Janssens H M, Devadason S G, Hop W C, LeSouëf P N, De Jongste J C, Tiddens H A
Dept of Paediatrics, Sophia Children's Hospital, and Erasmus Medical Centre, Rotterdam, The Netherlands.
Eur Respir J. 1999 Apr;13(4):787-91. doi: 10.1034/j.1399-3003.1999.13d15.x.
Pressurized metered dose inhalers (pMDI) are widely used together with spacers for the treatment of asthma in children. However, the variability of daily medication dose for pMDI/spacer combinations is not known. Electrostatic charge is a potential source of dose variability. Metal spacers have no static charge. This study assessed and compared within-subject variability of aerosol delivery of metal and plastic spacers. This was a randomized, crossover study in children with stable asthma aged 1-4 (group I, n=17) and 5-8 (group II, n=16) yrs. In both groups the amount of drug delivered to the mouth by a metal spacer (Nebuchamber) and one of two plastic (polycarbonate) spacers, i.e. Babyhaler in group I and Volumatic in group II was measured. The metal and plastic spacers were tested at home in a randomized order for 7 days each, using budesonide (200 microg b.i.d.). Aerosol was collected on a filter positioned between spacer and facemask or mouth. Budesonide on the filter was assessed by high performance liquid chromatography. 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.
压力定量吸入器（pMDI）常与储物罐一起广泛用于治疗儿童哮喘。然而，pMDI/储物罐组合的每日药物剂量变异性尚不清楚。静电荷是剂量变异性的一个潜在来源。金属储物罐没有静电荷。本研究评估并比较了金属和塑料储物罐气溶胶递送的受试者内变异性。这是一项针对1 - 4岁（I组，n = 17）和5 - 8岁（II组，n = 16）稳定哮喘儿童的随机交叉研究。在两组中，测量了金属储物罐（Nebuchamber）和两种塑料（聚碳酸酯）储物罐之一（I组为Babyhaler；II组为Volumatic）递送到口腔的药物量。金属和塑料储物罐在家庭中按随机顺序各测试7天，使用布地奈德（200微克，每日两次）。气溶胶收集在置于储物罐和面罩或口腔之间的滤器上。通过高效液相色谱法评估滤器上的布地奈德。每个儿童在7天内的平均滤器剂量（均值±标准差）表示为标称剂量的百分比。受试者内变异性表示为变异系数（CV）。I组中，Nebuchamber的平均滤器剂量为41.7±10.1%，Babyhaler为26.0±4.0%（p<0.001）。II组中，Nebuchamber的平均滤器剂量为50.2±9.2%，Volumatic为19.4±7.2%（p<0.001）。I组中，Nebuchamber的平均CV为34%，Babyhaler为37%（p = 0.44）。II组中，Nebuchamber的平均CV为23%，Volumatic为34%（p = 0.003）。在家中使用pMDI/储物罐的儿童，其气溶胶递送存在显著的受试者内剂量变异性。在5 - 8岁儿童中，金属储物罐的这种变异性低于塑料储物罐。无论年龄如何，递送到口腔的剂量金属储物罐比塑料储物罐高约两倍。
