Thrombosis, ASPHO Flashcards
(124 cards)
1
Q
3 parts of virchow’s triad?
A
endothelial injury
hypercoagulability
venous stasis
–> blood clot
2
Q
what are the vit k dep factors?
A
2,7,9,10
3
Q
bimodal distribution of clots..peaks?
A
<1 year (particularly <1 month) and during adolescenece 11-18
4
Q
acquired rfs for thrombosis…top 3? give 8 others
A
top 3= central venous catheters, cancer, cardiac disease…renal disease, liver diseae, rheum disease like lupus, IBD, DM, obesity, surgery, trauma, immonbility, infection, estrogen, dehydration, antiphospholipid syndrome
5
Q
what does fondaprinux target?
A
Xa
6
Q
what does heparin target?
A
Xa, IIa= thrombin
7
Q
3 times when you should eval for thrombophilia?
A
- non CVL-related clot
- recurrent clot
- acquired RF in pts with strong family hx of VTE (first degree relative <40 yrs or multiple relatives)
8
Q
what should you check for thrombophilia eval?
A
AT def Prot C def Prot S def Factor V Leiden mutation prothrombin G20210A mutation
9
Q
mild common thrombphilias?
A
Factor V Leiden, prothormbin gene mut
10
Q
severe rare thrombophilias?
A
prot c def, prot s def, at def
11
Q
explain fvl
A
factor 5 mutant becomes insensitive to activated protein c= a natural anticoagulant–> f5 becomes overly active…most common thrombophilia we see, 5% in white population
12
Q
explain G2021A mutatio in prothrombin
A
–> increase in prothrombin levels
13
Q
factor v ledin: what % don’t get a clot?
A
95% of hetero
14
Q
FVL: increase risk of clot from baseline?
A
4x higher
15
Q
FVL and obsetrics?
A
may play a role in some cases of unexplained recurrent late preg loss
16
Q
FVL hetero have a ___ recurrence risk
A
LOW…shouldn’t alter decision-making re: duration of AC
17
Q
PT mutation: increase risk of clot over baseline?
A
4x higher
18
Q
PT mutaiton: risk of VTE recurrence is ___
A
low
19
Q
what does protein s do?
A
helper protein for protein C
20
Q
what’s the most common? prot c, prot s, or at def?
A
Prot c def>prot s def> AT def
21
Q
high -very high risk of recurrence for pts with what thrombophilias?
A
prot c def
prot s def
at def
22
Q
typical prot c levels?
A
70-150%…<55%= problem
23
Q
typical prot s levels?
A
60-120%…<35%= problem
24
Q
typical AT levels?
A
110-140%…<40-60%= problem
25
which disorders are associate with warfarin skin necrosis? (2)
prot c def and protein s def
26
which disorder is asscoaited with hep resistance?
AT def
27
of protein c def, protein s def, adn AT def, which is most likely asscoaited iwth arterial clot?
prot c def
28
of protein c def, protein s def, adn AT def, which is most associate with preg-related VTE?
AT def
29
of protein c def, protein s def, adn AT def, which is most associated with fetal loss?
prot c def
30
of protein c def, protein s def, adn AT def, whihc is most asscoiated with VERY high risk of clot recurrence?
AT def
31
when does AT reach normal level?
age 6-12 mos
32
when does prot c reach normal level?
late teens/early 20s
33
when does prot S reach adult level?
6-12 months
34
how does homozygous prot c/prot s def present?
purpura fulminans
35
manage purpura fulmianns how?
- send off prot c and s!
- aggressive FFP replacment at time of presentation
- long term AC, prot C replacmenet (we can't replace prot S)
36
consier antiphospholipid antibody syndrome when?
- unprovoked VTE
| - new VTE in patient with underlying autoimmune disease
37
def'in of AAS?
persistent presence of antiphospholipid abs or lupus AC for at least 12 weeks in context of an acute thrombotic event
38
lab eval for AAS?
