3 - Anemia Flashcards
Describe physiology of hematopoiesis and blood cells.
decr O2 levels. renal release of erythropoietin stim red bon marrow enhance erythropoiesis incr RBC count and O2 capacity
Explain the etiology of anemia.
erythrocyte loss (bleeding, pregnancy) decr production (low erythropoietin, decr marrow response-->iron/b12/folate def; anemia chronic dz)
incr destruction:
genetic: sickle cell, G6PD, thalassemia, hereditary spheocytosis
acquired: TTP, hemolytic uremia synd, malaria
What are anemia-related lab values?
Hbg
Hct
RBC
Id risk factors for microcytic anemia.
*most commonly iron def
les common: Cu, Zn def
toxin poisoning
inherited disorders: thalassemias, defects of iron metabolism
Risk factors for normocytic anemia
acute blood loss (menses, GIB)
mixed anemias
chronic illness (erthropoeitin def)
sx of anemia
acute: tachycardia tachypnea orthostatic hyptn light-headedness angina
chronic: fatigue weakness HA SOB dizziness senstivity to cold pallor exacerbation of cardiac dz
Normal Hbg
M: 13.5-17.5 g/dL
F: 12-16 g/dL
normal Hct
M: 41-53%
F: 36-46%
normal RBC
M: 5.2+/-0.7 million/mcL
F: 4.6 +/- 0.5 million/mcL
normal RDW
11-15%
Acute bleed anemia considerations
drop in hgb or hct may not show until 36-48 h after leed
pregnancy anemia special considerations
in 3rd trimester 50% plasma volume expansion w 25% RBC expansion. polycythemic but dilute.
volume depletion anemia considerations
may nt show anemia until after rehydration
age anemia considertions
increased risk in elderly (.65 yoa)
smoker anemia considerations
Hct higher than normal, masking underlying anemia
altitude anemia considerations
higher lab values
consequences of iron def anemia
pica
angular stomatitis (crusting around mouth)
glossitis
koilonychia (flattening of nail beds)
consequences of iron def anemia
pica
angular stomatitis (crusting around mouth)
glossitis
koilonychia (flattening of nail beds)
Evaluating iron status…
High/low TIBC indicates…
low/high Fe saturation
for examples: high TIBD and low saturation –> body wants more iron!
normal TIBC
30%
IDA tx for peds
9-12 mo 3mg/kg of elemental once or twice d
older children: 6 mg/kg/d element dividing into 2-3 doses
IDA tx for adults
200 mg elemental iron daily esp when symptomatic
PO iron options
ferrous sulfate ferrous gluconate ferrous fumarate polysacchardie-iron complex (Niferex) arbonyl iron (Feosol)
What is the tab size, elemtnal iron, and daily regimen for ferrous sulfate?
also liquid
325 mg
65 mg (20%)
325 mg TID
What is the tab size, elemtnal iron, and daily regimen for ferrous gluconate?
300 mg
35 mg (12%)
600 mg tid
What is the tab size, elemtnal iron, and daily regiment for ferrous fumarate?
also liquid
300 mg
99 mg (33%)
300 mg bid
What is the tab size, elemtnal iron, and daily regiment for polysaccharide-iron complex (Niferex)?
also liquid
150 mg
100%
150-300 mg d
What is the tab size, elemtnal iron, and daily regiment for carbonyl iron (Feosol)?
50 mg
100%
50 mg TID
What are the SEs of PO iron?
epigastic distress
ab cramping
N/D or constipation
dark, discolored feces
What drugs interact with po iron to increase Fe abs?
ascorbate (vit C)
What drugs interact with iron to decrease FE abs?
H2-blockers PPIs cholestryamine tea calcium coffee wine
What drugs do Fe decr the abs of?
floroquinolones
tetracyclines
What are pt education points for po iron?
best abs’d on empty stomach
minimize GI SES by taking w food or smaller amts more freq
prevent constipation w stool softener, fluid intake
sep po iron from ilk/antacids-2 hr before or 2 hr after
keep out of reach of children
What are indications for IV iron?
severe Fe malabs noncompliance w po fe severe intolerance w po fe chronic uncontrollable bleeding diminisehed erythropoiesis--dialysis pts
**does not reseolve anemia more quickly than po Fe
Which type of IV iron requires a test dose?
iron dextran (INFed, Dexferrum) 25 mg, observe 1 hr
Which IV iron product can be administered to non-HD CKD patients/
iron sucrose (Venofer) 200 mg IV x 5 doses
Which IV iron product can interfere with MRIs?
ferraheme (Ferumoxytol)
Which iron product can be administered via TDI?
iron dextran
Describe dose, admin, SEs of iron dextran.
