CBC Flashcards
1
Q
anticoagulant:
EDTA optimal conc
A
1.5mg per mL of blood
2
Q
anticoagulant:
how many hours is blood valid in EDTA tube?
A
4 hours - room temp
24 hours - refrigerated (wbc, hct, plt)
3
Q
anticoagulant of choice for platelet count
A
EDTA
4
Q
why EDTA is preferred for platelet count?
A
EDTA prevents platelet aggregation
5
Q
t or f. ESR should be set up within 4 hours of collection (room temp) or 6 hours (refrigerated)
A
false, 2 hours.
6
Q
t or f. blood smear can be made from EDTA tube as long as they are made within 4 hours of blood collection.
A
false, 2 hours.
7
Q
mean platelet volume normal range
A
6.8 to 10.2 fl
8
Q
t or f. EDTA causes swelling of platelets (50% higher) during the first hour.
A
false
20% higher
9
Q
insufficient EDTA
cause:
effect:
A
- over-filled tube
- presence of clots
10
Q
EDTA color: inversions: lab section: optimal conc: action:
A
- lavender top
- 8 inversions
- hematology
- 1.5 mg per mL of blood
- chelation of calcium
11
Q
EDTA color: inversions: lab section: optimal conc: action:
A
- lavender top
- 8 inversions
- hematology
- 1.5 mg per mL of blood
- chelation of calcium
12
Q
CBC other name
A
hemogram
13
Q
RBC parameters (6)
A
RBC ct Hgb Hct RBC indices RDW Retic ct
14
Q
PLT parameters (2)
A
PLT ct
MPV
15
Q
heparin color: inversions: lab section: optimal conc: action:
A
- green top
- 8 inversions
- chemistry, OFT, and ABG
- 15-20 units per mL of blood
- binds antithrombin (inhibits thrombin and factor Xa)
16
Q
3 formulations of heparin
A
- ammonium heparin
- sodium heparin
- lithium heparin
17
Q
3.2% sodium citrate color: inversions: lab section: optimal conc: action:
A
- light blue top
- 3-4 inversions
- coagulation studies
- AC:blood ratio = 1:9
- chelation of calcium
18
Q
reference method for Hgb determination
A
cyanmethemoglobin (HiCN) method
19
Q
reagent used in HiCN method and its component
A
Drabkin’s reagent
- potassium ferricyanide
- potassium cyanide
20
Q
HiCN principle
A
Hgb + KFeCN > methemoglobin + KCN > cyanmethemoglobin
21
Q
potassium ferricyanide use:
potassium cyanide use:
A
- converts hemoglobin to methemoglobin
- provides cyanide ions
22
Q
HiCN is measured at what nm?
A
540 nm
23
Q
all types of Hgb may be measured in HiCN except:
A
sulfhemoglobin
24
Q
how many minutes should we allow for the full conversion of hemoglobin into cyanmethoglobin?
A
10 minutes at room temp
25
```
falsely elevated Hgb:
-high WBC and PLT ct
WBC > 20 000/uL
PLT > 700 000/uL
correction:
```
- centrifuge
| - measure Hgb at supernatant
26
falsely elevated Hgb:
-lipemia
correction:
- add 0.01 mL of the patient's plasma to 5 mL of the cyanmethemoglobin
- use this as reagent blank
27
falsely elevated Hgb:
| -Hgb S and Hgb C
- make a 1:2 dilution with dH2O
| - multiply the results from the standard curve by 2
28
falsely elevated Hgb:
| -abnormal globulins
-add 0.1 g of K2CO3 to the cyanmethemoglobin reagent
29
t or f. cyanmethemoglobin reagent is not sensitive to light.
false. it is photosensitive
30
handheld system that can measure Hgb conc
HemoCue
31
Hgb normal range
| children:
12-15 g/dL
32
Hgb normal range
| adult female:
12-15 g/dL
33
Hgb normal range
| adult male:
14-18 g/dL
34
another name for Hgb
respiratory pigment
35
1 g of Hgb can carry ___ mL of O2
1.34 mL
36
1 g of Hgb can carry ___ mg of iron
3.47
37
complete component of adult Hgb molecule (4)
- globin
- protoporphyrin IX (PPIX)
- ferrous iron
- 2,3-BPG molecule
38
examples of globin chains and their number of amino acids (6)
alpha - 141 aa
zeta - 141 aa
beta - 146 aa
epsilon - 146 aa
delta - 146 aa
gamma - 146 aa
39
PPIX + ferrous iron =
heme
40
transcribe 2,3-BPG
2,3-bisphosphoglycerate
41
where is 2,3-BPG produced?
