Hematology - Amanda Flashcards
1
Q
components of whole blood (and their %) are:
A
- Plasma 55%
- Erythrocytes 45%
- <1% “buffy coat”: leukocytes and PLTs
2
Q
What are we actually looking at for HCT?
A
erythrocytes
3
Q
Of the plasma, what are the elements of it? (%)
A
- Water 91%
- Proteins 7%
- other solutes 2%
4
Q
Examples of plasma proteins (3)
A
- Albumins (58%)
- globulins (38%)
- Fibrinogen (4%)
5
Q
Globulins role:
A
is in defense
6
Q
Fibrinogen role:
A
clotting protein
7
Q
What elements make up the HCT?
A
Erythrocytes (~5million!!)
PLTs
Leukocytes
8
Q
Name the different Leukoctyes: (5)
A
- Neutrophils
- Lymphocytes
- Monocytes
- Eosinophils
- Basophils
9
Q
Most common leukocyte is
A
neutrophil (60-70%)
10
Q
[blood] serum = (equation)
A
plasma - clotting factors
11
Q
normal HCT for men
A
40-45%
12
Q
normal HCT for females
A
35-40%
13
Q
rates of RBC production in the bone do what with age?
A
decline in many bones
14
Q
In early age, what bones are producing RBC’s?
A
all bones do
15
Q
feature of immature cells:
A
they’re BIG
16
Q
immature cells are found in
A
the bone marrow
17
Q
mature cells are found in
A
the blood stream
18
Q
immature cells are called
A
blast cells
-proerythroblast, lyphoblast, myeloblast, monoblast, megakaryoblast
19
Q
a baby RBC is:
A
reticulocyte
20
Q
Mature RBC’s are
A
erythrocytes
21
Q
pluripotent hematopoietic stem cell (PHSC) is
A
what multiple forms of different blood cells are formed from in the bone marrow
22
Q
3 functions of RBCs
A
- transport hgb
- transport O and CO2
- Acid-base buffer - pH control
23
Q
Normal MCV =
A
90-95 mm^3
24
Q
Erythrocytes/RBCs are missing what?
A
nucleus
25
w/o a nucleus, what can't a RBC do?
replicate / divide
26
life span of RBC
120 days
27
Daily production and destruction rate of RBC:
1% produced/destroyed each day
**2 million/sec
28
what enzyme is important for CO2 transport in the plasma
carbonic anhydrase
29
Production of RBC intrauterine is in
liver
spleen
lymph node
30
production of RBC <5yo in
all bones
31
production of RBC > 20 years
vertebra, sternum, ribs, and hipbone
32
erythropoietin is released from:
it does what?
kidneys (90%) and liver (10%)
-regulates RBC production/ stimulates in bone marrow
33
what stimulates release of erythropoietin?
hypoxemia
34
what vitamins are required for rbc maturation?
B12 and folic acid
35
macrophages destroy old rbc's by ____.
phagocytosis
36
HB is excreted as ___.
Iron is released to ___.
- bilirubin
| - transferrin
37
low levels of b12 and folic acid will show what in labs
more immature rbc's
38
Hypoxia stimulates rbc production... name two other examples/causes of stimulation
- high alt
| - copd
39
negative feedback control in RBC production does what
inhibits the stimulation release of erythropoietin
40
when rbc production is stimulated, production increases within how many hours?
when will we see an increase in the count?
