Acute Renal Failure

Question 1

What is acute renal failure (Acute kidney injury)

Answer 1

abrupt decline in kidney function, resulting in an ability to maintain fluid and electrolyte balance and excrete nitrogenous waste

Question 2

What is acute renal failure in the slides

Answer 2

Sudden onset, lowered glomerular filtration, increased N2+ waste

Question 3

What is the etiology of acute renal failure?

Answer 3

Trauma (hypovolemia)
Infection
Inflammation
Toxicity

Question 4

What is acute renal failure commonly defined as?

Answer 4

abrupt (within 48 hours) reduction in kidney function based on an increase in serum creatine level, a reduction in urine output, and the need for dialysis, or a combination of these factors

Question 5

What is prerenal kidney injury?

Answer 5

Most common form of AKI, decrease in renal blood flow, reversible if cause is identified and corrected before kidney damage

Question 6

What percentage of the cardiac output is received by the kidneys?

Answer 6

22%

Question 7

As renal blood flow falls,

Answer 7

the GFR decreases, the amount of sodium and other substances filtered by the glomeruli reduces, and blood flow needed ti reabsorb these substances is reduced

Question 8

What are the causes of pre-renal failure?

Answer 8

vascular volume (hemorrhage, loss of fluid volume), impaired perfusion due to heart failure/ cariogenic shock, anaphylaxis/ sepsis, drugs

Question 9

Why are elderly persons at risk?

Answer 9

Predisposed to hypovolemia and high prevalence of renal vascular disorder, aging of renal reserve

Question 10

What are the manifestations of acute renal failure?

Answer 10

sharp decrease in urine output, disproportional elevation of BUN in relation to serum creatine levels

Question 11

What is Intra-renal failure

Answer 11

results from conditions that damage structures within the kidney

Question 12

What are the manifestations of Intra-renal failure?

Answer 12

ischemia associated with prerenal injury, injury to the tubular structures of the nephron (most common), intratubular obstruction

Question 13

What are other infrarenal causes of AKI

Answer 13

acute glomerulonephritis and acute pyelonephritis

Question 14

What is post-renal failure

Answer 14

obstruction of urine outflow from the kidneys

Question 15

Where can obstruction occur in post-renal?

Answer 15

Ureter, bladder, urethra

Question 16

What is the most common underlying problem of post-renal?

Answer 16

Prostatic hyperplasia

Question 17

What is the treatment of post-renal

Answer 17

treating the underlying cause of obstruction so that urine flow can be reestablished before permanent nephron damage occurs

Question 18

What is the treatment

Answer 18

Urine tests to measure osmolality, urinary sodium concentration
Fluids to maintain normal fluid volume and electrolyte concentrations, adequate caloric intake is needed to prevent breakdown of proteins to increase nitrogenous waste, hemodialysis, continuous renal replacement therapy

Question 19

What are the recovery phases?

Answer 19

Oliguric Phase, Dieuretic phase, Convalescent phase

Question 20

What is the Oliguric Phase

Answer 20

Urine output is <500 ml/day
Increased BUN and serum creatine
Last three weeks

Question 21

What is the Diuretic phase

Answer 21

Urine output of >500 ml/day
Urine is very dilute, representing kidney’s inability to concentrate urine
Renal blood flow is improved
Last up to 2 weeks

Question 22

What is the convalescent phase

Answer 22

Serum tests of renal function return to normal

Lasts 3 to 12 months