exam 4- cbc Flashcards
1
Q
When to order a CBC
A
– Screening for anemia
– Suspect hematological disorder
– Toxic child
– Caution: well visit, well child with negative history
• Road to CBC Hell
• Well child with mild viral illness has transient abnormalities
2
Q
How 1To Approach the CBC
A
evaluate RBC line
evaluate WBC line
Evaluate platelets
Look at smear (cell morph)
3
Q
Normocytic RBC
A
rbc size is normal but not enough of them (anemia)
4
Q
Microcytic
A
RBC size is smaller than normal
5
Q
Macrocytic
A
RBC size is larger than normal
6
Q
MCV
A
Mean corpsucle volume
avg volume of red cells
7
Q
RDW
A
Red cell distribution width
Coefficient of ariation of RBC volume distribution
8
Q
3 important questions for red cell line
A
1) is child anemic
2) what kind of anemia does pt have? micro/normo/macro
3) if it is microscopic anemia, do one of the following indices
9
Q
Mentzer Index
A
RBC/MCV:
> 13: iron def.
10
Q
Rule of 3s
A
Measured Hgb calc should be 3x RBC
calculated HCT is 3x HgB
11
Q
Eleven Plus 1 point rule
A
11= 00.1 x (age in year) is lower limit of normal (3rd percentile) for hgb
12
Q
normocytic
A
RBC size normal but not enough of them
13
Q
Microcytic
A
RBC size is smaller than normal
14
Q
macrocytic
A
RBC size is larger than normal
15
Q
seventy plus 1 rule
A
70 + 1 x age years is lower limit of normal for MCV
16
Q
What values help you determine anemia?
A
– RDW (Red Blood cell distribution width)
– MCV (Mean corpuscle volume)
• What is low of normal?
• LLNL (MCV) = Age (yrs + 70)
– Only use once child is 2 years and up to 10
• After 10 values for adolescent are the
same.
17
Q
RDW
A
• Red Cell Distribution Width (RDW)
Coefficient of variation of the red cell volume
histagram distribution, i. e how much does the red
cell vary
– Very helpful in diagnosis of microcytosis
– RDW Normals
• In thalassemia minor may be 1 or 2 points over the
upper normal
• However in iron deficiency, frequently very elevated
ranging from 14-25
18
Q
Causes of Microcytic anemia
A
• Most Common: – Iron Deficiency and Thalassemia • Less Common: – Hemoglobin C disease, Hemoglobin D disease, anemia of inflammation – Hereditary pyropoikilocytosis (Lead Poisoning Rare – SideroblasCc anemia – Copper deficiency – Pyridoxine deficiency
19
Q
Causes of Iron Deficiency- dec absorption
A
Achlorhydria (producCon of gastric acid in the stomach is absent or low) Celiac disease Competing metal Fe deficiency Clay starch
20
Q
increased losses
A
GI GU Lung (pulm emosiderosis) joints facticious pregnancy lbood donation newborn exchange iatrogenic
21
Q
physio anemia in infancy
A
• Term Infant: Anemia in the first 2 to 3 months of life – physiologic anemia of infancy – not due to iron deficiency – Does not respond to iron therapy. • Preterm infants – appears at 1 to 2 months of age and is oten more severe.
22
Q
Normochromic anemias
A
Normochromic – Hereditary Spherocytosis – Hereditary Elliptocytosis – G6PD deficiency – Aplas)c anemia – Acute blood loss
23
Q
Macrocytic
A
– Vitamin B12 deficiency
– Folate deficiency
– Liver disease
– Lots of re)culocytes (due to hemolysis)
24
Q
Hemolytic Anemia
A
Sickle Cell disease
SC disease
Sickle Cell anemia
Sickle Thalassemia
25
White Cell line
• Suspected hematological disorder
• Evaluation of systemic disease or infection
• There is poor sensivity and specificity in
differenciating bacterial from viral infection
26
Factors that Interfere with the Normal
| WBC
```
AGE
– High neutrophil count
during the first several
days of life
• RACE
– African Americans have
lower WBC
• MINOR ILLNESS
– Widely variable
leukocyte count
– Neutropenia is not
uncommon during a viral
illness
• MEASUREMENT
METHOD
– Inherent error
```
27
Neutrophils fx
```
• First line of defense against bacterial
infection
– Major function:
• Phagocytosis
• Killing of microorganisms
–Enzymatic degradation
• At birth, decrease rapidly after birth within
first few days
• Infancy 20-30% of circulating WBC
• At age 5 years, equal neutrophil and
lymphocytes
• At puberty reaches 70% predominance
found in adult.