- 24hrs
| - 5 days
41
disease processes associated with reduced erythropoeitin response (anemia):
- infections
- AIDS
- Hypothyroidism
- Renal Disease
42
body stores Iron in:
- Hb (65%)
- liver
- spleen
- bone marrow
43
intracellular iron is stored in protein -iron complexes such as
Ferritin and hemosiderin
**stores are also low in anemia
44
circulating iron is loosely bound to the transport protein
Transferrin
45
the "graveyard" of RBCs is the
spleen
*Old RBC's get rigid/less flexible and get TRAPPED in the spleen
46
macrophages engulf dying erythrocytes and
separate Heme and globin. Iron is salvaged for reuse
47
heme is degraded to
bilirubin
48
the liver secretes bilirubin into the intestines as bile and metabolize it into
urobilinogen
49
degraded pigment leaves the body in the feces is called
stercobilin
50
Globin is metabolized into
amino acids --> released into circulation
51
Hb released into the blood stream is captured by
haptoglobin and phagocytized by macrophages
52
Fe++
iron
"2 for us"
53
Fe+++
ferrous form
54
Heme (biliverdin) is
free bilirubin
- insoluble in water
- toxic to CNS
- transported by albumin
55
Free bilirubin is removed from the blood by
the liver
| -conjugated w/glucuronate and excreted in bile (not urine)
56
in the intestine, bacteria convert conjugated bilirubin to
urobilinogen (soluble)
57
some urobilinogen is REABSORBED into the blood and excreted as
- urobilin in the urine
| - stercobilin in feces
58
daily iron need
7mg/1000cal
| ~10% is absorbed
59
iron absorption is INHIBITED by
- oxalates (spinach, rubarb)
- phosphates (vegetables)
- tannate (tea)
- carbonates
- clay
60
major site of iron absorption
duodenum and proximal jejunum
| *HCl promotes absorption
61
average daily loss for man and woman
men: 1mg/day
women: additional 14mg/period lost
62
what process puts a higher demand on iron requirments?
pregnancy
63
Transferrin has how many iron binding sites
2
64
transferrin is responsible for
the pink color of plasma
65
TIBC =
total iron binding capacity = 300 ug/ml
** this is less with disease
66
ferritin accounts for how much total "strorage iron"
30%
67
what is Hemosiderin? cause
Very high iron level
-can lead to multi-organ failure
- typically r/o excessive blood transfusion
68
hemoglobin consists of glboin (2 alpha, 2 beta polypeptide chains) and four heme groups. when all four heme groups are filled with iron, this =
100% saturated
69
heme moiety-iron containing
porphyrin
70
Fe++ binds to
O2
71
Adult HbA =
Alpha2 and beta 2
72
HbF has an increased affinity for O2. HbA facilitates the O2 movement from mother to fetus and:
a LEFT shift
more O2 loading
73
methemoglobin is
iron in the ferric form Fe+++
-presentation seen as gray-blue discoloration in pts fingernails
74
methemoglobin does not bind to O2 as readily, but has an increased afffinity for
CN-
cyanide
*resulting in defective O2 transpot = low o2 sat
75
Causes of MetHgb:
- Nitrates
- Benzocaine
- Prilocaine metabolites
76
tx for methgb:
iv methylene blue
*converts ferric to ferrous form
77
Causes for cyanide poisoning
- Nitroprusside (CN ions released)
- bitter almond oil
- KCN (potassium cn)
- wild cherry syrup
78
s/s of CN poisoning
Tachy, hypotension, coma, acidosis, Increased venous O2,
--leads to rapid death
79
Tx CN poisioning
1. Sodium Nitrite and Amyl Nitrites to oxidize Hb to metHb (inducing metHb)
2. the metHb binds to cyanide allowing cytochrome oxidase enzyme to go free and function (do its job)
3. Use Thiosulfate to bind to cyanide - forming thiocynate which is excreted by kidneys
80
Porphyrias are conditions of
(congenital) defective heme synthesis that leads to :
1. accumulation and
2. increase excretion of heme precursors (porphyrins)
81
What environment element, if exposed, can cause similar condition (porphyria)
Lead
82
Contraindications with porphyrias
- Benzo's
- barbiturates
*should avoid these in any pt w/porphyrias
83
Presenting Symptoms:
microcytic anemia, MR, HA, memory loss, demylination in adults
Condition and Affected enzyme:
- Lead Poisoning
| - Ferrochelatase
84
Presenting Symptoms:
Painful abd, pink urine, Polyneuropathy, Psychological disturbance, Precipitated by durgs
Condition and Affected enzyme:
- Acute Intermittent Porphyria
| - Uroporphyrinogen-I-synthase
85
Presenting Symptoms:
Blister, photosensitivity. most common porphyria
Condition and Affected enzyme:
- Porphyria Cutanea tarda
| - Uroporphyinogen decarboxylase
86
most common porphyria
Porphyria Cutanea tarda
87
porphyria's essentially mean...
