Pulmonary Diffusion Defect

Pulmonary diffusion defect refers to impaired transfer of gases, particularly oxygen and carbon dioxide, across the alveolar-capillary membrane. This defect can arise from structural changes in the lung parenchyma, thickening of the alveolar walls, or reduced pulmonary capillary blood volume. Conditions such as interstitial lung disease, emphysema, pulmonary vascular disorders, and certain congenital anomalies can all contribute to compromised gas diffusion, leading to hypoxemia, exertional dyspnea, and fatigue. Assessment of pulmonary diffusion defect relies heavily on measurement of the diffusing capacity of the lungs for carbon monoxide (DLCO), which provides an indirect evaluation of the efficiency of alveolar-capillary gas exchange. Additional diagnostic tools include arterial blood gas analysis, pulse oximetry, and imaging studies such as high-resolution CT to detect underlying parenchymal abnormalities. Functional exercise tests, like the six-minute walk test, help evaluate the impact of diffusion impairment on physical capacity. Management is primarily directed at addressing the underlying condition and mitigating factors that exacerbate hypoxemia. Oxygen supplementation, pulmonary rehabilitation, and pharmacologic interventions targeting inflammation or vascular remodeling can improve functional outcomes. In advanced cases, lung transplantation may be considered when conservative measures fail to maintain adequate oxygenation. Emerging research is exploring regenerative therapies and novel pharmacologic agents aimed at restoring alveolar-capillary integrity. By combining targeted treatment of the root cause with supportive strategies to optimize oxygen delivery, pulmonary diffusion defect management seeks to improve daily functioning, reduce complications, and enhance respiratory efficiency.