PE Pregnancy Flashcards
Virchow’s triad?
Stasis of blood flow, hyper coagulability and endothelial injury
Why are women in a hyper coagulable state in pregnancy?
To prevent PPH
What changes in pregnancy contribute to hyper coagulable state?
Increased: fibrinogen, thrombin, factor VIII
Reduced: protein S
Other: RFs eg prolonged rest if instrumental delivery
The course of d-dimer in pregnancy?
Start to rise in the second trimester and remain elevated for 4-6 weeks post partum
Any suspicion of VTE - action?
Start on LMWH until ruled out
For suspicion of a DVT - what investigation?
Compression duplex ultrasound.
If negative but still suspicious, repeat on days 3 and 7
ECG changes in Pulmonary Embolism?
T wave inversion, RBBB and s1Q3T3 pattern.
CXR changes in PE?
- Hamptom hump: peripheral wedge of airspace opacity, implies lung infarction.
- Westmarks sign: regional oligaemia and the highest predictive value
Fleishner sign: enlarged pulmonary artery
Investigations for PE?
Normally V/Q first line
V/Q to rule out - high negative predictive value and lower radiation to pregnant breast tissue. Slightly more foetal but acceptable.
CTPA - more readily available and lower radiation to foetus.
NB higher pregnant breast tissue risk
Does LMWH (enoxparin) cross placenta?
No
Most significant predictor of poor outcome in PE?
Hypotension (defines massive)
How might life-threatening PE present?
Shock, refractory hypoxaemia, RV dysfunction.
Normal symptoms: cough, haemoptysis, chest pain, SOB, low grade pyrexia/leucoytosis
How much does VTE risk increase in pregnancy?
5-fold
Physiological changes in pregnancy
After 28 weeks, blood volume/CO increase by 30-40%. (Protects maternal shock - less RBC lost)
Compression of IVC
Diaphragm elevation - loss of functional residual capacity by 20%
Maternal resuscitation position/notes
Left lateral tilt.
If suspect massive PE - immediate bolus of 50mg alteplase.
A: in 3rd trimester, narrowing of upper airways (smaller ET tube)
B: oxygen always.
C: Suspect hypovolaemia early
