1. Management of acute pulmonary embolism
Ala’Eldin Hassan Ahmed, MD, FRCP, FCCP
Faculty of Medicine, University of Khartoum

2. Acute Pulmonary Embolism
Consider pulmonary embolism as a possible diagnosis in any patient presenting with
acute shortness of breath.
Differential diagnosis:
 Acute severe asthma.
 Acute left ventricular failure.
 Tension pneumothorax.
 Exacerbation of chronic obstructive pulmonary disease.
 Mechanical airway obstruction.
Directed Approach to Acute Pulmonary Embolism:
History:
Clinical presentation of pulmonary embolism may be subtle, atypical or obscured by
other coexisting diseases. In a patient with suspected pulmonary embolism determine
the risks of pulmonary embolism (see table)
Physical examination:
 Assess haemodynamic instability: low blood pressure or the presence of acute
right heart failure.
Diagnostic studies:
1. See figures
For a stepwise approach for diagnosing pulmonary embolism please refer
to attached table (rules for predicting the probability of embolism) and
flowchart.
Notes:
 If the diagnosis of pulmonary embolism is strongly suspected start treatment
immediately (before investigations are done or their results are available).
See table: drug treatment of acute pulmonary embolism for drugs used.
 Intravenous unfractionated heparin is as effective as low-molecular-weight
heparin.
 For patients with severe renal failure unfractinated heparin is preferred over
low-molecular-weight heparin as low-molecular-weight heparin dose need to
be monitored.
 Begin oral anticoagulation therapy within 24 hours of starting heparin.
 Discontinue heparin when the INR has been >/= 2 for two consecutive days.
 Thrombolytic therapy have not been shown to be superior to anticoagulation
in the management of pulmonary embolism.
 Thrombolytic therapy may be considered for patients who are
haemodynamically unstable.

3. Drug treatment of acute pulmonary embolism
Drug Main
indication
Recommended dose
Unfractionated
heparin
Acute
pulmonary
embolism
 Give bolus dose of 5000 units IV (or 80U/kg
bolus). Followed by continuous infusion (in 5%
dextrose or normal saline) of at least 30,000 units
for the first 24 hours (18 U/kg/h.). Subsequent
dosing should maintain an aPTT value of 1.5 to
2.5 times the control value.
Low molecular
weight heparin
Acute
pulmonary
embolism
 Can be used as an alternative to unfractionated
heparin. Body weight adjusted doses should be
administered subcutaneously once or twice daily
without laboratory monitoring. Follow
manufacturers’ recommendations for dosing.
Streptokinse Acute
pulmonary
embolism
 May be given to patients who are
haemodynamically unstable (see text). Dose
250,000 units IV infusion ((in 5% dextrose or
normal saline) over 30 minutes. Should be
followed by unfractionated heparin infusion as
above, or SC low molecular weight heparin as
above.
Warfarin Acute
pulmonary
embolism
 Given orally as a single daily dose to maintain an
INR between 2.0 to 3.0.

4. Variable No of points
Risk factors
Clinical signs and symptoms of venous thrombosis 3
An alternative diagnosis deemed less likely than P.E. 3
Heart rate > 100 beats per minute 1.5
Immobilisation or surgery in the past 4 weeks 1.5
Previous deep vein thrombosis or P.E. 1.5
Haemoptysis 1
Cancer receiving treatment or treated past 6 months 1
Clinical probability
Low < 2.0
Intermediate 2.0 – 6.0
High > 6.0
Rules for predicting the probability of embolism

5. Diagnostic approach to a patient with low clinical probability pulmonary embolism
Low clinical probability of embolism
CT angiography
Negative CT angiogramPositive CT angiogram
Duplex ultrasonographyDiagnosis confirmed
PositiveNegative
Diagnosis
confirmed
Diagnosis ruled out

6. Diagnostic approach to a patient with high or moderate clinical probability of P.E
High or intermediate clinical probability
of embolism
CT angiography
Negative CT angiogramPositive CT angiogram
Duplex ultrasonographyDiagnosis confirmed
PositiveNegative
Diagnosis
ruled out
Diagnosis
confirmed
Negative Positive
Diagnosis
confirmed
Pulmonary angiography

7. Diagnostic approach to a patient with high or moderate clinical probability of P.E
High or intermediate clinical probability
of embolism
CT angiography
Negative CT angiogramPositive CT angiogram
Duplex ultrasonographyDiagnosis confirmed
PositiveNegative
Diagnosis
ruled out
Diagnosis
confirmed
Negative Positive
Diagnosis
confirmed
Pulmonary angiography