Heme & ID Flashcards
initial thrombus formation steps?
plt adhesion > shape change (flat), ADP TXA2 granule release > recruitemnt > aggregation.
vascular injury response (3)?
- vasoconstriction
- plt adhesion
- thrombin generation
intrinisic pathway?
collagen + prekallikrein + HMW kininogen + 12
activate 11
activate 9
add 8
activate 10
add 5
2
1 (fibrin)
extrinisic pathway?
tissue factor + 7
10 add 5
2
1
how is thrombin key to coagulation?
2 (thrombin) activate 1a to 1, 5 and 8, activates plt
what does fibrin actually do?
plt plug to bind plt via Gp2BA
normal anticoagulation (3)?
- AT3 antithorombin 3; binds and inhibits 2 (thrombin), 9, 10, and 11
activated by heparin - protein C: degrades 5 and 8 and fibrinogen (1)
- protein S: protein C cofactor
normal fibrinolysis (2)
- tissue plasminogen activator (TPA) released from endothelium and converts plasminogen to plasmin
- plasmin: degrades 5, 8, fibrinogen, and fibrin
* alpha 2 antiplasmin: inhibitor of plasmin (released from endothelium)
factor with shortest half life?
7
whose activity is lose in stored blood but not FFP?
due to lability….
5 and 8.
which factor not synth’d in liver?
8 with vonWillebrand factor.
Vit K factors?
2, 7, 9, 10, C, S
Vit K vs FFP onset?
Vit K 12 hours (IV), FFP is immediate
half life RBC, plt, PMN?
RBC 120 days, plt 7 days, PMN 1-2 days.
function of prostacyclin PGI2?
from endothelium. PREVENT CLOT.
decrease plt aggregation, promote vasodilation (antagonizes TXA2) increases cAMP in plt
function of thromboxane TXA2?
from platelets. INCREASE CLOT.
increase plt aggregation, promote vasoconstriction.
triggers Ca release in plt. exposes Gp2B3A-R and causes plt-plt bind, plt-collagen (GpIb-R).
pGE2
in hypothalamus; induce FEVER
cryoprecipitate contents?
vWF-8 and fibrinogen.
indication for cryoprecipitate?
von Willebrand’s disease, hemophilia A (8), low fibrinogen.
FFP contents?
ALL coagulation factors, C, S, AT-3**.
DDAVP and conjugated estrogen effect on clotting
cause release of 8 and vWF from endothelium.
prothrombin time measures?
extrinsic pathway… 2, 5, 7, 10, fibrinogen.
best to see liver synthetic function
partial thromboplastin time measures?
measures intrinsic (cannot see 7 and 13 fibrin stabilizing factor).
70-90 AC
activated clotting time goal
150-200 routine AC
>480 for bypass.
vWB disease AD vs AR?
Type 3 is AR. Type 1 and 2 are AD.
vWF role?
GpIb-R on plt link to GpIb on collagen*.
Type I vWB disease?
mild bleeding, most common*
issue: reduced vWF
treat: recomb 8-vWF, DDVP, cryo.
Type 2 vWB disease?
issue: defect in vWF molecule; doesn’t work
treat: recomb 8-vWF, cryo, DDAVP.
Type 3 vWB disease?
AR. rare. complete deficiency.
treat: recomb 8-vWF, cryo (DDAVP won’t work).
DDAVP
desmopressin; stim release of vWF from endothelium.
use in uremic pts 2/2 ESRD as well
use in Hemophilia A and vWB disease
hemophilia A deficiency?
- sex linked recessive.
how does hemophilia A present?
hemarthrosis.
coag abnormality in hemophilia A?
PTT prolonged, PT normal
newborns with hemophilia A?
might be OK because factor 8 crosses placenta.
if bleeding, hemophilia A? how to treat.
ice/immobilize (if joint) +++ factor 8 concentrate, or cryoprecipitate.
hemophilia B deficiency?
- sex linked recessive.
how to preop 8 and 9 levels in hemophilia pre and postoperatively?
