Yanai M, Hatazawa J, Ojima F, Sasaki H, Itoh M, Ido T
Dept of Geriatric Medicine, Tohoku University School of Medicine, Sendai, Japan.
Eur Respir J. 1998 Jun;11(6):1342-8. doi: 10.1183/09031936.98.11061342.
As freon is limited in its use as a generator for aerosol inhalation, powder particles are used as an alternative for inhalation therapy. The pulmonary deposition and clearance of inhaled powder particles was studied by positron emission tomography (PET) in ten patients with chronic obstructive pulmonary disease (COPD) and in five normal controls. The powder, 5 microm in mean diameter, was water soluble and labelled with 2-deoxy-2-[18F]-fluoro-D-glucose (18FDG). Powder inhalation was done with single deep inspiration from residual volume to total lung capacity. The initial deposition ratio in the right or left lung field to total inhaled dose, measured by an anteroposterior rectilinear scan, did not differ between normals and COPD patients. Ratios of radioactivity detected within the central and peripheral regions (the central to peripheral ratio) measured by the PET scan was not significantly different between COPD patients (4.8+/-2.6, mean+/-SD) and normals (2.6+/-0.8, mean+/-SD). However, the regional powder deposition in peripheral lung fields measured by the PET scan was significantly more uneven in COPD patients than in normal patients. The clearance rate of 18FDG, defined as the retention ratio of 18FDG activity to the initially deposited 18FDG at 60 and 120 min after inhalation, in the trachea, large bronchi or peripheral lung fields measured by tomographic scan showed a wider variation in COPD patients than in normals. To conclude, inhaled powder tended to be deposited more centrally and was distributed more unevenly in the peripheral lung in chronic obstructive pulmonary disease patients than in normals. This could be a limitation of powder inhalation used for therapy in chronic obstructive pulmonary disease patients.
由于氟利昂作为气雾剂吸入发生器的用途有限，粉末颗粒被用作吸入治疗的替代物。通过正电子发射断层扫描（PET）研究了10例慢性阻塞性肺疾病（COPD）患者和5名正常对照者吸入粉末颗粒后的肺沉积和清除情况。该粉末平均直径为5微米，可溶于水并标记有2-脱氧-2-[18F]-氟-D-葡萄糖（18FDG）。通过从残气量到肺总量进行单次深吸气来进行粉末吸入。通过前后直线扫描测量的右肺或左肺野初始沉积率与总吸入剂量之比，在正常人和COPD患者之间没有差异。通过PET扫描测量的中央和外周区域内检测到的放射性比率（中央与外周比率），在COPD患者（4.8±2.6，平均值±标准差）和正常人（2.6±0.8，平均值±标准差）之间没有显著差异。然而，通过PET扫描测量的外周肺野区域粉末沉积在COPD患者中比正常患者明显更不均匀。通过断层扫描测量的气管、大气道或外周肺野中18FDG的清除率，定义为吸入后60分钟和120分钟时18FDG活性与初始沉积的18FDG的保留率，在COPD患者中比正常人有更广泛的变化。总之，与正常人相比，慢性阻塞性肺疾病患者吸入的粉末倾向于更多地沉积在中央，并且在外周肺中分布更不均匀。这可能是慢性阻塞性肺疾病患者用于治疗的粉末吸入的一个局限性。
