Pulmonary Embolism

A pulmonary embolism (PE) occurs when material—most often part of a venous blood clot—travels through the right side of the heart and obstructs the pulmonary arterial circulation. Most thromboembolic PEs originate from a deep vein thrombosis (DVT), making DVT and PE two manifestations of venous thromboembolism (VTE). The immediate danger is not simply that a clot is present in the lung. Pulmonary arterial obstruction causes: impaired pulmonary perfusion + increased pulmonary vascular resistance This can progress to: right ventricular strain → right ventricular failure → decreased left ventricular filling → decreased cardiac output → hypotension → obstructive shock At the same time, impaired perfusion of ventilated lung tissue contributes to hypoxemia. For the RN, the priority is early recognition of an acute respiratory or hemodynamic change, rapid assessment of stability, support of airway/breathing/circulation, immediate escalation when deterioration is present, and safe monitoring during diagnostic and therapeutic management.