Brainscape's Knowledge GenomeTM

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


See full index

Urinary Exam 1 > Clinical Evaluation of GFR > Flashcards

Clinical Evaluation of GFR Flashcards

1
Q

What does Azotemia mean to the practitioner?

A

High BUN and High Creatinine

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

What are the 3 types of Azotemia?

A

Pre-renal
Renal
Post-renal

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

Decreased renal perfusion (dehydration, shock, Congestive Heart Failure)

A

Pre-Renal

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

Secondary to intrinsic renal parenchymal disease

A

Renal

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

a kidney disorder where numerous cysts enlarge in both kidneys reducing the amount of normal kidney tissue and thereby the kidney’s ability to function normally, leading to kidney failure

A

Renal Parenchymal Disease (PKD)

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

Impaired elimination from the body (obstruction, ruptured bladder)

A

Post-Renal

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

Clinical and biological abnormalities that accompany a critical loss of functioning nephrons

A

Uremia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

How do we measure kidney function?

A

Clearance

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

The volume of plasma that would have to be filtered by the glomeruli in 1 min. to produce a certain amount in the urine each min.

A

Clearance

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Formula for Clearance

A

C = U V/P

Ux = Urine concentration of x (mg/dl)
Px = Plasma concentration of x (mg/dl)
V = Urine output (ml/min)

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

What if x is resorbed by the tubules?

A

Cx < GFR, because ↓Ux and ↑Px

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

What if x is secreted by the tubules?

A

Cx > GFR, because ↑Ux and ↓Px

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

How are GFR and Clearance Related?

A

Creatinine clearance measurements will consistently be 10 to 20 percent higher than GFR in patients with a normal GFR and progressively higher as the GFR falls

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

When do we actually need to calculate GFR?

A
  • Patient who is PU/PD WITHOUT azotemia
  • Patient who may have another disease which causes PU/PD
    (hyperadrenocorticism, hyperthyroidism, diabetes mellitus, etc.)
  • Patient that may need a nephrectomy (need to know if other kidney
    is functioning)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What substance (x) do we use?

A
  • Freely filtered at glomerulus
  • Not plasma protein bound
  • Not metabolized
  • Non-toxic
  • Excreted only by kidneys
  • Neither reabsorbed nor secreted by the renal tubules
  • Stable in blood and urine and easily measured

Under these circumstances
CLEARANCE = GFR

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

Which substance meets all criteria for a good substance to measure Clearance so it = GFR, but difficult to use because must be infused IV over a period of time with constant urine collection?

A

Inulin

(Gold-standard for GFR determination)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Uses patients’ naturally made creatinine
- 24h urine collection (challenge in vet med)
- Slight underestimate of GFR

A

Endogenous - Creatinine Clearance Method

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q
  • Creatinine given SQ or IV in a high dose and 24h urine collection
  • Very good estimate of GFR
A

Exogenous - Creatinine Clearance Method

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q
  • Iodinated water-soluble contrast agent
  • Non-toxic, EXTRAcellular only, little protein binding and removed only by the kidneys
  • Newer and simpler way to estimate GFR in clinical setting
  • Give a specific dose IV
A

Iohexol Clearance

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What is a problem with Inulin, Creatinine Clearance Method, and Iohexol Clearance?

A

They measure GLOBAl GFR, Not individual kidney GFR

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q
  • Imaging method to determine individual kidney GFR, effective
    renal plasma flow, and filtration fraction
  • Give the isotope 99mTc-DTPA and image kidneys with a Gammacamera
A

Radioisotopes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What do we use in ‘real life’ (regular practice) to estimate the GFR?

A

BUN and Creatinine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Product of protein and aa catabolism

A

BUN

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Made in the LIVER with ammonia from aa’s

A

Blood Urea Nitrogen (BUN)

25
Q

Can be made from endogenous or exogenous proteins

A

Blood Urea Nitrogen (BUN)

26
Q

Freely permeable across cell membranes, distributed in Total body water

A

BUN

27
Q
  • Renal excretion most important
  • Filtered at glomerulus
  • Passively reabsorbed in tubules (most of it)
    * Less absorbed with rapid flow
    * More absorbed with slower flow rates
A

BUN

28
Q

BUN is NOT secreted by ______________

A

renal tubules

29
Q
  • Varies with protein intake and catabolism
  • Blood level of urea nitrogen reflect renal excretion of urea and protein catabolism
  • Requires no metabolic work by kidneys
  • Some degraded by bacteria
A

BUN

30
Q
  • High protein meal
  • GI bleeding
  • Increased catabolism
  • Drugs

Are all examples of what?

