S7C60 - Thromboembolism Flashcards
1
Q
PE
A
- pt becomes symptomatic when 20-30% of lung vasculature has been occluded
- DVT form in the popliteal, common femoral, superficial fem, pelvic, axially and jugular veins
2
Q
DVT
A
->2cm b/w R and L leg diameter 10cm below tibial tubercle i spredictive of DVT
3
Q
D-dimer false positive
A
- age >70yo
- pregnancy
- active malignancy or mets
- surgical procedure w/in 1w
- liver dz
- RA
- infxn (sepsis)
- trauma
4
Q
D-dimer false negative
A
- warfarin tx
- symptoms >5d
- small clots
- small infarction
- calf vein thrombosis (isolated)
5
Q
Ct chest and risk of cancer
A
-one CT chest increases the lifetime risk of fatal cancer or leukemia to 1:500
6
Q
PE decision rules
A
- ask yourself ‘do I have more than a low suspicion for PE’?
- low = probability that pt will have a PE in the next month is <15%
- yes: then order a diagnostic test
- no: apply the PERC rule, if all 8 factors are met then probability of VTE is <2%
- if any pERC is positive and risk is low/moderate then do the d-dimer (wells <4)
7
Q
PERC rule-out criteria
A
- age <50yo
- pulse ox >94% (on room air)
- HR <100
- no hx of VTE
- no surgery/trauma in past 4w
- no hemoptysis
- no estrogen use
- no uilateral leg swelling
8
Q
Diagnosis of PE
A
- must have post-test probability >80%
- either a positive CT or high probabiliyt V/Q scan or venous US with findings of DVT
9
Q
DVT
A
- low pretest probability (Well <1) plus negative d-dimer = no DVT
- if positive d-dimer then must get US
- moderate/high wells score should get US, if negative then d-dimer should be done
- if d-dimer also neg then no DVT
- if d-dimer postive and US neg then US should be repeated in 1 w
10
Q
Antithrombotic indications for VTE
A
- DVT - give thrombolytic if severe DVT causing phlegmasia cerulea dolens (however catheter directed thrombolysis is preferred if facility can accommodate)
- PE -
- massive PE = systolic BP <90 for >15 mins or SBP <100 in a pt with HTN
- give fibrinolysis
- sub-massive PE = normal or near-normal BP but evience of cardiopulmonary stress
- also give if cardiac arrest at any time, respiratory failure and hypoxemia with R heart strain
11
Q
Superficial thrombophlebitis
A
- NSAID or diclofenac gel
- if extensive then give give anticoagulation at the prophylactic dose (eg. enoxaparin 40mg SC daily)
12
Q
Contraindications to TPA for PE
A
- intracranial dz
- uncontrolled HTN
- recent major surgery or trauma (past 3w)
- metastatic cancer
13
Q
TPA - alteplase dose
A
100mg IV over 2h
14
Q
PE/DVT in pregnancy
A
- treat with UFH or LMWH
- warfarin is teratogenic
- use V/Q scan or low dose radiation CT
- V/Q has slightly higher risk of childhood cancer in offspring (1 in 280,000 vs 1 in 1million for unexposed children) but has less risk for breast cancer
- d-dimer threshold should be increased according to trimester:
- 750 nanograms/ml first trimester
- 1000 nanograms/ml 2nd trimester
- 1250 nanograms/ml 3rd trimester
15
Q
Indications for hospitalization in pts with DVT
A
- extenseive DVT with circulatory compromise
- increased risk of bleeding
- limited cardiorespiratory reserve
- risk of poor ocmpliance at home, inadequate support
- contraindication to LMWH necessitating IV heparin
- coexistant PE
- suspicion for HIT
- renal insufficiency requiring monitoring of anti-factor Xa level
