end stage kidney failure CHRONIC RENAL INSUFFICIENCY - Symptoms, Causes and Treatment Nephrology

CHRONIC RENAL INSUFFICIENCY - Symptoms, Causes and Treatment
Nephrology




We call renal failure the condition in which the kidneys lose their ability to perform their basic functions.

Renal failure can be acute (ARF), when sudden and rapid loss of renal function, or chronic (CRF) occurs, when this loss is slow, progressive and irreversible

In this article we are going to talk about the following points:

    What is chronic kidney failure?
    Symptoms of chronic renal failure.
    Diagnosis of CRI
    Causes of chronic kidney disease.
    Stages of chronic renal failure.
    IRC treatment.

Before moving on, see this short 3-minute video produced by the MD.Saúde team, which explains in a simple way kidney failure and the creatinine test (subtitles in Spanish):

Chronic renal failure is a disease characterized by the slow and continuous loss of renal function, causing the progressive accumulation of toxins in the blood.

The kidneys are organs responsible for various functions in our body, the main ones being:

- Elimination of toxins.
- Elimination of unnecessary substances or excess in the bloodstream.
- Control of electrolyte levels (mineral salts) in the blood.
- Control of the water level of the body.
- Control of the pH of the blood.
- Production of hormones that control blood pressure.
- Vitamin D production
- Production of hormones that stimulate the production of red blood cells by the bone marrow.

The patient with chronic renal failure has deficiencies in each of these functions, which leads to serious health problems in the advanced stages of the disease.
Symptoms of chronic renal failure

As the installation of chronic renal failure usually occurs little by little, our body has time to adapt to this malfunction of the kidneys, causing us to have no signs or symptoms until the very late stages of the disease. The main characteristic of CRI is to be a silent disease.

Many people think that they can identify a diseased kidney by pain or by decreasing the volume of urine. Nothing more false. The kidney has little innervation for pain and hurts only when it is inflamed or dilated. As in most cases of chronic renal failure none of that happens, the patient may very well discover that he needs dialysis without even having felt a single pain in the kidney in life.

The volume of urine is also not a good indicator of the health of the kidneys. Unlike acute renal failure (ARF), in which the reduction of urine production is a factor almost always present in chronic renal failure, as the loss of function is slow, the kidney fits well, and the capacity of eliminating water remains stable until well advanced stages of the disease. In fact, most patients who need to go on dialysis still urinate at least 1 liter a day.

Therefore, in most cases, even in well advanced stages of the disease, chronic renal failure does not cause any symptoms or signs.

Patients with CRF in advanced stages may have anemia and deterioration of blood pressure values ​​and edema of the lower limbs. When the kidney enters terminal phase, the symptoms that appear are tiredness to the efforts, nauseas and vomits, loss of appetite, loss of weight, difficulty to breathe, strong breath (with smell of urine) and generalized edemas.
Diagnosis of chronic renal failure

As there are no symptoms until the advanced stages of the disease, chronic renal failure can only be detected early through laboratory tests.

The test used for this purpose is the blood dosage of urea and creatinine. Creatinine is the best marker of kidney function. When the kidneys begin to lose function, their blood values ​​increase (Lee: CREATININA AND UREA).


Urine tests are also useful, as it is very common for patients with kidney disease to have protein loss or bleeding in the urine. To learn more about these topics, access the following links:

- URINE EXAMINATION - Leukocytes, Blood, pH.
- FOAMY URINE AND PROTEINURIA.
- CAUSES OF BLOOD IN THE URINE - HEMATURIA.

Laboratory tests also allow the early detection of complications of CRF, such as initial degrees of anemia, changes in electrolytes (mainly calcium, phosphorus and potassium), changes in the hormone PTH (which controls the health of bones), values of blood pH, etc.

Renal ultrasound is also an important test, since it shows the renal morphology, which can indicate if the kidneys already show signs of atrophy. However, it is important to keep in mind that a renal ultrasound without changes is not enough to rule out the hypothesis of chronic renal failure. Without the value of creatinine, nothing can be affirmed.
Causes of chronic renal failure

Several diseases can attack the kidneys and lead to permanent loss of function. In general, CKD occurs when the kidney suffers continuous and prolonged attacks, as in cases of patients with diabetes and poorly controlled hypertension.

- Amyloidosis.

If you have any of the above diseases, it is essential that you do a periodic monitoring of creatinine. Creatine, urea should be dosed at least once a year and a simple urine test performed.
Stages of chronic renal failure

The two kidneys filter on average 180 liters of blood a day, plus or minus 90 to 125 ml per minute. This is called a glomerular filtration rate or creatinine clearance.

The stages of chronic renal failure are divided according to the glomerular filtration rate, which can be estimated through the values ​​of blood creatinine. There are several formulas to estimate the degree of functioning of the kidneys from the creatinine values. Nowadays, most laboratories already do this calculation automatically when the creatinine dose is requested.

Renal failure is often a progressive disease, with the worsening of function over the years. Some factors such as poorly controlled hypertension and diabetes increase the risk of rapid loss of kidney function.

We divide the IRC stages as follows:

IRC stage I - Patients with creatinine clearance greater than 90 ml / min, but with none of the diseases described above (diabetes, hypertension, polycystic kidneys, etc.)

Patients with one or more of these diseases always have some degree of kidney damage that, however, may not yet be reflected in the blood's filtering capacity. They are patients with normal renal function, without any symptoms, but at high risk of long-term deterioration of renal function.

