L5: Urinalysis Flashcards
(111 cards)
1
Q
how to get a clean “catch”
A
clean nonfoaming disenfectant, allow to dry
discard first voided portion as it may contain urethral contaminants, collect midstream speciman
2
Q
Dark brown→ black urine
A
bile/bilirubin due to liver/bile disease
3
Q
turbidity causes
A
Crystal precipitation of amorphous material, bacteria, yeast, WBCs, RBCs, mucus, squamous epithelial cells, sperm prostatic fluid, lipids
4
Q
bile/bilirubin due to liver/bile diseases that can cause brown/black urine
A
alkaptonuria: lack of homogentisic acid oxidase
malignant melanoma: melanogen
5
Q
ash tray smell to urine
A
cigarrete smokers
6
Q
fruity smell to urine
A
ketone bodies
7
Q
putrid, foul smelling urine
A
bacteria of UTI
8
Q
Amino acid disorders that change urine smell
A
Phenylketonuria
Maple syrup urine disease
9
Q
Normal pH
A
4.5-8
10
Q
Urine pH reflects
A
serum pH
11
Q
acidic urine pH
A
4.5-5.5
12
Q
alkaline urine pH
A
6.-8.0
13
Q
Specific gravity
A
Concentration/weight of dissolved solutes
Ability of kidney to concentrate and dilute urine
14
Q
normal Specific gravity
A
1.003-1.035
15
Q
Isosthenuria
A
Fixed at 1.010→ kidney disease
→ same SG as initial plasma
16
Q
normal urine volume
A
500CC-2000CC/24 hours
17
Q
oliguria
A
<500 CC/24 hours
18
Q
anuria
A
<100 CC/24 hours
19
Q
polyuria
A
Excessive amounts, dilute, SG=1.0-1.002
20
Q
When does glucose appear in the urine
A
plasma glucose >150-180 mg/dL exceed renal threshold
21
Q
false negatives for glucose
A
ascorbic acid, aspirin
22
Q
Ketones are
A
Products of incomplete fat metabolism when carbohydrate stores are diminished
23
Q
When are ketones present
A
acidosis: DKA, rapid weight loss, fasting, starvation, pregnancy
24
Q
Proteins are mostly
A
albumin
reflect renal endothelial function
25
Elevated proteins indicate
Early sign of kidney disease
26
proteins are overestimated in
concentrated urine
27
proteins are underestimated in
dilute urine
28
proteins false positive due to
pyridium
29
can moderately increased albumin be detected by a urine dipstick?
No
| Must perform a special test
30
If a patient has persistently positive proteins on dipstick, the next step is to
quantify albumin:
abumin: creatinine ration
24 hour urine sample
31
high risk patients to screen for moderately increased albumin
DM
HTN
CVD
32
causes of blood in urine
hemoglobin or myoglobin
| have to centrifuge to determine which
33
false negatives when hematuria is present
ascorbic acids
34
hematuria testing sensitivity
5-10 RBC/ .05-.3 mg/DL of hemoglobin
35
nitrite is produced by
enterobacteriaceae that reduce nitrates→ nitrite
36
nitrite indicates
UTI
37
false negatives for nitrite
urine in bladder < 4 hours
| different bacteria don’t have enzymes
38
leukocyte esterase
Released by lysed neutrophils and macrophages
39
leukocyte esterase + nitrate both positive
increased sensitivity for UTI
40
false positives for leukocyte esterase
vaginal contamination, trichomonas
41
bilirubine and urobilinogen
Used in conjunction to determine pathology
| Both normally negative
42
bilirubin turns urine
brown
43
Hemolytic disease findings
(-) bilirubin
| Increased urobilinogen
44
Hepatic disease findings
(+/-) bilirubin
| Increased urobilinogen
45
Biliary obstruction findings
(+) bilirubin
| normal urobilinogen
46
RBCs in urine appear
refractile discs, shriveled
47
normal RBCs
0-3 RBC/HPF
48
cause red urine that isn't hematuria
beeturia, phenazopyridine, porphyria, other
49
causes of >3 RBC/HPF:
```
Renal/lower urinary tract trauma
Kidney stones
Glomerular damage
Tumors
UTI
Acute tubular necrosis
Nephrotoxins
Vaginal bleeding
Cancer: kidney, bladder, prostate
Benign prostatic hypertrophy
```
50
If urine is red:
centrifuge it
51
Red sediment after centrifuging urine means
hematuria
52
Red supernatant after centrifuging urine
do a dipstick heme
53
a negative dipstick heme means
the red urine was a false positive
54
a positive dipstick heme means
myoglobin or hemoglobin: centrifuge blood sample and evaluate plasma color
55
clear centrifuged plasma color
myoglobinuria
56
red centrifuged plasma color
hemoglobinuria
57
WBCs appear
Lobed nuclei and refractile cytoplasmic granules
58
Normal WBCs
0-5 WBC/HPF
59
5-10 WBC/HPF
suspicious for UTI
60
>20 WBC/HPF
UTI
61
bacteria
0-4+/HPF
| May or may not be significant, depends on method of collection and how long it stands for
62
Renal tubular and transitional epithelial cells
Slough from tubule lining in small numbers normally
63
large numbers of renal tubular and transitional epithelial cells
tubular degeneration
64
Oval fat bodies definition and appearance
Degenerated tubular cells containing abundant lipoproteins
Appear refractile
Exhibit “maltese cross” under polarized light microscopy
65
Presence of oval bodies
nephrotic syndromes
66
Squamous epithelial cells
Large polygonal squamous epithelial cells with small nuclei normally present in small numbers
67
large numbers of squamous epithelial cells
contaminated by skin or external urethra
68
casts are formed
only in the distal convoluted tubule or collecting duct
69
RBC/WBC are measured
Number per high power field (hpf)
70
casts are measured
Number per low power field (lpf)
71
Hyaline casts
Very pale, slightly refractile. Composed of mucoprotein tamm-horsfall protein secreted by tubule. normal.