defective heme
88
5 types of anemias
1. Microcytic hypochromic anemia
2. Macrocytic Anemia
3. Hemolytic Anemia
4. Hemoglobinopathies
5. Aplastic Anemia
89
presenting Hct and Hgb < what in male vs female
Male: < 12.5 g/dl and 40%
Women: <11.5 g/dl and 36%
90
compensatory mechanisms to increase O2 delivery:
Increases in:
- CO
- 2,3 DPG
- p50
- Plasma Vol
Decrease in: blood viscosity (to improve bf)
91
anemia shift O2-hb cure to
the RIGHT
92
Definitive Diagnostic for anemia:
Blood Smear
-also get h/h, reti index, and RBC indices
93
In a normal blood smear, the seen WBC's have how many lobes
3
| <6 is not abn
94
Describe smear image of Microcytic Hypochromic cells
-small, pale cells, central white, almost colorless
95
Microcytic Hypochromic anemia is known as
iron def. anemia
96
Describe smear image of Macrocytic cells
Big cells , central white is almost diminished
- WBC is even bigger and have 6 lobes
(6+ is abn)
97
Describe smear image of Sickle Cell anemia cells
you'll see sickled cells
98
MCV in MICROCYTIC HYPOCHROMIC Anemia
<80 fl
99
tx for MICROCYTIC HYPOCHROMIC Anemia
if iron deficient:
- iron and rbc's
chronic anemia: (RA, lupus, ca)
- tx underlying cause
100
classic features of MICROCYTIC HYPOCHROMIC Anemia - iron deficient
- iron deficient anemia
- MCV < 80fl
- HIGH TIBC (Increased Ferritin, Increased Serum Iron
101
classic features of MICROCYTIC HYPOCHROMIC Anemia - chronic
Low TIBC (Increased Ferritin, Increased Serum Iron
102
Iron deficiency anemia
| Causes
- Almost always due to blood loss e.g. menstrual loss, GI loss
- Dietary deficiency
- Breast feeding ( decreased iron) ,
- pregnancy ( increased requirement)
- Defective absorption of iron
- decreased Heme synthesis
103
“small pale cells”
Hypochromic microcytic
104
male pts with iron def anemia, what do we assume?
- bleeding
- always colon cancer until r/o.
"he has it until we prove he doesn't"
105
Impaired utilization of iron and diminished response to erythropoietin
Anemia of chronic disease
106
Low TIBC, Increased Ferritin, decreased serum iron
chronic anemia
107
clinical features of iron deficiency anemia
```
Pallor Hb < 7g/dl)
Fatigue, generalize weakness
Dyspnea on exertion
Orthostatic lightheadedness
Hypotension if acute
```
108
Defective DNA synthesis due to folate or Vit B12 deficiency= (type of anemia)
megaloblastic anemia
109
Macrocytic anemia (aka)
megaloblastic anemia
110
reasons for megaloblastic anemia
- B12 deficiency
- Lack of Intrinsic factor
- folate deficiency
111
how and where is b12 absorbed
- b12 binds to IF
- absorbs in the terminal ileum
- stored in liver for 3-4 yrs
112
in terminal ileitis like crohn's disease, what kind of anemia do you likely have?
megloblastic anemia/ b12 deficiency
113
most common cause of B12 deficiency
pernicious anemia
| - lack of IF
114
s/s of this are similar to b12 deficiency w/o the NEUROLOGICAL SYMPTOMS
folate deficiency anemia (macrocytic anemia)
115
MCV of Macrocytic anemia
>100 fL
116
Clinical findings of B12 deficiency
- Neurological– paresthesia ,ataxia due to demyelination
| - Cerebral and psychiatric manifestation; UMN lesions signs, dementia, incontinence, impotence
117
Clinical findings
| Megaloblastic anemia
-RBCs– large , oval, fragile
| Hypersegmented polys : 6+ lobes “hallmark”
118
“hallmark” finding in megaloblastic anemia
6+ lobes of the wbc; hypersegmented polys
** recognize in picture**exam
119
what is the purpose of a Schilling test
– if corrects with IF --> pernicious anemia
- if corrects with antibiotics --> bacterial overgrowth
120
tx of megaloblastic anemia
- Combination of folic acid and Vit B12 for life
- Folic acid alone should NEVER be given in macrocytic anemia because it will fix the anemia but exaggerate neurological signs and symptoms.