100% preop.
A/8: 80-100% for 2 wks after OR.
B/9: 30-40% 2-3 days after OR.
coag abnormality in hemophilia B?
PTT prolonged
PT normal
treat hemophilia B bleeding?
recombinant 9 or FFP.
factor 7 deficiency bleeding? how to treat.
prolonged PT
normal PTT
treat wiht recombinant 7 or FFP.
acquired thrombocytopenia Rx-related etiology?
heparin
H2 blockers famotidine.
glanzmann’s thrombocytopenia
G2B3A-R deficiency on plt
cannot bind together via fibrin
treat: plt
Bernard Soulier thrombocytopenia?
Gp1b-R deficiency on plt.
treat: plt
what level of uremia causes plt dysfxn
BUN > 60-80.
inhibits by inhibiting release of vWF.
treat: HD, DDAVP for acute reversal, cryo (if bleeding)
HIT Ab
IgG heparin-PF4 Ab causing plt destruction.
HIT pathogenesis
plt die… causing plt aggregation and thrombosis***
HIT 1 vs 2
1: non-immune (don’t treat)
2: IgG Abx - Factor 4
clinical manifestation of HIT?
plt < 100 but >20, plt drop > 50% from admission, thrombosis on heparin.
WHITE clot. ALL WITHIN 5-10 DAYS OF EXPOSURE.
how to dx HIT?
ELISA for Ab’s, SRA (serotonin release assay).
treat HIT?
stop heparin, start argatroban (direct 2 inhibitor); don’t give plt
DIC lab abnormalities
thrombocytopenia
low fibrinogen
high fibrin split products (high D dimer)
prolonged PT
prolonged PTT
DIC etiology
intiated by tissue factor. but multifactorial (treat the cause).
ASA MOA?
inhibit COX, decrease TXA2.
when to stop ASA and plavix and coumadin?
7 days preop.
plavix/clopidogrel MOA?
ADP-R antagonist.
what if new stent (need plavix) and need to go to OR?
bridge with eptifibatide (integrilin) Gp2B3A inhbitor
plt goal for periop?
50K preop
20K postop
bleeding issues after prostate surgery?
release of UROKINASE can activate plasminogen causing thrombolysis.
treat: amicar (inhibit fibirnolysis by inhibiting plasmin)
factor V leiden MC what?
MC congenital hypercoagulability d/o
resistance to activated protein C (defect is on factor V)
how to treat Factor V leiden?
heparin, warfarin
how to treat hyperhomocysteinemia?
folic acid, B12.
G20210A
prothrombin gene defect causing hypercoagulability
treat: AC
protein C/S deficiency tx?
AC.n
antithrombin 3 deficiency?
hypercoagulable.
heparin doesn’t work…
treat: recombinant AT-3 concentrate, FFP, warfarin
Polycythemia vera treat?
keep Hct < 48, plt < 400 before OR
treat: phlebotomy, ASA, hydroxyurea
APLS
antiphospholipid antibody syndrome .
ass’d SLE
PTT prolonged but HYPERCOAGULABLE
Ab to phosphos: cardiolipin (mitochondria) and lupus anticoagulant (cell membrane)
dx APLS?
PTT prolonged, not better with FFP
positive Russell viper venom time
false positive RPR test for syphilis
treat APLS?
heparin, warfarin
MC acquired hypercoagulable state?
tobacco.w
why anticoagulate on bypass?
Factor 7 (Hageman factor) is activated
who is most susceptible to warfarin skin necrosis?
protein C deficient ppl
because C and S short half life so have a relatively hyperTHROMBOTIC state.
Virchow’s triad?
- stasis
- endothelial injury
- hypercoagulability.
postop DVT tx?
1st: coumadin 6 mos
2nd coumadin 1 yr
3rd or PE: lifetime coumadin
amicar indication? = a-FIBRINOLYTIC
- urokinase bleeding after prostate
- DIC
- persistent bleeding after bypass
- thrombolytic overdoses
inhibits PLASMIN.
warfarin MOA
inhibits Vit K dependent carboxylation of glutamic residues on VKORC
heparin MOA
antithrombin 3 activator
increase neutralization of 2a prothrombin and Xa (pre X)
lovenox does not neutarlize 2a. just X.
half life of heparin?
