Uremia

Uremia (Latin: Uremia) is a condition in which the level of urea (urea) in the blood is significantly elevated. Urea is the end product of protein metabolism, which is formed in the body when protein molecules are broken down. Normal blood urea levels are maintained by healthy kidneys, which filter urea from the blood and excrete it with the urine. [1]

Causes of the uremia

Uremia usually occurs as a consequence of impaired kidney function, which is unable to effectively filter and remove urea from the blood. It can be caused by a variety of reasons. Here are some of them:

1. Chronic kidney failure (CKD): CKD is one of the most common causes of uremia. It develops gradually as a result of long-term kidney damage, usually due to other medical conditions such as diabetes, arterial hypertension, autoimmune diseases, and others.
2. Acute kidney failure: Acute kidney failure can occur suddenly due to trauma, infection, poisoning, medications, or other emergencies that harm the kidneys.
3. Glomerulonephritis: This is an inflammatory kidney disease that can damage the glomeruli, the small filtering units of the kidneys.
4. Hydronephrosis: This is a condition in which urine cannot flow out of the kidney normally, which can cause increased pressure in the kidney and damage its function.
5. Urinary tract obstruction: Obstructions or blockages in the urinary tract caused by bladder stones, tumors, or other causes can interfere with the normal excretion of urine, resulting in impaired kidney function.
6. Sepsis: Severe infection such as sepsis can damage the kidneys and cause uremia.
7. Impaired blood flow to the kidneys: Insufficient blood supply to the kidneys caused by heart failure, shock, low blood pressure, and other factors can also lead to uremia.
8. Other Rare Conditions: There are other rare medical conditions and genetic disorders that can cause uremia.

Pathogenesis

The pathogenesis of uremia is related to impaired kidney function and the accumulation of metabolic wastes, including urea, in the blood. Normally, the kidneys perform the important function of filtering blood and regulating the balance of electrolytes, fluids, and waste products in the body. When kidney function is impaired, urea and other metabolic products begin to accumulate in the blood, leading to uremia.

The pathogenesis of uremia generally involves the following major steps:

1. Damage to renal structures: Uremia can be caused by a variety of reasons that result in damage to renal structures. These may include chronic renal failure, acute renal failure, inflammation, infection, trauma, or other conditions.
2. Decreased filtration capacity: When kidney structures are damaged, their ability to filter blood is impaired. This leads to decreased filtration of urea and other substances from the blood in the primary urine.
3. Metabolic waste accumulation: Urea, creatinine, and other metabolic wastes begin to accumulate in the blood because the kidneys cannot excrete enough of them in the urine. This process may be gradual, especially in cases of chronic renal failure, or more rapid in cases of acute renal failure.
4. Onset of symptoms: As blood urea levels rise, symptoms of uremia appear, such as fatigue, swelling, nausea, kidney pain, itching, and others. In the case of acute kidney failure, symptoms may develop quickly and be more severe.

Symptoms of the uremia

The symptoms of uremia can be varied and can vary depending on the degree of kidney dysfunction, how quickly the disease progresses, and other factors. Here are some of the most common symptoms:

1. Fatigue and weakness: Constant fatigue and weakness can be among the first symptoms of uremia.
2. Swelling: Swelling (edema) can develop, usually in the legs, lower legs, feet, and around the eyes (under the eyes). Swelling is caused by fluid retention in the tissues due to impaired kidney function.
3. Thirst and changes in urination: Patients may experience intense thirst and increased urination. At the same time, the urine may become paler.
4. Itchy skin: Itchy skin (pruritis) can be one of the unpleasant symptoms. It is usually associated with the accumulation of metabolic waste in the blood.
5. Digestive disorders: Patients may experience nausea, vomiting, and appetite may decrease.
6. Kidney pain: Kidney or back pain can occur due to stretching of the kidney capsules with swelling and increased kidney size.
7. Thinking disorders and drowsiness: Uremia can affect brain function, causing lethargy, drowsiness, concentration disorders, and other psychiatric symptoms.
8. High blood pressure: Blood pressure levels may increase.
9. Joint and muscle pain: Pain and stiffness in joints and muscles.
10. Respiratory disturbances: In rare cases, uremia can cause respiratory disturbances and gasping.

Symptoms may worsen as renal dysfunction increases and metabolic wastes accumulate in the blood.

