MindMap Gallery Pathophysiology of Acute Renal Failure
Acute renal failure, also known as acute kidney injury (AKI), is a sudden and rapid decline in kidney function. The pathophysiology of acute renal failure involves several interconnected mechanisms.
Edited at 2023-10-04 16:16:25Pathophysiology of acute renal failure
Definition
Acute renal failure is a sudden and severe impairment of kidney function leading to a rapid decline in the ability to excrete waste products and maintain electrolyte balance.
Causes
Pre-renal causes
Hypovolemia: decreased blood volume leading to reduced renal blood flow.
Hypotension: low blood pressure resulting in inadequate perfusion of the kidneys.
Renal artery stenosis: narrowing of the renal arteries leading to reduced blood flow to the kidneys.
Intrinsic renal causes
Acute tubular necrosis: damage to the renal tubules caused by ischemia or toxins.
Glomerulonephritis: inflammation of the glomeruli in the kidneys.
Interstitial nephritis: inflammation of the renal interstitium.
Post-renal causes
Urinary tract obstruction: blockage of the urinary tract preventing the flow of urine.
Prostatic hyperplasia: enlargement of the prostate gland obstructing urine flow.
Pathophysiological mechanisms
Reduced glomerular filtration rate (GFR)
Decreased renal blood flow leads to reduced GFR.
Impaired filtration of waste products and electrolyte imbalance.
Accumulation of toxins in the blood.
Tubular dysfunction
Damage to the renal tubules impairs reabsorption and secretion functions.
Decreased reabsorption of water, electrolytes, and nutrients.
Increased excretion of water and electrolytes.
Inflammation and tissue damage
Inflammatory response triggers cellular damage in the kidneys.
Interstitial edema and infiltration of inflammatory cells.
Destruction of glomeruli and tubules.
Clinical manifestations
Oliguria
Decreased urine output, less than 400 mL per day.
Fluid retention, leading to edema and hypertension.
Accumulation of waste products in the body.
Electrolyte imbalance
Hyperkalemia: high levels of potassium in the blood.
Hyponatremia: low levels of sodium in the blood.
Metabolic acidosis: increased acidity in the blood.
Fluid and electrolyte disturbances
Volume overload: excessive fluid accumulates in the body.
Hypernatremia: high levels of sodium in the blood.
Hypocalcemia: low levels of calcium in the blood.
Complications
Uremia
Build-up of waste products in the blood.
Symptoms include fatigue, anorexia, and mental status changes.
Can lead to life-threatening complications if left untreated.
Fluid overload
Excessive accumulation of fluid in the body.
Causes pulmonary edema and respiratory distress.
Increases the risk of cardiovascular complications.
Electrolyte disturbances
Imbalances in sodium, potassium, calcium, and phosphate.
Disrupts normal cellular function and nerve conduction.
Can lead to cardiac arrhythmias and muscle weakness.
Treatment
Fluid and electrolyte management
Correcting volume depletion and electrolyte imbalances.
Restricting fluid intake in cases of fluid overload.
Administering intravenous fluids as needed.
Addressing underlying causes
Treating infections or removing urinary tract obstruction.
Adjusting medications that may contribute to renal failure.
Managing underlying conditions such as hypertension or diabetes.
Renal replacement therapy
Hemodialysis: removal of waste products and excess fluid from the blood.
Peritoneal dialysis: using the peritoneal membrane to filter waste and fluid.
Kidney transplantation: replacing the damaged kidney with a healthy one.
Prognosis
The prognosis of acute renal failure depends on various factors such as the underlying cause, the severity of kidney damage, and the promptness of treatment.
Early intervention and appropriate management can improve the chances of recovery and prevent complications.
However, in severe cases or when treatment is delayed, acute renal failure can progress to chronic kidney disease or end-stage renal disease.