pulmonary embolism lms Flashcards
presentation of PE
acute - within minutes of pulmonary arterial occlusion
subacute - days to weeks, sometimes due to multiple small PEs
chronic - CTEPH
CTEPH
chronic thromboembolic pulmonary hypertension
one of the causes of chronic pulmonary hypertension
very insidious course
average delay is usually over a year
symptoms of PE
non specific
breathlessness
chest pain - may be central and mimic MI
syncope/collapse or feeling of impending collapse often on exertion
pleuritic chest pain and haemoptysis - not common
signs of PE
may be none
may be in cardiovascular collapse - with raised HR, raised RR, drop in BP
swollen calf - if DVT present
raised JVP but difficul;t to elicit
pleural friciton rub or localised crackles
hypoxaemia on pulse oxymetry - may be normal at rest but desat on exertion
how can you ellicit hypoxic signs
walk your patient around the ED with a pulse oximeter on and see if they desat
risk factors
active cancer - may be undiagnosed at presentation
immobility - chronic medical problemss or post op or ICU
lower limb/pelvic surgery
previous VTE
thrombophilia
pregnancy/puerperium
air travel/oestrogen therapy
wells criteria
clinical assessment for pulmonary embolism
includes:
- clinical symptoms of DVT (leg swelling, pain on palpation)
- other diagnosis less likely than pulmonary embolism
- heart rate
- immobilisation
- previous DVT/PE
- haemoptysis
- malignancy
massive PE
also called high risk PE
one that is immidiately life threatening
drop in systolic to under 90 or drop in BP of over 40 or more for more than 15 minutes with no other cause
caardiopulmonary arrest
submassive PE
intermediate risk PE
does not cause haemodynamic compromise
acutd right ventricular dysfunction demonstrated on ECHO but not haemodynamically unstable
D dimer
not specific
often positive in unwell immobile patients
only useful if negative in a low risk patient to rule out DVT or PE
not indicated if there is a risk factor present
when should you skip using the d dimer test
if there is a risk factor present, or symptoms duggestive of possible PE or if they score high enough on the Wells criterica
then just go straight to the diagnostic test
ECG findings
usually not helpful
findings are usually non specific
sinus tachycardia
non specific ST changes
S1 Q3 T3 - seen in life threatening right ventricular strain, usually in near or total cardiovascular collapse
commonest ECG abnomality in PE
sinus tachy
CXR findings
also usually non specific
can rule out other causes eg. cardiac failure, pneumonia, pneumothorax
often appears normal
any abnormalities are subtle and usually only recognised in retrospect
CTPA
good sensitivity and specificity
available 24/7
may reveal other pathologies as well
cons:
- needs contrast which may be contraindicated
- often reveals irrelevant minor abnormalities
- sensitivity declines with time after event
- high radiation dose
V/Q scan
better to identify chronic CTEPH
low radiation dose - better for young patients and pregnant women
cons
- less sensitive
- very diifficult to interpret in presence of chronic heart/lung disease
- not available out of hours
if the patient is in cardiovascular collapse
will be too unwell to move to radiology for a CTPA
bedside echocardiogram - will show acute right ventricular dilationand strain
may even see a clot extending into the right atrium
treatment for the stable patient with first episode of VTE
oxygen to keep sats above 94%
subcut low molecular weight heparin - enoxaparin (clexane)
switch to oral anticoagulation for 3-6 monthss
- warfarin (titrate to INR 2-3)
- novel oral anticoagulatns such as Rivaroxaban
follow up
3 months with repeat imaging
should have thrombophilia screen
overall 10% risk recurrance
for the patients with 2nd episode of VTE
lifelong anticoagulation
treatment of massive PE
need to be managed and resused on ICU
expensive thrombolysis with alteplase of tenecteplase
surgical pulmonary embolectomy - only available in tertiary centres of cardiothoracic surgery
treatment for submassive PE
thrombolysis is very controversial
not currently recommended in guidelines
should be managed as a stable patient
complications
sudden death
bleeding - from treatment
cardiac arrythmias - aF / tachyarrythmias
pleural effusion
peripheral PE: ppulmonary infarctions, ppulmonary infarcts can cavitate
chronic pulomonary embolism CTEPH