Stages

Stages of uremia can be assessed based on creatinine levels and creatinine clearance in the blood, as well as the presence of symptoms and a comprehensive examination. The following stages are usually distinguished:

1. Preremic stage: In this stage, uremia may be asymptomatic or have minimal symptoms. Blood levels of metabolic wastes may be elevated but not yet causing significant symptoms. Renal function may be reduced but not to a critical degree.
2. Uremic stage: In this stage, the level of urea and other metabolic wastes in the blood is significantly elevated. Characteristic symptoms such as fatigue, swelling, itchy skin, nausea, vomiting, changes in urination, etc. Appear. Kidney function is significantly impaired and patients require medical intervention, including dialysis (artificial renal clearance) or kidney transplantation.
3. Chronic uremia: If uremia becomes chronic, it may be the result of chronic renal failure, in which kidney function gradually deteriorates over time. In this stage, the level of metabolic wastes in the blood remains elevated and patients require ongoing treatment and monitoring.
4. Terminal uremia is a condition in which kidney function is so severely impaired that it can no longer be restored or maintained without the use of dialysis or kidney transplantation. It is the final, most severe stage of kidney failure, when the kidneys are no longer able to perform their basic functions, such as filtering blood and removing metabolic waste from the body.

Patients with terminal uremia often require ongoing medical care and treatment to maintain vital body functions. There are two main treatments for terminal uremia:

1. Dialysis: Dialysis is an artificial kidney procedure in which the blood is cleaned of metabolic waste and excess fluid. Patients may undergo hemodialysis (done through a machine) or peritoneal dialysis (using special fluid in the abdomen). Dialysis may be a temporary or permanent treatment option for terminal patients.
2. Kidney transplantation: A kidney transplant is a surgical procedure in which a donor kidney is transplanted into a patient. After a successful transplant, the patient can usually lead a more normal life without the need for dialysis. However, these surgeries can be complicated and require constant medical supervision and immunosuppressive medications.

The terminal stage is a serious and severe condition, and treatment for this condition requires specialized medical care and support. Patients are advised to work with a team of medical professionals to choose the best method of treatment and management of this condition.

It is important to note that stages may progress differently in different patients, and evaluation of the degree of uremia requires a comprehensive assessment, including clinical symptoms and laboratory test results.

Forms

Depending on the cause and characteristics of uremia, several forms or types of this condition can be distinguished:

1. Chronic uremia: This is a form of uremia that develops gradually over a long period of time, usually as a result of chronic kidney disease. Patients with chronic uremia may have mild to minimal symptoms in the early stages, but as kidney function worsens, symptoms become more severe. Treatment of chronic uremia involves supportive therapy, including diet, medications, and monitoring of kidney function.
2. Acute uremia: This form of uremia develops rapidly, most often due to acute kidney failure, which can be caused by trauma, infection, poisoning, or other emergencies. Acute uremia is accompanied by severe symptoms and requires immediate medical intervention. Treatment may include dialysis and treatment of the underlying disease.
3. Uremic Syndrome: This term is used to describe the complex of symptoms and complications that can occur due to uremia. Uremic syndrome can include symptoms such as fatigue, swelling, itchy skin, nausea, vomiting, changes in urination, as well as more serious complications such as cardiac abnormalities, nervous system dysfunction, and others.
4. Compensated and decompensated uremia: These terms can be used to describe the degree of stability of uremia. The compensated form means that the body is still able to maintain relatively normal organ function despite the presence of levels of metabolic waste in the blood. The decompensated form indicates that the body is no longer able to compensate for the accumulation of waste and serious symptoms and complications develop.

Complications and consequences

Uremia is a serious medical condition, and it can cause a variety of complications, especially if left untreated or unchecked. Here are some of the complications that can occur:

1. Swelling: Uremia can cause fluid retention in the tissues, leading to swelling, especially in the legs, shins, and feet. This can lead to increased body volume and additional stress on the heart.
2. Cardiovascular complications: Uremia can affect the heart, causing increased blood pressure, arrhythmias (irregular heart rhythm), pericarditis (inflammation of the outer lining of the heart), and other heart and blood vessel problems.
3. Nervous System Complications: Uremia can cause symptoms such as drowsiness, irritability, headaches, shaking, seizures, and even disturbances of consciousness. These symptoms can cause intellectual and mental impairment.
4. Bone lesions and mineral imbalances: Uremia can cause disturbances in bone metabolism, leading to osteoporosis and an increased risk of bone fractures. Blood calcium and phosphorus levels can also become disturbed.
5. Decreased immune function: Uremia can weaken the immune system, making the body more vulnerable to infections.
6. Gastrointestinal complications: Patients may have digestive problems, nausea, vomiting, diarrhea, and other gastrointestinal symptoms.
7. Hematologic disorders: Uremia can affect hematopoiesis and cause anemia (decreased hemoglobin levels), thrombocytopenia (decreased platelet count), and other blood system disorders.
8. Brain poisoning: An acute brain disorder called uremic encephalopathy may occur, which is manifested by seizures, disorientation, hallucinations, and decreased consciousness.

