Pulmonary Embolism Flashcards
Clinical manifestations of venous thromboembolism include?
-Pulmonary embolism
-Deep vein thrombosis
Incidence of VTE
-100-200 per 100,000 (Europe)
-Acute and lethal (mortality 1/2-10% of deaths in hospital)
-Chronic disease and disability (CTEPH/ Chronic Thromboembolic Pulmonary Hypertension and post-thrombotic syndrome)
-PREVENTABLE
-3rd most frequent cardiovascular disease
Pathogenesis of PE
-Clot usually arises in deep veins of legs, travel through R heart and pulmonary artery, wedge in approximate calibre of vessel
=Larger= proximal= more cardiovascular compromise (impair CO)
-Most patients have no leg symptoms
-Thrombi may originate in pelvis, arms, or right heart
What causes clots?
-Coagulation cascade
-Virchow’s triad (flood flow, (hyper)coagulability, vessel wall)
-Fractures: trauma to blood vessels, bed-ridden so stasis, inflammatory process hypercoagulability
Why does PE kill people?
-Increased RV afterload (trying to push blood around clot)
=Dilate (hard work)
=Hormonal activation
=Myocardial inflammatory activation
=Right ventricular ischaemia
=Contractility decreases so output drops
=Decreased LV pre-load
=Low CO
=Systemic BP drops
=Reduced RV coronary perfusion
=Reduced RV oxygen delivery
=Cardiogenic shock!!!
=Death
Strong Risk Factors for PE
-Fracture of lower limb
-Hospitalisation for HF or AF (<-3 months)
-Hip or knee replacement
-Major Trauma
-MI (<-3 months)
-Previous VTE
-Spinal Cord Injury
Moderate Risk Factors for PE
-HOSPITALISED WITH INFLAMMATORY MARKERS
-Arthroscopic knee Sx
-Autoimmune disease
-IBD
-Blood transfusion
-Central venous lines
-CCF
-Respiratory failure
-EPO -stimulants
-HRT
-IVF
-Infection (pneumonia/ UTI/HIV)
-Cancer
-OCP
-Stroke (paralytic)
-Postpartum
-Superficial VT
-Thrombophilia
Weak risk factors for PE
-Bed rest >3 days
-DM
-HTN
-Immobility due to sitting (car/plane)
-Old
-Laparoscopic surgery
-Obesity
-Pregnancy
-Varicose veins
PE presenting characteristics
-Dyspnoea
-Pleuritic chest pain (worse on inspiration, sharp)
-Cough
-Substernal chest pain
-Fever
-Haemoptysis
-Syncope
-Unilateral leg swelling
PE Investigations
-X rays= no acute changes normally
-ECG= right heart strain, usually sinus tachycardia
-Acute ECHO= RV larger than left, septum in toward LV
-CTPA (CT pulmonary angiogram- standard diagnostic test)
Well’s score
-Clinical probability
=Risk factors
=Current clinical state
=Overall probability score
What is the D-Dimer test?
-Fibrin breakdown by-product
-Sensitive (high likely someone with PE has elevated D-Dimer)
-Low specificity (includes inflammation)
-RULE OUT
Considerations after diagnosis of PE
-Re-consider risk factors (provoked or unprovoked)
-Risk stratify= Pulmonary Embolism Severity Index (PESI/sPESI- risk of death)
-Other parameters:
=RV dysfunction- CT or ECHO
=Myocardial injury- troponin
=Shock or hypotension= high risk
Acute treatment for high risk (death within 1 month) PE
-Cardiorespiratory Arrest- ALS (acute life saving)+ Bolus IV thrombolysis
-Systemic thrombolysis (not yet arrested)
=Alteplase bolus +2hr infusion
=Subsequent IVI Unfractionated heparin
=Critical Care environment
-Catheter-directed lysis (+USS)
-Surgical embolectomy
Describe fibrinolysis
-Plasminogen activators (active plasmin)
=Breakdown fibrin into products
=Actively clot bust
