Risk Factors CHE Venous stasis Malignancy Prior dvt obesity ·Age>70 ° Estrogen/OCP ° Prolonged Bed Rest ° Pregnancy(esp3 Immobilization months post partum) Surgery requiring Lower ext injury 30 minutes general Previous anesthesia thrombophlebitis Orthopedic surgery Coagulopathy Stroke MBBS project, Zhongshan Hospital
MBBS project, Zhongshan Hospital Risk Factors • CHF • Malignancy • Obesity • Estrogen/OCP • Pregnancy (esp 3 months post partum) • Lower ext injury • Previous thrombophlebitis • Coagulopathy • Venous Stasis • Prior DVT • Age > 70 • Prolonged Bed Rest • Immobilization • Surgery requiring > 30 minutes general anesthesia • Orthopedic Surgery • Stroke
Virchow's triad Rudolf virchow postulated more than a century ago that a triad of factors predisposed to venous thrombosis Local trauma to the vessel wall Hypercoagulability Stasis of blood flow It is now felt that pts who suffer a Pe have an underlying predisposition that remains silent until a acquired stressor occurs MBBS project, Zhongshan Hospital
MBBS project, Zhongshan Hospital Virchow’s Triad • Rudolf Virchow postulated more than a century ago that a triad of factors predisposed to venous thrombosis — Local trauma to the vessel wall — Hypercoagulability — Stasis of blood flow • It is now felt that pts who suffer a PE have an underlying predisposition that remains silent until a acquired stressor occurs
Impairment in coagulant regulation Factor v leiden mutation Protein c deficiency Protein S deficiency Antithrombin deficiency Prothrombin gene mutation a20210 Anticardiolipin antibodies ° Lupus anticoagulant ° Hyperhomocystinemia MBBS project, Zhongshan Hospital
MBBS project, Zhongshan Hospital Impairment in coagulant regulation • Factor V Leiden mutation • Protein C deficiency • Protein S deficiency • Antithrombin deficiency • Prothrombin gene mutation A20210 • Anticardiolipin antibodies • Lupus anticoagulant • Hyperhomocystinemia
Pathophysiology Increased pulmonary vascular resistance Impaired gas exchange Alveolar hyperventilation Increased airway resistance Decreased pulmonary compliance MBBS project, Zhongshan Hospital
MBBS project, Zhongshan Hospital Pathophysiology • Increased pulmonary vascular resistance • Impaired gas exchange • Alveolar hyperventilation • Increased airway resistance • Decreased pulmonary compliance
Right Ventricular Dysfunction Progressive right heart failure is the usual immediate cause of death from pe As pulmonary vascular resistance increases, right ventricular wall tension rises and perpetuates further right ventricle dilation and dysfunction Interventricular septum bulges into and compresses the normal left ventricle MBBS project, Zhongshan Hospital
MBBS project, Zhongshan Hospital Right Ventricular Dysfunction • Progressive right heart failure is the usual immediate cause of death from PE • As pulmonary vascular resistance increases, right ventricular wall tension rises and perpetuates further right ventricle dilation and dysfunction • Interventricular septum bulges into and compresses the normal left ventricle