Brainscape's Knowledge GenomeTM

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


See full index

Block 9 Week 5 Meg > Patterson: Approach to Patients With Renal Disease > Flashcards

Patterson: Approach to Patients With Renal Disease Flashcards

1
Q

What hormones are produced by the kidney?

A

renin
erythropoietin
calcitriol

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

How do post patients with kidney problems present?

A

most pts present asymptomatically with abnormal creatinine, GFR, urinalysis, or BUN

SOME pts have blood in the urine, flank pain, or extra-renal symptoms of HTN, edema, confusion

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

measured or estimated value of # of total functioning nephrons

A

GFR

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

What is the normal GFR for a man? For a woman?

A

men: 130 ml/min
women: 120 ml/min

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

What happens to GFR with age? What is the average GFR of a 70+ yo patient?

A

it decreases about 0.75 ml/min per year

a 70+ patient probably has a GFR around 60ml/min

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

What could cause a decreasing GFR?

A

loss of nephron function
or
superimposed problem influencing filtration

  • possible to have progressive renal disease and a normal GFR
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What is the equation used to measure the GFR?

A

clearance = U(x) * V/P(x)

U(x) = urine concentration
P(x) = plasma concentration
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

a substance 100% filtered by glomeruli- no reabsorption or excretion therefore can estimate GFR

A

inulin

**not used clinically, because it’s expensive and not practical

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

Product of muscle and dietary metabolism

Used to estimate GFR if muscle mass and diet remain constant

A

serum creatinine

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

What is the relationship between serum creatinine and GFR?

A

inverse relationship

as SCr increases, GFR decreases

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

What is the average serum creatinine in men? In women?

What populations have a higher serum creatinine? Lower?

A
  1. 13 mg/dl in men
  2. 93 mg/dl in women

**higher in blacks and young pts
lower in elderly and Hispanics

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

What are some things that can interfere with the serum creatinine measurement, and make it less reliable?

A

variations in creatinine production, like amputees or vegetarians
drugs that block secretion of creatinine like H2 blockers
creatinine assays can mistake other compounds for creatinine
large meat meals

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

This is probably the best equation used to calculate serum creatinine

A

CKD-EPI

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

Why is a 24 hour creatinine clearance not totally useful?

A

it’s complicated to get a complete urine collection over 24 hours
also, it overestimates the GFR by about 10%

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

When is the BUN elevated?

A

high protein diet
trauma
hemorrhage (GI bleeds)

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

When is the BUN low?

A

low protein diet

liver disease

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

When will the BUN/creatinine ratio become elevated?

A

when you’re dehydrated –> increased Na+ and H20 absorption –> increased urea absorption –> increased BUN compared to SCr

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What is the normal BUN/SCr ratio? What does a BUN/SCr greater than 20:1 suggest?

A

15:1

If greater than 20:1, suggestive of pre-renal failure

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Measures the percent of filtered sodium that is excreted in the urine

A

fractional excretion of filtered sodium (FENa)

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

What does a FENa less than 1% indicate?

A

pre-renal acute kidney injury

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

If a patient is on diuretics, FENa is no longer a good indicator of pre-renal AKI. What should you use instead?

A

FEurea

**FEurea less than 35% suggests pre-renal AKI

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

What are the 3 parts of a urinalysis?

A

appearance: note the color and clarity
dipstick evaluation: blood, leukocyte esterase, nitrates, pH, urobilinogen, proteins, ketones, glucose pH
microscopic analysis: cells, casts, crystals, bacteria

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

If the urine is turbid, what does this suggest?
If the urine is hazy, what does this suggest?
If the urine is milky, what does this suggest?

A

turbid: infection, crystals, or leukocytes
hazy: mucus
milky: chyluria from nephrotic syndrome with dyslipidemia and oval fat bodies, profolol

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

If the urine is blue, black or pink, what does this suggest?

A

inborn errors of metabolism

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

If the urine is red/brown, what should you do? How do you analyze it after that?

A

spin it

if there is a clear supernatant on top with a red sediment at the bottom = hematuria (RBCs)

is the supernatant on top is red, there’s hemoglobin or myoglobin in the urine - or beets or food dyes

26
Q

What is the normal pH of urine? What should it be if you have metabolic acidosis?

A

4.5-8.5

pH at least 5 in metabolic acidosis

27
Q

In a UTI with urease producing organisms, what would you expect the pH to be?

A

well urea –> NH3 will elevate the urine pH to 7+

28
Q

weight of urine compared with the weight of an equal volume of distilled water.
Used roughly as an estimate of the ‘concentration’ of urine (urine osmolality)

A

specific gravity

29
Q

How is the specific gravity different from urine osmolality?

A

Uosm is affected by the number of particles in the urine

specific gravity is affected by the number and size of particles in urine

**glucose and protein will increase the SG, but not necessarily the Uosm

30
Q

At what blood glucose level will glucose spill into the urine?

A

180mg/dl

31
Q

What kind of ketones would a UA pick up in the urine? When might you see ketones in the urine?

A

detects acetoacetic acids, but not beta-hydroxybutyric acid or acetone

elevated ketones in starvation and Atkin’s dieters

32
Q

What protein is measured in a UA?

A

only albumin
immunoglobulin light chains are not detected
if urine protein is less than 300mg/day, it’s not detected

33
Q

What should you do if a urine dipstick is positive for protein?

A

Do a spot urine protein/creatinine ratio

**more practical than a 24 hour urine protein

34
Q

What components of the blood will cause positive results on a urine dipstick?