LAC, anticardiolipin abs, anti-beta 2 glycoprotein
39
how do you manage AAS?
long term ac
40
LAC: dx how?
dilute Russell viper venom tire (dRVVT), activated PTT or StaClot test...LA are characterized by correction fo the prolonged clotting time when you add phospholipid to the patient sample but NOT when you add control palsma, confirming that the coagulation inhibitor is phospholipid-dependent
41
4 signs/sx of DVT
acute swelling
pain/tenderness
red/purple discoloration
warmth
42
4 acute signs/sx of catheter related clots?
extremity sewlling
extremity pain
discoloration
line malfucntion
43
chronic signs of catheter-related clot? (3)
catheter occlusion
prominent chest wall veins
recurrent bacteremia
44
triad for PE?
chest pain, SOB, hypoxia...but only seen in 20% of kids with PE....also can get fever, cough, hemoptysis, rapid/irreg pulse
45
4 signs/sx of cerebral sinovenous thrombosis?
h/a
sz
cranial nerve palsies
papilledema
46
RFs for CSVT? 5
```
dehydration
lymphadenitis
ear infection--> mastoiditis
jugualr vein catheterization
neonatal age group
```
47
3 anatomic variants associated with unprovoked VTE?
May Thurner syndrome
Thoracic outlet syndrome
IVC atresia/anomalies
48
May Thurnder: increased risk of VTE where?
left sided iliofemoral clots
49
what is May Thurner?
narrowed left iliac vein due to compression from right iliac artery
50
most commonly see May Thurner in which pts?
females in the 2nd adn 3rd decade of life
51
throacic outlet syndrome aka?
paget-schroetter syndrome
52
Thoracic outlet syndrome associated with DVTs where?
axillary, subclavian
53
TOS due to?
compression of veins by extra rib, muscle group
54
TOS associated with?
repeititve activity: baseball, softball, swimming, volleyball
55
TOS: management?
first rib resection
56
5 tx options for VTE?
```
UFH
LMWH
fondaparinux
parenteral direct thormbin inhibitors
vit k antagonists
direct oral anticoagnats
thrombolysis
```
57
UFH: binds reversibly to ___; after binding, increases ___'s ability to inhibit ___ and ____...does it bind other palsma proteins?
AT; AT; thrombin; Factor Xa; yes
58
UFH: chains of varying lengths: sizes?
5k-40k Da
59
LMWH size chains?
<8k Da
60
LMWH binds to and accelerates the activity of ____ but with a preferenctial and longer-lasting effect on ___
AT; Xa...less able to inhibit thombin and bind to other plasma proteins thn UFH!
61
fondaparinux binds to enhances activity of ___ by ___-fold...does it bind to other plasma proteins? does it have direct effect on thrombin?
AT; 300; no; no
62
explain the mech of UFH
binds to and increases AT inhbiition of Factor 10A and thrombin
63
explain the mech of LMWH
binds to and increases AT inhibition of 10 a and thormbin, BUT with a preferential and longer-lasting effect on Xa
64
explain teh mech of fondaparinux
binds to adn STRONGLY enhances actvity of AT, only inhibits 10A with NO DIRECT EFFECT on THROMBIN
65
other activity of UFH?
binds non-specifically to a variteyt of other palsma protiens
66
other activity of LMWH?
less able to bind other plasma proteins
67
other activity of fondaparinux?
does not bind to tohter plasma proteins
68
UFH: monitoring?
PTT, ACT, anti-Xa
69
LMWH monitoring?
Anti-Xa
70
fondaparinux monintroing?
anti-Xa that's calibrated for fonda
71
act stands for?
activated clotting time
72
Adv of UFH?
good first choice for pt who is unstable or may need a procedure soon; short half life of 30 min; reversible with protamine
73
disadv of UFH?
continuous infusion
74
LMWH advs?
SC injection
easier to use in stable pt
more predictable pharmacokinetics
longer half life: 4-7 hrs
75
disadv of LMWH?
requires good renal functon
| incomplete reversal with protamine
76
monitor UFH how often?
daily, and 4 hours after any dose changes
77
PTT target in UFH?
65-80, or 1.5-2.5x baseline
78
PTT sensitive to what?
improper collection, anemia, low plts, factor defs, LAC, pt age
79
preferred way to monitor UFH?
anti-xa, has most consistnet results
80
ACT: sensitive to?
plt counts and function, factor defs, ambient temp, hypothermia, LAC
81
anti-10a target?
0.3-0.7
82
anti-10a affected by?
hemolysis, high bili, high triglycerides
83
LMWH: obtain anti-10a level how many hours after dose? goal range? goal range for ppx?
4-6 hours
0. 5-1
0. 1-0.3
84
infant <3 months need ___ doses of heparin and more ___ ___ due to a ___ ___ __ ____
higher; frequent monitoring; larger volume of distribution
85
heparin affects what when drawing sample from central cath? (2)
thrombin time, PTT...you could do a PTT HEPARINASE to see if that PTT prolongation was due to heparin
86
RFs for HIT?
