Pulmonary thrombo-embolism is an important cause of morbidity and mortality, especially among the hospitalized patients.  A vast majority of clinically significant pulmonary emboli (PE) arises from deep venous thrombosis.

Predisposing Factors

  • Venous disease of the lower extremities.
  • Cancer.
  • Heart failure.
  • Recent major surgery.
  • Prolonged immobilization.
  • Paralysis.
  • Strong family history of thrombosis.
  • Pregnancy.


  • Dyspnoea
  • Pleuritic chest pain
  • Apprehension
  • Cough

Physical Findings

  • Tachypnoea
  • Tachycardia
  • Inspiratory crackles
  • Swelling of calf
  • Localized tenderness
  • Slight rise in local temperature suggests DVT.

Diagnosis of Thrombo-embolism

Diagnosis is based on Clinical suspicion and General Diagnostic Evaluation

  • Blood Complete Exam:  Leucocytosis
  • E.C.G – To rule out other cardiac causes of tachypnoea, tachycardia
  • Arterial Blood Gases:  (ABGs)
  • Arterial hypoxaemia usually accompanied with hypocapnia.
  • Normal PaO2 can occur in 14 % of patients with acute pulmonary embolism.
  • Specific Diagnostic Studies
  • Ventilation – perfusion (V-Q) lungs scan is indicated in all clinically stable patients with suspected pulmonary embolism.
  • Pulmonary Angiography for confirmation & diagnosis and thrombolytic therapy.  These facilities are presently available only at a few centers including Punjab Institute of Cardiology.
  • X-Ray Chest       Absence of vascular marking on the affected side



A- Supportive Care:-Oxygen Therapy

B- Prevention of Recurrent Emboli is the major therapeutic goal.

Anticoagulation: Heparin I/V.  A bolus of heparin (80 units/kg) followed by continuous infusion (18 units/kg/hr) titrated individually to achieve an activated partial thromboplastin time (aPTT) between 1½ and 2½ times the control value, continued for 5-10 days.  If APTT is not available, clotting time should be monitored with the help of capillary tubes at 2-3 times the baseline level

  • Oral warfarin can be given with the initiation of heparin. Starting dose 5 mg / day for first 2 days, followed by daily dose adjusted to the international normalized ratio (INR) of 2.0-3.0.  Warfarin should be continued for 3 months.
  • I/V heparin should be started immediately on basis of clinical suspicion of PE and without waiting for definitive studies to be obtained.

C- Specific Therapy

  • Systemic thrombolytic therapy with Streptokinase, urokinase should be considered in the treatment of patients who have extensive iliofemoral venous thrombosis or acute massive embolism.
  • Thrombolytic therapy has not yet been shown to reduce the mortality in patients with DVT or PE.

Pulmonary embolectomy that can only be carried out in cardiac surgery units.


Cite this article as:
Burhan Ahmed, MD, "Pulmonary embolism," in Medicalopedia, March 26, 2011, [Permalink: https://www.medicalopedia.org/1130/pulmonary-embolism/].