Pulmonary Embolism

A pulmonary embolism (PE) occurs when material—most commonly part of a venous thrombus—travels through the right side of the heart and obstructs the pulmonary arterial circulation. Most thromboembolic PEs originate from a deep vein thrombosis (DVT), so DVT and PE are collectively called venous thromboembolism (VTE). PE can range from a small embolus with mild symptoms to extensive pulmonary vascular obstruction causing acute right ventricular failure, obstructive shock, and cardiac arrest. For the RN, the priority is to recognize an unexpected acute respiratory or haemodynamic change, determine whether the patient is stable, support airway, breathing, and circulation, and escalate care promptly. Clinical sequence: DVT → embolus travels to lungs → pulmonary arterial obstruction → impaired pulmonary perfusion + increased RV workload → hypoxaemia and possible obstructive shock