Small Group: Acute Renal Failure

Question 1

What is the formula for clearance?

Answer 1

Cl = ([Urine]/[Plasma]) x average rate of urine production

Question 2

Clearance is __________.

Answer 2

the volume of blood that is cleared of something per minute

Question 3

What are rigors?

Answer 3

Sudden feelings of chills accompanied with rising temperature

Question 4

Creatinine clearance is an ___________-estimation of clearance because it is secreted. Urea is an ______-estimation of clearance because it is absorbed.

Answer 4

over; under

Question 5

Hypotension can cause renal acute-kidney injury because ___________.

Answer 5

ischemia can kill the tubular cells

Question 6

What is FENa?

Answer 6

FENa is the fraction of excreted sodium

Question 7

What is the formula for FENa?

Answer 7

FENa = ([urine sodium]/[plasm sodium]) / ([urine creatinine]/[plasma creatinine]) x 100

Question 8

FENa will be greater than 2 in __________ disorders.

Answer 8

intrinsic

Question 9

FENa will be less than 1 in ___________ disorders.

Answer 9

pre-renal

Question 10

FENa will start out less than 1 and move to greater than 2 in ____________ disorders.

Answer 10

post-renal

Question 11

Recall that angiotensin II affects the _________ arteriole.

Answer 11

efferent

Question 12

Why does angiotensin II cause constriction in the efferent arteriole?

Answer 12

Hypovolemia decreases the pressure of the glomerulus. The body constricts the efferent arteriole to increase GFR pressure and preserve filtration.

Question 13

Rhabdomyolysis causes ___________ kidney injury.

Answer 13

Intrinsic - > tubular

Question 14

What is CPK?

Answer 14

Creatine phosphokinase

Question 15

Other than ultrasound/imaging, what are some ways to look for obstructive renal disease?

Answer 15

Place a catheter after the patient has voided. If the reserve volume is greater than 150 ml, then obstruction is likely. Also, catheters should relieve the acute-renal failure symptoms.

Question 16

Why does recovery from obstructive renal disease tend to go down the longer the obstruction is in place?

Answer 16

Because the reduction in single-nephron glomerular filtration rate causes afferent arteriole vasoconstriction. Prolonged vasoconstriction leads to ischemic injury.

Question 17

Which arteriole does angiotensin II induce vasoconstriction in?

Answer 17

The efferent (to maintain glomerular pressure)

Question 18

Although most membranous nephropathy is idiopathic, about 1/3 of cases are associated with these diseases: _____________.

Answer 18

SLE
HBV
HCV
Heavy metal poisoning
Cancer
Gold

Question 19

All those with nephrotic proteinuria should receive __________.

Answer 19

low-salt diets, ACE inhibitors, and BP-controlling agents

Question 20

What is a differential diagnosis for nephritic syndrome?

Answer 20

Anti-GBM disease/Goodpasture's
Vasculitis
Post-infectious GN
Lupus
MPGN
IgA nephropathy

Question 21

What serological test can direct the diagnosis to MPGN?

Answer 21

Hepatitis titers

Question 22

How is IgA nephropathy treated?

Answer 22

ACE inhibitors and steroids

Question 23

How is Wegener’s treated?

Answer 23

Rituximab
Steroids
Cyclophosphamide
Plasma exchange