Thromboembolism and Pulmonary Embolism Overview

Pulmonary embolism originates from a deep vein thrombosis in less than 50% of cases.

Fat embolism syndrome is characterized by patients being mostly asymptomatic.

Air embolism can manifest as Caisson disease, which involves gas bubbles persisting in the skeleton.

Amniotic fluid embolism is a rare cause of maternal mortality.

In systemic thromboembolism, most emboli come to rest in the upper limbs.

Venous thrombosis rarely causes infarction because bypass channels rapidly open.

Shock leads to cellular hypoxia due to increased tissue perfusion.

Septic shock is most frequently triggered by gram-negative bacterial infections.

Cardiogenic shock can be associated with myocardial infarction.

White infarcts occur in tissues with dual circulations such as the lungs.

Oedema and effusions are nearly balanced with a small net movement of fluid out of the tissues.

Ischaemia is defined as the deprivation of affected tissue from vital nutrients, especially oxygen.

Thrombosis can be caused by changes in the intimal surface of the vessel, blood flow patterns, and blood constituents.

Venous thrombosis often starts at a valve due to turbulence, and a common risk factor is immobilization.

Arterial thrombosis commonly results in oedema, varicose veins, and ulcers.

Embolism refers to a detached mass carried by the blood that causes tissue dysfunction or infarction at its distant site.

Reduced plasma oncotic pressure is a common cause of oedema in conditions like nephrotic syndrome.

Shock is characterized by circulatory collapse that impairs tissue perfusion.

Thrombosis can occur in both arterial and venous systems but not in embolism.

Inflammatory effusions often have higher protein content and cellular debris compared to non-inflammatory effusions.