• Most abundant type of WBC
• Also known as Polymorphic Nuclear
Leukocyte
• Can see granules when stained
• Band is the immature Neutrophil
– Is an acute phase response
```
28
Neutropenia
```
• Add the neutrophils and Bands together
and multiply by the total WBC count
• What is neutrophil count if WBC is 4,500
with 2 Bands, and 10 neutrophils?
4,500
X .12
540 is the ANC
```
29
Classification of Neutropenia
```
In African Americans, 30% may have 1000
as normal
• Caucasian 8000 to 1500 normal
• Mild neutropenia: 1500-1000
• Moderate neutropenia: 1000-500
• Severe neutropenia:
```
30
Increased Neutrophils
– Physiologic – newborn, stress exercise
– Acute hemorrhage
– Acute bacterial infecCon
– Metabolic derangement—diabetes, acidosis, anoxia, burn,
seizures
– Drugs-epinephrine, steroids, lithium
– ConnecCve Cssue disease-JIA, Inflammatory Bowel disease
– Hematological disorders—Cancers, hemolysis splenectomy
31
WBC Eval
• Shit to the let is an increase in the number of
immature neutrophils—bands and metamyelocyte -
>5% bands
• Absolute lymphocytosis
– Physiologic 2 months to 4 year
– Increased in pertussis, TB, mononucleosis, CMV, measles,
adenovirus, syphilis
– Leukemia
• Lymphopenia
32
Lymphocytes:
```
Small mononuclear cells
• Coordinate/execute immune response via
release of inflammatory cytokines
• Bone marrow/Thymus are primary
lymphoid organs
• Secondary organ is spleen
```
33
Lymphocytosis
```
greater than 5000)
• Response to acute viral infections
• Chronic infections states such as TB,
Syphilis
• Also seen in ALL, Non Hodgkin's Lymphoma
```
34
Monocytes
1- 10 % of Leukocytes
• Large cells with blue-gray cytoplasm
• Reniform (kidney) shaped (i.e. folded nuclei)
• Efficient at digesCon of fungi and
microbacteria
• Return of Monocytes precedes return of
neutrophils by 1-2 days
35
Basophils
Less than 1% of Leukocytes
Contain large cytoplasmic granules and sulfated
acidic proteins
• Express IgE receptors
• Release Histamine when stimulated
• Above 150u/L= Basophilia which is associated
with hypersensitivity reactuions
36
Basophilia is associated w viral infections such as
varicella
flu
TB
37
Eosinophils
```
Bilobed nucleus with a red
granulocyte filled cytoplasm
• Fight parasites
• Control Allergic Reactions
• Eosinophilia usually seen when
Eosinophils make up more than 10% of
WBC’s
• Hypereosinophilia persisting for months can cause tissue damage
```
38
WBC Evaluation: Eosinophilia
500 cells per mm2
• N – Neoplasm
– Hodgkin's lymphoma (HL) is commonly associated with eosinophilia.
– Can also occur with carcinomas,
– Can be related to the breakdown of tumor cells
– Neoplastic cells have shown to produce factors that increase eosinophil producCon.
• A - Addison's disease
– Decreased cortisol levels lead to eosinophilia, because normally cortisol sequesters
eosinophils back into the lymph nodes.
• A - Allergy/asthma
– asthma, allergic rhinitis, and drug reacCons. (remember eosinophilic esophagiCs, too)
• C - Collagen vascular (autoimmune) disease
– Eosinophilia can be associated with rheumatoid arthritis, polyarteriCs nodosa, and ChurgStrauss
syndrome, among others.