Patients with normal creatinine, but with changes in the urine test, with signs of hemorrhage or protein loss in the urine, are also introduced at this stage.

IRC stage II - Patients with creatinine clearance between 60 and 89 ml / min.

This can be called the pre-insufficiency phase. They are people with low loss of renal function, being the earliest stage of kidney failure.

As the kidneys lose function naturally with age, many older people may have slightly reduced kidney function. This fall is only a sign of aging of the kidneys. Therefore, it is very common to find elders with criteria for stage II CRI. If the patient does not have possible diseases that attack the kidneys, such as diabetes or hypertension, this slight loss of kidney function does not mean major problems in the medium / long term.



In stage II, the kidney can still maintain its basic functions, and the blood creatinine is still very close to the normal range. However, it is important to bear in mind that these patients are at risk of worsening renal function if they are exposed, for example, to drugs toxic to the kidneys, such as anti-inflammatories or contrasts for radiological examinations.

IRC stage III - Patients with creatinine clearance between 30 and 59 ml / min.

This is the stage of chronic kidney failure declared. Creatinine is already above reference values ​​and early complications of the disease begin to develop. The kidney has already reduced its ability to produce the hormone erythropoietin, which controls the production of red blood cells (RBCs) by the bone marrow, leading to a progressive anemia (Lee: 7 SYMPTOMS OF ANEMIA).

Another problem that begins to arise is bone injury. Patients with kidney failure have a disease called renal osteodystrophy, which occurs through the elevation of PTH and the fall in the production of vitamin D, hormones that control the amount of calcium in the bones and blood. The final result is a demineralization of the bones, which begin to remain weak and sick.

Stage III is the phase in which patients should start treatment and be accompanied by a nephrologist since, from this point, the progression of renal failure is usually relatively rapid if there is no adequate treatment.

IRC stage IV - Patients with creatinine clearance between 15 and 29 ml / min.

This is the pre-dialysis phase. This is the time when the first symptoms begin to appear and laboratory tests show several changes.

The patient has high levels of phosphorus and PTH, established anemia, low blood pH (increased acidity in the blood), potassium elevation, weight loss and signs of malnutrition, worsening of hypertension, bone weakness, increased risk of heart disease. heart, decreased libido, decreased appetite, fatigue, etc.

Due to fluid retention, the patient may not notice the weight loss, since the weight can be maintained or even increased. The patient loses muscle mass and fat, but retains fluid and can develop small edema in the legs.

At this stage the patient must begin to prepare to enter dialysis, with indication for the construction of the arteriovenous fistula.

IRC stage V - Patients with creatinine clearance less than 15 ml / min.

This is called the phase of terminal renal failure. Below 15-10 ml / min the kidney no longer performs the basic functions and the start of dialysis is indicated. At this time, patients begin to feel the symptoms of kidney failure called uremia symptoms.

Although they are still able to urinate, the volume is not so great and the patient begins to develop large edema. Blood pressure is out of control and potassium levels in the blood are high enough to cause cardiac arrhythmias and death. The patient has already lost a lot of weight and can not eat well. Nausea and vomiting, especially in the morning. It tires easily and anemia, if it is not being treated, is usually at dangerous levels.

If dialysis is not started, the picture progresses, and those that do not reach death due to cardiac arrhythmias can evolve with pulmonary edema or mental changes such as disorientation, seizures and even coma.

When ultrasound of the kidneys is performed, they are usually atrophied, with reduced sizes.

Some patients can reach stage V with few signs and symptoms. Despite the few symptoms, these have numerous changes in laboratory tests, and the longer if you delay the start of dialysis, the worse will be bone and heart lesions, malnutrition and the risk of malignant arrhythmias. Many times, the first and only symptom of ESRD is sudden death.
When should the patient with CRF be accompanied by a nephrologist?

Early routing to the nephrologist can change the natural history of the disease. When the evolution of the patients referenced in stage III is compared with those referred only in the final stages of stage IV or stage V, it is observed that:

- A reduction in the rate of loss of kidney function (3.4 ml / min per year versus 12 ml / min per year), that is, patients not accompanied by a nephrologist lose kidney function up to 4 times faster.
- Better control of arterial hypertension and, consequently, less lesions in other organs.
- Lower incidence of bone injuries.
- Lower incidence of malnutrition and weight loss.
- Lower mortality rate.
Treatment of chronic renal failure

There is no cure for chronic kidney failure, because it is a reflection of the irreversible damage of parts of the kidneys. There is also no medication that makes the kidneys work well again.

Generally, the purpose of CRI treatment is to prevent the spread of the disease or, in the worst case, decrease the rate of renal function loss.

It is essential to control blood pressure. Values ​​persistently above 140/90 mmHg are aggressive to the kidney, accelerating the loss of renal function. In patients with diabetes, glucose control is also very important. In patients with proteinuria (loss of protein in the urine), their control with medications helps to preserve kidney function.

The patient with CRF should avoid nephrotoxic drugs such as anti-inflammatories and some antibiotics, mainly the aminoglycoside class.

There is no cure or specific treatment for the improvement of renal function, the accompaniment with the nephrologist is important to avoid the complications of CRF. There are remedies for the control of anemia, electrolyte changes, bone metabolism, edema, etc.

In the final stages of the disease, when the kidneys no longer work, the recommended treatment is hemodialysis, peritoneal dialysis or kidney transplantation.