Pulmonary Embolism and Pulmonary Hypertension Flashcards
describe thromboembolic disease
deep venous thrombosis
pulmonary embolism
describe pulmonary embolism
blockage of pulmonary artery by blood clot, fat, tumour or air (iatrogenic)
usually preceded by DVT, the DVT may silent
describe pulmonary infarction
if blood flow and oxygen to lung tissue is compromised the lung tissue may die
describe DVT
proximal (ileo-femoral veins);
most likely to embolise and lead to chronic venous insufficiency and venous leg ulcers
distal (polpiteal);
least likely to embolise
describe clinical presentation of DVT
can be whole leg or calf involved depending on the site swollen hot red tender
describe differential diagnosis for DVT
popliteal synovial rupture (Baker’s cyst)
superficial thrombophlebitis
calf cellulitis
describe investigations of DVT
1st line;
ultrasound doppler leg scan - non-invasive, exlcudes popliteal cyst and pelvic mass
CT scan - ileo-femoral veins, IVC and pelvis
D-dimer test may be elevated
describe clinical presentation of pulmonary embolism
dependant on size;
large - cardiovascular shock, low BP, central cyanosis, sudden death, hypoxic
medium - pleuritic pain, haemoptysis, breathless
small, recurrent - progressive dyspnoea, pulmonary hypertension, right heart failure, progressive breathlessness
describe risk factors associated with DVT and pulmonary embolism
thrombophilia;
family history, frequency, site, age
contraceptive age;
increased if smoker
HRT
pregnancy (blood thickens)
pelvic obstruction (compressing into venous system); uterus, ovary, lymph nodes
trauma;
road traffic accident
surgery;
knee, hip, pelvic
immobility;
bed rest, long haul flights (dehydration)
malignancy
obesity
pulmonary hypertension
vasculitis (rare, inflammatory condition of blood vessels)
describe prevention of DVT
early post-op mobilisation
TED compression stockings
calf muscle exercises
subcutaneous low dose mol wt heparin periopeatively
direct oral anticoagulant (DOAC) medication;
dabigatran - direct thrombin inhibitor
rivaroxaban/apixaban - direct inhibitor of activated factor Xa
describe symptoms of pulmonary embolism
shortness of breath (acute onset) chest pain (pleuritic) haemoptysis leg pain/swelling collapse/sudden death
describe signs of pulmonary embolism
tachycardia tachypnoea cyanosis fever (not major) low BP crackles rub pleural effusion low PaO2, low sats (type 1 respiratory failure due to impaired gas exchange, but not CO2 is being retained)
describe tests of pulmonary embolism
CXR; normal before infarction basal atelectasis consolidation pleural effusion
predicted scores - Well’s criteria, Geneva
pulmonary embolism severity index (PESI) - risk stratification (how likely to die)
ECG - acute right heart strain pattern
d-dimers usually raised (normal = -ve)
troponin +/- BNP/pro-BNP
isotope lung scan - identifies ventilation/perfusion, V/Q = mismatch) . Sensitive for small peripheral emboli and perfusion defect before infarction
CT pulmonary angiogram (CTPA) - images pulmonary artery filling defect to pick up larger clots in proximal vessels. Good for unwell patinets
ultrasound - detects silent DVT
echocardiogram - measure pulmonary artery pressure and right ventricular size (acute dilation of right ventricle in keeping with acute pulmonary embolism)
describe underlying causes of pulmonary embolism
obvious - surgery, pregnancy, malignancy, immobility autoantibodies (SLE) - antinuclear, anti-cardiolipin abs thrombophilia screen (rare); anti-thrombin-III deficiency, protein C or S deficiency, factor V leiden, increased VIII
describe treatment of DVT/pulmonary embolism
anticoagulation prevents clot propagation - tips balance to thromobolysis/body dissolves clot
therapeutic dose of S/C low molecular weight heparin - LMWH - dalteparin/fragmin, once daily injection, no monitoring
start warfarin simultaneously (RarE)
rare - IV heparin
antagonises Vit K dependent prothrombin - takes 3 days
after 3-5 days stop heparin when INR>2
alternative treatment;
DOACs (direct oral thrombin inhibitor (dabigatran)) or factor X inhibitor (rivaroxaban/apixaban)
IVC filter to prevent embolisation from large ileofemoral/IVC clot - recurrent PEs (large)
thrombo-embolectomy (RaRE)
intra-catheter directed thrombolysis
EKOS (ultrasound enhanced catheter thrombolysis)
empirical treatment if high clinical suspicion whilst awaiting results
