Bisgaard H
Department of Paediatrics, National University Hospital, Copenhagen, Denmark.
Allergy. 1999;54 Suppl 49:97-103. doi: 10.1111/j.1398-9995.1999.tb04396.x.
There is an increasing awareness of the importance of reliable aerosol delivery, with emphasis on the dose delivered to the lungs, optimal clinical control, cost-effectiveness, and safety in children. Dose prescription should relate to the expected lung dose rather than the factory-dispensed dose, as at present. The device determines the lung dose. Clearly, therefore, the device should be considered an integral part of the prescription. Drug approval processes should clearly specify the device, and discourage the use of other devices. This would rationalize the choice of devices. Important new insights into factors essential for drug delivery to the airways have been acquired in recent years. Nasal inhalation increases systemic bioavailability, reduces lung dose, and adds to its variability; hence, face masks to prevent nasal breathing have been developed. Similarly, dead space in the inspiratory line causes a proportional reduction in lung dose; hence, attention should be paid to reducing such dead space. Plastics in spacers cause a rapid loss of drug due to electrostatic attraction of the aerosol. The residence time of the aerosol, i.e., the time available for inhalation, is increased in nonelectrostatic spacers, allowing less compliant children enough time to obtain a full dose. Eliminating the electrostatic charge can change the lung dose by several times; hence, nonelectrostatic materials should be used in future spacer devices. Compliance is the biggest problem in drug delivery to children. The inhaler design process should be reversed, adapting technology to the child. Interactive microchip technology should provide intelligent devices that react to correct handling and breathing maneuvers. An intelligent nebulizer has been developed that adapts nebulization to the child's breathing pattern, nebulizing only during inhalation and avoiding loss of aerosol during exhalation. An automatic device (AirPac) has been developed that transforms a dry-powder inhaler, Turbuhaler, into a spacer. In addition to the general advantages of spacer treatment, this device offers the advantage of a drug aerosol delivered without use of propellants or additives. The mechanical actuation ensures highly repeatable drug delivery. Finally, a nonelectrostatic, tower-shaped spacer provides a stable aerosol, which remains airborne for a prolonged period. The spacer is equipped with a face mask that prevents nasal breathing. Such features should improve our ability to treat young children with inhaled drug aerosols.
人们越来越意识到可靠的气雾剂递送的重要性，重点在于递送至肺部的剂量、最佳临床控制、成本效益以及儿童用药的安全性。剂量处方应与预期的肺部剂量相关，而不是像目前这样与工厂配发的剂量相关。装置决定肺部剂量。因此，显然应将装置视为处方的一个组成部分。药物审批过程应明确指定装置，并不鼓励使用其他装置。这将使装置的选择更加合理。近年来，人们对气道给药的关键因素有了重要的新认识。经鼻吸入会增加全身生物利用度，降低肺部剂量，并增加其变异性；因此，已开发出防止经鼻呼吸的面罩。同样，吸气管路中的死腔会导致肺部剂量成比例降低；因此，应注意减少此类死腔。储雾罐中的塑料会因气雾剂的静电吸引而导致药物迅速损失。在无静电的储雾罐中，气雾剂的停留时间（即可供吸入的时间）会增加，使不太配合的儿童有足够时间获得全剂量。消除静电荷可使肺部剂量改变数倍；因此，未来的储雾罐装置应使用无静电材料。依从性是儿童给药中最大的问题。吸入器的设计过程应颠倒过来，使技术适应儿童。交互式微芯片技术应提供能对正确操作和呼吸动作做出反应的智能装置。已开发出一种智能雾化器，它能根据儿童的呼吸模式调整雾化，仅在吸气时雾化，避免呼气时气雾剂损失。已开发出一种自动装置（AirPac），它将干粉吸入器Turbuhaler转变为储雾罐。除了储雾罐治疗的一般优点外，该装置还具有无需使用推进剂或添加剂即可递送药物气雾剂的优点。机械驱动确保药物递送具有高度可重复性。最后，一种无静电的塔形储雾罐可提供稳定的气雾剂，使其在空气中长时间悬浮。该储雾罐配有防止经鼻呼吸的面罩。这些特性应能提高我们用吸入药物气雾剂治疗幼儿的能力。