60-90 min.
lovenox half life
6 hours
heparin clearance
by reticuloendothelial system (spleen, macrophages)
half life warfarin
40 hours
heparin vs warfarin placental barrier?
heparin does not cross; warfarin does.
SE long term heparin?
osteoporosis, alopecia.
protamine reaction?
hypotension, bradycardia, decreased heart function (cross reacts with NPH insulin or previous protamine exposure).
dabigatran MOA
direct thrombin inhibitors
half life: 12 hours
reversal dabigatra (pradaxa)
praxbind = idarucizumab
or HD
eliquis and xarelto half lives
eliquis (apixaban) 12 hours
xarelto (rivaroxaban) 6 hours
argatroban MOA
direct 2 inhitor REVERSIBLE.
half life 50 min
good for HIT.
bivalrudin MOA
direct 2 inhibitor REVERSIBLE
half life 25 min
argatroban vs bivalrudin metabolized by?
argatroban: liver
bivalrudin: proteinase enzymes in blood
hirudin MOA
direct 2 inhibitor IRREVERSIBLE. leeches.
most potent.
hirudin / hirulog half life
40 min
ancrod?
malayan pit viper venom. stimulates TPA release.
absolute CI for uro/strepto/tpa?
active internal, recent CVA/NSGY < 3 mos, intracranial pathology, recent GI bleed
major CI for u/s/tpa?
recent < 10 day surgery, organ Bx, OB delivery, LV thrombus, active peptic ulcer, recent major trauma, uncontrolled HTN, recent eye surgery
which blood products do not have HIV risk?
albumin, serum globulins
what is screened for in blood
HIV
HBV
HCV
HTLV
syphilis
West Nile Virus
how to treat warfarin coagulopathy?
IV Vit K with PCC (faster than FFP)
4 factor vs 3 factor PCC
3: 2, 9, 10
4: 2, 7, 9, 10 + C/S
Why does stored blood have higher affinity for oxygen?
Low 2,3 DPG causes increase affinity.
What type of hypersensitivity is ABO incompatibility?
Type II. Ab mediated.
Dx of acute hemolysis from ABO incompatibility?
Haptoglobin < 50
Free Hgb > 5
Increase IndBili
sx of acute hemolytic transfusions reaction?
chills, lightheadedness, back pain
stop the transfusion!
What is the most common transfusion reaction?
Febrile nonhemolytic transfusion reaction.
= urticaria, fever within 60 seconds
Febrile nonhemolytic transfusion reaction pathogenesis?
Recipient Ab against donor WBCs. (Cytokine release).
Mgmt febrile nonhemolytic transfusion reaction?
Stop transfusion, WBC filter and antihistamines for future transfusions.
MOA TRALI?
Donor Ab against recipient WBCs causing clot in pulmonary capillaries.
Leads to pulmonary edema < 6… very fast.
causes hypotension and respiratory sx
MC cause of death from transfuions reaction?
TRALI.
MOA hypocalcemia in large transfusion?
Citrate in blood products binds Ca.
calcium required for coagulation
ca is required in the clotting cascade (hypocalcemia; relative coagulopathy)
Cell mediated immunity includes what cytokines and cells?
IL 2, IL 4, IFN-gamma
MHC class I on all nucleated cells to activate CD8
also CD4, NK cells, macrophages.
how do NK cells work?
recognize non-self-MHC
recognize anything bound by a bunch of Abs
MHC-II
DR DP DQ
on all APCs.
activates CD4 to then activate helper T cells
stimulates Ab formation after B cell interaction
Ab mediated immunity (humoral) cytokines, cells?
IgM, IgG, IgA, IgD (on B cells), IgE
what does helper T cell CD4 release? = cell mediated immunity
IL2, IL4 (mature to plasma), IFN y (activate macrophage) cytotoxic T cells CD8
Which Ab are opsonins?
