Hematology Flashcards
What are sx of anemia based on
Severity of disease
Sx w/ HCT >30-35
None
Sx w/ HCT 25-30
Dyspnea worse on exertion
Fatigue
Sx w/ HCT 20-25
Lightheadedness
Angina
Sx w/ HCT
Syncope
CP
What kills you in anemia
MI
What conditions are indistinguishable for myocytes in the heart
Anemia
Hypoxia
CAD
Carbon monoxide poisoning
First clue to etiology of anemia
MCV
Causes of low MCV
Fe def
Thalassemia
Sideroblastic anemia
AOCD
Only microcytic anemia with elevated retic count
Alpha-thalassemia
Causes of high MCV
B12/Folate def Sideroblastic anemia Alcohol Azathioprine, 6-MP, hydroxyurea Liver disease/hypothyroidism Zidovudine, phenytoin MDS
2 main causes of normocytic anemia acutely
Blood loss
Hemolysis
Retic count in normocytic anemia
Elevated when there is hemolysis
Treatment for severe anemia
pRBCs
When do you transfuse anemic pt
Symptomatic
HCT 25-30 in elderly pt or one w/ heart disease
What is symptomatic anemia
SOB
Lightheadedness, confusion, syncope
Hypotension, tachy
CP
What to transfuse for IgA def pts
IgA def donor FFP
HCT of pRBCs
70-80%
Whole blood w/ 150mL plasma removed
Effect of pRBC on HCT
Each unit raises HCT by 3 points
Who doesn’t get FFP
Hemophilia A, B
Von Willebrand
What does FFP replace
Clotting factors
What does cryoprecipitate replace
Fibrinogen (for DIC)
Has high VIII and VWF
MCV in microcytic anemia
Decreased
What is the main reason for Fe def anemia
Blood loss
Body needs for Fe
Normal - 1-2mg/day
Menstruating - 2-3
Pregnant - 5-6
What is the suspected etiology of AOCD
Fe trapped in macrophages or ferritin so Hb synth doesn’t occur
How does renal failure cause AOCD
Deficiency of EPO
When is sideroblastic anemia macrocytic
MDS
MCC sideroblastic anemia
Alcohol
Less common causes of sideroblastic anemia
Pb poisoning
Isoniazid
B6 def
Most likely anemia with GI bleeding
Fe def
Most likely anemia with menstruation
Fe def
Most likely anemia with cancer/chronic infection
AOCD
Most likely anemia with RA
AOCD
Most likely anemia in alcoholics
Sideroblastic
Most likely anemia with Asx pts
Thalassemia
Best initial test for microcytic anemia
Fe studies
MC microcytic anemia with target cells
Thalassemia
Which anemia has low ferritin
Fe def
Which anemia has high Fe
Sideroblastic
Which anemia has normal Fe studies
Thalassemia
Fe def iron studies
Low ferritin
High TIBC
AOCD Fe studies
High ferritin
Low TIBC
Unique lab features of Fe def
Increased RDW
Increased platelets
Single most accurate test for Fe def
Bone marrow Bx for stainable Fe
NEVER done
Unique lab features for sideroblastic anemia
Prussian blue staining for ringed sideroblasts (most accurate)
Basophilic stippling
Type of anemia in Chronic renal failure
Normocytic
Most accurate test for Thalassemia
Hb electrophoresis
Most accurate test for alpha-thalassemia
Genetic studies
Thalassemia with HbH and increased retics
3-del
HbH are beta tetrads
1 gene deletion features of B-thal
Increased HbF, HbA2
2 gene deletion features of a-thal
Mild anemia
Normal electrophoresis
3 gene deletion features of B-thal
Normal HbF
4 gene deletion features of a-thal
gamma-4 tetrads (Hb Bart)
CHF causes death in utero
RDW in thalassemia
Normal
Rx Fe def
Oral ferrous sulfate
IM Fe if insufficient
Rx AOCD
Fix underlying problem
Only Anemia from ESRD responds to EPO
Rx Sideroblastic anemia
Correct cause
B6/pyridoxine replacement
Rx Thalassemia
B - Lifelong chronic transfusions (NOT 3-del)
Fe overload - Deferasirox, deferiprone, defereoxamine
First step in Macrocytic Anemia
Peripheral smear
What is macrocytic anemia
Presence of hypersegmented neutrophils
What does B12/Folate defiency do that alcoholism cannot
Hypersegmented neutrophils
Causes of B12 deficiency
Pernicious anemia
Pancreatic insufficiency
Vegan
Crohn’s/Celiac/Sprue/Radiation/Terminal ileum damage
Blind loop syndrome/Gastrectomy/Gastric bypass
Diphyllobothrium latum/HIV
Causes of B9 deficiency
Goat’s milk, Celiac
Psoriasis and skin loss/turnover (sickle cell)
Phenytoin, Sulfa
MTX usage in RA
MC neuro abnormality in B12 deficieny
Peripheral neuropathy
Classic neuro loss in B12 defiency
Posterior column damage (position and vibratory)
AKA Subacute combined degeneration