121
how to perform a schilling test
- Intramuscular “flushing dose” of Vit B12 (unlabelled) is given to saturate binding sites
- Oral radiolabelled VitB12 is given
- % of radiolabelled VitB12 is measure in 24-hr urine
- Low urinary excretion (<5%) of labeled Vit B12 supports absorption defect of Vit B12 (+ve Test)
- Repeat the test with intrinsic factor (IF)
- High urinary excretion of labeled Vit B12 shows that absence of IF is the cause. [Because Vit B12 needs IF for its absorption]
122
Hemolytic anemia is the result of:
RBC membrane defects
- Hereditary spherocytosis
- Hereditary elliptocytosis
- Acanthocytosis (change in shape “spiny” RBCs)
- Stomatocytosis (deformed RBCs)
123
Spectrin's role
protein that keeps RBCs in shape
124
Spectrin defect
hereditary spherocytosis form of hemolytic anemia
125
RBC enzymatic deficiency
Glucose-6-phosphate dehydrogenase (G6PD) deficiency
126
Most common enzyme deficiency disorder:
who and how get it?
G6PD deficiency
- 1% of African American,
- X-linked.
- Reduce glutathione level
127
in patients with a G6PD deficiency, what medications should be avoided?
***Avoid nitroprusside and prilocaine --> cyanide toxicity
Also avoid sulfa, aspirin, penicillin, streptomycin, quinidine, methylene blue --> hemolytic crisis
128
Mismatched blood transfusion
Autoimmune hemolytic anemia
result in what form of anemia
hemolytic anemia
129
Direct Coomb’s test is used to distinguish between
immune vs. nonimmune mediated RBC hemolysis
130
hereditary spherocytosis looks like on blood smear:
small spherical RBCs with lack of central pallor)
| -- dark purple RBC
131
Hemoglobinopathies include
sickle cell anemia
132
sickle cell anemia is a result of:
Valine substitutes with glutamine in the 6th position of the beta-hemoglobin chain (HbS)
Distorted RBCs shape like sickle; short life span
133
sickling of the RBC's greatest complication
ischemia!
| thrombosis, cvas and infections
134
"autosplenectomy"
necrosis of spleen
135
what vaccination's must pts with sickle cell be sure to get?
**exam
- PNA
- salmonella
**exam**
136
Prevention of sickle cell crisis:
- Hydration
- O2
- Low PO2 triggers sickling (30-40 mmHg)
- Maintain high cardiac output
- Avoid stasis
137
Preop considerations for sickle cell:
```
Infection control
Hydration
Crit 30-40%
HbA ~ 50%
Partial exchange transfusion
**Avoid hypo or hyperthermia, hypoxemia or hypovolemia
```
138
Treatment for sickle cell
Hydroxyurea (increased HbF) , BMT
| HbF interferes formation of HbS
139
Pancytopenia characterized by
severe anemia,
neutropenia,
thrombocytopenia
caused by failure or destruction of myeloid (bone marrow) stem cells – “DRY TAP”
140
primary and secondary aplastic anemia
Primary
- Idiopathic
Secondary
- Drugs- chemotherapy (MCC), antibiotics, antidepressants. ethanol
- Chemical- benzene
- Radiation, X-ray
- Malignancy
141
treatment of aplastic anemia
Withdrawal of offending agent, BMT
142
thalassemia types
Alpha-thelassemia
-- Underproduction of -globulin chain
Beta-thelassemia
- - beta-minor vs. Beta-major thalassemia
- -Common in Mediterranean population (thalassa=sea)
- - Underproduction of beta-globulin chain
- -Compensatory rise in HbF
- -Result severe anemia, hepatosplenomegaly
143
treatment of thalassemia
- Packed RBC transfusions
| - Folic acid
