Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Renal > Lab Tests For The Kidney > Flashcards

Lab Tests For The Kidney Flashcards

1
Q

What is the normal function of the kidney?

A
  • Homeostasis
    • excretion of waste roducts
    • water balance
    • acid-base balance
    • electrolyte balance
  • Hormonal
    • hemodynamics
    • red blood cell production
    • bone metabolism
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is filtered rate? what is excreted rate? what does this lead to?

A

filtered rate (mg/min)= PlasmaX(mg/min) * GFR (ml/min)

excreted rate(mg/min) =urineX (mg/ml) * urine flow (ml/min)

filtered rate=excretion rate

GFR=Urine * Urine flow/ plasma

Clearance= U* V/P

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

WHat is the equation for clearance? What is X? what are some exogenous markers?

A

Clearance= Ux* V/Px

Clearance of creatine is used to represent GFR

Characteristics?

freely filtered

non-toxic

not secreted

not reabsorbed

not changed during excretion

Exogenous markers: inulin, Iothalamate, Iohexol

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

How is creatine produced? WHy is it a good measure of GFR?

A

Creatine is produced from metabolism of muscle creatine and from dietary meat intake

  • released into circulation on a constant basis
    • freely filtered
    • non-toxic
    • secreted-small amount in proximal tubule
    • not reabsorbed
    • not changed during ecretion
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Assuming that the GFR is 120ml/min with a serum creatine of 1mg/dl, what is the difference in GFR between a serum creatine of 4mg/dl and a serum creatine of 5mg/dl?

A

6ml/min

Creatine quadruples, GFR must decrease to 1/4=30ml/min

Creatine has quintupled, GFR must decrease to 1/5= 24 ml/min

difference between creatine of 4mg/dl and 5 mg/dl is 30 ml/min-24 ml/min=6ml/min

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

what are the normal values for serum creatine? men, women and children

A

men= 0.9-1.3mg/dl

women= 0.8-1mg/dl

children= 0.5-1mg/dl

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

how is creatine related to msucle mass?

A
  • sincre creatine production is largely from muscle creatine, greater muscle mass leads to greater creatine production
  • black, men and younger adults have more muscle mass, and blacks also have a higher creatine generation rate
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Is creatine an exact measure of calculated kidney function?

A
  • creatine clearance overestimates GFR due to a small amount of secretion in the tubules
  • measured clearance requires 24 hours of urine collection
  • creatine production is dependent on muscle mass
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What is the Cockcroft Gault Formula based on? WHo should you be careful using it on?

A
  • not adjusted for body surface area

Serum Creatine

Age

Weight

Gender

  • developed when obesity was less common
  • use with caution in obese or edematous people
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What is MDRD study equation based on? how does it do at estimating GFR?

A

Serum creatine

age

gender

race

**It underestimates GFR if the actual GFR is greater than 60 . ml/min/1.73m2

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What is the CKD-EPI equation based on?

A

more accurate with estimated GFR greater than 60ml/min/1.73m2

it is a much more complicated equation

serum creatine

age

gender

race

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What is cystatin?

A

protein produced by all nucleated cells

freely filtered

production seems less affected by age and gender than creatine

new estimating equations based on cystatin C, either lone or with creatine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

How is chronic kidney disease defined? At what point do you need dialysis?

A

GFR<60ml/min/1.73 for >3 months and other evidence of kidney damage

need dialysis when GFR<10ml/min

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

How do you define acute kidney injury? Can we use the equations about GFR for acute kidney disease? What are early signs?

A

acute kidney injury occurs over hours to days/acute sustained reduction in renal function/25% increase in creatine

No! the equations only relate for a steady state

so formulas cannot be used, new steady state is needed, serum creatine rises, early signs can be decreased urine output!

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What is the RIFLE criteria for stratifying AKI? what is the timeline for it? what is the timeline for the AKIN criteria? what are they both weighted on?

A

Risk

Injury

Failure

Loss of Funciton

ENd stage renal disease

ovr not more than 7 days

AKIN criteria is within 48 hours

*****they are bosth weighted on urine output and creatine changes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

how fast does creatine change during injury?

A

it takes time for creatine to rise!

typically about 48 hours from time of injury for there to be any change

even if GFR is 0, creatine typically only increases 1-2mg/dl/day therefore it can’t be used for acute well!

17
Q

creatine is a functional marker of _____

but now we instead are looking for what?

A

creatine is a function marker of organ damage,

but now we are looking for biomakers which are foot prints of actual organ damage

18
Q

is it possible to have chronic kidney disease and a normal GFR?

A

yes!

19
Q

Total urinary protein should be ________

At what point is it considered nephrotic?

Nephrotic syndrome has low ____ and ______

A

urinary protein should be less than 150mg/day

urine protein of greater than 3.5g/24 hours is nephrotic

nephrotic syndrome has low serum albumin and edema

20
Q

what does a urine dipstick show?

A

a negative and positive reading for protein in the urine by urine dipstick

primarily detects albumin

it is dependent on urine concentration and isnt an actual value, just + marks, it is considered semi-quantitative report for proteinuria

21
Q

What is microalbuminuria?

A
  • it meads there is moderately increased albumin in the urine
  • most of the total urinary protein is made up of tubular proteins
  • albumin in the urine is abnormal
  • microalbuminuria is defined as
    • 30-300mg albumin per 24 hours
    • 30-300 mg/albumin/g of creatine
  • this is usually below dipstick threshold!!
22
Q

What are the 2 quantitative tests for proteinuria?

A

24 hour urine

spot urine sample

23
Q

WHat is overflow

A

when you have an increase in protein in the urine that is not albumin

24
Q

WHen you have increase in albumin in the urine that is due to?

A

glomerular damage

25
Q

what are qualitative test for proteinuria?

A

protein electrophoresis of serum or urine

when done in serum you should see a big spike for albumin, if you see another big spike that is a different protein and is indicative of something making large amounts of protein in the body, for example cancer

26
Q
A

Renal (7 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions