PE

Question 1

Definition?

Answer 1

Consequence of venous thrombosis formation in the distal venous system, leading to obstruction of the pulmonary vessels.

Question 2

RFs?

Answer 2

• Dyspnoea
	• Active cancer
	• Recent surgery or hospitalisation
	• Previous DVT
	• Pregnancy
Immobilisation

Question 3

ddx?

Answer 3

• Unstable angina-ST depression
• NSTEMI-high troponin, ST depression
• STEMI- ST elevation ,high troponin, central chest pain
• Pneumonia-cough with sputum, high infection and consolidation on CXR
• Bronchitis-cough ,wheezes high D dimer and normal CXR
• COPD-wheeze, low breath sounds, CXR signs, RV dysfunction
• Asthma-wheezes, normal results, less breath sounds
• CHF-dyspnoea, tackles, signs of HF
• Pericarditis-fever, pain on sitting up,ST elevation,
• Cardiac tamponade-hypotension, muffled heart sounds, high JVP, effusion
• Pulmonary hypertension-oedema, right axis deviation on ECG
• Pneumothorax-tracheal deviation, hyper resonance
• Costochondritis-chest pain breathing in, tenderness,
Panic attack -faint, palpitations , fear

Question 4

Epidemiology?

Answer 4

Age: >50
Sex:male
Ethnicity:

Question 5

Aetiology?

Answer 5

• Vessel wall damage
• Venous stasis
Hypercoagulability

Question 6

CP?

Answer 6

• Dyspnoea
  
  • Chest pain- pleuritic/worse with inspiration
  • Signs of DVT
  • Risk factors
  • Hypoxaemia
  • Meets PERC rules
  • Positive Wells score
  • Tachycardia
  • Acute RV dysfunction
  • Syncope
  • Haemoptysis
  • Dullness on percussion
  • Split second heart sound
  • Fever

Question 7

PERC rule?

Answer 7

>50
HR >100
O2<95%
PMH?
trauma or surgery?
exogenous oestrogen use?
haemoptysis?
unilateral leg swelling?

Question 8

Wells score for PE?

Answer 8

signs?
surgery or immobile>3 weeks
PMH
HR>100
haemoptysis
active cancer

Question 9

Pathophysiology?

Answer 9

• Mechanism:thrombus formation(seeVirchow’s triad)→deep vein thrombosisin the legs orpelvis(most commonlyiliacvein)→ embolizationtopulmonary arteriesviainferior vena cava→ partialor complete obstruction ofpulmonary arteries
• Pathophysiologic response of thelungto arterial obstruction
• Infarctionandinflammationof thelungsandpleura
○ Causespleuriticchest painandhemoptysis
○ Leads tosurfactantdysfunction→atelectasis→ ↓PaO2
○ Triggers respiratory drive→hyperventilationandtachypnea→respiratory alkalosiswithhypocapnia(↓PaCO2)
○ Impairedgas exchange
§ Mechanical vessel obstruction→ventilation-perfusionmismatch→ arterialhypoxemia(↓PaO2) and elevatedA-a gradient(see “Diagnostics” below)
§ Cardiac compromise
□ Elevatedpulmonary arterypressure (PAP) due to blockage→ rightventricular pressure overload→ forwardfailure with decreasedcardiac output→hypotensionandtachycardia
• Increased-decreased perfusion or over-ventilation-too much oxygen, not enough blood to diffuse into-Increased V/Q

Question 10

Investigations?

Answer 10

• CTPA-can see thrombus RV enlargement and diameter greater than 0.9
  
  • Echo-abnormal ejection or contractility, dilation,tricuspid regurgitation, pulmonary hypertension,thrombus
  • D dimer-Elevated,low specificity but high sensitivity
  • FBC-thrombocytopenia,anaemia,polycythaemia
  • ECG-sinus tachycardia,right BBB,S1Q3T3,atrial arrhythmias,ST/T wave abnormalities,right axis deviation,P pulmonale
  • U &E-normal
  • Coagulation studies-choice of anticoagulation
  • LFTS-choice of anticoagulation
  • ABG-hypoxaemia,hypocapnia,
  • CXR-atelectasis,pleural effusion,hemidiaphragm,
  • Venous US-cannot be compressed completely
  • Cardiac biomarkers-high troponin, BNP
  • V/Q scan-shows areas not perfused properly-

Question 11

Management haemodynamically unstable?

Answer 11

• Resp support-
  
  • targeting an initial oxygen saturation of 94% to 98% (this may need to be adjusted to 88% to 92% in patients at risk of hypercapnic respiratory failure)
• Fluid resuscitation-
  
  • Give intravenous fluids if SBP is <90 mmHg and the JVP is not elevated
  • Normal saline or Hartmann’s

Question 12

Confirmed PE-haemodynamically unstable?

Answer 12

• Heparin-stop after 24 hrs
• Thrombolysis-alteplase/streptokinase over 2 hrs
• LMWH or DOACs-titrate off after heparin-note for cancer/preg
• Vasoactive drug-if low BP
• Surgical embolectomy or catheter directed treatment-
  
  • Patients who are unable to receive thrombolytic therapy because of bleeding risk
  • Insufficient time for effective systemic thrombolysis
  • Failed thrombolysis.

Question 13

M-If CI to thrombolysis?

Answer 13

• Unfractionated heparin
• Alternative anticoagulant
• Vasoactive drug
• Surgical embolectomy or catheter directed treatment

Question 14

M-If CI to anticoagulation?

Answer 14

• Vasoactive drug

* Surgical embolectomy or catheter directed therapy

Question 15

M-Haemodynamically unstable?

Answer 15

• Anticoagulation-
  
  • apixaban or rivaroxaban; low molecular weight heparin (LMWH) is an alternative if these are unsuitable
• Risk assessment-
  
  • Pulmonary Embolism Severity Index (PESI)
  • Patients with hypotension or shock. All such patients are high-risk and must be managed accordingly with urgent primary reperfusion and anticoagulation
  • Pregnant women
  • Patients with active cancer; use the HESTIA score instead.
• Outpatient management/risk review

Question 16

M-ongoing?

Answer 16

• Long term anticoagulation-3 months
• Increase doses
Venous filter

Question 17

prognosis?

Answer 17

• Mortality often due to cardiogenic shock Secondary to RV collapse
Hypotension linked to increased mortality

Question 18

Complications?

Answer 18

• Chronic thromboembolic pulmonary hypertension
	• Heparin associated thrombocytopenia
	• Acute bleeding during treatment
	• Pulmonary infarction
	• Cardiac arrest
Recurrent DVTs