50 mg/mL inj
bolus inj w max dose 100 mg/d
TDI possible
admin over 2-6 hr
fever, malaise, flushing, myalgias, ANAPHYLAXIS
Describe dose, admin, SEs of iron sucrose (Venofer)?
20 mg/mL inj
HD pts: 100 mg IV slow inj for 1-3x /wk for 10 doses
non-HD: 200 mg IV x 5 doses
may admin IVP at 1 mL/min and admin over 20 min
SEs: cramps, hypoTN, N/V,D, HA
Describe dose, admin, SEs of ferric gluconate (Ferrlicit)
12.5 mg/mL
125 mg (10 mL) 1-3 x /wk for 8 doses (total dose 1000 mg)
admin over 1 hr
cramps, N/V, flushing, hypoTN, rash, pruritis, hypersensitivity
Descibe dose, admin, SEs of ferraheme (Ferumoxytol).
30 mg/mL inj
510 mg (17 mL) inj followed by 510 mg 3-8 d later
admin 1 mL/sec
hypersensitivity
N/D, constipation; interfere w MRI
Agents used for IDA + CKD
Injectafer (ferric carboxymaltose), non-HD CKD
Triferic (ferric pyrophosphate)
HD-dep CKD
How to calculate LBW? (confused as to what this means)
males = 50 kg + 2.3 (in > 5 ft)
females=45.5 kg + 2.3 (in >5 ft)
How to calculate PE iron dextran dosing in pts w anemia secondary to blood loss.
mg iron = blood loss x hematocrit
mL and decimal fraction
What are iron monitoring parameters?
monitor TSAT and ferritin q 3 mo
KDIGO: no supplemention of Fe is TSAT >50% or ferritin >500 mg/mL
What determines the duration of Fe supplementation for anemia?
incr Hb 1 g/Dl q 2-3 wk
for many pts 3-4 mo but could be longers
Why do we want to avoid iron overload?
gastric ulcer
met acidosis
internal organ damage (brain, liver, d/t iron deposits)
IDA tx is 3-6 mg/kg/d elemetal Fe
toxicity at 10-20 mg/k/d
severe tox @ 50 mg/kg/d
What are ind for blood transfusion?
symptomtic anemia
Hg <8 g/dL
How large is a unit of PRBC and what is the expected change?
300 mL
Hb incr 1 g/dL
Hct incr 3%
What are complications of transfusions?
iron overload acquired infx hyperviscosity alloimmunization volume overload transfusion rxns (TRALI)
What are causes of macrocytic anemia?
emolyss/reticulocytosis B12 or folate def EtOH abuse (nutrition def) liver dz hypothyrodism drugs (chemo)
Describe B12 def.
pernicious anemia.
must be obtained externally, bound to potin in food, released by HCL, ombine w intrinsic factor for abs.
RDA: 2 mcg/d
body sotres 2-5 mg in liver
drug intx: H2 blocker, PPI, metformin
What are Sx of B12 def?
paresthesias, peripheral neuropahty, depressed tendon reflex
psych: irrit, mood changes, memory, impairment, depression, psychosis
dysphagia
glossitis
muscle weakness
anorexia
What is B12 def Tx?
oral B12 (cyanocobalamin) 1-2 mg d for 1-2 wks then 1 mg d for life used in pernicious anemia for maintenance
PE cyanocobalamin
1 mg IM or deep SC inj d for 1 wk then wkly for 1 mo then monthly for life
food (green leafy vegs and meats)
What are causes of folate def?
inadequate intake ; alcoholism, elderly
decr’d abs: extensive jejunal resetion, dz that imp abs
inadquate utilization
hyperutilization: preg, cancer, chronic inflamm, growth spurts, HD
drugs:
folate antag: methotrexate, TMP, phenytoin, phenobarbital
anti-metabolites: azathioprine, 6-mercaptopurine, 5-flourouracil
folate def tx
PO supp
1 mg d for most
up to 5 mg d for malabs pts
500 mcg d for anticonvulsant meds
Dietary intake: remember banana bags for alcohols (no longer used)
Describe anemia of chronic dz.
common form of anemia seen clinically.
dx of exlcusion
assoc’d w incr’d morbidity and mortality
causes: CKD, infx, cancer, autoimm
What is the tx for anemia of chronic dz?
