VTE in pregnancy Flashcards
Risk factors for VTE
Smoking
Parity > 3
Age >35 years
BMI >30
Reduced mobility
Multiple pregnancy
Gross varicose veins
Immobility
FH VTE
thrombophilia
IVF pregnancy
RCOG guidelines when to start prophylaxis for VTE in pregnancy
28 weeks if there are three risk factors
First trimester if > 4 or more of these risk factors
WHat additional scenarios is prophylaxis for VTE required in
Hospital admission
Surgical procesdures
Prev VTE
Medical conditions - cancer, arthritis
High risk thrombophilia
Ovarian hyperstimulation
When are risk assessment for VTE performed in pregnancy
At booking
After birth
What should women with higher risk of VTE get?
LMW heparin unless contraindicated
Examples of LMWH
Enoxaparin
Dalteparin
Tinzaparin
When is prophylaxis for VTE started in high risk vs v high risk pregnancies
V high risk - asap
high risk - 28 weeks
Continued throughout antenatal period and for 6 weeks postnatally
When is prophylaxis against VTE stopped
When woman goes into labour
Started immediately after delivery UNLESS PPH, spinal anaesthetic or epidurals
When is mechanical prophylaxis considered and what are the options
When LMWH contraindicated
Intermittent pneumatic compression
Anti-embolic compression stockings
Presentation of DVT
Unilateral
Calf or leg swelling
Dilated superficial veins
Tenderness to the calf - particuarly over deep veins
Oedema
Colour changes to the leg
Presentation of DVT
Unilateral
Calf or leg swelling
Dilated superficial veins
Tenderness to the calf - particuarly over deep veins
Oedema
Colour changes to the leg
How to measure leg swelling
Measure the cirucmference of the calf 10cm below tibial tuberosity
>3cm difference between calves is significant
Presentation of PE
SOB
Cough with or without blood
Pleuritic chest pain
ypoxiaH
Tachycardia
Raised resp rate
Low grade fever
Haemodynamic instability causing hypotension
Investigation for DVT
Doppler US
Guideline - repeat negative US scans on day 3 and 7 in patients with high index suspicion for DVT
What investigations do women w sus PE need
CXR
ECG
Options for definitive diagnosis of PE
CTPA
VQ scan
CTPA vs VQ scan
- CTPA is the test for choice for patients with an abnormal chest xray
- CTPA carries a higher risk of breast cancer for the mother (minimal absolute risk)
- VQ scan carriers a higher risk of childhood cancer for the fetus (minimal absolute risk)
What normal measures are not useful in VTE in pregnant women
Wells score not validated
D-dimers not helpful
What is a VQ scan
involves using radioactive isotopes and a gamma camera, to compare the ventilation with the perfusion of the lungs. First, the isotopes are inhaled to fill the lungs, and a picture is taken to demonstrate ventilation. Next, a contrast containing isotopes is injected, and a picture is taken to demonstrate perfusion. The two images are compared. With a pulmonary embolism, there will be a deficit in perfusion, as the thrombus blocks blood flow to the lung tissue. This area of lung tissue will be ventilated but not perfused.
When should LMWH be started if VTE suspected
AS soon as suspected - dont wait for diagnosis
How long is LMWH continued for
Remainder of pregnancy
Six weeks postnatally or 3 months total - whichevers longer
Can switch to a DOAC after delivery
Treatment for massive PE and haemodynamic compromise
Unfractionated heparin
Thrombolysis
Surgical embolectomyy
W
