Ch4: Hematology Flashcards
viral infection blood cell
lymphocytes
bacterial infection blood cell
neutrophils
allergic reaction blood cells (2)
eosinophils, basophils
blood cell that cleans up debris, will be elevated in patients who have started to turn the corner on recovery from an infection or injury
monocytes
if there is bleeding, this blood cell will be elevated in response
platelets
suspected type of anemia: pt presents with dizziness, tachycardia, low BP
acute blood loss (uncommon in primary care)
why can chronic low-volume blood loss cause iron deficiency anemia?
iron from the RBCs wasted via blood loss cannot be recycled. clinically significant blood loss can be as little as a few mL/day.
suspected type of anemia: chronic PPI use
IDA or B12 deficiency anemia
PPIs associated with B12 and iron malabsorption
long-term use of metformin is associated with malabsorption of….
B12 (deficiency
= macrocytic anemia)
normal RBC lifespan
90-120 days
normal Hgb to Hct ratio
1:3 (1 g Hgb to 3 percentage points Hct)
Hgb 10, what is the expected Hct?
30%
Hgb 12, what is the expected Hct?
36%
what happens to the Hgb:Hct ratio in severe dehydration?
Hct goes up (hemoconcentration)
Normal MCV
80-96 fL
MCV
mean corpuscle volume (size of the RBCs; average volume of the RBCs that are in circulation)
microcytic definition
MCV <80 fL
normocytic definition
MCV 80-96 fL
macrocytic definition
MCV >96 fL
MCH, MCHC
mean cell hemoglobin (average mass of Hgb per RBC)
mean cell hemoglobin concentration (average concentration of Hgb per RBC)
hemoglobin makes up ___% of the RBCs volume
90%
normal MCHC
31-37 g/dL
hypochromic MCHC
<31 g/dL
RDW
RBC distribution width (variation in red blood cell size)
which lab value is the index of variation in RBC size?
RDW
normal RDW
11.5-15% (0.115-0.15 proportion)
abnormal RDW
> 15% (>0.15 proportion)
elevated
Likely the earliest laboratory indicator of an evolving microcytic or macrocytic anemia
RDW
anisocytosis
abnormal variation in RBC size (indicated by the RDW)
normal reticulocyte percentage
1-2%
the body’s normal response to anemia is to attempt correction via increasing the number of….
reticulocytes (new young RBCs)
normocytic normochromic anemias: MR B CALM
- marrow failure
- renal failure (chronic)
- blood loss (acute)
- chronic disease**
- aplastic anemia
- leukemia
- metastasis (cancer)
most common reason for normocytic normochromic anemia in primary care
anemia of chronic disease
if the cell is normal size (normocytic), it is always the same….
color (normochromic)
most common etiologies of microcytic anemias with elevated RDW (2)
- lead toxicity (mostly children)
- iron deficiency**
most common reason for microcytic anemia in primary care
iron deficiency anemia
expected findings for iron deficiency anemia on CBC
- low Hgb
- low Hct
- low RBCs
- low MCV
- low MCHC
- increased RDW
single BEST test for iron stores in suspected iron deficiency anemia
ferritin
most common causes for microcytic anemias with normal RDW
thalassemia minors
- alpha thalassemia minor (trait)
- beta thalassemia minor (trait)
at risk groups for alpha thalassemia (1)
asian, african
at risk groups for beta thalassemias (3)
mediterranean, middle eastern, african
expected findings for thalassemia on CBC
- low Hgb
- low Hct
- elevated RBCs
- low MCV
- low MCHC
- RDW normal
next step test when you suspect thalassemia on a routine CBC
hemoglobin electrophoresis for evaluation of hemoglobin variants
major differences between iron deficiency anemia and the thalassemias minor on CBC
IDA = low RBCs, elevated RDW
thal = normal to elevated RBCs, RDW normal
most common causes for macrocytic, normochromic anemias with elevated RDW: FAT RBC
- Fetus (pregnancy)
- Alcohol excess
- Thyroid (hypo)
- Reticulocytosis
- B12 and folate deficiency
- Cirrhosis and chronic liver disease
most common reason for macrocytic anemias in primary care (3)
- folate deficiency
- alcoholism
- b12 deficiency
young, new RBCs are [smaller vs. larger] than mature RBCs
immature = larger
next step test when you see macrocytic anemia on a CBC
serum vitamin B12 and folate
expected findings for B12 or folate deficiency anemia on CBC
- low Hgb
- low Hct
- low RBCs
- elevated MCV
- normal MCHC
- elevated RDW
drug-induced macrocytosis without overt anemia can be caused by…. (3)
- alcohol excess
- anticonvulsants (carbamazepine [Tegretol], phenytoin [Dilantin])
- methotrexate
alcohol is the most common
expected findings for a drug-induced macrocytosis on CBC
- normal Hgb
- normal Hct
- normal RBC
- elevated MCV
- normal MCHC
- normal RDW
alcohol levels that can cause macrocytosis
5 or more drinks per day for males, 3 or more drinks per day in female
if a medication is causing macrocytosis but not anemia, do you need to always discontinue the drug?
