Objective 1: Define Acute and Chronic Renal Failure

Renal Failure

A condition in which the kidneys cannot adequately remove metabolic waste or maintain normal fluid, electrolyte, and acid-base balance.

Normal Kidney Functions

Filter blood, eliminate urea and creatinine, regulate water and electrolytes, and maintain acid-base balance.

Acute Renal Failure (AKI)

An abrupt decline in kidney function occurring over hours or days, resulting in decreased GFR and impaired waste elimination.

Chronic Renal Failure (CKD)

A gradual, generally irreversible loss of kidney function occurring over months or years due to progressive nephron destruction.

Glomerular Filtration Rate (GFR)

The amount of filtrate produced by the kidneys; decreases when kidney function declines.

Azotemia

Accumulation of nitrogen-containing waste products, particularly BUN and creatinine, in the bloodstream.

Nephron Destruction

Loss of functioning kidney units, reducing the kidneys' ability to filter blood.

Compensatory Hyperfiltration

Increased filtration activity by remaining nephrons to compensate for the loss of functioning nephrons.

Fibrosis

Formation of scar tissue that replaces normal functioning kidney tissue.

End-Stage Renal Disease (ESRD)

The final stage of CKD in which kidney function is severely diminished and dialysis or transplantation is generally necessary.

Acute Renal Failure Reversibility

Often reversible when the underlying cause is identified and treated early.

Chronic Renal Failure Reversibility

Generally irreversible because functioning nephrons have been permanently destroyed and replaced by scar tissue.

Acute Kidney Injury Causes

Decreased renal perfusion, direct kidney tissue injury, or obstruction of urine flow.

Chronic Kidney Disease Complications

Anemia, hypertension, metabolic acidosis, electrolyte imbalances, and renal bone disease.

What is renal failure?

A condition in which the kidneys cannot adequately eliminate metabolic waste or maintain fluid, electrolyte, and acid-base balance.

What are the normal functions of the kidneys?

Filter blood, eliminate waste, regulate water and electrolytes, and maintain acid-base balance.

What is acute renal failure?

A sudden decline in kidney function occurring over hours or days.

What is chronic renal failure?

A gradual, generally irreversible loss of kidney function occurring over months or years.

What happens to GFR during acute kidney injury?

GFR decreases suddenly, reducing the kidneys' ability to filter blood.

Why do BUN and creatinine increase during renal failure?

The kidneys cannot adequately filter and eliminate these metabolic waste products.

Why is acute kidney injury potentially reversible?

The underlying cause may be corrected before permanent kidney damage occurs.

What happens if acute kidney injury is severe or prolonged?

Permanent kidney damage and chronic kidney disease may develop.

Why is chronic renal failure generally irreversible?

Progressive nephron destruction and fibrosis replace functioning kidney tissue with scar tissue.

What happens to remaining nephrons during early CKD?

They increase their individual filtration activity to compensate for lost nephrons.

What is fibrosis in chronic kidney disease?

Replacement of normal functioning kidney tissue with nonfunctioning scar tissue.

What is end-stage renal disease?

The final stage of kidney disease in which kidney function becomes severely diminished.

What treatments are generally necessary during ESRD?

Regular dialysis or kidney transplantation.

What is the main difference between AKI and CKD?

AKI develops suddenly and may be reversible; CKD develops gradually and is generally irreversible.