A

Non-Renal Factors that INCREASE BUN

31
Q
  • Pre-renal – slow tubular flow rates = more reabsorption
  • Renal
  • Post-renal
A

Renal Factors that INCREASE BUN

32
Q
  • May reflect high tubular flow rates (lots of urine made) with decreased urea resorption
  • Low protein diet
  • Liver dysfunction or portosystemic shunt
    *Urea not made
  • Anabolic steroids - slow protein catabolism

Are examples of what?

A

Decreased BUN

33
Q
  • Product of muscle breakdown (phosphocreatine)
  • Produced at a relatively constant rate for an individual
A

Creatinine

34
Q

Creatinine
- Rate of production determined by age, sex, and muscle mass
- Young animals have a ___________ creatinine

A

lower

35
Q

Creatinine
- Rate of production determined by age, sex, and muscle mass
- Males have a slightly ___________ creatinine

A

higher

36
Q

Creatinine
- Rate of production determined by age, sex, and muscle mass
- Well-muscled animals have a __________ creatinine than poorly
muscled ones (e.g. Greyhounds)

A

higher

37
Q

Creatinine
- Rate of production determined by age, sex, and muscle mass
- ________ (is/is not) influenced by diet

A

is not

38
Q

Creatinine
- Rate of production determined by age, sex, and muscle mass
- _________ (is/is not) metabolized in the body

A

is not

39
Q

Non-Renal: uncommon
* Massive muscle necrosis
* Prolonged strenuous exercise
* Greyhound Norma

A

Increased Creatinine

40
Q

Renal: Important
* Pre-renal – decreased renal perfusion to kidneys (dehydration, shock)
* Primary renal – can’t filter (not enough functional nephrons to do the job)
* Post-renal – can’t eliminate (obstruction of ureters, urethra, or ruptured urinary tract)

A

Increased Creatinine

41
Q
  • Muscle loss – only one that is really significant (think ancient skinny cats)
  • Small size
  • Young age
A

Decreased Creatinine

42
Q

After eliminating pre-renal and post-renal causes…
Increased BUN and Creatinine indicate that at least 75% of
____________ are NOT functioning

A

nephrons

43
Q

Pre-renal azotemia is usually ________

A

Mild

44
Q

Post-renal azotemia can be __________

A

severe

45
Q

What is it that you CAN’T tell from BUN and Creatinine?

A
  • Cause of azotemia
  • Reversibility of azotemia
  • Origin of azotemia (pre-renal, renal, post-renal)
  • Acute vs. chronic disease
  • Progressive vs. non-progressive disease
46
Q
  • Made by all cells and excreted almost exclusively by the KIDNEYS
  • Increases in the serum earlier than creatinine
    *EARLIER detection of kidney disease
  • Not affected by muscle mass
A

SDMA (IDEXX)

Symmetric dimethylarginine

47
Q

When do you get a Urine Specific Gravity?

A

BEFORE fluids or diuretics are given

48
Q

Localization of Azotemia:
*If the animal can concentrate its urine, its NOT ____________ in origin

A

renal

49
Q

Localization of Azotemia:
*If it concentrates but not as much as it should, it is partially ____________ in
origin

A

renal

50
Q

Localization of Azotemia:
*If the animal ________ (can/cannot) concentrate its urine, some or all of it is renal in origin (unless drug interference)

A

cannot

51
Q

The BUN is increased for which types of Azotemia?

A
  • Prerenal
  • Renal
  • Postrenal
52
Q

The Creatinine is increased for which types of Azotemia?

A
  • Prerenal
  • Renal
  • Postrenal
53
Q

What type of Azotemia is the following?

  • Increased BUN & Creatinine
  • USG > 1.030 (concentrated)
  • BUN, Creatinine is better after IV fluids
  • Dehydrated
  • able to urinate
  • no abdominal fluid
  • no large firm bladder
A

Pre-Renal

54
Q

What type of Azotemia is the following?

  • Increased BUN & Creatinine
  • USG < 1.030 (not very concentrated)
  • BUN & Creatinine DOES NOT get better after fluids
  • Hydrated/Dehydrated (variable)
  • Able to urinate unless anuric
  • no abdominal fluid
  • no large firm bladder
A

Renal

55
Q

What type of Azotemia is the following?

  • Increased BUN & Creatinine
  • USG is Variable
  • BUN & Creatinine DOES NOT get better after fluids
  • Hydrated/Dehydrated (variable)
  • NOT able to urinate
  • Maybe abdominal fluid
  • Maybe large firm bladder
A

Post-Renal

56
Q

normal level of creatinine in cats is:

A

0.6 and 2.4 mg/dL

57
Q

What are some causes for PU/PD?

A
  • Kidney Disease
  • Hypercalcemia
  • Hyperadrenocorticism
58
Q

What MUST be done before moving to a water deprivation test in evaluating PU/PD?

A

A first morning urine sample specific gravity

Urinary Exam 1 (11 decks)

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