COPD患者におけるディスクヘラー(R)からの最大吸入気流量測定

Peak Inspiratory Flow from a Diskhaler in Patients with Moderate COPD

要旨

　この研究では，以前に報告したディスクヘラー^(R)吸入時のマウスピース内圧から最大吸入気流量(PIF)を求める方法を発展させて，自宅で薬剤吸入時のPIFを測定する方法を考案した．さらに，中等症COPD患者2名で，対照期間(2週間)後に，2週間毎日サルメテロールを吸入させ(試行期間)，PIFを自己測定させた．患者1では，自宅での平均PIFは，朝が103.3±4.8(mean±SD)，夕が99.5±6.7l/minであった．朝のピークフロー(PEF)は対照期間の242.3±20.1から試行期間は255.0±17.2l/minと増加したが有意差はなかった．夕のPEFは234.4±13.6から270.0±28.3l/minと有意に増加した．患者2のPIFは朝が93.4±5.9，夕が86.3±6.5l/minであった．朝のPEF171.1±15.3は試行期間に188.7±32.3l/minと増加したが有意差はなかった．夕のPEFも174.3±29.3から172.2±17.9l/minで有意差はなかった．以上より装置の実用性を確かめるとともに，中等症のCOPD患者もディスクヘラーからの十分な吸入気量が得られると推定した．

Summary

　We have reported the linear relationship between the power of peak inspiratory flow rate(PIF) and negative pressure in the mouthpiece of a Diskhaler. By measuring mouthpiece pressure we estimated exactly the daily PIF during inhalation of salmeterol from a Diskhaler in two moderately severe COPD patients. Following a two-week control period, the patients inhaled salmeterol(50μg, bid) daily from the Diskhaler for two weeks. In the first patient, the mean morning PIF during the control period was 103.3±4.8l/min(mean±SD) and the evening PIF was 99.5±6.7l/min. Although morning PEF was not significantly increased by salmeterol therapy(242.3±20.1 vs. 255.0±17.2l/min) the evening PEF significantly increased from 234.4±13.6 to 270.0±28.3 l/min. In the second patient, morning and evening PIFs were 93.4±5.9 and 86.3±6.5l/min. Although the morning PEF increased from 171.1±15.3 to 188.7±32.3l/min, the difference did not reach statistical significance. The evening PEF did not show any significant changes(174.3±29.3 vs. 172.2±17.9l/min). We concluded that our PIF estimation method was useful for estimation of PIF from a Diskhaler in patients with moderately severe COPD. The COPD patients may inhale from the Diskhaler almost as strongly as healthy subjects do.