Pulmonary Embolus

Pulmonary Embolus

Pathology:                   Embolusin the pulmonary vasculature that has classically travelled from a deep vein ofthe leg (DVT) via the right heart or a right atrial thrombus in AF.


Aetiology:                    Virchow’sTriad:

Venous stasise.g. immobility, CCF, dehydration and venous obstruction

Endothelial Injury e.g. trauma, inflammation and previous thrombosis

Hypercoagulable state e.g. malignancy, oestrogen therapy, surgery and  

                                              abnormalities of the clottingcascade


Symptoms:                   Acute Minor: Pleuritic pain, dyspnoea

Acute Major: Central chest pain, dyspnoea

Sub-Acute/Chronic:Progressive dyspnoea


Signs:                              Acute Minor: hyperventilation,haemoptysis, hypoxia, fever, effusion

Acute Major: As above + hypotension, cyanosis, engorgedneck veins and collapse

Sub-Acute/Chronic: hyperventilation, raised JVP


Investigations:          Chest X-Ray: Often normal, elevation ofa hemi-diaphragm and linear atelectasis,

small effusions or wedged shaped infarcts may be present

ECG: Sinus tachycardia, right heart strain or S1Q3T3

ABG: Low PaO2 and PaCO2

D-dimer: If clinical probability is intermediate or lowthen a negative d-dimer is a

     reliable rule-out of thromboembolicdisease

CTPA: Initial investigation for non-massive PE’s

V/Q Scan: Used in those who can not tolerate CT contrast


Treatment:                  Thrombolysis: Clinically massive PE andmarked haemodynamic compromise

Anticoagulation: Low molecular weight heparin thenWarfarin with a target INR of 2.0-3.0.

LMWHcontinued until 2 consecutive days of target INR achieved due to initialprothrombotic effect of Warfarin.

IVC filter: Aim to prevent further clot reaching pulmonaryvasculature.


Complications:          Pulmonaryhaemorrhage, pulmonary hypertension, CCF, recurrent episodes


Prognosis:                    MassivePE 30-60% mortality, most occur in the first 1-2 hours of care



Text Box: Virchow’s Triad Mnemonic:
“HE’S Virchow”
Hypercoagulable State
Endothelial Injury
Stasis (Venous)











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