In this lecture, Dr. Ana Crawford presents the definition, etiology, and pathophysiology of pulmonary emboli.

She describes various etiologies of pulmonary emboli while discussing their effects on gas exchange and hemodynamics as well as the ways in which pulmonary emboli can present clinically.

She discusses the pulmonary emboli resulting from:

• Thrombus/blood clot
• Amniotic fluid
• Fat
• Air

She outlines how an embolus will move from the lower systems and end up in the lungs.

Virchow's triad is presented:

• Venous Stasis
• Endothelial Injury
• Hypercoagulable States

She discusses how deep venous thrombi (DVTs) become emboli, lodge in the lungs, and how they can disrupt the pulmonary perfusion and gaseous exchange in the lungs. She discusses how hypoxia is detected in such patients.

She discusses, if the pulmonary emboli increase shunt, or increase the dead space? 

V/Q mismatch, both physiological and pathological, is presented in the light of pulmonary emboli.

She discusses the risk factors for thrombosis:

• Hereditary 
  • Protein C
  • Protein S
  • Antithrombin Deficiency
  • ETc
• Acquired
  • Immobility
  • Recent Surgery
  • Malignance
  • Etc

She then discusses how the fat particles dislodge and result in fat embolism syndrome? And, the situations in which this can happen. 

Definition and presentation of the pulmonary embolism are discussed next. Labs for a massive or high-risk pulmonary embolism are reviewed.

Diagnostic scoring for a pulmonary embolism is discussed. Following scoring methods are presented:

• Wells Score
• Geneva Score
• D-dimer Cutoff