unit 12 PE and DVT

• Which risk factors should you look out for in pulmonary embolisms?risk factors can be divided into transient and persistent - label which is which

  • Immobility, including ‘economy class syndrome’ with air travel (transient)

  • Surgery (transient)

  • Malignancy from an active cancer (transient)

  • Obesity (persistent)

  • Pregnancy (transient)

  • Contraceptive pill use (transient)

  • Thrombophilic conditions (e.g. factor V Leiden or the prothrombin 20210A gene mutation). (persistent)

  increasing age (persistent)
• which triad is for epithelial injury and what are its factors?

  virchow's triad:

  1. endothelial injury
  2. vascular stasis/abnormal blood flow
  3. hypercoagulability

  this causes a thrombus fromation
• name two types if VTEs (venous thromboembolisms):

  PE - pulmonary embolism

  DVT - deep vein thrombus
• how do PE cause their signs (tachyponea and tachycardia)?

  PE -> obstruction of the pulmonary arteries -> hypoxia and pulmonary collapse -> tachypnoea to compensate -> activation of the ANS -> tachycardia due to the non-selective response on beta and alpha receptors
• what is the most common type of embolism for a PE? what are other types

  VTE -> prolonged hospital admittance

  Air thrombus -> catheter insertion

  Fat -> long-bone fracture

  Amniotic -> less frequent
• why is it important for a doctor to be familiar with VTE?


  • life-threatening
  • preventable - those who are hospitalized, peurperium, surgery
  • difficult to dx - symptoms and initial investigations are non specific, diagnostic delays can have consequences
  • need to consider how it and its treatment will interact with comorbidities - like they will probably be put on anticoags if needed
  • morbidity and sequelae can impact quality of life in the future
• how does endothelial injury contribute to the formation of a thrombus?

  • promotes the adhesion and aggregation of platelets
  • production of pro-coagulant factors;
  • examples in the heart and arterial system: Over ulcerated plaques in Atherosclerosis, Endocardial injury in MI- mural thrombus, Traumatic or inflammatory vascular injury -  vasculitis
• how does abnormal blood flow contribute to the formation of a thrombus?

  prevents blood from diluting the clotting factors at the site of endothelial injury

  there are two types of abnormal flow:

  • stasis - maybe an obstuction is prevent blood flow, the platelts encounter the endothelium -> loss of laminar blood blood flow -> allows for the activation of clotting factors -> thrombus (venous thromboembolism)
  • turbulence - physical trauma to the endothelium, countercurrents and local pockets of flow (near valves or cardiac thrombus)
• how does a hypercoagulable state promote the formation of a thrombus:

  primary: Leiden factor V, congenital antithrombin III deficiency

  secondary: increased concentration of fibrinogen and prothombin. E.g. immobilisation, MI, Heparin induced thrombocytopaenia syndrome, Antiphospholid antibody syndrome
• Antiphospholid antibody syndrome is..

  Antiphospholipid syndrome (APS) is caused by the body's immune system producing abnormal antibodies called antiphospholipid antibodies. 
• •Heparin induced thrombocytopaenia syndrome

  Heparin-induced thrombocytopenia (HIT) is a severe complication that can occur in patients exposed to any form or amount of heparin products. A fall in platelet counts and a hypercoagulable state characterize HIT.
• what features are characterisitic in the formation of an arterial thrombus?

  • secondary to an atheroma
  • mainly platelets
  • in the brain - middle cerebral artery, coronary arteries
  • caused by endothelial injury
• what are the characteristic features of a venous thrombosis?

  • slow blood flow and pressure
  • contains platelets, fibrin and RBCs
  • seen in deep calf veins and the hepatic portal vein
  • see stasis
• this image shows a feature of arterial thrombi what is it called and what is it?

  Lines of Zahn -> the lines are the laminations of fibrin and platelets

  
• image of a renal vein thrombosis

  
• what are the 5 outcomes of a thrombus?

  lysis - from thrombolytic activity

  propogation (increase in size) - thrombus becomes a focus for thrombosis

  organisation - invasion of the thrombus into the connective tissue layer, causes it to become firm and white

  canalisation - when new lumen lined with endothelial cells form in an organised thrombus

  embolisation - part of the embolism dislodges, travels through the circulation and becomes bound to a new site
• of the five outcomes a thrombus can have which one does this show?

  canalisation

  
• what does this image show of the five outcomes of a thrombus?

  this shows organisation, can see that the organisation has continued till it has blocked off the artery

  original vessel delineated by the interal elastic lamina

  
• embolisms can be solid (thrombus), liquid (amniotic fluid), gas (air)

  most common are thromboembolism

  air embolism in deep sea divers

  fat and bone marrow embolism from long bone fractures

  tumour embolism
• how does a PE get cause symptoms like SOB and haemoptysis?

