摘要
加压计量吸入器(pMDI)与间隔器一起被广泛用于儿童哮喘的治疗。然而,pMDI/间隔剂组合每日用药剂量的可变性尚不清楚。静电电荷是剂量变化的一个潜在来源。金属垫片没有静电荷。本研究评估和比较了受试者体内金属和塑料垫片气溶胶输送的可变性。这是一项在1-4岁(I组,n=17)和5-8岁(II组,n=16)的稳定哮喘儿童中进行的随机、交叉研究。在两组中,测量了通过金属间隔片(Nebuchamber)和塑料间隔片(聚碳酸酯)中的一个(即Babyhaler组和Volumatic组)送入口腔的药物量。采用布地奈德(200微克/天)在家中随机顺序测试金属和塑料垫片,每个垫片7天。气溶胶通过放置在隔离器和口罩或嘴之间的过滤器收集。采用高效液相色谱法测定滤膜上的布地奈德。 The mean filter dose for each child (mean+/-SD) during the 7 days was expressed as a percentage of the nominal dose. Within-subject variability was expressed as coefficient of variation (CV). Mean filter dose in group I was 41.7+/-10.1% for Nebuchamber and 26.0+/-4.0% for Babyhaler (p<0.001). Mean filter dose in group II was 50.2+/-9.2% for Nebuchamber and 19.4+/-7.2% for Volumatic (p<0.001). Mean CV in group I was 34% for Nebuchamber and 37% for Babyhaler (p=0.44). Mean CV in group II was 23% for Nebuchamber and 34% for Volumatic (p=0.003). There was substantial within-subject dose variability in aerosol delivery in children using a pMDI/spacer at home. This variability was lower for the metal than for the plastic spacer in children 5-8 yrs of age. The dose delivered to the mouth was about two-fold higher for the metal than the plastic spacer independent of age.