VTE Pregnancy Flashcards
Physiological changes in pregnancy with coagulable state
Physiological hypercoagulable state
Increase in factor 8,9,10
Fibrinogen rises by 50%
Decreased fibrinolytic activity
Endogenous anticoagulants like protein S and antithrombin fall
This risk is present from the T1 and to 12 weeks post partum
APTT is normal
Vasodilation in the lower limbs, Decreased flow L>R due to compression of the L iliac vein by the R iliac artery + ovarian artery
What is the highest direct cause of maternal mortality in the UK
PE
Kills 5-10 woman/ year
When is the greatest risk for VTE
Post partum
How much is the risk of VTE increased compared to the general population
6X increased risk
This is doubles if you have an ElLSCS
EMLSCS doubles the risk compared to an ELLSCS
What is the actual risk of VTE after a caesarean?
1-2%
Which leg
90% L side
increased risk venous stasis
iliofemoral is much more common then in the non pregnant patient
clinical assessment for VTE
Not reliable
clinical judgement will be wrong in 30-50% of cases in pregnancy
oedema and leg pain are common in pregnancy without VTE
What are the exam signs of PE
Tachycardia Tachypnoea Raised JVP Loud second heart sound R ventricular heave
If there is pulmonary infarction a fever and pleural rub may be present
Risk factors for VTE
Thombophilia Heritable Anti thombin deficiency Protein C or S deficinecy Factor V leiden Prothrombin gene G20210A
Acquired
Anti phospholipid syndrome
Persistent high antibodies
medical comorbidities: Cancer, HF, SLE, IBD/joint disease nephrotic syndrome, T1DM with nephropathy, sickle cell disease, IVDU Age over 35 P3 BMI over 30 Gross varicose veins Paraplegia
Pregnancy related Multiple pregnancy Current PET LSCS Prolonged labour Midcavity rotational operative delivery still birth preterm birth PPJ over 1 L or requiring transfusion
Transient factors Hyperemesis and dehyration Surgical procedure in pregnancy Overian hyperstimulation Admission / immobility Systemic infection req antibiotics or admission Long distance travel - over 4 hours
What investigations are needed for the diagnosis of an acute DVT?
Compression duplex ultrasound should be undertaken where there is clinical suspicion of DVT.
If ultrasound is negative and there is a low level of clinical suspicion, anticoagulant treatment can
be discontinued. If ultrasound is negative and a high level of clinical suspicion exists, anticoagulant
treatment should be discontinued but the ultrasound should be repeated on days 3 and 7.
What investigations are needed for the diagnosis of an acute pulmonary embolism (PE)?
What does the ECG show?
What does the CXR show?
Women presenting with symptoms and signs of an acute PE should have an electrocardiogram
(ECG) and a chest X-ray (CXR) performed.
ECG R axis deviation RBBB Peaked T waves in lead 2 S1Q3T3 can be normal in pregnancy - not reliable CXR - areas of translucency in underperfused lung Atelectasis Wedge shaped infarction Pleural effusion
What if sx of PE and DVT - what test?
In women with suspected PE who also have symptoms and signs of DVT, compression duplex
ultrasound should be performed. If compression ultrasonography confirms the presence of DVT,
no further investigation is necessary and treatment for VTE should continue.
In women with suspected PE without symptoms and signs of DVT, a ventilation/perfusion (V/Q) lung
scan or a computerised tomography pulmonary angiogram (CTPA) should be performed.
If the CXR is abnormal - what Ix is best next in PE work up ?
When the chest X-ray is abnormal and there is a clinical suspicion of PE, CTPA should be performed
in preference to a V/Q scan.
Compare and contract CTPA with VQ scanning
Women with suspected PE should be advised that, compared with CTPA, V/Q scanning may carry
a slightly increased risk of childhood cancer but is associated with a lower risk of maternal breast cancer; in both situations, the absolute risk is very small.
Where feasible, women should be involved in the decision to undergo CTPA or V/Q scanning.
Ideally, informed consent should be obtained before these tests are undertaken.
What baseline blood investigations should be performed before initiating anticoagulant therapy?
Before anticoagulant therapy is commenced, blood should be taken for a full blood count,
coagulation screen, urea and electrolytes, and liver function tests.
Performing a thrombophilia screen prior to therapy is not recommended.