To prevent and treat complications, it is important to seek timely medical attention, maintain kidney function, and monitor metabolic waste levels in the blood.

Diagnostics of the uremia

Diagnosis of uremia involves a number of laboratory and clinical methods that assess the level of metabolic wastes in the blood and kidney function. Here are the main diagnostic methods:

1. Measuring blood urea levels: This test assesses the concentration of urea in the blood. Elevated urea levels may indicate impaired kidney function and the presence of uremia.
2. Measuring blood creatinine levels: Creatinine is a metabolic product that is also used to assess kidney function. Elevated creatinine levels may indicate kidney problems.
3. Estimation of the glomerular filtration rate (GFR): GFR is a parameter that estimates the rate at which the kidneys filter blood. It is an important indicator of kidney function.
4. Urinalysis: Urinalysis can help detect changes in urination, the presence of protein, red blood cells, and other abnormalities that may indicate renal dysfunction.
5. Clinical symptoms: The doctor also pays attention to clinical symptoms such as swelling, thirst, itchy skin, fatigue, changes in urination and others.
6. Instrumental examinations: Sometimes ultrasounds of the kidneys or other organ areas may be needed to detect structural changes.
7. Kidney biopsy: In rare cases, it may be necessary to take a sample of kidney tissue for detailed examination (by biopsy).

Diagnosis of uremia is usually performed by nephrologists (kidney specialists) and includes both laboratory and clinical methods. The results of these tests help to determine the degree of renal dysfunction and the level of the pathological condition, which in turn helps in choosing the best treatment and monitoring the patient's condition.

Differential diagnosis

The differential diagnosis of uremia involves identifying and distinguishing this condition from other medical conditions that may have similar symptoms. It is important to keep in mind that symptoms of uremia can be nonspecific and can occur in a variety of medical conditions. Here are a few conditions that may have similar symptoms and require differential diagnosis:

1. Acute renal failure: This condition may present with similar symptoms such as edema, nausea, vomiting, changes in urination, and elevated blood levels of creatinine and urea. Differentiating between acute renal failure and uremia may require more detailed laboratory tests.
2. Diabetic Ketoacidosis: This complication of diabetes can cause vomiting, thirst, blood sugar levels and metabolic disturbances, which can have similar symptoms.
3. Hypercalcemia: High levels of calcium in the blood (hypercalcemia) can cause similar symptoms such as nausea, vomiting, itchy skin, and changes in urination.
4. Some infectious diseases: Some bacterial and viral infections can cause thirst, fever, and changes in urination.
5. Poisonous substances and poisoning: ingestion of toxic substances can cause symptoms similar to uremia.
6. Other types of acute and chronic renal failure: There are several types of renal failure that may have similar symptoms. Differentiation between them may require more detailed studies of renal function and other clinical findings.

To make an accurate differential diagnosis and rule out other conditions, patients are usually prescribed laboratory tests, examinations and specialist consultations. Doctors base their diagnosis on a combination of clinical findings and laboratory results to determine the exact cause of symptoms and select the appropriate treatment.

Treatment of the uremia

Treatment of uremia depends on its cause, severity and stage of development, as well as the general condition of the patient. The main goals of treatment are:

1. Eliminating or reducing the cause of uremia: If the pathologic condition is due to a disease, the underlying disease must be treated. For example, medications may be used to control blood pressure, diabetes mellitus, and other conditions associated with chronic kidney disease.
2. Improvement of kidney function: If kidney function is reduced, medication and measures to maintain renal function may be required. In some cases, dialysis (artificial renal clearance) may be recommended to remove metabolic wastes from the blood.
3. Control of metabolic waste levels: Treatment also involves controlling the levels of metabolic wastes, such as urea and creatinine, in the blood. This may require a diet restrictive of protein and certain other substances, as well as taking medications to help lower levels of these wastes.
4. Symptomatic treatment: Medications may be prescribed to relieve symptoms. For example, anti-nausea medications can help with nausea and vomiting, and antihistamines can soothe itchy skin.
5. Diet and lifestyle: Patients may be recommended a special diet, including restriction of protein, salt and other substances. It is also important to maintain a healthy lifestyle, including physical activity, blood pressure and blood sugar control.
6. Supportive therapy: Depending on the patient's condition and the severity of the disease, other supportive therapies such as blood transfusions, treatment of anemia, and control of other medical problems may be required.

