Week 2 UA Flashcards

1
Q

Where does concentration of dilution of urine occur? Secretion? What is it all influenced by?

A

o Loop of Henle, distal tubules, collecting ducts
o Proximal convoluted tubules
o BP, ADH, acid-base balance, fluid balance, nutrient intake

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

• What is urine? Components? How much produced every day?

A

o Continuously formed ultra-filtrate of plasma
o Urea, chloride, sodium, potassium, creatinine, bicarb, uric acid
o 1 -1.8 (avg ~ 1.4) L every day from 17 L of filtered plasma

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

Urine is old dx technique. What does it reveal?

A

Kidney, liver fxn; metabolic processes; infx dz; nutritional status; occult dz

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

What occult dzs can urinalysis reveal?

A

Glomerulonephritis; hypertensive nephropathy; renal failure; DM (end stage renal dz); urinary tract neoplasms

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

What acute conditions is urinalysis a good tool for?

A

Abdominal pain; back pain; dysuria; urinary frequency/urgency; hematuria

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

What dzs is urinalysis routine monitoring for? Routine screening?

A

Chronic renal dz; liver dz; high BP; diabetes

Annual check-up; family hx renal dz

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

What are the major causes of end stage renal dz?

A

Diabetes; high BP; glomerulonephritis; cystic kidney dz; other

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

How should a urine sample best be collected?

A

Fresh voided; analyze in 1 hr at rm temp (cells and casts will degen over time; bacterial overgrowth will alter results); ok to fridge up to 4 hrs

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

What is the “clean catch mid-stream” method?

A

o Cleanse external genitalia w/ mild antiseptic, begin urinating, then position container to collect sample
o Decrease potential contamination of: skin, vaginal cells, bacteria

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

• What are other UA specimen collection methods?

A

o Voided urine
o Bagged specimen (pediatric)
o Hospitalization: suprapubic aspiration; catheterization

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

• Why is first morning void the best sample? Disadvantage? Is it practical?

A

o Most concentrated sample of day; best for protein, bilirubin, nitrites, ability to concentrate urine
o Not great for cells or casts which can deteriorate in bladder overnight
o Not practical; random specimens typically collected in office

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

• What are physical measurements/components of urinalysis?

A

o Physical (macroscopic): color, clarity, sp gravity
o Chemical composition (dip stick): pH, protein, bilirubin, ketones, leukocyte esterase, glucose, blood, urobilinogen, nitrite
o Microscopic: cells, microorganisms, casts, crystals, debris

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

• What is normal color of urine?

A

o Yellow: pale to deep, or amber
o Pigment is urochrome (urobilin), from bilirubin metabolism
o Usually darker, higher sp grav in concentrated urine
o Pale dilute urine is straw, or colorless

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

• What are 2 non-pathological colors of urine?

A

o Red: beets, rhubarb, menstrual blood

o Bright Yellow: riboflavin (B2)

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

• What are pathological colors of urine?

A

o Red/brown: hematuria: intact RBCs; hemoglobinuria: lysed cells
o Orange/amber: bilirubinuria: jaundice
o Green: infection: pseudomonas
o Brown/black: melanin: malignant melanoma
o Colorless: very dilute: DM, DI
o Many drugs affect color

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

• What are different aspects of the clarity of urine?

A
o	Normal: clear
o	Cloudy: WBCs, bacteria, amorphous urates (acidic), amorphous phosphates (alkaline), epithelial cells, hyperuricosuria (purine rich foods)
o	Hazy: mucus, protein
o	Milky: fat/lipids
o	Smoky: RBCs
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

• What are some causes of different odors to urine?

A

o Sweet/fruity: uncontrolled diabetes (ketonuria)
o Foul/pungent: bacterial infection (ammonia)
o Musty: phenylketonuria (PKU)
o Fruity/grape juice: pseudomonas infection
o Maple syrup: maple syrup urine dz

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

• What tests are on a UA dipstick? What can give false (-)?

A

o 10: glucose, bilirubin, ketones, sp gravity, blood, pH, protein, urobilinogen, nitrite, leukocyte esterase
o Some have ascorbic acid: false (-) by reacting with reagents on test strip

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

• What does sp gravity indicative of? How can it be measured?

A

o Concentration abilities of kidneys; hydration status

o Refractometer: manual method of determining SG; replaced

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

• Normal values of sp grav? Distilled water?

