Chronic kidney failure and its treatment

Chronic kidney failure is a progressive deterioration of kidney function that is characterized by a decrease in the kidney's filtering capacity of the blood and the consequent accumulation of nitrogenous substances in the blood, mainly urea and its derivatives, as well as creatinine, for a period of time greater than three months. The final state of this situation is what we know as uremia or uremic syndrome.

How is it produced?

Any sustained alteration of the functioning, whether due to failure of the organ's irrigation or due to direct damage to its tissues, can lead to chronic kidney failure. The main cause of chronic kidney failure is kidney failure caused by diabetes.

The other two sets of causes of chronic kidney failure are glomerular lesions and vascular causes, nephroangiosclerosis secondary to conditions such as high blood pressure, dyslipidemia (high levels of cholesterol or triglycerides in the blood) or smoking.

Other causes are hereditary diseases with kidney involvement, such as Alport syndrome or polycystic disease, or chronic interstitial lesions caused by toxins, such as some antibiotics and anti-inflammatories. In many cases, however, the cause is never reliably determined.

Due to the progressive involvement of the renal tissue, the number of nephrons, the functional unit of the kidney, decreases and the rest have to face an overload of work, which causes them to increase in size to compensate. As the number of nephrons decreases, the filtering surface and therefore the filtering capacity of the blood decrease, causing polyuria and the accumulation of nitrogenous substances in the blood, which is toxic to cells.

Likewise, there is an alteration in the hormonal function of the kidney, which produces less erythropoietin, which eventually establishes anemia, and less calcitriol, which affects calcium absorption.

Symptoms

Until 65% of the kidney's ability to function has been lost, nephrons that increase in size to compensate for the task of those that have been lost can assume kidney function, so until that moment the patient may not present any symptoms. It is from that moment, when the lost function is between 65% and 80%, that urea and creatinine begin to accumulate in the blood and the symptoms of polyuria and nocturia appear. As kidney failure progresses, edema, arterial hypertension, anemia and alterations of lipids and salts in the blood begin to develop.

From the moment that the kidney function that has been lost is greater than 80%, the state of uremia or uremic syndrome is established, in which alterations occur in various organs due to the accumulation of nitrogenous substances in the blood.

cardiovascular alterations are the main causes of death in these patients. Arrhythmias, cardiac muscle involvement, pericardial inflammation, arterial hypertension and heart failure due to fluid retention occur.

At the digestive level, there can be a lack of appetite, nausea and vomiting, digestive bleeding and interruption of bowel movements.

The nervous system is very sensitive to the accumulation of urea, which can lead to polyneuropathies, involvement of various nerves, especially in the lower extremities, altering first sensitivity and then mobility. It can also affect the brain, causing drowsiness, stupor, and in advanced cases, coma.

Hematological alterations occur, with anemia due to the lack of erythropoietin that stimulates the formation of red blood cells, and alterations in leukocytes, which predisposes to infection. Likewise, coagulation is also impaired, increasing the risk of bleeding.

Water and sodium are retained, causing edema. In advanced stages, potassium accumulates in the blood, which can cause heart rhythm, muscle and nerve conduction disturbances.

Bone metabolism is affected, since by reducing the production of vitamin D, calcium is not absorbed correctly at the intestinal level, and the accumulation of phosphorus in the blood that the kidney cannot purify causes a decrease in calcium in the blood and an increase in the hormone. parathyroid (PTH), which is involved in calcium metabolism. This produces renal osteodystrophy, a renal cause of bone involvement that includes osteomalacia, osteitis fibrosa cystica, and osteosclerosis, as well as the accumulation of calcium in non-bone areas, such as joints, skin or eyes.

At the skin level, a yellowish coloration can be seen, spontaneous bruising can occur and the sweat, rich in urea, left a whitish residue known as uremic frost. There may be itching due to the accumulation of calcium in the skin.

Diagnosis

The diagnosis is based on the symptoms that the patient presents as well as the laboratory abnormalities. blood tests show an increase in urea above 40 mg / dl, an increase in creatinine above 1.2 mg / dl, a decrease in hemoglobin, hematocrit, sodium and calcium levels, and an increase in potassium, phosphorus and magnesium in the blood, as well as in PTH.

An ultrasound scan shows a reduced kidney size with alteration of the normal structure of the viscus.

Treatment

He must always be of the cause if it is known, correcting diabetic, hypertensive or other recognizable causes. Conservative treatment should be based on protein and caloric restriction, on reducing the intake of fluids and sodium to improve edema, and in advanced stages, on restricting the consumption of potassium and phosphorus.

The lack of calcium in the blood and the alterations in phosphocalcic metabolism should be corrected by providing calcium carbonate and vitamin D. Similarly, anemia should be corrected by the administration of erythropoietin or blood transfusion if necessary. Hypertension will be corrected with antihypertensive drugs, mainly ACEIs and ARBs.

When conservative treatment is not enough, dialysis should be considered, that is, a process by which the blood is filtered externally, so that the patient loses water, potassium, urea, creatinine and phosphorus and is administered sodium and bicarbonate. Most dialysis patients receive hemodialysis. An arteriovenous fistula is made (a vein is modified so that it can receive a large volume of fluid) and she undergoes hemodialysis about three times a week. It is a treatment that, like all others, can have side effects, such as hypotension, cramps, anemia, fever or bone complications.

In some patients, dialysis is performed at the peritoneal level, injecting dialysis fluid into the abdomen, so that the patient's own peritoneum acts as the filter membrane. It is done in elderly patients, with problems to perform an arteriovenous fistula or in patients with a high hemorrhagic or cardiovascular risk.

Kidney transplantation is another therapeutic option. The ideal transplant candidate is a young patient without associated systemic diseases and who does not suffer from active infections, intractable malignant tumors, glomerulonephritis with a high probability of recurrence in the transplanted organ, or who has a short life expectancy. Despite advances in transplantation, graft rejection is a possibility that always exists.

Precautionary measures

If you have a systemic disease that can affect the kidney, such as diabetes or high blood pressure, you should have strict control of these pathologies and carry out regular checks on kidney function.

In addition, care should be taken to avoid the indiscriminate and unsupervised use of medications such as anti-inflammatories and some antibiotics. In the same way, to ensure an adequate supply of blood to the kidney and its proper functioning, you should maintain a balanced diet, consume 1.5-2 liters of water daily and do physical exercise on a regular basis.