The two kidneys play a major role in the organism, even though they are rather small organs, each weighing just under 200 grams and measuring 10 cm in length. If they no longer perform their function of excreting waste products and toxins adequately, many complaints result that can be life-threatening without treatment.
What is renal failure?
The kidneys have many tasks – one of the most important is to excrete urinary, nitrogenous metabolic waste products and toxic substances with the urine. If the kidney tissue becomes diseased, this ability is limited and the substances accumulate in the organism and poison it. In addition, the body becomes overhydrated. Such kidney failure can occur either suddenly (acute renal failure) or gradually worsen over a long period of time (chronic renal failure). In the latter form, because healthy kidney tissue can help take over the tasks of the diseased part for a long time, the disease is often discovered by chance or only at a late stage.
Causes: How does renal failure develop?
The causes are many and differ between the two forms. Acute renal failure is usually the result of a sudden lack of blood flow to the kidneys. This may be due to sudden blood loss, such as occurs after a serious accident, or to an abrupt drop in blood pressure, as in shock. Another common cause is poisoning that damages the kidney tissue (e.g., bacterial toxins in infections) or allergic damage to the renal corpuscles (usually caused by drugs, fungi or X-ray contrast media). Chronic renal failure, on the other hand, is usually caused by inflammation of the renal corpuscles (glomerulonephritis) or kidney damage as a result of long-term diabetes (diabetic nephropathy) or high blood pressure. Less common triggers include kidney stones, cystic kidneys, inflammation of the renal pelvis or urinary tract, and abuse of certain pain medications (especially phenacetin).
Who is affected?
In 2009, there were about 95,000 patients in Germany whose kidney function was so poor that they had to undergo treatment – equivalent to more than one person per thousand inhabitants. Around 70,000 of these were treated with dialysis procedures, and just under 25,000 with a kidney transplant. Currently, about 1.5 times more women than men have the disease. It is striking that in recent years not only the incidence (number of new patients requiring treatment) and the prevalence (number of patients per million population) have been steadily increasing, but also the average age of those affected. This fact is not surprising when one considers that, on the one hand, people are getting older overall and, on the other, patients with chronic diseases such as diabetes or high blood pressure are living longer than they used to. This makes kidney disease not only a medical problem, but also an economically relevant one. The cost of dialysis and concomitant diseases is around €44,000, while kidney transplantation costs €18,000 per year. The total cost of all kidney replacement procedures (dialysis and transplantation) is currently estimated to be between €2.0 billion and €2.5 billion.
Symptoms and progression in renal failure
The symptoms that occur depend on the form and stages of the disease as well as the underlying and concomitant diseases.
Acute renal failure
Initially, the symptoms of the underlying disease, such as severe infection, are usually in the foreground. After hours to days, urine production decreases (oliguria) until it stops completely (anuria). Sufferers are tired, nauseous and increasingly unresponsive. As water is stored in the body, especially in the lungs, breathing problems may occur. Cardiac arrhythmias are also not uncommon. The doctor distinguishes between four phases in the course of the disease, which are also reflected differently in the blood. With timely treatment, acute kidney failure can be completely reversed in many cases – but if it starts too late, it can be fatal.
Chronic renal failure
This form also progresses in four stages. As long as the kidneys can compensate for the loss of function, there are often no symptoms or only increased urination at night. However, the changes can already be detected in the laboratory. This stage can last several years. Often there is then a drop in performance and malaise.The increasing destruction of the kidney tissue leads to increasingly severe complaints in various organs due to the retained waste products and water. These include yellowing and itching of the skin due to the stored urinary toxins, sleep and concentration disorders, headaches, nausea, vomiting, diarrhea and taste disorders. Too high or low blood pressure, cardiac arrhythmia or inflammation and respiratory problems also occur. In addition, anemia occurs (due to reduced erythropoietin produced by the kidney, which is used for blood formation), coagulation disorders, increased susceptibility to infections, and bone softening (since the kidney is also involved in vitamin D metabolism). In the final stage of the four stages, terminal renal failure, the urine poisoning (uremia) also leads to severe disorders of the nervous system such as seizures, confusion and unconsciousness, even coma. Only lifelong dialysis treatment or kidney transplantation saves the patient from death at this stage.
How is the diagnosis made?
In addition to symptoms, kidney values in the blood are the most important auxiliary diagnostic parameter. Therefore, in order to counteract deterioration of kidney function in a timely manner, they must be monitored regularly in kidney patients. In order to check water retention, intake and output can be balanced (i.e. the fluid supplied is documented and body weight measured) In addition, urine and ultrasound examinations are performed. Other tests depend on the symptomatology and the suspected underlying disease.
Treatment: what therapy is available?
Treatment also depends on the form and stage. Acute renal failure requires rapid hospitalization. There, on the one hand, the underlying disease is treated – only when this is overcome is the prognosis favorable, since the tissue changes usually regress. If the disease cannot be controlled, the mortality rate is very high. On the other hand, symptomatic therapy is carried out with infusions, adapted nutrition and medication. Dialysis is often required temporarily. In the chronic form, which is always accompanied by irreversible tissue loss, the first three stages focus on treatment of the underlying disease (e.g. good control of diabetes or high blood pressure, removal of kidney stones, etc.) and diet. Often diuretics are prescribed as well as drugs to counteract bone changes. Against anemia, the missing hormone erythropoietin is administered. In the final stage, the patient must undergo lifelong dialysis or a kidney transplant.
Sufferers must pay attention to diet
In order to delay dialysis for as long as possible in chronic kidney failure, the cooperation of the affected person is of great importance. Close and regular contact with the attending physician, preferably a kidney specialist (nephrologist), is very important. Adherence to a diet low in protein, phosphate and potassium and rich in calcium is also significant in counteracting a deterioration in kidney function. Even trivial infections must be treated as soon as possible. It is important to know that many drugs, even non-prescription ones, are excreted through the kidney, which is why their dose must be reduced. Therefore, when self-medicating, the doctor should always be asked for advice.