A

RBCs
hemoglobin
myoglobin

**look at microscopic analysis to see if there’s RBCs, if they’re dysmorphic, etc

35
Q

What is leukocyte esterase in the UA?

A

it tells you if you have lysed PMNs and macrophages in your urine

36
Q

What do white blood cells + nitrites in the urine suggest?

A

E.Coli –> UTI

37
Q

What do white blood cells, but NO nitrites in the urine suggest?

A

sterile pyuria

38
Q

What kind of crystals can you get in the urine?

A

uric acid: like after lymphoma or leukemia after treatment with chemotherapy (lysed DNA remnants –> uric acid)

calcium phosphate: associated with kidney stones

magnesium ammonium phosphate crystals

39
Q

If you have RBCs in the urine, what are some common causes? How can you tell if the blood in the urine is non-glomerular or glomerular?

A

common after exercise, sex, menses, UTI

non-glomerular hematuria: isomorphic rbcs (more likely a GI bleed)
glomerular hematuria: dysmorphic rbcs

40
Q

If you see acanthocytes in the urine (RBCs with small pieces hanging off), what should you think?

A

glomerulonephritis

41
Q

If you see white blood cells in the urine, what’s your differential?

A

UTI
nephrolithiasis
glomerulonephritis
interstitial nephritis

42
Q

If you see Eos in the urine, what should you think of?

What is one complication of finding eos in the urine?

A

interstitial nephritis

you have to use a stain (Wright’s or Hansel’s) to see the eosinophils

43
Q

What are casts in the urine?

A

they are cells that have been sloughed from the lumen or have gathered in the lumen, formed to the shape of the lumen, and were excreted - the cells are help together by mucoprotein

44
Q

What are some pathologic types of casts?

A

RBC casts –> think glomerulonephritis

WBC casts –> think pyelonephritis or kidney inflammation

granular muddy brown casts –> think acute tubular necrosis

45
Q

Rapid loss of kidney function resulting in retention of nitrogenous waste products
Injury begins before loss of excretory function manifesting increased creatinine, decreased urine output, acidosis, hyperkalemia, etc…
Occurs in up to 50% of ICU patients
+/- recovery of lost kidney function

A

acute kidney injury

46
Q

If you have a stage 1 acute kidney injury, how much will your creatinine increase? What about stage 3?

A

stage 1: SCr increases 1.5 to 2 fold, or by 0.3mg/dl or more

stage 3: SCr increases by more than 3 fold, or by more than 0.5mg/dl

47
Q

What are the three categories of acute kidney injury? Where does most acute kidney injury occur?

A

pre-renal: due to inadequate blood flow to the kidney, so decreased GFR

renal: instrinsic problem in the kidney that damaged filtering mechanism

post-renal: due to an obstruction, which backs up the system and increases filtration pressure

**60% of kidney injury is pre-renal

48
Q

List some causes of pre renal disease

A 
blood or fluid loss
BP meds (low BP)
hemorrhage
heart attack/heart disease
liver failure
severe dehydration
aspirin, ibuprofen (these meds block COX and prostaglandin formation, so you get more vasodilation)
49
Q

What are some post-renal causes of AKI?

A

urinary tract obstruction due to stones, tumor, or prostate enlargement

50
Q

What are some renal, or intrinsic causes of AKI?

A 
blood clots in arteries/veins of kidney
cholesterol deposits in kidney vessels
glomerulonephritis 
infection
chemo drugs and antibiotics
toxins like alcohol or cocaine
51
Q

List some meds that can be associated with AKI

A

ACE inhibitors
diuretics
chemotherapy
NSAIDS

52
Q

What happens to your urine sodium, urine concentration and urine output in pre-renal AKI?

A

low volume –> afferent arteriole senses this and increases renin secretion –> RAAS system causes reabsorption of Na+/H20

so urine [Na+] will be low
urine concentration will increase
less urine output

**small volume of concentrated urine

53
Q

What can be done to quickly recover from pre-renal AKI?

A

hydration!

54
Q

What do these lead to?

Decreased circulating volume
Intravascular volume depletion
Reduced renal blood flow
Severe vasodilation

A

pre-renal AKI

55
Q

What happens to the BUN/SCr ratio in pre-renal disease?
What happens to the urine sodium?
What will the FeNa be like?

A

increased BUN/SCr because there is reduced flow, which allows for greater reabsorption of creatinine

urine sodium will be less than 20

FENa will be less than 1%

56
Q

Disease of the small to large vessels of the kidney
Disease of the glomeruli (primary or secondary)
Nephritic –inflammatory with active urine sediment – casts, cells, dysmorphic RBCs
Nephrotic- >3.5 grams protein/24 hrs. Very minimal cells and casts
Disease of the tubules and interstitium

A

Intrinsic (renal) AKI

57
Q

inflammatory with active urine sediment – casts, cells, dysmorphic RBCs

A

nephritic

58
Q

greater than 3.5 grams protein/24 hrs. Very minimal cells and casts

A

nephrotic

59
Q

If you see buddy brown casts, what should you think of?

A

acute tubular necrosis

60
Q

If you see eosinophils, RBCs and leukocyte casts, what should you think of?

A

acute interstitial nephritis

61
Q

If you see hematuria, proteinuria, RBC casts, and dysmorphic RBCs, what should you think of?

A

acute glomerulonephritis

62
Q

If you suspect a post-renal AKI, such as nephrolithiasis, BPH/prostate cancer, or a pelvic tumor, what should you do?

A

ultrasound of the kidneys

Block 9 Week 5 Meg (5 decks)

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