Acute renal failure is characterized by rapid onset of renal dysfunction and increased metabolic waste products in the blood. It can be caused by pre-renal issues which decrease blood flow to the kidneys, intra-renal issues involving direct kidney damage, or post-renal issues obstructing urine flow. Symptoms include electrolyte imbalances, decreased urine output, and buildup of waste products in the blood. Treatment focuses on supporting blood volume and pressure, correcting fluid and electrolyte levels, and using dialysis to filter waste if the kidneys are no longer functioning properly.

1. ACUTE
RENAL
FAILURE
By: Miss Santoshi Naik
Assistant Professor
Yenepoya Pharmacy College & Research centre

2. Definition
Acute renal failure is a syndrome characterised
by rapid onset of renal dysfunction, chiefly
oliguria or anuria, and sudden increase in
metabolic waste-products (urea and creatinine)
in the blood resulting in azotemia.

3. Etiopathogenesis / Causes of Acute
Renal Failure
Pre- renal
causes
Intra- renal
causes
Post –renal
causes

4. 1) Pre- renal causes
 Accounts for 55-60% of Acute renal failure.
 Causes: inadequate cardiac output and hypovolaemia or
vascular disease causing reduced perfusion of the kidneys
 It is characterized by sudden decrease in blood flow to
nephrons which ultimately leads to functional disorders or
depression of Glomerular filtration rate.

5. 2) Intra – renal causes
 Accounts for 35-40% of Acute renal failure.
 It is characterized by disease of renal tissue.
 Causes: vascular disease of the arteries and arterioles within
the kidney, diseases of glomeruli, acute tubular necrosis due to
ischaemia, nephrotoxin.

6. 3) Post – renal causes
 Accounts for < 5% of Acute renal failure.
 It is characterized by obstruction to the flow of urine along the
renal tract.
 Causes: Mass within lumen or wall of the tract or external
compression on ureters, urinary bladder or urethra,
vasoconstriction (decreased renal blood flow).

7. Clinical features of Acute renal failure (ARF)
It depends on the cause of ARF and the stage of the disease at which the
patient presents.
It includes one of these 3 major patterns:
1) Syndrome of acute nephritis
2) Syndrome accompanying tubular pathology
- Oliguric phase
- Diuretic phase
- Recovery phase
3) Pre – renal syndrome

8. 1) Syndrome of acute nephritis
 This is associated with glomerulonephritis (inflammation of
glomerulus).
 Results in increase in glomerular permeability and decrease in
glomerular filtration rate.
 Characteristic features: mild proteinuria, haematuria,
oedema.

9. 2) Syndrome accompanying tubular pathology
 ARF is caused by destruction of the tubular cells of the nephron.
 Disease progresses in 3 stages:
a) Oliguria phase
 Lasts for 7-10 days with urine output less than 400 ml/day.
 Leads to accumulation of waste products of protein metabolism in
the blood and resultant azotaemia, metabolic acidosis,
hyperkalaemia, hypernatraemia and hypervolaemia

10. b) Diuretic phase
 Healing of tubules results in improving the urinary output.
 This is because of drawing water & sodium by high levels of
creatinine & urea in the tubules so as to be excreted.
 Effects: Dehydration & electrolyte imbalance
c) Recovery phase
 Full recovery of tubular cells occurs in half cases while others
terminate in death.
 Time period for recovery – upto 1 year.

11. 3) Pre – renal syndrome
 It occurs because of secondary disorders like ischaemia
(decrease blood flow to tissues) & not due to glomerular or
tubular damage.
 Causes of ischaemia: renal arterial obstruction, hypovolaemia,
hypotension or cardiac insufficiency.
 Due to depressed renal blood flow, there is decrease in GFR
causing oliguria, azotaemia (elevation of BUN and creatinine)
and oedema

12. Symptoms of Acute renal failure
 Electrolyte imbalance
 Hematuria (Blood in urine)
 Oliguria (decreased urine output)
 Dehydration
 Pale skin
 Poor appetite

13. Diagnosis of Acute Renal failure
 Routine laboratory tests (creatinine & blood
urea nitrogen)
Ultrasound of kidney
 Kidney biopsy

14. Treatment of Acute Renal Failure
1) Support of blood volume & blood pressure
2) Correction of fluid & electrolyte imbalances
3) Dialysis of kidney
4) Low protein & high carbohydrate diet to minimize formation
of nitrogenous wastes.