Chapter 7 BOMB GM MTB Step 3 Hematology Flashcards
1 Anemia (in general) -gen cp -severe Sx
“-ALL forms of anemia: *fatigue*/tired/malaise with subj ““loss of energy””.
-severe Sx: SOB, lightheaded, AMS/confusion”
Anemia DDx
MICH
Methemoglobinemia
Ischemic heart Dz/CAD
CO (carbon monoxide) poisoning
Hypoxia
Q describes craving for Pt. to chew on ice or dirt - think?
*pica* 2/t *iron def* anemia
on CCS, what pe should you pick for anemia w/u? potential positive findings? T/F: no unqiue physical findings in anemia to allow a specific Dx
1) gen app: *pallor*
2) CV: *flow murmur* (usu 1-2/4 systolic murmur)
3) chest: *no (+) but just do bc of SOB to help r/o other causes*
4) ext: pallor
5) HEENT: *pale conjunctiva*, possibly jaundice, scleral icterus
T: no finding is sp enough to key in to Dx
Anemia -BI Dx test -additional initial tests (10) -most imp Dx test -MA Dx test
- BI: *CBC* w/ periph smear
- other initial (10): retic ct., haptoglobin, LDH, total/direct bili, TSH w/ T4, B12/folate lvl, iron studies + UA w/ micro
- most *imp: iron studies*
- MA: *BM biopsy*
iron studies values (5)
- Fe (iron in blood)
- ferritin (stored iron)
- TIBC (total iron binding capacity aka thirst for iron)
- Fe sat (opposite of TIBC; amt of iron that is saturated w/ Hb)
- RDW (width; measures range of variation of RBC’s)
how to categorize anemia
from CBC, ck
1) ck Hb/HCt (H/H): F 37-42; M 45-50
*2) MCV* (mean corpuscular volume, or mean cell V): measure of the avg V of a RBC/corpuscle
-tells you *micro, macro or normocytic* (SIZE)
*3) MCHC* (mean corp [Hb]): measure of [Hb] in a given V of pRBC’s
- tells you if problem w/ synth of Hb
- tells you *hypo, hyper or normochromic* (COLOR)
i) MICROCYTIC ANEMIA -DDx
-*TAILS: T*hallasemia, *A*nemia of Chronic Dz (ACD), *I*ron deficiency, *L*ead poisoning, *S*ideroblastic
if H&P says: *blood loss* (hmrg) OR *elevated platelet ct.* - think this type of anemia? -BIMA Dx test? -^expected values? -Tx
- *iron def*
- BI Dx: *iron studies*; MA: BM biopsy
- lo Fe, *lo ferritin, hi TIBC*, lo Fe-sat, *hi RDW*
- Tx: PO ferrous sulfate
only anemia assoc w/ incr RDW CCS: T/F do BM biopsy
*iron def*: since less iron, new cells are prog smaller so RBC width changes over time
F: do not do. just bc its MA doesn’t mean its clinically done.
if H&P says: *Hx of RA or ESRD* - think this type of anemia? -problem -BIMA Dx test? -^expected values? -Tx
*ACD*
- iron stores are hi but constipated so cant release
- BI Dx: *iron studies*; MA: *none*
- lo Fe, *hi ferritin, lo TIBC*, nl/lo Fe-sat, lo RDW
- correct underlying Dz
T/F: any chronic infectious, inflm or CT Dz can lead to ACD
T: it can
if H&P says: *a-Sx-ic Pt. w/ lo MCV and smear shows target cells* - think this type of anemia? -problem -most common -BIMA Dx test? -^expected values? -Tx
*Thalassemia*
- problem with alpha or beta globin chain prod
- common is B-thal minor
- BI Dx: *iron studies*; MA: *Hb electrophoresis*
- iron studies *NL*
- none
Hb electrophoresis results
if B-thal: *incr HbA2 & HbF*
if alpha: *nl* results (bc *MA* Dx’d by *DNA sequencing* instead)
T/F: alpha vs beta thal have a diff MA test
T:
*beta*-thal: *Hb electrophoresis* (shows incr HbA2, HbF)
*alpha*-thal: *DNA sequencing* (needs more hardcore test to pick up this less common thal)
lead poisoning/exposure gets categorized under this anemia -other possible causes (2)? -problem -BIMA Dx test? -^expected values? -Tx
*Sideroblastic Anemia*
- *EtOH* (alcoholic) or *INH* use
- problem: iron build up inside Mt of RBC
- BI Dx: *iron studies*; MA: *Prussian blue stain* (stains + for Fe, helpful bc there’s an excess here)
- iron studies: *hi Fe* (excess)
- if minor: Rx *pyridoxine supp*; major: remove toxin
IRON STUDIES RESULTS: match results with possible micro anemia -hi RDW -nl iron studies -hi ferritin, lo TIBC -lo ferritin & Fe, hi TIBC -hi Fe
- hi RDW: iron def
- nl: Thal
- hi ferritin: ACD
- lo ferritin/Fe: iron def
- hi Fe: sideroblastic anemia
T/F: oral ferrous sulfate can turn stool black when can this be confusing?