no
how marked is the macrocystosis in alcohol- or drug-induced macrocytosis?
modest
CBC returns:
- RBCs WNL
- Hgb WNL
- Hct WNL
- MCV elevated
- MCHC WNL
- RDW WNL
you suspect….
drug-induced macrocytosis, most commonly from excess alcohol intake. otherwise can be from anticonvulsants or methotrexate
CBC returns:
- RBCs low
- Hgb low
- Hct low
- MCV elevated
- MCHC WNL
- RDW elevated
you suspect…..
macrocytic anemia, most commonly folate or B12 deficiency. ca also be caused by alcohol excess. other causes include pregnancy, hypothyroid, reticulocytosis, and cirrhosis or chronic liver disease
FAT RBC: Fetus Alcochol Thyroid Reticulocytosis B12 and folate Cirrhosis
CBC returns:
- RBCs elevated
- Hgb low
- Hct low
- MCV low
- MCHC low
- RDW WNL
you suspect….
thalassemia minor / thalassemia trait (alpha or beta)
CBC returns:
- RBCs low
- Hgb low
- Hct low
- MCV low
- MCHC low
- RDW elevated
you suspect….
microcytic anemia, most commonly from iron deficiency. in children, may be caused by lead toxicity
CBC returns:
- RBCs low
- Hgb low
- Hct low
- MCV WNL
- MCHC WNL
- RDW WNL
you suspect…
normocytic anemia, most commonly anemia of chronic disease. may also be caused by a host of other conditions:
MR B CALM
- marrow failure
- renal failure
- blood loss (acute)
- chronic disease
- aplastic anemia
- leukemia
- metastasis (cancer)
_____ requirements increase in reticulocytosis
micronutrient
e.g., if they have a B12 deficiency anemia. you will supplement the deficient B12, but they will still need other micronutrients to replenish their blood supply including extra iron and folate for a bit. So an MVI with all of these might be a good choice
what is epoetin alfa (Epo)
biologically identical to endogenous erythropoietin from the kidney, induces erythropoiesis
uncommon to use Epo in primary care. what are some indications where this might be used?
helpful for severe anemias, particularly in the presence of advancing renal failure.
EPO supply is diminished in CKD, usually beginning when the eGFR reaches <49
normal eGFR
90-120 mL/min
EPO supplementation may be most useful in severe anemias of chronic disease when the eGFR reaches….
<49 mL/min
90% of your EPO is produced by the ….. and 10% by the…..
90% by kidneys
10% by the livers
vegans need to supplement with….
B12
most common anemia in childhood
iron deficiency
most common anemia during pregnancy
iron deficiency
most common anemia during women’s reproductive years
iron deficiency
most common anemia in the elderly
- anemia of chronic disease
- iron deficiency
- pernicious anemia (especially older WOMEN, as this is autoimmune process)
if the MCHC is normal, they do not have a problem with….
iron
conjunctival pallor indicates a Hgb of less than…
<9 g/dL
____ anemias present like an acute bleed with painless jaundice
hemolytic
type of murmur you hear in someone with profound anemia, third trimester of pregnancy, or severely ill
hemic murmur
next test:
MCV low, MCHC low, RDW normal
hemoglobin electrophoresis (concern for thalassemia minor)
next test:
low MCV, low MCHC,RDW elevated
ferritin (sounds like IDA)
next test:
MCV high, MCHC normal, RDW elevated
B12 and folate (two most common macrocytic anemias)
a normal RDW means that new cells being created are the same size as the old cells. you have thus ruled out…..