low suspicion await test results before treatment
moderate suspicion, weight out pros and cons
describe treatment of pulmonary embolism
thrombolysis - tissue plasminogen activator (tPA) - tenecteplase
life threatening PE (massive);
low BP <90mmHg
severe hypoxaemia, imminent of actual cardiac arrest
explain contraindications of pulmonary embolism
relative - pregnancy/post partum, anticoagulants, TIA<6 months, refractory hypertension, advanced liver disease, active peptic ulcer disease, refractory resuscitation
absolute - haemorrhagic stroke/stroke of unknown origin, ischaemic stroke <6 months, cerebral neoplasm or trauma, recent major surgery, trauma, head injury, GI bleeding, known bleeding disorder, aortic dissection, non-compressible puncture
describe the duration of treatment for pulmonary embolisms
dependant on balance of risk;
life long - recurrent DVT/PE
6 months - unprovoked 1st PE, high risk proximal DVT
3 months - provoked PE/temporary risk factor, unprovoked low risk distal DVT
IV drug abusers or active cancer
life threatening PE in young men who have high risk of recurrence - life long treatment
DASH score and HERDOO2 for woman
describe risk of bleeding/over anti-coagulation
address underlying cause - drug interaction, chronic liver disease, heart failure
if bleeding stop anticoagulant and reverse effect
LMWH and warfarin - long half life
consider prothrombin complex concentrate or fresh frozen plasma
reverse warfarin with vitamin K (liver disease)
reverse heparin with protamine
no reversible agent available for NOACs
describe pulmonary hypertension
normal mean pulmonary arterial pressure = 12-120 mmHg
pulmonary hypertension >25mmHg
measured with right heart catheter (secondary invasive)
systolic pulmonary arterial pressure can be estimated with ECHO doppler (possible if >40mmHg but varies with age/weight)
describe causes of pulmonary hypertension
pulmonary venous hypertension (left heart disease);
left ventricular systolic dysfunction - ischaemic
mitral regurgitation/stenosis
cardiomyopathy - alcohol, viral
pulmonary arterial hypertension (PAH);
primary pulmonary hypertension
hypoxic - COPD, OSA, pulmonary fibrosis
multiple PE - chronic thromboembolic PH (CTEPH)
vasculitis - SLE, PAN, systemic sclerosis
drugs - appetite suppressants - fenfluramine
HIV
cardiac left to right shunt - ASD, VSD
describe cor pulmonale
right heart disease caused by lung disease
fluid retention due to hypoxia +/- heart failure
can complicate COPD, fibrotic lung disease, chronic Pe, chronic ventilatory failure (obesity/kyphoscoliosis)
describe clinical signs of pulmonary hypertension and right heart failure
central cyanosis - if hypoxic
dependant oedema
raised JVP with V waves (due to secondary tricuspid regurg)
right ventricular heave at left parasternal edge
murmur of tricuspid regurgitation
load P2
enlarger liver (pulsatile)
describe investigations of pulmonary hypertension
ECG - rhythm, axis, p pulmonale, right bundle branch block
CXR - cardiomegaly
sats and arterial blood gases
pulmonary function with DLCO (diffusion capacity)
Echo;
right ventricular systolic pressure
right ventricular dimensions and function
left ventricular dimensions/function
valvular disease
cardiac catheterisation - measures mean pulmonary arterial pressure
d dimer
VQ scan - determines small peripheral perfusion defects
CT pulmonary angiogram - large central clots, mosaic perfusion pattern (small vessel clots)
cardiac MRI
auto-antibodies if vasculitis suspected
describe treatment of primary pulmonary arterial hypertension
exclude other secondary causes;
primary disease of the pulmonary arteries/arterioles
progressive exertional breathlessness
worsening PH leads to right heart failure
poor prognosis of 3 years without treamtnet
pharmacologic treatment;
prophylactic anticoagulation (warfarin)
oxygen if hypoxic
pulmonary vasodilators - primary disease only;
calcium channel blocks (oral nifedipine, diltiazem)
Endothelin antagonist (Oral Bosentan, Macitentan)
PDE5-inhibitor (Oral Sildenafil/Tadalafil)
Prostanoids (IV Epoprostenol or Inhaled Iloprost)
Soluble Guanylate Cyclase stimulator (Riociguat)
lung transplant
describe chronic thromboembolic pulmonary hypertension (CTEPH)
riociguat - pulmonary arterial vasodilator
pulmonary endarterectomy - curative (2% operative mortality)
