Acute renal insufficiency

Acute renal failure can have various causes. Depending on the cause, patients are either dehydrated (dehydrated) or fluid overloaded (edematous). The kidney values in the blood increase and the urine production decreases.

Acute renal insufficiency has a fairly good healing tendency if treated quickly and professionally, but can last up to 6 weeks. This is often followed by a recovery phase in which increased urine is produced. If acute renal failure is part of a multiorgan failure (i.e. several organs cease to function within a short time), the prognosis is much less favorable.

Prerenal cause: The kidney itself is working normally, but the fluid balance of the organism is disturbed. Dehydration, severe blood loss, very low blood pressure, shock and severe infectious diseases with sepsis can lead to prerenal kidney failure. This form of acute renal failure presents itself with oliguria (low urine production) and highly concentrated urine.
Affected patients must be treated carefully with intravenous fluid.
Intrarenal cause: The kidney no longer performs its tasks, or only to a limited extent. Drugs, poisoning, contrast media, inflammation of the renal corpuscles, rhabdomyolysis (rapid breakdown of muscle fibers), malaria and other tropical infectious diseases can lead to intrarenal acute renal failure.
Postrenal cause: Here, the cause of kidney failure lies behind the kidney: the draining urinary tract is constricted. Causes include a pelvic tumor, ureteral stones, ureteral tumors or an oversized prostate. An ultrasound examination can quickly identify the cause of acute postrenal kidney failure.

Chronic renal insufficiency

Stages of renal insufficiency An important reference value for renal function in renal insufficiency is the glomerular filtration rate (GFR), which in healthy individuals is 95 to 120 milliliters per minute. The GFR indicates how much blood volume the kidneys can filter in a given time unit. It is therefore a parameter for the function and filtration of the kidneys.

As renal insufficiency increases, the GFR deteriorates.

Stage 1: Describes a reduced GFR, but this is at least 90ml/min Although the filtration capacity of the kidneys is slightly reduced, renal function is not impaired with regard to excretion of urinary substances. Those affected often have no symptoms at this stage, and may have edema or discolored urine.
Stage 2: Here the GFR is between 60-89ml/min.
The kidney function is mildly restricted.
Stage 3: A GFR between 30-59ml/min defines stage 3 renal insufficiency, resulting in a moderate impairment of kidney function and elevated blood levels of creatinine and urea. Patients show the first symptoms of renal insufficiency such as high blood pressure, fatigue and poor performance. The risk of cardiovascular disease is significantly increased in this stage of renal insufficiency.
Stage 4: If the GFR falls to values between 15 and 29 ml per minute, this is referred to as stage 4 renal insufficiency.
In this stage, patients suffer from severe symptoms such as loss of appetite, nausea and vomiting, tiredness, itching, edema and nerves

Here we will now explain the classification according to the so-called kidney values, whose concentration in the blood can be determined. The most important of these urinary substances are creatinine and urea, which must be excreted with the urine. When kidney function decreases, the kidney values increase, which is why they are used as markers for kidney function.

Urinary Poisoning

Stage 1: Creatinine levels are in the range of 1.2 to 2mg/dl at this stage.The function of the kidney may be limited at this stage, but it does not have to be, because other metabolic processes of the body can also lead to a slight increase in creatinine. Conversely, slight kidney insufficiency may also be present if creatinine levels are normal: Only with a limited kidney function with a GFR below 60ml/min does creatinine inevitably increase. In stage 1 patients have no or only few symptoms: The urine may be brightly discolored (decreasing ability of the kidney to concentrate), in addition increased protein in the urine (foaming urine) and slight edema occur.
Stage 2: Now the creatinine levels are between 2 and 6mg/dl.
This stage is called “compensated retention”. This means that although urinary substances remain in the body, they are still excreted in sufficient quantities.
Stage 3: In stage 3, however, this is no longer the case: urinary substances remain in the blood to a high degree, which is called “decompensated retention”. The creatinine levels are between 6-12mg/dl.
Patients have clear symptoms of renal insufficiency: high blood pressure, fatigue, loss of performance, nausea, itching, bone pain, severe edema.
Stage 4: The creatinine levels in stage 4 are above 12mg/dl. Stage 4 describes terminal renal failure with massive restriction of renal function. Rapid dialysis treatment is required to excrete the urinary substances.
Dialysis treatment is necessary until a suitable donor kidney for a kidney transplant can be found. If the patients are not treated by dialysis, life-threatening uremia (uraemia) occurs with unconsciousness and coma.

Acute renal insufficiency: In the case of acute renal insufficiency, the treatment is first of all directed at the underlying disease. In addition, a symptomatic therapy of renal insufficiency can be performed, which includes a balance of the fluid and electrolyte balance of the patient.

In concrete terms, this means the documentation of the fluid intake (drinks, infusions) and the fluid discharged (urine, sweating, diarrhea, vomiting, etc.) including daily weighing. In addition, in order to maintain urine production, special drainage agents (loop diuretics) are administered.

The last option for treating renal insufficiency is a so-called renal replacement therapy. In this therapy, the patient’s blood is cleaned outside the body of excess water and urinary substances and then filtered and returned (hemodialysis, hemofiltration, combined procedures). Chronic renal insufficiency: In the treatment of chronic renal insufficiency, it is important to prevent the progression of the disease and to start treatment early.

Initially, this can be attempted conservatively: Treatment of the underlying disease, discontinuation of kidney-damaging drugs, lowering blood pressure (elevated levels damage the kidneys), low-protein diet (to reduce renal blood filtration), increased fluid intake, administration of loop diuretics (draining agents), control of electrolytes, reduction of cardiovascular risk factors. If the effect is insufficient, the chronic form of renal insufficiency as well as the acute form is treated by renal replacement therapy. If this therapeutic option fails, the possibility of a kidney transplantation remains.

Acute renal insufficiency: In intensive care patients with acute renal insufficiency, the mortality rate is 60%. On the one hand, the underlying disease influences the mortality rate, on the other hand, acute renal failure itself – regardless of the disease causing it – is a prognostically unfavorable factor, as it has a damaging effect on bodily and organ functions. Chronic renal failure: The prognosis of the chronic form in dialysis therapy (kidney replacement therapy) depends on the patient’s age.

Overall, the 10-year survival rate is about 55%, but it decreases with increasing age. If an organ transplantation has been performed, optimal blood pressure adjustment, treatment of high blood lipids (hyperlipidemia) and protein loss in the urine (proteinuria), normal weight and abstinence from nicotine are decisive for a good prognosis. The origin of the new organ also plays a role, because in the case of a cadaver donation the kidney still functions in 70% of patients after 5 years, whereas in the case of a living donation it functions in up to 90%.In principle, the earlier kidney failure is detected and treated, the better the prognosis and life expectancy.

In the case of chronic kidney weakness, there is usually no cure and life expectancy can be shortened. Especially the simultaneous occurrence of kidney weakness and diabetes mellitus has a negative effect on life expectancy. Consequential damage such as diseases of the cardiovascular system can lead to serious complications. In cases of pronounced renal insufficiency, dialysis procedures and, in the best case, a donor kidney can improve the quality of life and prolong life expectancy.