IgM and IgG
Which Abs fix complement?
2 IgG adn 1 IgM
Primary lymphoid organs?
Liver, bone, thymus.
Secondary lymphoid organs?
Spleen and lymph nodes.
How to manage nontetanus prone wounds, not UTD?
Give tetanus toxoid.
How to manage tetanus prone wound if UTD?
Give tetanus toxoid still unless 3 doses have been within past 5 years.
Tetanus prone wound not UTD.
Tetanus toxoid with tetanus Ig.
MC anaerobe in colon? MC aerobe?
Anaerobe Bacteroides. Aerobe E. Coli.
How to treat candiduria?
Just remove foley; watch. No antifungal.
ART for HIV PEP
AZT zidovudie and ritonavir (recall ribavirin is HCV)
within 1-2 hours of exposure
MC neoplasm in AIDS?
Kaposi sarcoma
MC lymphoma in HIV?
Stomach > rectum; mostly B cell non-Hodgkins
2nd mC reason for laparotomy in HIV (1st is CMV)
MC causes of UGI and LGI bleeds in HIV?
UGI: Kaposi, lymphoma
LGI: CMV, bacterial, HSV
Primary SBP tx?
IV CTX
Dx primary SBP?
Ascites > 250 PMN or positive Cx
How to tx Hep C
Sofosbuvir and ribavirin
exposure to unknown blood if not Hep B Vax’d
PEP within 72 hours of exposure (0.3%)
And HBIG and Hep B vaccine (23-37%)
Continue serology testing for Hep C don’t need to tx though (1.8%)
MC infection in txp pt? Q
CMV
colitis, pneumonitis (MC deadly infection of it )
What cell transmits CMV?
Leukocytes.
CMV dx
Serology and stain: leukocyte inclusion bodies.
Tx cmv
Ganciclovir (CMV Ig if severe infection or + donor liver)
MC aspiration PNA spot?
Sup seg
bug = S.pneumo (cover for poly anaerobe too though)
Brown recluse spider bite?
Tx: dapsone
which nucleotide do sulfonamides effect?
purines; PABA analogue.
which nucleotide does trimethoprim TMP effect?
purine; inhibits DHF reductase (dihydrofolate).
bacteriostatic abx?
tetracycline, clindamycin, erythromycin, bactrim
most common method of antibiotic resistance?
transfer of plasmids (I.e. of B-lactamase)
MRSA resistance mechanism
mutation of cell wall binding protein.
VRE resistance MOA?
mutation in cell wall binding protein. like MRSA.
genamicin resistance MOA?
modifying enzymes leads to decrease in active transport of gentamicin into the bacteria.
vanc peak and trough?
peak: 20-40 ug/mL
trough 5-10 ug/mL
gentamicin peak and trough?
peak 6-10 ug/mL
trough <1 ug/mL
what to do if peak too high?
decrease AMOUNT of each dosei
what to do if trough too high?
decrease FREQUENCE of dose
ampicillin coverage vs pencillins?
GPCs but also includes ENTEROCOCCI.
augmentin and unasyn vs penicillins?
also includes GNRs and some anaerobic.
anti-pseudomonals?
ticarcillin, piperacillin, cefepime, cipro, levo, ceftazidime, (+aminoglycodies… gentamicin)
generations of cephs.
1st: GPC
2nd: GPC + GNR + little anaerobic
3rd: GNR some Pseudo.
MOA cilastin with carbapenems?
prevents renal hydrolysis and increases half life
aminoglycoside SE (rev and irrev)
reversible nephrotoxicity
irreversible ototoxicitya
macrolide coverage
GPCs (think: PNA) and is prokinetic…
MOA amphotericin
bind ergosterols in wall and laters membrane permeability
SE of amphotericin (decreased by liposomal type)
nephrotoxicity, hypokalemia, anemia, fevers.
