Acute renal failure (ARF), also known as acute kidney failure or acute kidney injury, is a rapid loss of renal function due to damage to the kidneys, resulting in retention of nitrogenous (urea and creatinine) and non-nitrogenous waste products that are normally excreted by the kidney. Depending on the severity and duration of the renal dysfunction, this accumulation is accompanied by metabolic disturbances, such as metabolic acidosis (acidification of the blood) and hyperkalaemia (elevated potassium levels), changes in body fluid balance, and effects on many other organ systems. It can be characterised by oliguria or anuria (decrease or cessation of urine production), although nonoliguric ARF may occur. It is a serious disease and treated as a medical emergency.
Acute (sudden) kidney failure is the sudden loss of the ability of the kidneys to remove waste and concentrate urine without losing electrolytes.
Cause of Acute Renal Failure
Pre-renal (causes in the blood supply):
• Hypovolemia (decreased blood volume), usually from shock or dehydration and fluid loss or excessive diuretics use.
• 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).
• Infection usually sepsis, systemic inflammation due to infection.
• Severe burns.
• Sequestration due to pericarditis and pancreatitis.
• Hypotension due to antihypertensives and vasodilators.
• Trauma & severe haemorrhage.
• Severe vomiting & diarrhea causing dehydration.
Intrinsic (damage to the kidney itself):
• Toxins or medication (e.g. some NSAIDs, aminoglycoside antibiotics, iodinated contrast, lithium, phosphate nephropathy due to bowel preparation for colonoscopy with sodium phosphates).
• 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, stimulants 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 be 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.
• Acute pyelonephritis.
• Acute tubular necrosis.
• Blood incompatibility
Post-renal (obstructive causes in the urinary tract) due to:
• Medication interfering with normal bladder emptying (e.g. anticholinergics).
• Benign prostatic hypertrophy or prostate cancer.
• Kidney stones.
• Due to abdominal malignancy (e.g. ovarian cancer, colorectal cancer).
• Obstructed urinary catheter.
• Drugs that can cause crystalluria and drugs that can lead to myoglobinuria & cystitis.
OTHER CAUSES of Acute Renal Failure
• Malignant hypertension.
• Disorders associated with child birth; PPH, placenta previa.
Symptoms of Acute Renal Failure
• Bloody stools.
• Breath odor.
• Brusing easily.
• Changes in mental statusor mood.
• Decreased appetite.
• Decreased sensation, especially in the hands or feet.
• Flank pain (between the ribs and hips).
• Hand tremor.
• High blood pressure.
• Metallic taste in mouth.
• Nausea or vomiting, may last for days.
• Persistent hiccups.
• Prolonged bleeding.
• Slow, sluggish movements.
• Swelling – generalized (fluid retention).
• Swelling of the ankle, feet, and leg swelling.
• Urination changes:o Decrease in amount of urine.
o Excessive urination at night.
o Urination stops completely.
• Cardiac arrhythmia.
• Congestive cardiac failure.
• Pulmonary oedema.
• Uraemic coma.
• Secondary infection.
GENERAL MANAGEMENT of Acute Renal Failure
• Correct cause.
• Maintain fluid, electrolyte balance.
• Bed rest.
• Restrict fluid to an amount equal to the volume of urine produced.
• Salt intake is also restricted.
• Protein, sodium & potassium intake is restriction.
• Diet should be high in carbohydrate content.
• Correct anaemia.
• Maintain daily record ofo Body weight.
o Fluid intake.
o Urine output.
o Blood urea.
o Serum electrolytes