ESAs: epoetin alpha (epogen), darbepoetin alpha (Aranesp)
What is the blackbox warning on ESAs?
incr risk of death and serious life-threatening CVEs in pts w a target Hb >12 g/dL
What are the differences in ESA doses?
epogen 3x/wk
aranesp once weekly
What are SEs of ESAs?
HTN
HA
epogen: arthralgias
Aranesp: D, hypoTN, infx
Describe SCA?
sickle cell anemia
inherited dz: 1th chromosome, beta-2 globulin (Hb)’
poor oxygenation, decr pH, decr T, incr osmolarity–> precipitation and polymerization –> long, rigid RBCs –> micovascular infarcts
How does SCA present?
chornic anemia fever and pallor arthralgia scleral icterus ab pain wkness anoreia fatigue enlarged liver, spleen, heart hematuria
How to evaluate SCA.
decr: Hg
incg: bilirubin reticulocytes platelets whte blood cell count sickled cells on smear
What are acute complications of SCA?
acute chest syndrome
sickle cell crises
priapism
What are chronic complications of SCA?
pulm HTN bone and joint probs ocular probs cholelithiasis CV probs depression
Describe acute chest syndrome.
leading cause of death in pts w SCD (1/2 of pts will have at least once)
pres: new pulm infiltrate, resp sx, fever (sometimes), unclear response to Abx.
Tx of acute chest syndrome.
early recog pain manage broad-specrum Abx supportive care (o2, fluids)--caution: pul edema steroids controversial
Describe sickle cell crises.
- vasoocclusive pain crises
no permanent damage
lcalized pain - acute splenic sequestration crises: sudden enlargement of spleen and liver.exacerbates anemia, hypoTN, shock
assoc’d w viral/bac infx
Tx of vasoocclusiv epain crises
hydration: adults: 3-4 L/d
peds: 1.5-2x maintenacnce
analgesia
Tx of acute splenic sequestration crises.
blood transfusion to correct hypovol
broad spectrum abx
recurrent=poor prognosis, chronic transfusions
Describe priapism d/t SCD and Tx.
prolonged, painful erection
can cause impotence
tx: analgesia
irrigation/aspiration
vasoconstriction: PE, Epi
vasodilation: terbutaline, hydralazine
How to maintain health in pts w SCA.
immunization: flu, pneumo
PCN: <3yo PCN VK 125 mg po bid
>=30 yo and <5 yo PCN VK 250 mg po bid
folate
How is hydroxyurea used in SCA tx?
anti-neoplasic
incr prod of HbF (fetal)
decr sickle cell crises, transfusion, acute chest, and mortality
***dose 10-15 mg/kg/d (max 35 mg/kg/d)
monitor: Hb, MCV, CBC: q 2 wk until stable then q4-6wk (ANC and platelets)
SEs: bone marrow suppression, skin ulcers, N/D/C
Describe the role of butyrate in SCA tx.
natural FA
limited data
IV inf req’d
incr HbF not sustained
How is pain managed in SCA?
mild to mod: NSAID/APAP
mod to sev: NSAID/APAP, opiod if pain persists
sev:
opioid (PCA poss)
resuce opioid
adjuvant meds (NSAID< antihistmines)
How are chronic transfusions used in SCA?
used as acute and chronic tx stroke prevention decr acute chest, vassoocclusive crises, organ damage may reverse organ damage goal is to decr HbS (sickle)
What is thalassemia?
inherited dz: too much Hb
What is hematochezia?
BRBPR
What is melena?
black, tarry stools
If Hg, RBC, WBC, and platelets all low, consider…
APLASTIC ANEMIA.
chek meds: NSAIDs (phenylbutazone), sulfonamides, acyclovir, gancyclovir, chloramphenicol, anti=epeleptics (phenytoin, carbamazepine, valproic acid), nifedipine
check parovirus B10 IgG/M,
hepatitis
HIV
If Hb and platelets are low consider…
TTP or HUS
TTP: thrombotic thrombocytopenic purpura
HUS: hemolytic-uremia synd
–> check smear for schistocytes
if RF, E Coli exposure–> HUS
if RF neurologic changes, fever –> TTP
What is the normal RDW according to Kakeeh?
