Урология - Renal failure

Acute and chronic renal failure

Acute renal failure

Sudden impairment of filtration, secretory and excretory function of kidneys, or single working kidney due to the influence of different endogenous and exogenous factors on it’s parenchyma. All nephrones can be affected or glomerular apparatus or all part of the renal tubules.

Prerenal factors

Decreasing of blood pressure – decreasing of blood flow in renal parenchyma – reduction of glomerular filtration (blood loss, sepsis, shock)

Decreasing of blood pressure – influence of toxic products on renal parenchyma – necrosis of tubular epithelium (transfusion of incompatible blood, crush-syndrome, big burns, bacterial shock, allergic shock)

Loss of water and electrolytes – decrease of blood volume – decrease of glomerular filtration rate (non-stop vomiting, diarrhea, inappropriate use of diuretics)

Renal factors

Immunoalergic affection of kidneys – precipitation of ummune complex at the glomerulas ( acute nephritis, lupus, Goodpasture syndrome, acute interstitial nephritis, haemolutico-uremic syndrome)

Influence of nephrotoxic factors –necrobyotic changes in epythelial cells of tubules with tearing them off from the basic membrane (salts of mercury, urane, copper, poisonous mashrooms, medicines – sulfanilamides, aminoglycosides, uric acid etc.

Postrenal

Obstruction of upper urinary tract (bilateral or unilateral in case of one functioning kidney)

Occlusion by stone of blood clot

Compression by a tumor

Arenal

 Bilateral nephrectomy (very rarely)

Initial stage

Depends on the cause

Circulatory collapse

Hyperhydration

Huperasotemia

Oliguric stage

Lasts for 2-12 days

The main and the most dangeruos stage

Urine volume is less than 500 ml, urine has dark color, content of protein and cylindersis is elevated, density is 1003-1010, osmolarity 350-360 mosmol/l

Na is less than 50 mmol/l

Anorexia, nausea, diarrhea,drowse

Hyperasotemia – urea 32-50 mmol/l, creatinine 0,5-0,9 mmol/l.

Hypernatriemia, hyperkaliemia, phosphatemia 4-5 mmol/l.

Metabolic acidosis

Tahypnoe, fluid lung

ECG – elevation of T, widening of QRS, depression of S_T

Intestinal bleeding

Anaemia

Pain at lumbal area, enlargement of renal contour at plain X-Ray