Importance of Pulmonary Embolism Anatomy in Ventilatory Distress and Haemodynamics

Pulmonary embolism (PE) is a leading cause of morbidity and mortality, with clinical outcomes strongly influenced by the anatomical distribution of emboli. This review explores the impact of PE anatomy on ventilatory distress and haemodynamics, emphasising the distinction between proximal and distal emboli. Proximal emboli, located in the main or lobar pulmonary arteries, significantly impairing pulmonary flow, increase pulmonary artery pressure and cause severe right ventricular dysfunction, necessitating prompt intervention. Distal emboli, while less severe, still pose risks, especially in patients with cardiopulmonary comorbidities, potentially leading to localised ventilation-perfusion mismatch and hypoxaemia. Therapeutic approaches vary by clinical status and embolus location, with systemic thrombolysis or catheter-directed therapy preferred for unstable patients with usually proximal PE, while anticoagulation suffices in stable cases, most of which involve distal emboli. Understanding PE anatomy and its relationship with PE haemodynamic and ventilatory failure is critical for risk stratification, treatment guidance and improvement of patient outcomes.