3 nutritional deficiencies (iron, folate, B12)
which nutritional supplements increase bleeding risk and need to be d/c 7-10 days before elective surgeries and used in caution with other anticoagulants (3)
- ginseng
- gingko
- fish oil
Cooley’s anemia, aka….
beta thalassemia MAJOR (would be discovered in childhood because it is so severe)
sickle cell anemia is autosomal [dominant vs. recessive]
recessive
both parents need sickle cell TRAIT and the child needs to inherit two copies of the affected gene
what is the Hct on CBC telling you
% of whole blood that is red blood cells
Normal Hgb for women
12-16 g/dL
Normal Hct for women
37-47%
Normal Hgb for men
14-18%
Normal Hct for men
42-54%
next step in your work-up when CBC demonstrates a normocytic anemia
look for endocrine, liver, and renal disease
- TSH
- LFTs
- BUN/creatinine
if normal, look for an iron-deficiency anemia (serum iron, TIBC, % saturation, ferritin)
if still normal, refer for bone marrow biopsy with a hematological specialist
the normocytic anemia of chronic disease will progress to a _____ anemia if left untreated
microcytic anemia
next best test when you have a normocytic anemia
reticulocyte count
what do you expect for TIBC in iron deficiency anemia
high
microcytic anemia in men and post-menopausal females should be considered a sign of ______ until proven otherwise
GI bleeding
consider colonoscopy and endoscopy
good dietary sources of iron for those with iron deficiency anemia (3)
- red meat
- beans/legumes
- green, leafy vegetables
oral iron supplementation regimen for iron deficiency anemia
ferrous sulfate 300mg PO TID on an empty stomach x1 month, come back for lab work and should see an increasing reticulocyte count. Track CBC until it is back to normal range.
(2) primary side effects of oral iron supplementation
- stomach upset (ok to take with a meal to increase compliance if they cannot tolerate on empty stomach)
- constipation
hypersegmented polymorphonuclear leukocytes (HPL) present on peripheral smear indicates a ______ anemia
megaloblastic (folate or B12)
NO hypersegmented polymorphonuclear leukocytes (HPLs) found on peripheral smear indicates a _______ anemia
non-megaloblastic
(2) types of macrocytic, megaloblastic anemias
folate and B12 deficiency
(3) types of macrocytic, non-megaloblastic anemias
- alcoholism (70%)
- hypothyroidism
- cytotoxic drugs
what is the role of the Schilling test in low B12 anemias
a 24-hr urine test that determines whether or not intrinsic factor is being produced
folate and B12 deficiencies can both interfere with absorption of ______
iron
differential causes for folate deficiency anemias
- alcoholism
- malabsorption condition
- celiac disease
- chronic hemolytic disease
- excessive intake of fava beans
- hyperthyroidism
- inadequate intake of fresh vegetables
- medications
- pregnancy/lactation
- renal hemodialysis
- sprue
- TPN
dietary sources high in folic acid
- liver
- wheat bran/grains fortified
- green, leafy vegetables
- beans
folic acid supplementation regimen for deficiency
folic acid 1-5mg PO QD until their Hct is normal. should see reticulocyte count increasing first
have them come back in 7-10 days, then 3 months
(2) lab tests to consider when CBC demonstrates a macrocytic anemia
serum B12 level, schilling test (24 hour urine)
sore tongue from atrophic glossitis, think of this type of anemia…
B12 deficiency
neurologic involvement (e.g., neuropathy in feet), think of this type of anemia….
B12 deficiency (s/t decrease in myelin integrity)
one type of B12 deficiency anemia is an autoimmune condition
pernicious anemia, s/t decreased production of intrinsic factor from destruction of the gastric parietal cells
underlying causes for B12 deficiency anemia
- lack of protein intake (vegan)
- pernicious anemia (autoimmune)
- malabsorption syndromes (e.g., after bariatric surgery)
- bacterial or parasitic infections of the bowel
- chronic pancreatic insufficiency
- crohn’s disease
- gastrectomy, ileal resection
- hyperthyroidism
- medications
- sprue
- pregnancy/lactation
treatment for diagnosed pernicious anemia
IM injections of B12 Q1 month for the rest of life
hemolytic and sickle cell anemias are both ___cytic
normocytic