Which deficiency is associated with increased methylmalonic acid levels
B12
LAb values common to B12 and folate deficiency
Megaloblastic anemia Increased LDH and indirect bili Decreased retic Hypercellular marrow Macroovalocytes Increased homocysteine
Why is B12 NL in 1/3 of pts with B12 def
Carrier protein transcobalamin is acute phase reactant and may be elevated
Confirmatory test for pernicious anemia
Anti-intrinsic factor
Anti-parietal cell
Why is retic count low in macrocytic anemia
RBCs destroyed as they leave the marrow
Why does pancreatic insufficiency cause macrocytic anemia
Pancreatic enzymes are needed to absorb B12
What can result from B12/folate replacement
Hyperkalemia
What is common in all hemolysis
Decreased HCT Increased LDH, indirect Bili, retics Decreased haptoglobin NL/Increased MCV Hyperkalemia Folate deficiency
What does haptoglobin do
Transfers Hb from intravascular to extravascular
What is chronic hemolysis always associated with
Bilirubin gallstones
Why is urine dark in hemolytic anemia
Increased Hb
What can prolongued hemoglobinuria lead to
Renal failure/ATN
MCC hemolysis
Sickle cell
Retic count in sickle cell
Always High
Precipitants of vasoocclusive crisis
Hypoxia
Dehydration/Contrast
Infection/Fever
Cold Temperatures
Common features of sickle cell pts
African american
Pain in chest, back, thighs +/- fever
Common manifestations of sickle cell
Bilirubin gallstones Infection from autosplenectomy Osteomyelitis Retinopathy Stroke Cardiomegaly Leg skin ulcers Avascular necrosis
Best initial test sickle cell
Peripheral smear
Most accurate test sickle cell
Hb electrophoresis
What is the only Sx in sickle cell trait
Hematuria
Isosthenuria
Large volume HCT drop in pt with sickle cell
Parvovirus B19
Dx - PCR (best) or IgM
Rx - IVIG
Seen in neutrophils in Ehrlichia infections
Morulae
Cause of Howell-Jolly bodies
Splenectomy
Rx Sickle cell
O2/Hydration/Analgesia
Folate chronically
Pneumococcal vaccine
Prophylaxis for sickle cell crisis
Hydroxyurea
Rx if fever/white count in sickle cell
Ceftriaxone
Levofloxacin
Moxifloxacin
Don’t wait for culture
When to use exchange transfusion in severe vasoocclusive crisis
Acute chest
Priapism
Stroke
Visual disturbance from retinal infarction
What is hereditary spherocytosis
Defect in RBC cytoskeleton leading to loss in flexibility
Most common features in hereditary spherocytosis
Recurrent hemolysis Intermittent jaundice Splenomegaly FHx anemia/hemolysis Bilirubin gallstones
Dx tests hereditary spherocytosis
Low MCV
Increased MCHC
Neg Coombs
Most accurate test for hereditary spherocytosis
Osmotic fragility
Rx hereditary spherocytosis
Folate replacement
Splenectomy
Causes of Autoimmune hemolysis
50% Idiopathic CLL Lymphoma SLE, RA PCN, alpha-methyldopa, rifampin, phenytoin, quinidine
Most accurate test autoimmune hemolysis
Coombs
Best initial therapy autoimmune hemolysis
Steroids
Other Rx for autoimmune hemolysis
Splenectomy (if reccurent)
IVIG (if not responding to steroids)
Rituximab, azathioprine, cyclophosphamide, cyclosporine (if splenectomy doesn’t control)
Alternative drugs to steroids in autoimmune hemolysis
Azathioprine
Cyclophosphamide
Cyclosporine
Mycophenolate mofetil
What is cold agglutinin disease
IgM Abs against RBC
What is cold agglutinin disease associated with
EBV
Waldenstrom
Mycoplasma pneumoniae
Where does cold agglutinin disease present
“Cold” body parts
- Nose, ears, fingers, toes
Most accurate test for cold agglutinin disease
Cold agglutinin titre
Rx cold agglutinin disease
Stay warm
Rituximab or plasmapheresis
Cyclophosphamide, cyclosporine
What are cryoglobulins associated with
Hep C
Joint pain
Glomerulonepheritis
Who gets G6PD def
Men (XR)
What is the MCC oxidative stress in G6PD def
Infection
Causes of oxidative stress in G6PD def
Dapsone Quinidine Sulfa drugs Primaquine Nitrofurantoin Fava beans
MC features in G6PD def
African American/Mediterranean
Sudden anemia and jaundice
Normal spleen
Best initial test for G6PD def
Heinz bodies and bite cells
Most accurate test for G6PD def
G6PD level 1-2mos after hemolytic episode
Stain used for heinz bodies
Methylene blue
Rx G6PD def
Avoid oxidative stress
Cause of HUS/TTP
Deffiency of ADAMTS 13 (metalloproteinase)