• P- Parasites -Typically associated with parasites that invade tissues, like T. canis and
helminthes (worms).
39
Platelet line
```
• Life span is 8-9 days
• One third are
sequestered in the spleen
• Normal count 150,000 to
450,000
• Pseudothrombocytopenia
– ArCficially low count due
to clumping
– EDTA-dependent
anCbody against
platelets
– Suspect if the low
platelet count and
paCent is well
– Clumps of platelets on a
blood film from EDTA
specimen
```
40
platelet and bleeding categories
>100,000
– No bleeding
50,000 to 100,000
– Small amount of
bleeding may offer
ater trauma
20,000 to 50,000
• Mild cutaneous
bleeding
5,000 to 20,000
• Moderate cutaneous
and mucosal bleeding
41
Thrombocytosis
• ACUTE PHASE REACTANT
• DefiniCon: platelet count >450,000/mm3
• Causes:
– InfecCon, collagen disease malignancy, stress, post
operaCve, iron deficiency, following marrow recovery
or splenectomy or in myeloproliferaCve disease (rare)
• Manage by treaCng the underlying disease and/
or benign neglect unless over 1 million
repeatedly
42
RBC shapes
```
• Red blood cells
– Poikilocytosis (difference in shapes)
– Anisocytosis (difference in size)
– Hypochromia (pale cells)
– Microcytosis (small cells)
– membranopathies (spherocytosis,
ovalocytosis, elliptocytosis)
– Basophillic sCppling (aggregated ribosomal DNA and mitochondrial
fragments) seen in lead poisoning
and thalassemia
• Red Blood Cells
– Spherocytes
• ArCfactual, immune mediated hemolyCc anemia, spherocytosis
– Nucleated erythrocytes-hemolyCc
disease
– Schistocytes and helmet cells (microangiopathic hemolyCc anemia
– Speculated erythrocytes and
acanthoctyes (spur cells) in
pyruvate kinase deficiency
– Bite or blister cells in Glucose-6-
phosphate deficiency
– Target cells in iron deficiency, liver
disease hemoglobinopathies,
postsplenoectomy
– Howell jolly bodies splenic
hypofuncCon
```
43
WBCs
• White blood cells
– Atypical lymphocytes (predominately an acCvated T
lymphocytes responding to the B-cell infecCon)
– Metamyelocyte
– Blasts
– Dohle Bodies are bluish cytoplasmic inclusions in
neutrophils in bacterial infecCon, burns,
myelodysplasia, pregnancy
– Chediak Higashi syndrome: giant azurophilic granules
in lymphocytes
44
ThALASSEMIA
• Prevalent in America – estimates of 2 million carriers in US
• Likely related to protective effect of thalassemia traits on
malarial disease
• Hemoglobinopathy – dysfunction of the synthesis of
hemoglobin
– Thalassemias -deficit in the production of one of the hemoglobin
chains
• Iron Deficiency Anemia and Thalassemia Trait are the most
common causes of microcytic anemia in Peds.
45
Hemoglobin Production
```
• Four globin chains
• In utero fetal hemoglobin (HbF)
– Two alpha globin chains
– Two gamma globin chains
• Hemoglobin A (HbA)
– Two alpha chains
– Two beta chains
• Hemoglobin A2
– Two alpha chains
– Two delta chains
```
46
Normocytic Anemia
• Blood loss
• Decreased production of red blood cells
– Marrow failure
• Increased destruction of red blood cells
– Hemolytic Anemia
Distinguished by reculocyte count
Decreased in states of decreased production
Increased in destruction of red blood cells
47
Reticulocyte count- reasons to order
• Reasons for ordering this test
– Normocytic anemia
– Acute blood loss ( usually doubling of reticulocyte
count in first 24 hours)
– Problems with bone marrow
– Response to anemia therapy
– Infections
• Parvovirus causes aplasia of bone marrow since there
is no new RBC production for 7 days
– Drugs causing hemolysis or bone marrow aplasia
48
Reticulocyte Production Index
• Corrected reticulocyte count
• Raw reticulocyte count: misleading in anemic
patients.
