VTE Flashcards
Prevalence of PE in pregnancy?
2-6%
At what stage (ante/intra/postpartum) is the risk of a VTE highest?
Postpartum
What are the symptoms of a DVT and PE?
DVT - leg swelling, tenderness, erythema, pain, lower abdominal pain ( if extension into pelvic vessels)
PE - dyspnoea, chest pain,
haemoptysis and collapse
Low grade pyrexia and leucocytosis can alconoccur with both
How do u diagnosis acute DVT?
Compression lower limb duplex ultrasound
What percentage of patients with untreated DVT will develop PE?
15-24%
In what percentage of pregnant patients is PE fatal?
15%
- of these 66% will die within 30mins of embolic event
What is the sensitivity and negative predictive value of serial compression ultrasonography in detecting DVT?
Sensitivity - 94.1%
Negative Predictive Value- 99.5%
How do u diagnosis an acute PE?
- Computerized Tomography Pulmonary Angiogram
- more readily available than V/Q, shows other lung pathology
- low radiation to fetus, relatively high dose to maternal breast tissue (20mGy) = increased risk breast ca
- bismuth Shields over breast decrease risk by 20-40%
- Ventilation/Perfusion lung scan
- neg predictive value of 99%
- slight increased risk of childhood cancers
If CTPA not available:
- Cxray: normal in 50%, features of PE include atelectasis, effusion, focal opacity, pulmonary oedema (kurly b lines - indicate thickened, oedematous interlobular septa)
- helps to exclude lung infection, pneumothorax and lobar collapse.
*negligible radiation dose <0.01mSv
ECG is of limited diagnostic value and is abnormal in 41% of pts with PE.
- most common abnormalities: T wave inversion, S1Q3T3 pattern and Rt bundle branch block.
- Also helps to exclude other causes
T/F. Tranexamic acid is assoc with an increased risk of VTE?
False
How many current risk factors (other than prev VTE or Thrombophilia) are required for thromboprophylaxis/lmwh throughout the antenatal period?
4 or more
How many current risk factors (other than prev VTE or Thrombophilia) are required for thromboprophylaxis/lmwh from 28 weeks gestation?
3
Patient has 2 current risk factors for VTE (other than prev VTE or Thrombophilia). What’s your advice ?
CONSIDER prophylactic LMWH for at least 10 days postpartum
T/F. All women requiring antenatal prophylactic LMWH should continue prophylaxis for 6 weeks postnatally?
True - usually this is true, however a postnatal assessment should always be made.
How should a pt with a single previous VTE (not related to a major surgery) be managed?
-Prepregnancy counselling
-Management plan for VTE in pregnancy should be made
- should be offered thromboprophylaxis with LMWH throughout antenatal period.
If pregnant refer to an expert in thrombosis in pregnancy
Management of a pt with a previous thrombophilia-asscoiated VTE?
Thrombophilias may be HERITABLE or ACQUIRED.
For VTEs due to Antithrombin deficiency a Multi-disciplinary team approach is needed.
- MFM specialist with collaboration with a haematologist with expertise w/ thrombosis in pregnancy.
– consider antenatal anti-Xa monitoring
— consider potential need for antithrombin replacement at START of labour or PRIOR to csection. - Offer thromboprophylaxis with higher dose LMWH (either 50%, 75% or full therapeutic dose) antenatal and for 6 weeks postpartum OR until returned to oral anticoagulant therapy post delivery.
— as most pts would have been managed on oral anticoagulation.
For other heritable thrombophilic defects can be managed with standard doses of thromboprophylaxis as they are lower risk.
ACQUIRED thrombophilia
- Pts with Antiphospholipid syndrome/APS are usu on long term anticoagulation.
- manage with haematologist and rheumatologist w/ expertise in this area.
- Offer thromboprophylaxis with higher dose LMWH (either 50%, 75% or full therapeutic dose) antenatal and for 6 weeks postpartum OR until returned to oral anticoagulant therapy post delivery.