A

o Water= 1.000
o Normal= 1.005-1.030
o Usually= 1.010-1.025
o Under 2 yrs= 1.001-1.018

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

• What is high/low SG called?

A

o High=hypersthenuria, >1.025

o Low-hyposthenuria, 1.001-1.010

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

• What are the 2 measures of solute concentration in urine?

A

o Specific gravity

o Osmolality: preferred for pts with renal dz

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

• What are some pathologies which show increased SG? Decreased?

A

o Diabetes mellitus- glycosuria; proteinuria/nephrotic syndrome; drug effects, eg radiographic contrast dyes; dehydration; SIADH (pituitary tumor); CHF; toxemia of pregnancy
o High fluid intake; chronic renal dzs (always at 1.010=isosthenuria); diabetes insipidus (ADH insufficiency); diuretics; glomerulonephritis

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

• What will give a high false positive SG? Low false positive?

A

o High= proteinuria -> over-estimation of kidney concentration ability
o Low= highly buffered alkaline urine; >1% glucose or urea

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

• How is glucose filtered by kidneys? How much should be in urine?

A

o By glomerulus; filtrate levels approximate blood glucose levels; reabsorbed in proximal renal tubules
o None, unless blood levels over 160-180 mg/dL -> glucosuria
o Normal is <0.5 g per day
o Few ppl normally have a little glucose due to less efficient renal tubules

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

• What are causes of glucosuria?

A

o DM, Cushing’s syndrome, pheochromocytoma, acromegaly (chronic pancreatitis, drugs…)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

• What do you do if you find unexpected glucosuria?

A

o Test blood for glucose

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

What gives glucose false (+)? False (-)?

A

o Pos= oxidizing agents
o Neg= ketones, ascorbic acid, aspirin
o Also, reactivity of glucose test decreases as SG increases

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

What causes ketones in urine? What does it mean?

A

o From metabolism of fatty acids and fats
o Result of altered carb metabolism
o Higher conc in blood leads to: electrolyte imbalance, dehydration, acidosis and eventual coma

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

• What is normal ua ketone level? What ketones are detected?

A

o Normal=negative

o Dipsticks only detect acetoacetic acid (but also contains beta-hydroxybutyric acid, acetone)

31
Q

• What is predominant ketone in diabetic ketoacidosis?

A

o BHB; strength of reaction may not correlate with severity of acidosis

32
Q

• What conditions show ketonuria?

A

o DM: more common in type 1

o Increased metabolic states: hyperthyroidism, fever, pregnancy

33
Q

• What gives ketone UA false (+) and false (-)?

A

o Pos= drugs (levodopa metabolites, phenylketones, phthaleins); highly pigmented urine
o Neg= prolonged air exposure (because ketones volatize)

34
Q

• What is normal UA blood? What does it detect?

A

o Normal=negative

o Free Hb=lysed RBCs (hemoglobinuria); Hb=intact RBCs (hematuria); Mb (muscle protein)

35
Q

• What maybe source of blood in urine?

A

o Glomerular dz; kidney stones, pyelonephritis, trauma, cystitis, bladder CA, prostate CA, exercise hematuria, MI, contamination

36
Q

• What gives blood UA false (+) and false (-)?

A

o Pos= microbial peroxidases; myoglobinuria; menstrual blood

o Neg= nitrites; ascorbic acid; increased SG decreases test reactivity

37
Q

• What is normal UA pH? How do kidneys maintain acid-base balance? When is it higher?

A

o 4.5-8.0 (usually 6.0)
o Re-absorption of Na and excretion of H+
o Higher after meals (“alkaline tide”)

38
Q

• What is pH run over effect?

A

o Buffers from protein test (ph=3) spill to pH test, making pH look more acidic

39
Q

• What is ddx for alkaline pH?

A
o	Alkalosis: metabolic or respiratory
o	UTI (proteus, pseudomonas)
o	Gastric suction, vomiting, renal tubular acidosis
o	Diet: vegetarians, high citrus intake
40
Q

• What is ddx for acidic pH?

A
o	Acidosis: respiratory or metabolic
o	DM
o	Starvation
o	COPD
o	UTI (E coli)
o	Diet: high meat, cranberries
41
Q

• What is normal protein? What does it indicate? What is function of slit pores?

A

o Negative: undetectable < 150 mg/day
o Sensitive indicator of Kidney function
o In normal glomerular membrane are too small for high MW proteins; have neg charge to repel proteins

42
Q

• What are causes of proteinuria?

