DVT and pulmonary embolism Flashcards
what is virchow triad ?
the factors that lead to the formation of thrombosis
endothelial injury
hypercoaguability
abnormal blood flow
what are the congenital deficiencies that cause thrombophilia ?
1- congenital deficiency of anti-thrombin,
protein C or S
2- factor V leiden
3- prothrombin gene mutation
what is an example of acquired thrombophilia ?
antiphospholipid syndrome
what are the differential diagnosis of lower limb DVT ?
infective celulitits
erysipelas
ruptured bakers cyst.
calf hematoma
lymphatic problem
ortho problem
what is the investigation of choice for DVT ?
duplex ultrasound
what is the significance of the d-dimer test in VTE ?
high sensitivity but low specificity
its greatest utility id for its negative predictive value
what is the treatment for confirmed uncomplicated proximal lower limb DVT ?
1- start immediately with heparin , start warfarin at the same time
2- continue the heparin for at least 5 days till the warfarin reaches peak effect
3- discontinue heparin once INR has reached the target of 2.5 for 2 days
how long should warfarin be taken ?
1- in patients with DT provoked by surgery or non surgical transient factors, it should be taken for at least 3 months - irl 6 months
2- patients with cancer provoked DVT are at high risk off recurrence, so LMWH rather than warfarin for 6 months
what are the complications of DVT ?
1- pulmonary embolism
2- post thrombotic syndrome
3- severe acute venous obstruction (phlegmasia cerulae dolens )
4- paradoxical embolism
when is paradoxical embolism seen ?
rare
infarction is seen within the systemic circulation as a consequence of pulmonary embolism in an individual with atrial septal defect
what is upper limit DVT ?
thrombosis of the subclavian, axillary or brachial branch
what is the investigation of choice in cases of upper limb DVT ?
ultrasound imaging
how can PE cause circulatory collapse ?
due to right sided heart failure
what are the different levels of severity of PE ?
high risk - circulatory collapse due too right sided heart failure
intermediate risk - haemodynamically stable patient but with evidence of right ventricular strain
low risk - haemodynamically stable patient with no signs of right sided heart strain
what is the first choice for investigations in PE ?
CTPA
what is a good alternative to CTPA ?
ventilation perfusion scan
a normal V/Q scan excludes the diagnosis
when can an echo be useful ?
in massive PE
what is the most accurate imaging modality for the diagnosis of PE ?
pulmonary angiography
what is the treatment of patient with low risk PE ?
the same as for acute DVT
give heparin and warfarin together
what is the treatment for patients with intermediate risk PE ?
unfractionated heparin
followed by daily sc LMWH
follow with warfarin
what is the treatment foor massive PE ?
thrombolysis is the first line treatment followed by unfractionated heparin then continue the patient in warfarin