Evaluation of acute renal failure

Evaluation of acute renal failure

Abrupt decline in renal function (proportional to the decline in GFR). Acute renal failure can survive if determined to be the cause and proper treatment. If not will lead to permanent damage to the kidneys.

The most accurate test to diagnose acute renal failure

- Measure GFR mediated clearance of creatinine. Creatinine is an endogenous product of the process of muscle catabolism. Speed ​​produce stable creatinie: 1 mg / min.
- Formula: U x V / P. 80% of the creatinine clearance of the GRF and 20% is excreted through the kidney tubules.
Factors affecting serum creatinine
- Body Size: as creatinine is a product of muscle catabolism.
- Age: kidney in adults, the decreased GFR increased creatinine concentration.
- Trauma skeletal muscles
- Drugs: cephalosporine, cimetidine, trimethoprim affect the filtering process and the process of renal tubular secretion of an increase in serum creatinine.
Correlation between plasma creatinine and creatinine clearance of
Renal function can be monitored by plasma creatinine values. Plasma creatinine inversely proportional to the clearance of creatinine. If creatinine 1mg/dl, GFR is 120 ml / min. If creatinine is 2mg/dl, GFR was 60 ml / min. If creatinine is 4mg/dl, GFR was 30 ml / min ..... When creatinine increased from 1 to 2 mg / dl, 50% of kidney function is lost.
Disorders associated with acute renal failure
High blood pressure, circulatory overload, congestive heart failure, nausea, vomiting, fatigue, lassitude, encephalopathy and bleeding. Other metabolic disorders include:

Serum creatinine
Serum potassium
Phosphore, Magne
Bicarbonate (metabolic acidosis)
Platelet function

Acute renal failure before renal

Acute renal failure before kidney: 50 - 70% of the causes of acute renal failure, usually caused by reduced blood flow to the kidney, and constriction of arterioles to reduced perfusion pressure of glomerular capillaries, resulting in decreased glomerular filtration rate, leading to rising tubular reabsorption of water and salt causes oliguria.
The causes include:
- Reducing the extracellular fluid volume: due to dehydration, hemorrhage, excessive use of diuretics, diarrhea, burns, infection, buried syndrome, acute pancreatitis.
- Reduced cardiac output: cardiomyopathy, arrhythmias, coronary artery disease, cardiac shock. Long-term congestive heart failure condition will also reduce renal blood flow
- Status of direct renal vasoconstriction as a result of infection, liver disease and medicine.
- The acute renal failure before renal drugs, including angiotensin-converting enzyme inhibitors (ACEI) and steroid anti-inflammatory (NSAID). ACEI reduces angiotensin II leads to a decrease in renal perfusion pressure, and dilate the arterioles, resulting ultimately reduce the glomerular capillary filtration pressure.
Patients had renal artery stenosis condition very susceptible to acute renal failure due to this reason. NSAIDs inhibit the cyclooxygenase reduce eicosanoid (renal vasodilatation functions) consequences is spasm of arterioles of the kidneys.

Acute renal failure in kidney

20 - 30% of the causes of acute renal failure and is most commonly due to acute tubular necrosis. The motivating factor causing acute tubular necrosis: renal acute renal failure before last, nephrotoxic drugs (aminoglucosid, intravenous dye with iodine, cisplatin, amphotericin B, pentamidine - patients with diabetes or multiple myeloma is very sensitive to the nephrotoxic drugs) and sub-pigmentation (due to intravascular hemolysis or lysis of skeletal muscle after injury).
Other rare causes include vascular disorders of the kidneys: thrombosis in place, embolism, malignant hypertension, high blood uree hemolytic syndrome, inflammation of blood vessels. Sometimes glomerulonephritis level and renal interstitial inflammation can lead to acute renal failure.
Acute renal failure after kidney
<10% of the causes of acute renal failure. Any cause that obstructs the flow of urine from the manifold to the end of the urethra also cause kidney following acute renal failure.
What urine tests useful in the diagnosis of acute renal failure
- If there are sub-latex: infection
- State the blood: pathological suggested gravel, trauma, urinary tract tumors
- Head of red blood cells, proteinuria: hints glomerular disease.
- If there are special crystals: uric acid, cysteine: suggestions tract.

The rate of urinary sodium excretion and urinary sodium concentration
Before kidney
<1%; <30 mEq / l
In kidney
Tubular necrosis

Interstitial nephritis


Renal vascular disease

Renal tubular epithelial cells, cylindrical particles
State latex, head leukemia

Proteinuria, red head
blood cells, red blood cells


> 1%;> 30mEq / l

> 1%;> 30 mEq / l

> 1%;> 30 mEq / l

> 1%;> 30 mEq / l
After kidney

Screws from outside

Hematuria, urine pus, crystals
Malignant cells



Principles of treatment of acute renal failure

Prerequisites are to have an accurate diagnosis. Treatment mainly consists of: stopped the nephrotoxic drugs, reimbursement circulatory volume, cardiac rehabilitation, relieve urinary tract deadlock, regulate water and electrolyte disorders. If acute renal failure caused by metabolic poisoning the whole body must be indicated dialysis.