A

o Functional renal: severe muscular exertion; pregnancy; glomerulonephritis; nephrotic syndrome; orthostatic proteinuria; renal tumor/infection
o Pre-renal: fever; renal hypoxia; hypertension
o Post-renal: cystitis; urethritis/prostatitis; contamination w/ vaginal secretions

43
Q

• When does transient proteinuria occur? What does 1+ mean?

A

o Fever, stress, exercise, CHF

o 30 mg/dL=significant

44
Q

• What is the protein confirmation qualitative test?

A
o	Sulfosalicylic acid (SSA + heat) precipitation test, more than just albumin
o	0, 0-no turbidity
o	1-10, Trace-slight turbidity
o	10-30, 1+ print can be read
o	40-100, 2+ white cloud w/o precipitate
o	150-350, 3+ white cloud w/ fine precip
o	>500, 4+ flocculent precipitate
45
Q

• What gives protein UA false (+) and (-)? What does it detect?

A

o Pos=vaginal secretions, hematuria, pyridium, highly alkaline
o Neg=dilute
o Most sensitive to albumin
o Doesn’t detect: globulins, glycoproteins, bence-jones proteins

46
Q

• What is normal bilirubin UA?

A

o Negative

47
Q

• How does bilirubin get in urine?

A

o Lysed RBCs -> Hb -> heme and globin -> biliverdin -> reduced to unconjugated bilirubin (not soluble) -> liver via albumin -> conj w/ Glucuronic acid -> conjugated bilirubin (soluble) -> secreted by hepatocytes into bile -> excretion in feces

48
Q

• What can cause bilirubinuria?

A

o Gallstones
o Cholestasis: drugs, pregnancy
o Bile duct obstruction; intrahepatic or Extrahepatic
o Acute hepatitis
o Congenital defects in bilirubin metabolism (Dubin-Johnson syndrome, Rotor’s syndrome)

49
Q

• What causes false (+) and (-) in bilirubin UA?

A

o Pos=fecal contamination; Rx: pyridium indicans

o Neg= nitrites, light, ascorbic acid

50
Q

• How does urobilinogen get in urine?

A

o From metabolism of conjugated bilirubin by intestinal flora
o Most is further metabolized to stercobilin and excreted with stool
o Some reabsorbed via Enterohepatic circulation -> liver; most re-secreted into bile,
o **some into general circulation -> excreted by kidneys

51
Q

• What is normal UA urobilinogen? Increased by? Decreased?

A

o Normal= 0.2-1.0 mg/dL
o High= intravascular hemolysis, intestinal obstruction, early stages of acute hepatitis
o Low= occurs, but dipstick doesn’t have sensitivity to detect it

52
Q

• What causes false (+) and (-) for UA urobilinogen?

A

o Pos= fecal contamination, beets, pigmented drug metabolites
o Neg= antibiotics, formaldehyde, prolonged air exposure

53
Q

• What are normal UA nitrite levels? Increased by?

A

o Normal= negative

o High= indicates UTI; many gram (-) bacteria produce enzyme nitrate reductase -> reduce urinary nitrAtes to nitrItes

54
Q

• What causes false (+) and (-) UA nitrites?

A

o Pos= pyridium; beets; bacterial growth in old samples

o Neg= ascorbic acid; low nitrate diet; high SG

55
Q

• What is normal UA leukocyte esterase? What does it indicate?

A

o Normal = negative
o Screen for WBCs = likelihood of UTI
o Pts may be asymptomatic even with a significant infection
o Non-urinary causes: appendicitis, pancreatitis

56
Q

• What causes false (+) and (-) UA leukocyte esterase?

A

o Pos= vaginal secretions

o Neg= glucose, protein, increased SG, oxalates, some abx

57
Q

• What is microscopic urine analysis?

A

o Centrifuged and sediment is examined for formed elements
o Epithelial cells, RBCs, WBCs, mucus, bacteria, casts, crystals, yeast
o Artifacts (starch/talc crystals, fibers)
o Trichomonas vaginalis
o Eggs of schitosoma haemotobium
o Pinworm eggs

58
Q

• What are abnormal findings per High power field (HPF, 400x)?

A

o >3 erythrocytes
o > 5 leukocytes
o > 2 renal tubular cells
o > 10 bacteria

59
Q

• What are abnormal findings per low power field (LPF, 200x)?