T: confusing if Pt. on this but there’s a concern for GI bleed (ie blk stools), *don’t* jump to *colonoscopy* right away. instead do guaiac testing (hemoccult) bc it can diff b/w ferrous sulfate and elemental iron. (only Fe in Hb or Mb can make stool guaiac card +)
HbH Dz -what is it -structure -gen problem -Cx finding
- Hemoglobin H disease (HbH): form of *alpha-thal* in which moderate to severe anemia develops 2/t decr prod of alpha globin chains -> excess beta globin chains then combine with each other to form hemoglobin H
- beta-4 tetrads (one missing)
- 3-gene del
- only *micro anemia w/ hi retic ct.*
micro anemia w/ hi retic ct.
HbH Dz/a-thal major
70 yo F CBC shows decr HCt (32; nl 37-42) with decr MCV 70 (nl 80-100). NBS? then?
NBS: ck stool via hemoccult. if (+) colonoscopy, *if (-) STILL DO COLONOSCOPY*: she is > 50 so do it anyway for routine screening. that plus fact she has micro anemia (cont to next Q)
unexplained micro anemia in Pt. > 50 most likely 2/t
*colon cancer* so ck *colonoscopy*
why is sigmoidoscopy usu wrong answer when ck for colon cancer? when is capsule endoscopy done?
bc does NOT inspect R colon; miss 40% of cancers
done to eval bleeding when upper & lower endoscopy are nl & source of bleeding is still beleived to be in SI
only form of ACD that reliably reponds to EPO is 2/t?
ESRD (bc kidney makes EPO)
extravascular hemolysis - what is it?
hemolysis that occurs outside vessels (ie *spleen & liver*) so you *CAN’T* see it on smear
ii) MACROCYTIC ANEMIA -cp -DDx -BIMA Dx
- like ALL anemia: fatigue. diff seen with each type
- DDx: if *megaloblastic, B12 or folate def*
- BI Dx: *CBC w/ periph blood smear (hyper-segmented PMN’s & oval cells*); MA: *B12 or folate lvl* (will be low)
megaloblastic anemia def’n
smear showing hyper-segmented PMN’s (avg lobe # on nl WBC = 3.5. *if > 4* or if more than *5% have > 5 lobes*, Pt. has *MEGALOBLASTIC ANEMIA* as well as macrocytic anemia (macrocytosis ie big cells ie incr MCV).
CCS: what to order if suspect B12/folate def (4)
CBC w/ periph smear (BI)
also (3): bili lvl & LDH (both incr) + retic ct. (decr)
T/F: up to 30% of Pt w/ B12 def can have NL B12 lvl.
T: bc trans-cobalamin in acute phase reactant so any stress can cause its elevation leading to false incr of B12. continue to next Q for NBS
^NBS (if you suspect B12 def but B12 lvl is nl)
order *METHYLMALONIC ACID LVL* (INCR only in B12)
- rmr stockton (B*12*) and *MALONE*
- also rmr *homocysteine (HC)* incr in both B12 and folate so *not* helpful
NBS to confirm *etiology* of B12 def
order *anti-parietal cell Ab’s* & *anti-IFx Ab’s*
-both help confirm or r/o *pernicious anemia* (allergy to parietal cells so type of AI d/o against part of stomach) as etiology of B12 def.
T/F: Schilling’s Test is rarely done
T: very old. this method NOT NEC if auto-Ab’s present
a) vitamin B12 def -cp T/F: neuro problems resolve w/ Tx T/F: least common neuro problem is periph neuropathy
-fatigue + *Neuro findings* (usu *periph neuropathy* but any Sx can develop that fx PNS or even CNS); also has smooth tongue (*glossitis*) & *diarrhea*
T: do resolve w/ Tx *if* have been present for short period of time
F: periph neuropathy is *MOST* common; *least* common is *dementia*
after B12 replacement Tx, order of improvement
FIRST: retic ct. improves
THEN: neuro Sx improve LAST
vit B12 def often seen with this Rx
*METFORMIN*: blocks B12 absorption so body is effectively deficient
think metformin/DM also has periph neuropathy
b) folate def -cp
-fatigue *w/o *Neuro findings (rmr vit *B9* def is *BENIGN*)
T/F: both B12 and folate Tx’d w/ replacement
T: both. folate will even correct BLOOD problems of B12 def *BUT* worsen neuro Sx.
watch for this when Tx-ing B12 def
watch for *hypoK* when Tx-ing B12 def
iii) HEMOLYTIC ANEMIA -cp -labs (4)
- sudden onset wknss/fatigue
- hi (3): indirect bili, retic ct., LDH; *lo: haptoglobin*
diff b/w extravascular & *intravascular* lab abnormalities
INTRA has all the same ab-nl of EXTRA but ALSO shows following (3):
- ab-nl *smear* bc intravascular (schistocytes, helmet cells, fragmented cells)
- Hb-uria
- hemosiderinuria (metabolic, oxidized prod of Hb in urine)
for CCS, in suspected case of EV hemolysis order these (5)
BI: CBC w/ periph smear
also (4): LDH, bili, retic ct., haptoglobin lvl
if you suspect hemolytic anemia, first thing you want to improve
*1st improve retic ct.*, then try to eliminate hyper-segmented PMN’s
iii) SICKLE CELL ANEMIA *(SCA) IMP* -cp
-severe pain in: chest, back, thighs
must do this (A) in sickle cell Pt., esp if this (B) happens
- must do phys exam
- if Pt. has fever AFTER you give O2, fluids, analgesics & Abx