MOA azoles
inhibit ergosterol synthesis. (for cell wall) via inhibiting cytochrome p450 14a-demethylase
MOA micafungins
inhibit synthesis of cell wall GLUCAN.
MOA amphotericin B
prevent fungal growth by binding cell membrane sterols and causing cell death via LYSIS.
liposomal = less nephrotoxicity
TB Rx?
RIPE.
rifampin (RNA polymerase) - hepatotox, GI sx
Isoniazid (inhibit mycolic acid) + B6 - hepatotox
pyrazinamide - hepatotox
ethambutol - retrobulbar neuritis
ganciclovir side effect (give for CMV)
myelotoxicity, CNS toxicity
-cyclovir MOA
inhibit viral DNA polymerase.
enterococcus and cephalosporins?
resistant to ALL CEPHALOSPORINS.
Methotrexate and 5-FU nucleotide effect?
Purine.
Leucovorin effect on methotrexate and 5-FU?
MTX: Reverse effects by re-supplying folate.
5-FU: increases toxicity
TEG thromboelastography
clot formation and lysis to identify abnormalities at multiple points in the coagulation process
guide resuscitation efforts and selection of products to give coagulopathic patients
how to treat the TEG
a-angle high - cryo
Lysis% high - TXA
Max amplitude low - plt
K time (20 mm clot) - cryo
R time (start clot) - FFP
significant BAL Cx?
10,000+ CFU
HAART in elective surgery
Continue through surgery; don’t stop.
Dosing considerations (MIC) for B-lactam abx
β-Lactam antibiotics are most effective when drug levels exceed the MIC (minimum inhibotry concentration)
Therefore, dosing should keep the drug level above the MIC for more than 50% of the time between doses. In addition, frequent doses or continuous infusions have also been shown to increase effectiveness.
VAP dx and mgmt
Obtain Cx.
Start broad-spectrum abx
**Therapy should be narrowed or stopped in about 48 to 72 hours based on the culture results rather than automatically continued for the full 8-day course.
Don’t need to wait for CT scan necessarily.
duration of C diff tx
10 days
vancomycin or fidaxomicin over metronidazole. The dosage of vancomycin is 125 mg orally 4 times daily or fidaxomicin 200 mg orally twice a day for 10 days. If access to vancomycin or fidaxomicin is limited, metronidazole can be used, 500 mg orally 3 times a day
C diff pathogenesis
toxin A (ELISA)
mucor vs aspergillus on GMS stain
Aspergillus: septated hyphae with narrow branching angles.
Mucor: nonseptated hyphae with broad, branching angles
GVHD
after stem cell/BM txp
transplanted immune WBCs attack host body cells
T and B
palm and sole rash, GI distress
leukotrienes
from arachidonic
PRO INFLAMMATORY…
chemoattraction of adhesion, bronchoCONSTRICTION, MUCUS production, increased cap PERMEABILITY
vancomycin infusion reaxtion
hypersensitivity with rapid infusion
direct degranulation mast cells/basophils
so stay awy from relaxants/opioids (fentanyl/tramadol OK) and other abx to prevent more histamine
HCV needlestick exposure
0.1-1.8% infection..
so just wait and only treat if YOUR blood is infected
HCV treatment
sofosbuvir and ribavirin = TREATMENT CURE
HCV to ca vs cirrhosis
cirrhosis 15%
chronic infection 60%
HCC 1-5%
liver txp #1 reason
US: HCV
world: HBV
HBV needlestcik
give PEP ASAP (even if pregnant)
HIV needlestick
give PEP ASAP
then PEP x 4 wks
(but if not confirmed patient, just w8 (like HBV)
HIV exposure risk
blood transfusion 70%
infant form positive 30%
needle 0.3%
mucous 0.1%
B cells can secrete what without helper T
IgM
B cells need what to become plasma
IL5 and IL 6
IL4 from helper T stimulate B to become plasma
what labs to get in vWB disease suspicion?
