Objectives
At the end of this lecture the student should be able to
Name the common disorders of pulmonary circulation (embolism, vasculitis,
alveolar haemorrhage and pulmonary hypertension).
Describe pulmonary embolism (PE) and discuss it as follows:
o Definition.
o Substances other than thrombus that can embolize into the pulmonary
circulation.
o Pathogenesis and risk factors.
Compare and contrast the clinical features of:
o Small/medium pulmonary embolism.
o Massive pulmonary embolism.
o Multiple, recurrent pulmonary emboli.
Clinical prediction score.
List the usual laboratory and radiological investigations
Normal Pulmonary Circulation
Pulmonary Circulation disorders
Diseases that might affect pulmonary vasculature may include:
 Autimmune diseases ( vasculitides, anti-basement membrane antibodies)
 Infection (schistosomaisis)
 Congenital
 Neoplastic (hemangiomas)
 Pulmonary embolism
 Pulmonary hypertension
Pulmonary embolism
Definition:
 Abrupt blockage of a pulmonary artery or one of its branches –
most commonly = embolus from deep veins of the lower limbs
 Pulmonary embolism + DVT = venous thromboembolism VTE
Stasis
Hyper coagulobility
Endothelial injury
Epidemiology
 300.000-650,00 patients each year
 Annual incidence of VTE is 1in 1000 persons.
 Incidence increases with age
 Male = female (recurrent VTE commoner in males)
 - US data
Causes and Risk Factors
Prothrombotic factors
Virchow triad
Antithrombotic factors
Causes and Risk Factors
Should be considered in history
Hereditary factors
• Deficiency of natural
anticoagulants (ATIII,
protein C & S
• Resistant to inhibitors
factor V Leiden
• Increased coagulation
factors e. g VIII , XI etc
• Defect in fibrinolytic
pathway
dysfirinogenemia
Acquired factors
• Immobilization
• Major surgery/ trauma
• Central venous catheter
• Obesity
• Malignancy
• Pregnancy
• Advanced age
• Medical illness e.g. SLE
mixed
• hyperhomocysteinemia
• Elevated level of Lpa
• Low level of TFP
inhibitors
Causes and Risk Factors
Clinical Presentation
 Can be difficult to diagnose (no specific signs and symptoms).
 There are 3 clinical syndromes associated with pulmonary embolism:
1.
Small/ Medium sized emboli
2.
Large (massive) emboli
3.
Recurrent small embli
Clinical Presentation
1-Small/ medium pulmonary embolism: (Embolus in terminal P vessel)
 Chest pain
 Breathlessness
 Haemoptysis
O/E
 Tachypnoea
 Pleural rub
 Crackles
 Pleural effusion
 May be fever
 Cardiovascular examination is normal
Clinical Presentation
2-Massive pulmonary embolism (obstruction of R V outflow)
 Rare
 Sudden collapse
 Severe chest pain
 Shock (pale, sweaty)
 Syncope
Clinical Presentation
O/E mainly cardiac signs
 Tachypnoea
 Tachycardia
 Hypotension
 Cyanosis
 Raised JVP prominent ‘a’ wave
 R. ventricular heave, gallop, widely splits2
 The chest is usually clear
Clinical Presentation
3-Multiple recurrent pulmonary emboli:
 Increased breathlessness over weeks or months
 Weakness, syncope occasional angina (exertion)
O/E (pulmonary hypertension)
 Right ventricular heave
 Loud P2
Clinical Presentation
List of Investigations
Non imaging tests:
1. Plasma D-dimers ( -ve result excludes diagnosis)
2. ECG (SI, QIII,TIII)
Non invasive imaging tests:
1. Chest radiography
2. CT angiography (the BEST diagnostic test)
3. Ventilation / Perfusion scan ( -ve result excludes diagnosis)
4. Doppler ultrasonography
5. Echocardiography
List of Investigations
Invasive imaging tests
1.
Pulmonary angiography
2.
Contrast venography
 ABG:
• Low PCO2
• Low PO2
Investigations
Investigations
Diagnostic Approach
1- Symptoms
& signs
suggestive of
PE
2-Clinical
prediction
score
3- Select appropriate
test
Diagnostic Approach
Clinical prediction score:
I.
Revised Geneva score
II.
Wells score
Revised Geneva score:
 low risk
 Intermediate risk
 High risk
0- 3
4- 10
>10
Diagnostic Approach
Revised Geneva score
Items of the Revised Geneva Score
Points for Revised Version
Age > 65 years old
1
Previous history of PE or DVT
3
Surgery or fracture within 1 month
2
Active malignancy
2.
Unilateral leg pain
3
Hemoptysis
2.
Heart rate (bpm)
75-94
3
≥ 95
5
Pain on lower-limb deep venous palpation and unilateral
oedema
4
Diagnostic Approach
Differential Diagnosis
 Myocardial infarction
 Pericarditis
 Aortic dissection
 Pneumonia
 Pleurisy
 Chest wall pain
 Congestive heart failure
Treatment
Treatment goals
 Stabilize the patient
i.
Oxygen for hypoxia
ii.
Analgesics for chest pain
 Prevent extension of current thrombus (short term)
i.
Parenteral anticoagulants – heparin
ii.
Oral anticoagulants - warfarin
Treatment

Prevent recurrent VTE (long term)
i.
Continue anticoagulation (warfarin) for 6 weeks- 6month- indefinitely
ii.
Life style changes
iii.
Graduated compression stockings
iv.
IVC Filter
 Lysis or removal of a thrombus in case of haemodynamic instability
(massive PE):
i.
Thrombolytic therapy e. g. streptokinase
ii.
Pulmonary embolectomy
Prevention
 Avoid prolonged immobilization
 Smoking cessation
 Contraception (non hormonal)
 Obesity should be treated
 Thromboprophylaxis in high risk patient
Other Rare Causes of Pulmonary
Embolism
 Fat embolism (long bone fractures, acute pancreatitis)
 Air embolism (decompression sickness, iatrogenic)
 Amniotic fluid embolism (postpartum)
 Septic embolism (sepsis)
 Tumor embolism
Summary
 Pulmonary embolism is usually caused by a thrombus in the deep proximal
veins of the legs that breaks off and lodges in the lungs
 Patient may be a symptomatic or may present with typical symptoms
including dyspnoea & chest pain. Massive pulmonary embolism may present
with hypotension, shock or sudden death.
 An integrated diagnostic approach involving clinical prediction rules and non
invasive testing can be used to evaluate patients.
 The aggressiveness of treatment is dependent on the severity of pulmonary
embolism.
 Prevention of DVT in hospitalized patient is crucial to preventing embolism.
References
 Kumar & Clark’s Clinical Medicine 8th edition
 /https://www.clinicalkey.com