  emboli from the thrombus, most are from the deep veins but some are from the pelvic veins. pass through the venous system and through the right heart to the pulmonary arterial tree where it forms a pulmonary embolism.

  emboli cause obstruction and an increase in pulmonary arterial blood pressure (pulmonary hypertension) -> ventilated areas are not perfused by blood due to the obstruction which leads to the 'DEAD SPACE EFFECT' -> SOB, it can also cause pulmonary infarctions which lead to chest pain and haemoptysis (coughing blood)
• what would happen to the lung parenchyma by an embolus in a middle-sized artery?

  obstruction and possibly rupture of the downstream capillaries -> leads to anoxia and pulmonary haemorrhage -> HOWEVER they do not normally cause infarctions as these areas receive dual blood supply which leads to red infarcts (looks red because there is an alternative blood supply)

  
  

  apart form a PE this can occur when there is poor blood perfusion like Left sided HF or poor bronchial circulation

  
• Anticoagulants are the standard treatment for DVT and it divided into three stages, what are these 3 stages:

  1. acute phase - to prevent the thrombus from extending
  2. maintenance phase
  3. long-term phase

  the last two phases are to prevent the reoccurance of a thrombus
• your patient has a DVT/ PE how do you manage this from when they are handed over to you?

  • ABCDE examination
  • patients with confirmed DVT/PE are given LMWH
  • if the patient has renal imparements/failure/increased risk fo bleeding they should be offered throbolytic therapy or a embolectomy
  • patients with an increased risk of bleeding should be treated with UFH (unfractioned heparin)
  • continue anticoagulants for 5 days or until INR is 2.0
• if your patient is at an increased risk of bleeding and has a DVT/PE what shoould you prescribe them?

  cannot prescribe them LMWH - precribe them UFH
• which drug is a vitamin K ANTagonist?

  warfrin
• non-vitamin K antagonists like riveroxiban are also recommended by NICE
• Vitamin K antagonists require constant monitoring to make sure the INR is in target range

  non vitamin K antogonists do not require this as now there are reveribility agents for them (like idarucizumab for dabigatran etexilate)
• which coagulation factors are dependent on vitamin K?

  2, 7, 9, 10
• what can be implanted into a patient with re-occuring thromboembolisms or are contraindicated to anticoagulants?

  Inferior Vena Cava filters - prevent thrombi from getting into the heart and thus pulmonary circulation
• what does the gender recognition act allow for?

  people with gender dysphoria can change their legal name by applying for a gender recognition certificate (GRC)
• what is needed for a gender recognition certificate?

  1.  medical diagnosis of gender dysphoria

  2.  A report from a medical professional detailing any medical treatment

  3.  Evidence (e.g., bank statements) of having lived for at least two years in their new gender

  4.  A statutory declaration that they intend to live in the acquired gender until death

  5.  If married, the consent of their spouse/civil partner

  6.  Payment of a fee of £140 (exceptions apply)

  7.  Submission of documentation to a Panel
• gender reassignment is a protected characteristic under the Equality Act
• what is deadnaming?


  use of a trans person’s birth name without consent. This can be upsetting and risk a breakdown in patient-doctor relationships. The students may consider the concepts of deadnaming and mis-gendering and should reflect on how healthcare professionals can create a supportive environment for transgender patients. It may be important to determine whether gender identity is relevant to people’s healthcare needs.
• your patient thinks they have a DVT, what are classic signs and symptoms of DVT?

  • pain and swelling on one leg (can check the difference between the cirumference of the calfs)
  • leg is red and warm
  • tenderness along the course of the deep veins
  • dilation along superficial veins

  
• what are common signs and symptoms in PE?

  • pleuritic chest pain, breathlessness, haemoptysis, tachypnea and tachycardia
  • syncopeal episodes, hypotension or shock, myocardial ischaemia, can be associated with the chest pain
• what may you hear on ausculation of a patient with PE?

  crackles and a pleural rub
• your patient has a severe presentation of PE, seen by tachypnoeia and tachycardia with peripheral shutdown, what are possible ausculation and clinical findings?

  • raised jugular venous pressure (JVP) with an a-wave (large amplitude wave seen when examining the jugular vein)
  • auscultation - right ventricular heave, gallop rhythm (involves the 3 and 4th heart sounds forming a gallop sound) and a widely split 2nd heart sound
• what is the most common symptom and the most common sign for PE?

  symptom - dysponea

  sign - tachyponea
• which symptoms indicate a massive PE?

  • dysponea
  • syncope
  • hypotension
  • cyanosis
• what indicates a PE near the pleura?

  pleuritic chest pain, cough or haemoptysis