PTT
plasma levels of vWF antigen
vWF activity (ristocetin cofactor)
factor VIII activity
SCDs MOA
TPA release; reduce fibrinolysis
improve veous return
type and screen vs crossmatch
screen also looks for preformed Abs to minor antigens
what bug can be transmitted with blood transfusion??
Chagas disease
HBV pathogenesis destruction
CD8s bind MHC I receptors on the virus; majority of liver injury
MHC class I A B C architecture
single chain with 5 domains
MHC class II DR DP DQ architecture
2 chains with 4 domains each
most important APC
dendrites
most common overall Ig
IgG
MC Ab in spleen
IgM
travels thru breast milk
IgA
crosses placenta
IgG
basophil vs mast cell
basophil in plasma
mast cell in tissue
IL2 in cancer
converts lymphocytes to
LYMPHOKINE ACTIVATED KILLER cells (enhance tumor response)
or TUMOR INFILTRATING LYMPHOCYTES (TILs)
for melanoma!
E. coli pathogenesis sepsis
LPS lipid A (endotoxin)»_space; activate macs , complement, coag cascade
MC bug SSI
S. aureus
exoslime in Staph is what kind of matrix
exopolysaccharid matrix
MC GNR in SSI
E. coli
MC anaerobe in SSI
Bacteroids (also MC anaerobe in the gut)
how many bug is a wound infaction
10^5
what produces ENDOtoxin
C. perfringens (alpha toxin) and B-hemolytic strep
MC infection postop
UTI
MC infectious death postop
HAP/VAP
MC HAP/VAP bug
S. aureus > Pseudomonas > E. coli
MC line bug
S. epi > S. aureus > YEAST
necrotizing fasciitis bugs
GAS (b hemolytic) > MRSA (both have exotoxin)
invasive aspergillosis
voriconazole
invasive candidiasis
mica vs anidulafungin
SBP in cirrhosis is moslty what bug
mostly monobacterial E. coli
SBP SECONDARY mostly what bug
polymicrobial POO bugs
DFI bugs
need to cover for PSA too (include staph, strep, anaerobes)
tx = ZOsyn, Unasyn
Septic arthritis bugs
include VANC…. cuz staphs, strep, gonococcal, H flu
cat dog human bite bug
MC - GAS
also cover…. human (Eikenella for joint injury)… cat/dog (pasturella multocida)
tx = Augmentin
skin infection (impetigo, erysipelas, cellulitis, follicutisi) bug
STAPH > strep
PD cath infection MC bug
STAPH EPI**»»> S aureus, PSA
PD cath infectoin tx
IP vanc + gentamicin
remove if > 4-5 days or if fungal/TB/PSA
iodofors for what bugs
GNR
GPC
not fungal
chlorhexidine gluconate for what bugs
GNR
GPC
FUNGUS
50S ribosome subunits (protein synth)
macrolides
linezolid
Synercid
30S ribosome subunits (protein synth)
aminoglycosides (gentamycin, tobra) – which are bacteriocidal
tetracycline - is the only bacteriostatic one
RNA polymerase inhbiitors
RIFAMPIN
makes oxygen radicals to break DNA
Flagyl
IL-1 and fever
macrophages release
cause PGE2 mediated fever
can release IL1 in alveolar macs during atelectasis
selectins
L: leukocytes
E: endothelial
P: platelets
for rolling adhesion
B2 integrins (CD 11/18)
on WBCs… .bind ICAMs
for anchoring adhesion
ICAM, VCAM, PECAM, ELAM
on endothelial cells… bind B2 on WBCs and plts
for tranesndothelial migration (diapedesis- foot)
leukotrienes
LTC4, LTD4, LTE4: slow reacting substrate for anaphylaxs
LTB4: chemotactic for inflammatory cells
cxc chemokinds
cysteine - something - cysteine
IL8 and PF4
for chemotaxis, angiogenesis, wound healing
oxidant and reagant
superoxide anion - NADPH oxidase
hydrogen peroxide - xanthine oxidase
cellular defense to oxidation
SOD
glutathione peroxidase or catalase for H2O2ri
primary mediator of reperfusion injury
PMN ss