Hematology Flashcards
What test should be ordered on all pts with anemia?
peripheral smear
What abnormal labs will be found in von willebrand dz?
VWF or antigen level
VWF activity
prolonged aPTT (affects levels of factor 8) in 50% of cases
*bleeding problem is a platelet adhesion issue
could do a mixing study (tells you if you are missing a factor)
What is the pentad of TTP?
intravascular hemolysis
low platelets
renal insufficiency
fever
neuro deficits
*not all 5 have to be present
How would you check for an inhibitor or deficiency?
Mixing study - all studies should correct when normal blood is mixed with the pt’s bloods
*if it doesn’t, there must an inhibitor eating up the old and new factors
How can you monitor response to iron oral repletion in iron deficiency anemia and what is long term management?
- check for increased reticulocytes 10-14 days after starting therapy
*if it hasn’t incr, may be a malabsorption issue and need IM or IV iron (but not great bc can cause necrosis)
- Check CBC in 1 month
- continue to tx for 2 months after Hgb recovers to replete stores
4*. can add vit C to incr iron absorption (elderly)
What are CBC and pertinent lab findings in TTP?
CBC: anemia and thrombocytopenia
Thrombi are tearing up the red blood cells in the little vessels
schistocytes on peripheral smear
LDH elevated
retic elevated (compensatory)
BUN and Cr elevated
What are causes of macrocytic anemia?
Vit B12 deficiency
folate deficiency
alcoholism
liver disease
How to treat Heparin induced thrombocytopenia?
stop all heparin! (including line flushes)
start argatroban (for renal fx), bivalirudin, or fondaparinux (for liver fx)
stop warfarin (could go back to warfarin after 5 days or stay on other anticoagulant) - or cont warfarin if INR is therapeutic (2-3)
repeat CBC, PT, PTT, INR
NEVER USE HEPARIN AGAIN
What are the iron study findings in anemia of chronic dz?
low serum iron
high ferritin
TIBC low bc can sense that there is ferritin and it doesn’t increase to try to compensate
How do you work up new bleeding with concern for hemopathy or liver pathology?
PT, PTT
Fibrinogen (helps look at DIC)
AST/ALT
LDH
Alk phos
Bilirubin
How to treat HUS?
Supportive care
(no plasmapharesis - different mechanism that TTP)
What is the differential for an older pt with ataxia, decr sensation in extremities, mild confusion/change in personality, and hyperreflexia?
vit B12 deficiency
tertiary syphilis
chronic alcoholism
thyroid dz (dementia - but doesn’t cause sensory deficits)
depression
How to work up a PLT drop with pt on heparin?
re-check CBC and peripheral smear
check serotonin release assay and platelet factor 4 assays to dx HIT (will be abnormal)
What to think of if sickle cell pt has sudden drop in Hgb of more than 3-4 pts?
Parvovirus B19 or folic acid deficiency
What is the most common cause of Vit B12 deficiecny?
(in USA) pernicious anemia
*antibiodies made to intrinsic factor and parietal cells
(in other countries) nutritional anemia
What is the natural hx of ITP in adults?
chronic and relapsing
only tx if PLTs <20K and symptoms
*if refractory to steroids - splenectomy
*if still refractory - rituximab
When can you confirm G6PD?
Test may be normal in acute period (bc old cells are gone and new cells don’t have low level of G6PD yet)
Must measure G6PD level later (2 months)
How do you treat acute hemolysis from G6PD?
transfusion if Hgb low and symptomatic
IV hydration
What clinical signs/symptoms are associated with TTP?
fatigue, dark urine, evidence of thrombosis (arterial: stroke), jaundice, fever
*microangiopathic syndrome causing thrombosis in kidneys, brain…etc
How do you treat von willebrand disease?
DDAVP (vasopressin) intranasally daily
*causes the release of subendothelial stores of VWF and factor 8
Avoid aspirin
If DDAVP doesn’t help in an acute bleed (rare), can replace factor 8 (contains both VWF adn Factor 8)
What physiologic conditions must be considered in sickle cell patients?
functional asplenia - cover encapsulated organisms
susceptible to dehydration due to renal damage and difficulty concentrating urine
can have severe anemia due to destruction of RBCs that can cause dyspnea (esp with parvovirus)
What factors are being tested in PT and PTT?
PT - factor 7
PTT - other factors
What electrolyte abnormality can go along with vit B12 deficiency treatment?
decreased K as cells are rapidly being made - if getting muscle cramps/proximal weakness need to check and replace K
How to dx heparin induced thrombocytopenia and what to think about for complications?
>50% drop in PLTs within several days of starting heparin
check serotonin release assay (abnormal) and platelet factor 4 antibodies (positive)
*get thombosis more often than bleeding - can lead to venous thrombosis (DVT, PE)
What is happening in thormbotic thrombocytopenic purpura and what is HUS?
large conglomerates are forming with vWF/platelets that get stuck in small vessel and cause shredding of RBCs as they pass through
*microangiomapthic hemolytic anemia
hemolytic uremia syndrome - renal failure with microangiopathic hemolytic anemia (happens from shigella toxin with E Coli 0157
How to work up reversible causes of dementia and concern for B12 deficiency?
CBC, peripheral smear
T4, TSH
BUN, Cr
CT head
VDRL, RPR
Homocystein level, methylmalonic acid level
What tests help you confirm pernicious anemia and vit B12 deficiency?
B12 level (may be low)
Anti-intrinsic factor and anti-parietal cell antibody (tells you if pernicious anemia vs nutritional)
methylmalonic acid (* BEST test)
How to treat iron deficiency anemia?
oral ferrous sulfate (3 times per day)
servere anemia - transfusion then oral
What must be considered in iron deficiency anemia in someone outside of pregnancy aged women?
occult GI bleed if it is a man or women outside of child-bearing age range
*less common - malabsorption - celiac, whipple’s disease
What is an important side effect of sulfa drugs?
bone marrow suppression (usually pancytopenia)
How to work up pts with acute jaundice and pallor?
CBC, LFTs, PT, PTT, Peripheral Smear, UA, U/S abdomen
What are the differences between extravascular and intravascular hemolysis?
Extravascular - subacute from RBC destruction in spleen and liver
*liver dz, infection ,heme malignancy, autoantibodies, membrane abnormalities
Intravascular - acute onset with hemoglobinemia and decrease in haptoglobin (gets consumed rapidly)
*TTP, HUS, DIC, malignant HTN