– Reticulocyte count is a percentage
• Number of reticulocytes as a percentage of the number
of red blood cells.
• In anemia, the patient's red blood cells are
depleted, creating an erroneously elevated
reticulocyte count.
• Corrects the reticulocyte count for the
degree of anemia
– evaluates whether the bone marrow’s
response is appropriate.
• ReCculocyte producCon should increase in
response to any loss of red blood cells
• Increase within 2–3 days of a hemorrhage
• Will peak in 6–10
49
RPI=
RPI = reticulocyte count X the patient’s
hemoglobin/ normal hemoglobin X .5
• Or Reticulocyte Index = Hematocrit/normal Hematocrit
• RPI >3: increased production of reticulocytes
suggesting either hemolysis or blood loss
• RPI
50
Lab signs of Hemolysis
```
Increased lactate dehydrogenase
(LDH)
• Increased unconjugated bilirubin
• Decreased serum haptoglobin
• RBC indices demonstrate an increase
in MCHC.
```
51
Urine dipstick
```
– PH
– Blood
– Protein
– Leukocytes
– Nitrites
– Urobilogen
– Specific gravity
```
52
Urine Dipstick pH
Alkaline specimen is indicaCve of urinary tract infecCon but in late
aternoon, may have higher pH and be normal
• Normal range is 4.5-8.5
• Alkaline (>7.0)
– Bacteriuria
– renal failure
– presence of anCbioCcs, sodium bicarbonate
– diet high in vegetables, citrus fruits and dairy products
• Acidic (
53
Urine dipstick-blood
Extremely sensitve and so will detect clinically
insignificantly amounts of hemoglobin or
myoglobin
• Mild
• Moderate
• Severe
54
Urine Dipstick nitrate and leukocyte Esterase
Negative nitrite result
– does not rule out UTI (poor sensitivity)
• Positive result is likely true-positive
– high specificity—whatever the collection method.
• Leukocyte esterase
– More sensitive (positive in disease) indicator of
infection than nitrites are
– Better when tested using a catheterized, rather
than a bagged, specimen.
• Negative nitrite result
– does not rule out UTI (poor sensitivity)
• Positive result is likely true-positive
– high specificity—whatever the collection method.
• Leukocyte esterase
– More sensitive (positive in disease) indicator of
infection than nitrites are
– Better when tested using a catheterized, rather
than a bagged, specimen.
55
Urine dipstick glucose/bili
• Urine should not contain glucose
• False posiCve can occur with ascorbic acid
• Most common reason for posiCve bilirubin is
old or poorly sealed dipsCck
56
urine dipstick-protein amounts
```
• trace (about 15 mg/dL)
• 1+ (about 30 mg/dL)
• 2+ (about 100 mg/dL)
• 3+ (about 300 mg/dL)
• 4+ (2,000 mg/dL or
greater).
• Urine dipstick measures
albumin
– Does not measure low
molecular weight
protein
```
57
dipstick interp.
```
• Urinary dipstick method
measures the concentration
of urine protein,
– false-negative resultsvery
dilute urine
specimen.
• If the urine sample has
specific gravity of ≤ to 1.015,
then 1+ is considered
positive
• If the urine sample has a
specific gravity of ≥ to 1.015
then >/= to 2+ is positive
• False-positive results
– Very alkaline or
concentrated specimens
– Gross hematuria
– Pyuria
– Bacteriuria
– Presence of contaminating
antiseptics
– Radiographic contrast
– Presence of heavy mucus,
blood, pus, semen or
vaginal secretion
• Trace positive proteinuria by
dipstick does not imply
pathologic proteinuria
```
58
quantitative urine tests
```
• Urine protein/creatinine ratio
– Random urine specimen
– More accurate quantification
– Normal ratio is .03 mg of albumin per milligram of
albumin is abnormal
```
59
Asymptomatic microscopic Hematuria
• In a study of 20,000 school aged children, 274
had a negative history and normal exam
• 0 had UTI
• 57 had hypercalcuria
• 3 had recent episode of poststreptococcal
glomerulonephritis
