University of Western Australia, Perth, Australia.
Telethon Kids Institute, Perth, Australia.
Paediatr Anaesth. 2020 Dec;30(12):1363-1377. doi: 10.1111/pan.14028. Epub 2020 Oct 18.
Perioperative respiratory adverse events account for a third of all perioperative cardiac arrests, with bronchospasm and laryngospasm being most common. Standard treatment for bronchospasm is administration of inhaled salbutamol, via pressurized metered dose inhaler. There is little evidence on the best method of attaching the pressurized metered dose inhaler to the artificial airway during general anesthesia.
The aim of this study is to investigate the best method to deliver aerosolized salbutamol via pressurized metered dose inhaler to the lungs of an anesthetized child.
We measured salbutamol delivered by pressurized metered dose inhaler through different sized tracheal tubes, supraglottic airway devices, and tracheostomies in vitro for methods commonly employed for connecting the pressurized metered dose inhaler to the artificial airway. Breathing was simulated for patients weighing 3, 16, 50, and 75 kg. Pressurized metered dose inhaler actuation coincided with inspiration.
A pressurized metered dose inhaler combined with an in-line non-valved or valved spacer, or the direct method, when delivered via tracheal tube, was linked with improved delivered dose of salbutamol, compared to all other methods for 3 or 50 kg simulated patients weights. The delivered dose when using a non-valved spacer was greater than all methods for 16 and 75 kg patient weights. A spacer improved delivery for the flexible supraglottic airway device type, and there was no difference with or without a spacer for remaining types.
Via tracheal tube and non-valved spacer, the following doses should be delivered after single actuation of a 100 µg labeled-claim salbutamol dose: ~2 µg kg per actuation to a 3 kg neonate, ~1 µg kg per actuation to a 16 kg child, and ~ 0.5 µg kg per actuation for a 50-75 kg child. The least effective methods were the syringe, and the uni- and bidirectional adaptor methods, which require replacement by the direct method if a spacer is unavailable.
围手术期呼吸不良事件占所有围手术期心脏骤停的三分之一，其中支气管痉挛和喉痉挛最为常见。支气管痉挛的标准治疗是通过压力定量气雾剂吸入沙丁胺醇。在全身麻醉期间，将压力定量气雾剂连接到人工气道的最佳方法几乎没有证据。
本研究旨在探讨将沙丁胺醇通过压力定量气雾剂输送到麻醉儿童肺部的最佳方法。
我们在体外测量了通过不同尺寸的气管导管、声门上气道装置和气管造口术输送的沙丁胺醇，这些方法常用于将压力定量气雾剂连接到人工气道。模拟了体重为 3、16、50 和 75kg 的患者的呼吸。压力定量气雾剂的触发与吸气同步。
与所有其他方法相比，对于模拟体重为 3 或 50kg 的患者，通过气管导管连接带内置无阀或有阀活瓣的储雾罐或直接方法，可改善沙丁胺醇的输送剂量。对于模拟体重为 16 和 75kg 的患者，无阀活瓣储雾罐的输送剂量大于所有方法。储雾罐改善了柔性声门上气道装置类型的输送，而带有或不带有储雾罐的其余类型之间没有差异。
通过气管导管和无阀储雾罐，在单次 100μg 标签声称剂量的沙丁胺醇后，应输送以下剂量：对于 3kg 的新生儿，每次给药约 2μg/kg；对于 16kg 的儿童，每次给药约 1μg/kg；对于 50-75kg 的儿童，每次给药约 0.5μg/kg。最无效的方法是注射器和单、双向适配器方法，如果没有储雾罐，则需要用直接方法代替。