Rapoport-Luebering Shunt of RBCs
42
transient resident of hemoglobin
2,3-BPG
43
purpose of 2,3-BPG
transfers oxygen to tissues
44
primary functions of Hgb (3)
- delivery of oxygen to the tissues
- carry CO2 away to the lungs
- binding, inactivation, and transport of NO
45
Hct normal range
| newborn
53-65%
46
Hct normal range
| adult females
35-49%
47
Hct normal range
| adult males
40-54%
48
layers of centrifugated blood
1. fatty layer
2. plasma layer
3. buffy coat
4. packed RBC
49
microhematocrit tube
length:
inner bore:
volume:
- 75 mm long
- 1.2 mm
- 0.05 mL of blood
50
red band microhct tube
AC:
used for:
- heparin
| - collection for non-AC blood
51
blue band microhct tube
AC:
used for:
- no anticoagulant
| - collection for AC blood (EDTA)
52
```
microhct procedure
blood volume to collect:
which side should blood enter:
which side should we seal:
sealing clay length:
microcentrifuge rpm and time:
margin of error:
```
- 2/3
- opposite side of color
- seal at side of color
- 4 to 6 mm
- 10,000 rpm, 5 minutes
- +/- 0.02 L/L
53
falsely increased hct: (4)
- dehydration
- hemoconcentration
- insufficient centrifugation
- buffy coat was read
54
falsely decreased hct: (4)
- hemolysis
- improper sealing
- increased AC concentration
- introduction of excess interstitial fluid
55
purpose of rule of three in CBC
used for checking validity of test results
56
limitation of rule of three in CBC
works only on normocytic, normochromic specimens
57
rule of three
Hgb formula:
Hct formula:
3 x RBC ct = Hgb
| 3 x Hgb = Hct
58
average volume of an individual RBC
mean cell volume (MCV)
59
MCV formula
(HCT/RBC ct) x 10
60
MCV normal range
80-100 fl
61
average weight or amount of Hgb in an individual RBC
mean cell hemoglobin (MCH)
62
MCH formula
(Hgb/RBC ct) x 10
63
MCH normal range
26-32 pg
64
what is not used in the classification of anemia?
MCH
65
normal MCV, high MCH
what does this indicate?
falsely increased Hgb (technical error);
| MCV and MCH should be paralllel
66
mean concentration of hemoglobin in the average RBC
mean cell hemoglobin concentration (MCHC)
67
MCHC formula
(Hgb/HCT) X 100
68
MCHC normal range
31-37 g/dL
69
hereditary spherocytosis MCHC
35-38 g/dL
70
neutrophils
```
nucleus:
cytoplasm:
size:
progenitor:
major stimulatory cytokine:
```
- 3-5 lobes
- pink w/ violet granules
- 9-15 um
- granulocyte-monocyte progenitor
- granulocyte colony-stimulating factor
71
3 major functions of neutrophils
- phagocytosis
- generation of neutrophil extracellular traps
- secretory function (transcobalamin I)
72
eosinophils
```
nucleus:
cytoplasm:
size:
increases in:
primary granules:
secondary granules:
```
- 2 lobes
- bright orange granules
- 9-15 um
- allergies and helminthic infections
- charcot-leyden crystal protein
- major basic protein (core)
73
which granules of eosinophil is responsible for neutralizing helminths?
major basic protein
74
basophils
```
nucleus:
cytoplasm:
size:
progenitor:
major stimulatory cytokine:
```
- difficult to observe
- densely stained w/ purple-black granules
- 10-16 um
75
monocytes
nucleus:
cytoplasm:
size:
- horseshoe-shaped, stringy chromatin, nuclear vacuoles may be present
- ground-glass appearance (azure dust), blebs may be observed
- 14-20 um
76
lymphocyte
nucleus:
cytoplasm:
size:
- round, deep-purple
- scanty, sky-blue
- 7-10 um
77
4 types of WBC diff count
- 100 cell diff
- 200 cell diff
- 300 or 400 cell diff
- 50 cell diff
78
routinely performed diff count
100 cell diff
79
performed when the WBC ct is >40 000/uL
200 cell diff
80
other cases that may need 200 cell diff (4)
>10% eosinophils
>2% basophils
>11% monocytes
more lymphocytes than neutrophils (except in children)
81
performed when the WBC ct is >100 000/uL
300 or 400 cell diff
82
performed when the WBC ct is 1 000/uL
50 cell diff
83
what smear is used for 50 cell diff?
buffy coat smear
84
gives the number of specific WBC type per 100 WBCs; not as informative and accurate
relative count
85
relative count % formula
(no of specific WBC type/100 WBCs counted) x 100
86
relative count normal range
```
N = 51-67%
L = 25-33%
M = 2-6%
E = 1-4%
B = 0-1%
```
87
gives the number of specific WBC type per uL; more informative and accurate
absolute count
88
absolute count % formula
relative count x WBC count
89
absolute count normal range
```
N = 1 600-7 260/uL
L = 960-4 400/uL
M = 180-880/uL
E = 45-440/uL
B = 45-110/uL
```