11-15%
what is normal TIBC, how to interpet?
250-400 mcg/dL
if high then need Fe supp
What is normal ferritin?
15-200 ng/mL male
F: 12-150 ng/dL
What is the normal folate lab?
1.8-15 ng/mL
What is normal B12 lab?
100-900 pg/mL
What is normal iron lab?
M: 50-150 mcg/dL
F: 40-150 mcg/dL
What are the drug-induced hematologic disorders?
aplastic anemia agranulocytosis megaloblastic anemia hemolytic anemia thrombocytopenia
Decribe aplastic anemia.
pancytopenia: anemia, neutropenia, and thromboytopenia (decr RBC, WBC, platelet)
Dx w 2 of following: WBC <3500 cell/mm^3
platelet <55k
Wb <10 g/dL
reticulocyte count ,30k
What are sx of neutropenia?
fever, chills, sx of infx
What are sx of thrombocytopenia?
buisability, petachiae (red pinpoints in skin), bleeding
***What are drugs that induce aplastic anemia?
carbamazepine phenytoin propylthiouracile TZ diuretics** sulfonamides methimazole
Describe agranulocytosis.
low levels of all granulocytes (granulocytopenia) and lack of their produciton in bone marrow
–neutropenia–drop in whitecount
Sx: sore throat, fever, malaise, wkness, chills, other s/sx infx
What drugs cause agranulocytosis?
antithyroid: methimazole, propylthiouracil
psyhotropic: clozapine, TCAs, cocaine/heroin
GI: sulfasalazine, H2-R antag
dermato: dapsone, isotretinoin
Abx: sulfonamides
antimalarials: chloroquine, quinine
anticonvulsants: phenytoin, valproic acid, carbamazepine
Describe D-I’d hemolytic anemia.
normocytic, incr reticulocyte count, (incr LDH, bilirubin)
genetic: SCA, G6PD def, thalassemias
acq’d: TTP, HUS, malaria
What drugs might inducehemolytic anemia?
phenytoin, phenobarbital, quinidine, many others
Describe glucose-G-phosphate dehydrogenase def.
most common enyme in erythrocytes.
brisk hemolysis when exposed to oxidative stress from drugs, infx, or toxins
Describe the two types of autoimmune hemolytic anemia.
warm-Ab-mediated: IgG Ab binds to erythrocyte suface.
Positive Coomb’s test.
caused by drugs.
tx w CSs or splenectomy
cold agglutinin dz: IgM binds to erythrocyte surface.
does not respond to CSs, but usually mild
Describe D-I’d megaloblastic anemia:
abnormal devo of megaloblast (RBC precursor)
incr MCV (fol/b12 def)
tx: d/c agent, folate supp
What drugs induce megaloblastic anemia?
methotrexate
cortrimoxazole
phenytoin
phenobaribtal
What drugs induce thrombocytopenia?
direct: chemo, organic solv, pesticides
imm rxn: quinine, quinidine, gold salts, sulfonamide abx, rifampin, glycoprotein IIb/IIIa inhib, heparin
platelet-reactive Abs: procainamide
Drug-dep Abs: heparin
Describe mech of heparin-induced thrombocytopenia and tx.
hep binds to platelet factor $, binds to IgG, binds to platelet.
plateslets removed,
thrombus formation decr platelets.
–> replace w non-hep anticoag (argatroban, lepirudin, bivalirudin)
describe methemoglobinemia.
> =1% methhemoglobin in blood.
Hb is in oxidized (Fe3_ state)–> can’t bind O2–> fxnal anemia.
deadly
caused by decr in reduction of methemoglobin. (congenital)
or D-I’d
List drugs that increase methemoglobin.
dapsone
topical anestehetics: benzocaine, lidocaine, prilocaine)
inh’d NO
What is tx for methemoglobin?
if <20% and asymp: no tx
if >20% and symp: methylene blue 1-2 mg/kg IV over 5 min.
avoid large doses >7 mg/kg