72
Red cell casts indicate
Glomerular or renal tubular injury
| GLOMERULONEPHRITIS
73
White cell casts indicate
Acute pyelonephritis, glomerulonephritis
74
Renal tubular cast cells
Injury to tubular epithelium: acute tubular necrosis
75
granular casts
Cellular casts which remain in tubules break down so that cells forming them degenerate into granular disease
coarse→ finely granular→ waxy cast
76
granular casts indicate
abnormality, but not specific
77
uric acid crystals indicate
Acidic urine, form secondary to hyperuricema
78
Crystine crystals indicate
Cystinuria: rare genetic cause of kidney stones
79
struvite crystals indicate
Crystalluria: secondary to infection by urease producing bacteria in alkaline urine
80
Calcium oxalate crystals
Form independent of pH, cause kidney stones, 2 forms: monohydrate/dihydrate
81
Urine culture indicates UTI when
>100,000 colonies/ml
| UTI still possible with fewer colonies esp if sx dysuria, frequencia, pyuria
82
major intracellular cation
serum potassium
83
potassium is excreted by
kidneys, controlled by distal nephron
84
who not to administer K+ to
impaired kidney function
85
Effects of aldosterone
1. Increases renal sodium reabsorption
| 2. Increases renal potassium excretion
86
Hyperkalemia
>5.0MEQ, >6.0--6.5 dangerous
87
Hyperkalemia presentation
Serum potassium >7
Ascending muscle weakness→ flaccid paralysis
Conduction abnormalities and arrhythmias
88
Mild hyerkalemia ECG
5.5-6.5 mEq/L peaked T waves
89
Moderate hyperkalemia ECG
6.5-8.0 mEq/L prolonged QRS complex
90
Severe hyperkalemia ECG
Vfib, asystole
91
Pseudohyperkalemia
due to hemolysis at venipuncture site→ repeat k+
92
Causes of hyperkalemia due to inadequate excretion of K+
1. Renal failure → check BUN/Creatinine
2. Medications:
aldosterone antagonist
K+ sparing diuretics
ACEI/ARBS
```
3. Hypoaldosteronism:
Addison’s disease (adrenal insufficiency)
Congenital Adrenal hyperplasia
NSAIDS
Renal tubular dysfunction
```
93
Causes of hyperkalemia due to Redistribution of K+: ICF→ ECF
1. Tissue damage (rhabdomyolysis)
2. Acidosis
3. Decreased insulin
94
.1 decrease in pH causes
| such as acidosis
.5-1.0 increased K+
95
causes of hyperkalemia due to excessive administration of K+
Rx K+ supplements
K+ containing salt substitutes, exp. In patient with some renal impairment
96
To rapidly correct hyperkalemia
Calcium chloride, IV (antagonizes K+)
Shift K+ from ECF to ICF
Sodium bicarb IV→ increases pH
Insulin + D50W → insulin shifts K+ into cells, D50W prevents hypoglycemia
97
to slowly correct hyperkalemia
Loop or thiazide diuretics
→ beware in decreased renal function
Hemodialysis if: kidney failure, very severe, refractory
98
when to send a hyperkalemic patient to the ER/ICU for monitoring
K+ >6.5
99
treat the underlying cause of hyperkalemia:
Stop meds: K+ sparing diuretic, ACEIs, ARBs, K+ supplements
Addison’s→ mineralocorticoid replacement
100
Hypokalemia is defined as
<3.5 mEq/L, <3→ dangerous
101
Hypokalemia presentation
Ascending muscle weakness/paralysis
Respiratory failure
Muscle cramping
Rhabdomyolysis
GI: N/V/A→ vomiting causes further hypokalemia
EKG: arrhythmias, U waves, flattened T waves, ST depression
102
To rapidly correct hypokalemia
1. Cardiac monitor
2. IV potassium chloride (KCl)
3. Check K+ every 2-4 hours
103
To slowly correct hypokalemia
orally
104
When correcting hypokalemia, be sure to
Check for hypomagnesemia: low K+ difficult to correct if not also corrected
105
Inadequate intake of K+ hypokalemia
usually in a patient who takes thiazide/loop diuretic→ use supplements/K+ rich foods to prevent
106
GI tract loss of K+ hypokalemia
Upper GI: vomiting, NG suction
→ metabolic alkalosis→ promotes K+ loss
Lower GI: diarrhea
→ metabolic acidosis
107
____ promotes K+ loss
metabolic alkalosis
108
Renal losses of K+ hypokalemia
Diuretics
Bicarb excretion
Mineralocorticoid excess:
Hyperaldosteronism
Cushing's syndrome
109
Redistribution of K+ from ECF to ICF hypokalemia
Metabolic alkalosis
Insulin administration
B adrenergic agonists
→ induce uptake of K+
→ promote insulin secretion
Hypokalemic periodic paralysis
110
.1 increase in pH causes
| such as alkalosis
K+ decrease by .5-1.0 mEq/L
111
pH and K+ have a _____ relationship
inverse
