Supplementary Material for: Impact of Body Position on Lung Deposition of Nebulized Surfactant in Newborn Piglets on Nasal Continuous Positive Airway Pressure

<b><i>Introduction:</i></b> The ideal body position during surfactant nebulization is not known. <b><i>Objective:</i></b> The aim of this study was to determine whether body positioning during surfactant nebulization influences surfactant distribution and deposition in the lungs. <b><i>Methods:</i></b> Twenty-four 12- to 36-h-old full-term<b><i></i></b>piglets (1.3–2.2 kg) on nasal continuous positive airway pressure (nCPAP) were randomized into four groups: lateral decubitus with right or left side up, prone or supine positions (<i>n</i> = 6 each). All animals received 200 mg kg^–1 of poractant alfa mixed with 200 MBq of ^99mtechnetium-nanocolloid via a customized eFlow-Neos investigational vibrating-membrane nebulizer. Surfactant deposition (percentage of the administered dose) was measured by gamma scintigraphy. <b><i>Results:</i></b> Comparing all groups, the mean total lung surfactant deposition was significantly higher in the prone position (32.4 ± 7.7%, <i>p</i> = 0.03). The deposition in this group was higher in the right lung (21.0 ± 8.6 vs. 11.3 ± 5.7%, <i>p</i> = 0.04). When nebulization was performed in the lateral decubitus, most of the surfactant was found in the dependent lung, regardless of which side the piglet lay on (right side up 15.3 ± 1.0 vs. 3.4 ± 1.0%, <i>p</i> = 0.06, and left side up 11.2 ± 9.8 vs. 1.8 ± 0.7%, <i>p</i> = 0.04). <b><i>Conclusions:</i></b> In spontaneously breathing animals on nCPAP, the prone position yielded the highest lung dose. Higher deposition rates in the dependent lung while on lateral decubitus indicates that deposition was also influenced by gravity.

**引言**：目前肺表面活性物质（surfactant）雾化吸入的最优体位尚未明确。
**研究目的**：本研究旨在明确肺表面活性物质雾化吸入时的体位是否会对其在肺部的分布与沉积情况产生影响。
**研究方法**：将24只出生12~36小时、体重1.3~2.2 kg的足月新生仔猪，置于经鼻持续气道正压通气（nasal continuous positive airway pressure, nCPAP）支持下，随机分为4组：右侧朝上侧卧位、左侧朝上侧卧位、俯卧位及仰卧位，每组各6只。所有受试动物均通过定制的eFlow-Neos研究型振动膜雾化器，给予200 mg·kg⁻¹的猪肺磷脂（poractant alfa）与200 MBq的锝-99m纳米胶体（^99mTechnetium-nanocolloid）的混合制剂。采用γ闪烁显像术（gamma scintigraphy）测定肺表面活性物质的沉积量，以给药剂量的百分比计。
**研究结果**：对所有组别进行比较后发现，俯卧位组的肺部总表面活性物质沉积量均值显著更高，为32.4 ± 7.7%（*p* = 0.03）。该组的右肺沉积量亦更高，为21.0 ± 8.6%，相较于左肺的11.3 ± 5.7%（*p* = 0.04）。当采用侧卧位进行雾化吸入时，无论仔猪朝向哪一侧，大部分肺表面活性物质均沉积于依赖侧肺部：右侧朝上组的依赖侧肺与非依赖侧肺沉积量分别为15.3 ± 1.0%与3.4 ± 1.0%（*p* = 0.06），左侧朝上组则分别为11.2 ± 9.8%与1.8 ± 0.7%（*p* = 0.04）。
**研究结论**：对于接受经鼻持续气道正压通气支持的自主呼吸动物而言，俯卧位可获得最高的肺部给药沉积量。侧卧位时依赖侧肺部的沉积率更高，这表明沉积过程同样受到重力的影响。