In cases of severe uremia where kidney function is completely lost, a kidney transplant may be required. This is a surgical procedure in which a donor kidney is transplanted into the patient. After a successful transplant, the patient can lead a more normal life without the need for dialysis.

Treatment should be supervised by nephrologists or kidney specialists who can develop an individualized treatment plan based on the characteristics of each patient.

Prevention

Uremia prevention focuses on preventing the development of kidney disease and keeping your kidneys healthy. Here are some basic measures to help reduce the risk of developing uremia:

1. Maintaining a healthy lifestyle:

   • Maintain a normal blood pressure level, as high blood pressure can damage the kidneys. Have your blood pressure measured regularly and follow your doctor's recommendations for blood pressure control.
   • Manage your blood sugar levels, especially if you have diabetes. Follow your diet, take your medications, and follow your doctor's recommendations.

2. Proper nutrition:

   • Moderately limit your protein intake, especially if you have chronic kidney failure. Protein can increase the strain on your kidneys.
   • Watch your salt (sodium) intake to reduce the risk of arterial hypertension and kidney problems.

3. Drinking regimen:

   • Drink enough water throughout the day to ensure normal urination and avoid the formation of kidney stones.

4. Avoid toxic substances:

   • Avoid drinking alcohol in excess and avoid using drugs.
   • Prevent contact with toxic chemicals in the workplace and at home.

5. Regular medical examinations:

   • Get regular medical checkups to detect and control chronic diseases such as hypertension and diabetes mellitus in time.
   • Follow your doctor's recommendations for monitoring your kidney health and kidney function, especially if you have risk factors.

6. Don't self-medicate:

   • Do not use medications without consulting your doctor, especially non-steroidal anti-inflammatory drugs (NSAIDs) and uncontrolled medications.

7. Maintaining normal weight and physical activity:

   • Maintain a healthy weight and engage in regular physical activity to improve your overall health and support your metabolism.

Taking preventive measures and getting regular checkups can help reduce your risk of developing uremia and other kidney diseases. If you have risk factors or already have kidney problems, talk to your doctor about preventing and managing kidney disease.

Forecast

The prognosis of uremia depends on many factors, including the cause of uremia, its severity, the timeliness of diagnosis and initiation of treatment, as well as the effectiveness of treatment and compliance with medical recommendations. In general, the following can be said:

1. Prognosis in acute renal failure: If uremia develops as a result of acute renal failure and timely treatment is given, recovery of renal function and complete recovery can be achieved in most cases.
2. Prognosis in chronic renal failure: In the case of chronic renal failure, the prognosis depends on the degree of kidney damage and the stage of the disease. Chronic renal failure usually progresses over time and the decline in kidney function can be a gradual process. It is important to monitor the kidneys regularly and initiate treatment and control measures as needed.
3. Prognosis in kidney transplantation: If kidney transplantation is successful, the prognosis is usually very favorable and the patient can lead a more normal life without the need for dialysis. However, recommendations for the care of the transplanted kidney and the administration of immunosuppressive drugs to suppress the immune response must be followed.

The prognosis may also depend on associated medical problems and the presence of complications. It is important to cooperate with doctors, follow treatment recommendations, and have regular checkups to monitor kidney health and prevent worsening of the situation. Seeking medical attention in a timely manner and following doctors' orders can significantly improve the prognosis for uremia.

Useful books and research on the topic of uremia

1. "Brenner and Rector's The Kidney" (Edition edited by J. Larry Jameson and Joseph Loscalzo) is one of the authoritative books on kidney disease, including information on uremia. Chapter title and authors may vary from edition to edition.
2. "Chronic Kidney Disease, Dialysis, and Transplantation" (Edition edited by Jonathan Himmelfarb and Mohamed H. Sayegh) is a book on chronic kidney disease, dialysis, and kidney transplantation, which includes information on uremia.
3. Medical articles and studies published in nephrology and kidney disease journals such as the Journal of the American Society of Nephrology and Kidney International. You can find specific studies and reviews related to uremia by conducting keyword searches of medical article databases.

Literature used

Mukhin, N. A. Nephrology: National Guide. Brief edition / ed. By N. A. Mukhin. - Moscow: GEOTAR-Media, 2016.