Thrombo-embolic disorders Flashcards
What are the thrombo-embolic disorders that could occur with pregnancy?
- DVT -> 75% occur antepartum (popliteal vein)
- PE -> 40-60% occur post partum (left pulmonary artery) -> 15% fatality
Why is pregnancy associated with increased tendency for blood clotting?
Virchow’s triad
- Stasis: due to abnormal blood flow
- Endothelial damage: during pregnancy & delivery
- Hyper-coagulability
-> increased production of clotting factors: VII, VIII, X, Von Willebrand’s, & fibrinogen
-> decreased anti-coagulants: Protein S & anti-thrombin
-> decreased fibrinolytic activity: increased plasminogen activation inhibitor
What are the risk factors for TED with pregnancy?
- maternal age > 35 years
- multi-parity 5 or more
- BMI > 30
- infections
- Pre-eclampsia
- immobility
- pelvic or leg trauma
- heavy smoking
- atrial fibrillation
- personal or family history of TED
- thrombophilia
- anti-phosphilipid antibodies & lupus anticoagulants
- operative delivery
- previous history of IUFD, early pre-eclampsia, IUGR, abruption
What is the commonest form of venous thrombosis in pregnancy?
Superficial thrombophlebitis
- occurs in 1% in existing varicose veins
- redness around vein is a reaction to blood clot
How is superficial thrombophlebitis diagnosed?
Clinically:
- tenderness
- erythema
- palpable cord-like vein
- pain
How is superficial thrombophlebitis treated?
symptomatic treatment
- compression bandage
- leg elevation
- encourage mobility
exclude DVT
What are the clinical features for DVT?
- pain
- local tenderness
- swelling
- change in skin color & temperature
- Homan’s sign
What is the prognosis of a calf DVT?
- 75-80% are benign
- 20-25% spread to involve proximal deep veins -> 50% risk of PE
What are the symptoms of a proximal (ilio-femoral) DVT?
involves entire limb
- pain
- swelling
- blue & warm (unimpaired arterial supply)
- pale & white (impaired arterial supply)
What investigations are preformed for DVT?
- Duplex ultrasonography: 97% specificity
- MRI: 100% in NON pregnant ladies
- D-dimer is not useful in pregnancy cause it normally increased with gestational age
What is the rate of maternal mortality from PE?
if untreated -> 13% within the first hour
What is the clinical picture of a pulmonary embolism?
- dyspnea
- tachypnea
- tachycardia
- haemoptysis
- pleuritic chest pain
- cyanosis
- pyrexia
- syncope/shock
How should PE be managed?
1- Start treatment immediately -> SC LMWH
2- Then investigate
- chest x-ray
- ECG
- ABG: acidosis
- compression duplex doppler
- CT angiography
What are the risks of radiological exposure to fetus?
radiation exposure of up to 0.05Gy (5 rad) in utero
- 1.2 - 2.4 -> oncogenicity relative risk
- 0.1% risk of absolute malignancy
How is the acute phase of TED treated in pregnancy?
1- IV or SC LMWH -> aPTT 2 - 2.5 control for 1 week
2- continue prophylaxis for 6 - 12 weeks postpartum (for PE 4-6 months)
3- elevate legs
4- graduated elastic compression stockings -> reduce edema
5- inferior vena cava filter -> in recurrent PE
6- thrombolytic therapy is teratogenic so only done if life saving (streptokinase & rivaroxaban)
7- thoracotomy & embolectomy
What are the complications that may arise with long term heparin therapy?
1- overdose -> reversed by protamine sulfate
2- osteoporosis
3- thrombocytopenia
monitor platelet count regularly
Why is Warfarin contraindicated in pregnancy?
it causes Fetal Warfarin Syndrome
- nasal hypoplasia
- depressed nasal bridge
- irregular bone growth
- intracranial fetal hemorrhage
What are the causes of thrombophilia?
INHERITED
- hyperhomo-cysteinemia mutation
- factor-V Leiden mutation
- mutation in prothrombin & prothrombin-II
- protein S
- protein C
ACQUIRED
- antiphospholipid syndrome
-> lupus anticoagulants antibodies
-> anticardiolipin antibodies
What is the clinical criteria for anti-phospholipid syndrome diagnosis?
1- Thrombosis -> 1 or more confirmed episodes of venous, arterial, or small vessels disease
2- unexplained recurrent pregnancy loss
3- pre-eclampsia or placental insufficiency occurring < 34 week
4- unexplained IUFD
What is the laboratory criteria for antiphospholipid syndrome?
- medium or high titer IgG or IgM anticardiolipin antibody
- lupus anticoagulant on 2 or more occasions at least 6 weeks apart
- aPTT is prolonged & not correctable by mixture with normal plasma
How is antiphospholipid syndrome treated?
low dose aspirin + heparin
The combination of aspirin + LMWH is effective in what cases?
1- recurrent fetal loss in APS
2- inherited thrombophilia
3- history of severe pre-eclampsia
4- IUGR
5- abruptio placentae
6- recurrent fetal loss
What are the risk factors for an amniotic fluid embolism?
- maternal age > 30
- multiparity
- complicated labour
occurs during labour or shortly after delivery & is life-threatening
What are the clinical features for a amniotic fluid embolism?
Acute onset of
- respiratory collapse
- cardiovascular collapse
- altered consciousness
- features of DIC
- multi-organ dysfunction
- fetal bradycardia
How is the diagnosis of amniotic fluid embolisms made?
- ABG -> respiratory acidosis
- CBC -> anemia, thrombocytopenia
- Coagulation studies -> prolonged PT
How is an AFE treated?
1- correct hypoxia -> high flow O2 or intubation
2- correct hypotension/shock -> vasopressors
3- correct anemia & coagulopathy -> platelets, FFP, PRBCs
4- emergency C-section
