital. It is not affected by external factors such as weather and traffic. (2) It can protect residual renal function and has little effect on the cardiovascular system. (3) No systemic anticoagulants are required, and there is no increase in the risk of bleeding. Disadvantages: (1) If the operation is not performed properly, peritoneal infection may occur; (2) It may not be suitable for patients with abdominal obesity; (3) It is not suitable for patients undergoing abdominal surgery or suffering from severe infection; (4) It is not suitable for patients with hernia, intestinal obstruction, or severe lumbar disc herniation; (5) It is not suitable for patients who cannot take care of themselves and have no one to help them.

Hemodialysis uses a hemodialysis machine to draw blood out of the body, remove excess water and toxins through the machine, and then return the fluid to the body. Go to the hospital for treatment 2 to 3 times a week, every other day, each time for 4 to 6 hours.

Hemodialysis requires the establishment of a dialysis access, which mainly includes temporary dialysis catheters, long-term dialysis catheters, arteriovenous fistulas, and artificial blood vessels. Among them, arteriovenous fistulas are the ideal access for long-term dialysis patients. Arteriovenous fistulas take 4 to 6 weeks to mature. We recommend that patients who choose hemodialysis should undergo intravenous fistula formation in advance if their conditions allow, in preparation for future dialysis.

For patients who need immediate dialysis and are not suitable for waiting, or patients with poor vascular conditions, we will recommend temporary dialysis catheter or long-term dialysis catheter placement according to the patient's condition, and then consider peritoneal fistula formation after the patient's condition stabilizes. Advantages: (1) More efficient. When combined with hyperkalemia, acidosis, heart failure, and drug poisoning, the treatment effect is better than peritoneal dialysis; (2) No need to operate by yourself, doctors and nurses will operate; (3) The removal efficiency of small molecules is higher than peritoneal dialysis, and combined with hemoperfusion and hemofiltration, it can also effectively remove medium-molecule toxins. Disadvantages: (1) For patients undergoing dialysis for the first time, especially those with high toxin levels, the probability of dialysis imbalance syndrome is greater than peritoneal dialysis; (2) There are also risks of dialysis catheter infection, fistula stenosis, and arteriovenous aneurysm formation.

Kidney transplantation is the process of implanting another person's healthy kidney into a patient's body through surgery, which is equivalent to having a normal kidney again. Patients do not need dialysis after transplantation, but they need to take anti-rejection drugs for life after surgery. Before kidney transplantation, physical assessment, matching kidney sources, and ethical review procedures are required. This is also a long-term planning and preparation process.