A

o > 3 hyaline casts or > 1 granular cast
o > 10 squamous cells (indicate contamination)
o Any other cast (RBCs, WBCs)

60
Q

• Presence of what other things is abnormal?

A

o Fungal hyphae or yeast, parasite, viral inclusions
o Pathological crystals (cysteine, leucine, tyrosine)
o Large number of uric acid or calcium oxalate crystals

61
Q

• What/why are common findings of bacteria in urine?

A

o Normal urine is sterile
o Most are gram (-) due to nearby GI tract
o May be contaminants from skin or genital tract
o Need to correlate with sxs and dip findings to evaluate significance

62
Q

• What is appearance of microscopic yeast?

A

o Budding and branching
o Smooth, colorless, oval, doubly refractile walls, candida albicans is most common
o If pt has glucose in urine; often immunocompromised

63
Q

• Where are epithelial cells from in urine?

A
o	Squamous (SEC)- contaminant from lower GU (distal 1/3 of urethra)
o	Transitional (TEC)- line urinary tract from renal pelvis to proximal 2/3 of urethra; occasional seen
o	Renal (REC)- from renal tubules, sometimes slough off, so rare cells are OK; more if tubular damage, pyelonephritis, other renal dz/trauma
64
Q

• What is microscopic appearance of SEC? TEC? REC?

A

o SEC: Large, flat, irregular-shaped cells
o TEC: 2-4x larger than leukocytes, round, pear-shaped, tail-like projections, large round nucleus
o REC: slightly larger than WBC, flat, cuboidal or columnar, one large round nucleus

65
Q

• Microscopic appearance of RBC? Normal?

A

o Pale or yellowish, smooth biconcave disc, no nucleus or cytoplasmic granules
o Normal= < 3 RBC/HPF

66
Q

• Where are casts from? Appearance?

A

o Formed in distal and collecting tubules (=same shape as tubule, =renal dz only)
o Colorless, semi-transparent “cigar” shape, usu w/o defined edges
o Cylindroids have tapered tail, formed in loop of Henle
o Acellular or cellular

67
Q

• Why do casts form? Associated with?

A

o Ph acidic, urine concentrated; readily dissolve in alkaline urine
o Assoc with proteinuria and urinary stasis

68
Q

• What are hyaline casts?

A

o Conglomerations of protein, indication of proteinuria
o Occasionally in normal urine
o Tamm-horsfall protein, a globulin, NOT detected on dipstick
o Short-term proteinuria: after exercise, fever, orthostatic proteinuria
o Appearance: large, transparent

69
Q

• What are chronic hyaline casts/proteinuria assoc with?

A

o Glomerulonephritis, pyelonephritis, CHF, CRF (chronic renal failure)

70
Q

• What are RBC casts?

A

o Formed in distal convoluted tubule; appear very dark, can see cell outline
o Pathological- bleeding from kidney due to reduced urine flow (RBCs + RBC casts means blood from kidney, not other part of urinary tract)
o Glomerulonephritis (PSGN); SBE (subacute bacterial endocarditis); renal infarcts, vasculitis, sickle cell anemia; SLE, malignant HTN, goodpasture’s syndrome

71
Q

• What are WBC casts?

A

o Mean infectious or inflammatory dz of kidney; Presence excludes lower urinary tract as source
o Acute pyelonephritis; glomerulonephritis; lupus nephritis
o Bigger and paler than RBC casts, can see cytoplasm contents

72
Q

• What are renal tubular epithelial (RTE) cell casts?

A

o Found in dzs that damage tubule epithelium: nephrosis, amyloidosis, heavy metal or other poisoning, glomerulonephritis, acute tubular necrosis, pyelonephritis
o Looks similar to WBC cast
o You can always get casts a mix of diff cell types, more often than not

73
Q

• What are other types of casts?

A

o Granular- degenerated cellular casts (stuck in tubule long time, eventually breaks down, looks granular, can’t see cells)
o Waxy or “broad”- degenerated granular casts, chronic destructive renal dz; “renal failure cast”; casts get wider as get older
o Fatty- chronic renal dz, nephrosis, nephrotic syndrome

74
Q

• What are crystals in urine?

A

o Not necessarily pathologic (dietary influences)
o Types depend on pH
o Can help dx metabolic dzs
o UTIs caused by proteus assoc with triple phosphate crystals (geometric)