PICU, NICU, heart surgery...has been receiving heparin for several days
87
what causes HIT?
due to formation of auto-antibodies against endogenous platelet factor 4...development of auto-ab takes about 5 days
88
do what if suspect HIT?
stop heparin! start direct thrombin inhibitor...test for HIT Ab (ELISA) and confirm with functional assay= serotonin release...AVOID plt transfusions unless severe hemorrahge
89
give 2 direct thrombin inhibitors. do they have reversal agents?
argatroban, bivalirudin...no
90
argatroban and bival: bind thrombin reversibly or no?
arg: reversible; bival: partially reversible
91
half life of argatroban?
45 min
92
bival half life?
25 min
93
elimination argatroban?
hepatic
94
bival elim?
renal
95
monitor bival how?
aPTT, ACT
96
argatroban: monitor how?
aPTT, ACT
97
antidote for bival and argatroban?
none
98
mech of warfarin?
inhibitors hte synth of vit k dependent clotting factors= 2, 7, 9, 10.....will also inhibit prot c and s because also vit k dependent--> actually leads to HYPERCOAGULABLE state at first because protein c and s decrease FIRST! this is why you need bridging
99
warfarin must be given with another AC for at lesat __ days until a therpeutic inr is reached
5
100
typical dose of warfarin?
0.1 mg/kg/day
101
what is INR?
ratio fo the patient's pt= prothrobin time and the rnomal mean PT
102
what can interact with warfarin? 8
antibiotics, gastroenteritis, anticonvulsants, anti-fungals, antacids, febrile illness, liver disease, vit k containing foods, infant formulas (have lots of vit k), mango, avocado, fish oil, soy milk, grapefruit
103
how to reverse warfarin?
vit k, FFP, PCC= prothormbin complex concentrate
104
adv of direct oral anticoag?
less bleeding than warfarin with similar efficacy
105
Xa inhibiting doacs to know?
apixaban, rivaroxaban
106
direct thrombin inhibitor?
dabigatran
107
which doac has phase 3 in kids?
rivaroxaban...liquid not yet available
108
give half lives of dabigatran, rivaroxaba, apixaban
dab: 11-14 hours (BID)
riva: 5-9 hours (QD)
apix: 9-14 (BID)
109
clearance of dabigatran?
renal
110
clearance of riva?
renal
111
clearance of apix?
mainly liver
112
provoked VTE: tx for how long?
if RF is reversbile, 3 months (6 weeks in neonataes)...if RF is chronic: 12 mos to lifelong
113
idiopathic VTE tx for how long?
6-12 mos
114
recurrent VTE tx for how long?
reversible RF: 6-12 mos
| chronic RF: 12 mos- lifelong
115
4 reasons for thrombolysis?
life threatening art thormb
intracardiac thrombus
PE with right heart strain or hypotension
extensive DVT (SVC syndrome, occlusive IVC thrombosis with renal compromise, large iliofemoral clot)
116
when NOT to do thrombolysis?
- active major bleeding
- significant potential for uncontrolled local bleeding
- surgery within preceding 10 days (neurosurgery 60 days)
- neurosurgery
- intracranial neoplasm/cerebral vascular lesion
- seizures within 48 hours
- sepsis
- uncontrolled severe htn
- contrast allergy
117
ways to give tPA?
catheter-driected
low-dose systemic 24-96 hours
high-dose systemic 6 hours
118
laboratory monitoring and goals in thrombolysis?
- fibirnogen: 100-200 (hsould decrease by 20-50%)
- d-dimer (elevatd)
- PTT (50-70), becuase give UFH at same time usually
- hgb stable
- plts >100k...think of thrombolysis= just like DIC!
119
post-thrombotic syndrome causes? 2
residual venous outflow, venous valvular insufficiency
120
RFs for PTS? (5)
```
adolescents
obesity
extesnive DVT (multiple vessels)
idiopathic or efffort-related upper extrem DVT
lack fo DVT resolution
```
121
PTS incidence?
25% in thsoe with extremity DVT
122
symptoms/signs of PTS?
pain, paresthesia, dialted vessels, swelling....also decreased QoL if mod-severe
123
how to prevent PTS?
- consider thromboprophylaxis is those with prolong hospitalization/immobilization/prescence of CVL/infection/chronic inflamm/prothromb chronic disease
- timely dx and initiation of therapy for VTE
124
4 ways to manage PTS?
- elastic compression stockings
- phys therpay
- elevating the affected extrem at rest
- mantaining a healthy wt
