Acute renal failure (ARF):is the sudden and severe reduction in previously normal renal function, may result from primary renal disease but is more frequently associated with other organ failure. Failure is often reversible, but should the kidneys fail to recover, permanent treatment will be required. ( Alexander et al, 2000). • Chronic renal failure (CRF)is the gradual and progressive reduction in renal function. Failure may occur over weeks, months or even years. (Alexander et al, 2000).
Causes • Renal failure, whether chronic or acute, is usually categorised according to pre-renal, renal and post-renal causes. Researchers also report finding a significant association between smoking, heavy alcohol intake and chronic kidney disease. • Pre-renal (causes in the blood supply): • hypotension (decreased blood supply), usually from shock or dehydration and fluid loss. • hepatorenal syndrome in which renal perfusion is compromised in liver failure • vascular problems, such as atheroembolic disease and renal vein thrombosis (which can occur as a complication of the nephrotic syndrome)
Renal (damage to the kidney itself): • infection usually sepsis (systemic inflammation due to infection),rarely of the kidney itself, termed pyelonephritis • toxins or medication (e.g. some NSAIDs, aminoglycoside antibiotics, iodinated contrast, lithium) • rhabdomyolysis (breakdown of muscle tissue) - the resultant release of myoglobin in the blood affects the kidney; it can be caused by injury (especially crush injury and extensive blunt trauma), statins, MDMA (ecstasy) and some other drugs • hemolysis (breakdown of red blood cells) - the hemoglobin damages the tubules; it may be caused by various conditions such as sickle-cell disease, and lupus erythematosus • multiple myeloma, either due to hypercalcemia or "cast nephropathy" (multiple myeloma can also cause chronic renal failure by a different mechanism)
Acute glomerulonephritis which may due to a variety of causes, such as anti glomerular basement membrane disease/Goodpasture's syndrome, Wegener's granulomatosis or acute lupus nephritis with systemic lupus erythematosus • Post-renal (obstructive causes in the urinary tract) due to: • medication interfering with normal bladder emptying. • benign prostatic hypertrophy or prostate cancer. • kidney stones. • due to abdominal malignancy (e.g. ovarian cancer, colorectal cancer). • obstructed urinary catheter.
RENAL FAILURE SIGNS & SYMPTOMS • Decreased urine output. • Weight gain • Uraemic symptoms of anorexia, nausea & vomiting, fatigue, itchy skin, metallic taste in the mouth, halitosis(bad breath). • Thirsty/dry mouth. • Breathlessness. • Fever & ankle swelling. • Congestive cardiac failure. • Confusion, twitching, irritability and convulsions.
Signs • Anuria or oluguria<400ml/day, raised urea & creatinine. • Peripheral or systemic oedema. • Weight loss, poor diet intake, dry flay skin, pale yellow skin colour. • Raised blood pressure. • Lowered blood pressure. • Abnormal, irregular pulse. • Increased respirations. • Raised temperature. • Depressed level of consciousness or seizures. • Electrolyte imbalance.
Cont’d. • Initially it is without specific symptoms and can only be detected as an increase in serum creatinine and as kidney function decreases • Blood pressure is increased due to fluid overload and production of vasoactive hormones leading to hypertension and congestive heart failure. • Potassium accumulates in the blood. • Erythropoietin synthesis is decreased. • Fluid volume overload. • Hyperphosphatemia. • Metabolic acidosis.
Diagnosis. • Blood test - to find out if waste substances have been filtered out • Urine test - to see if there is blood or protein in the urine. • Kidney scans such as MRI scan, CT scan or ultrasound - to find if there are any unusual blockages in urine flow. When kidney disease is advanced, the kidneys are shrunken, have an uneven shape and are firm to touch. • Kidney biopsy - taking a small sample of tissue to test the cells and look for damage • Calculating the glomerular filtration rate (GFR) - to check how efficiently the kidneys are filtering waste, in particular a substance called creatinine.
Treatment. • Treatment focuses on controlling the symptoms, minimizing complications, and slowing the progression of the disease • Three basic stages in treatment • Preserve remaining nephrons • Conservative treatment of uraemic syndrome • Renal dialysis and transplantation
Preserve remaining nephron function • Control of hypertension and heart failure • Treatment of superimposed urinary tract infection • Correction of salt and water depletion • Careful prescribing of drugs that are potentially nephrotoxic • Dietary protein restriction • Conservative management of uraemic syndrome • Reduce protein intake • Aluminium hydroxide to reduce intestinal phosphate absorption • Vitamin D and calcium supplements to increase serum calcium • Allopurinol to reduce serum uric acid • Erythropoietin to correct anaemia
Dialysis is the option for ongoing treatment, often used while waiting for a suitable transplant opportunity • Kidney transplant, in which a functioning kidney from a donor is surgically grafted into the patient, has a good rate of success
Differencies • Acute renal failure Most causes of acute renal failure can be treated and the kidney function will return to normal with time. Replacement of the kidney function by dialysis (artificial kidney) may be necessary until kidney function has returned. • Chronic renal failureChronic kidney damage is usually not reversible and if extensive, the kidneys may eventually fail completely. Dialysis or kidney transplantation will then become necessary
Another diagnostic clue that helps differentiate CRF and ARF is gradual rise in serum creatinine (over several months or years) as opposed to a sudden increase in the serum creatinine (several days to weeks).
References • Alexander, M.F, Fawcett, J.N. and Ruciman, P.J. (2000) Nursing practice Hospital & Homes. The Adult. 2nd Edition Edinburgh. Harcourt Publishers Limited. • Acute Renal Failure (online), Available from www.patient.co.uk/showdoc/400006 accesses on 07|11|2006 • Redmond et al (2004): Acute renal failure: recognition and treatment in ward patients. Nursing Standard 18, 22, 46-53.