Thromboembolism Flashcards
When is the highest risk for VTE during pregnancy?
Postpartum! Weeks following delivery
Third tri is greater risk than 1st/2nd tri
Most common thrombophilia?
Factor V Leiden Mutation
High Risk Thrombophilias
Factor V Leiden HOMOzygote
Prothrombin Mutation HOMOzygote
*Heterozygous for both conditions
Antithrombin Deficiency
Low Risk Thrombophilias
Factor V HETERozygote
Prothrombin Mutation HETERozygote
Protein C Deficiency
Protein S Deficiency
Antiphospholipid Antibody
Tx of VTE while pregnant
Theraputic dosing LMWH fpr 3-6 months, continue PPx dosing after this and for 6 wks postpartum
Tx for Hx of PROVOKED DVT in past (not estrogen related)
Antepartum surviellence
+/- PPx dosing for 6 wks PP
Tx for Hx of UNPROVOKED DVT in the past
PPx or theraputic LMWH antepartum
Continue 6 wks PP
Tx for Low risk thrombophilia
No prior DVT
No FmHx DVT
Antepartum surviellence
+/- PPx dosing for 6 wks PP if risk factors
Low Risk Thrombophilia
w/ FmHx of DVT (first degree)
Surviellence or PPx dosing antepartum
PPx dosing for 6 wks PP
Tx for High Risk Thrombophilia
w/ no Hx of DVT
PPx dosing antepartum and for 6 wks PP
High risk thrombophilia w/ hx of VTE
Theraputic dosing antepartum, continue for 6wk PP
When should anticoagulation begin postpartum?
4-6h after vaginal delivery
6-12h after C/S
- Consider if they had neuraxial blockade
- PPx or low dose LMWH (12h after placement, 4h after removal)
- Intermediate/Adjusted dose LMWH (24h after placement, 4h after removal)
Do Unfractionated Heparin and LMWH cross the placenta?
Nope!
Can you used direct thrombin inhibitors or Factor Xa inhibitors in pregnancy?
Not recommended!! Insufficient evidence - THEY DO CROSS the placenta
*Detectable in breast milk as well!
When is Warfarin acceptable in pregnancy?
In women with mechanical heart valves due to high risk of thrombus despite heparin
Anticoagulation in pregnant patient with suspected HIT?
Fondaparinux preferred agent
= enhances activity of antithrombin, but only enhances degradation of 10a
Clotting risk in pregnancy of Factor V Leiden + Hx personal hx of VTE?
Risk is 10%
What procoagulants increase in pregnancy?
All except
Factor 2, 5 and 9 STAY THE SAME
What anticoagulants decrease in prengnacy?
Protein S decreases
Protein C stays the same
Antithrombin stays the same
Dosing for PPx, intermediate and adjusted dose LMWH?
PPx 40 mg Daily
Intermediate 40 mg BID
Adjusted Dose = 1 mg/kg Q12
Dosing for PPx, and adjusted dose UFH?
PPx 5-10K units daily
Adjusted Dose > 10K Q12h
Best diagnostic imaging modality for a patient with renal insufficiency?
VQ scan
What gestational age is most appropriate to transition from LMWH to UFH?
36-37w
What thrombophilia test is NOT reliable during prengnacy?
Protein S
What thrombophilia test is NOT reliable with active clot?
Protein C
Antithrombin
Most important risk factor for developing VTE in pregnancy?
Hx of thrombosis
What is the MOST appropriate management of a pregnant patient with a heterozygous mutation for factor V Leiden mutation?
Surveillance w/ out anticoagulation
Which of the following is the BEST medication to reverse the effects of heparin
Protamine Sulfate
By how much does a personal history of venous thromboembolism (VTE) increase the risk of VTE in pregnancy
3-fold to 4-fold
What is the increased risk of VTE in pregnant/PP patients compared to non-pregnant?
Pregnant/Postpartum women have a 4-5 fold increased risk
What is the BEST estimate of risk of venous thromboembolism (VTE) in a pregnant patient who is heterozygous for factor V Leiden mutation with a personal history of VTE?
10%
Most common presenting sign of DVT in pregnancy?
PAIN + swelling
Target anti-Xa level for LMWH when using weight based/adjusted dose? When should it be drawn?
4 hours after injection
Target = 0.6-1.0 units/ml
MOA of Heparin
Co factor for antithrombin
Increases inhibition of thrombin and Factor Xa
What lab helps to monitor Heparin? What is the theraputic goal?
PTT
1.5-2.5 x control
Reversal agent for Heparin? Dosing?
Protamine Sulfate
1 mg/100 U heparin
Heparin PPx dosing?
5,000 units BID
Benefits of LMWH compared to Heparin?
Longer half life (easier dosing)
Decreased risk of HIT
No reversal
Still need to monitor: Anti Xa Q4-6 wks during pregnancy
Draw lab 4 hours after dosing
