Bossé Dominick, Beaulieu Alexandre, Avoine Olivier, Micheau Philippe, Praud Jean-Paul, Walti Hervé
Faculté de Médecine et des Sciences de la Santé, Département de Pédiatrie, 3001, 12e Ave. Nord, Sherbrooke, Québec, Canada J1H 5N4.
J Appl Physiol (1985). 2010 Aug;109(2):501-10. doi: 10.1152/japplphysiol.01042.2009. Epub 2010 Jun 10.
This study aimed to implement low-frequency forced oscillation technique (LFFOT) in neonatal total liquid ventilation (TLV) and to provide the first insight into respiratory impedance under this new modality of ventilation. Thirteen newborn lambs, weighing 2.5 + or - 0.4 kg (mean + or - SD), were premedicated, intubated, anesthetized, and then placed under TLV using a specially design liquid ventilator and a perfluorocarbon. The respiratory mechanics measurements protocol was started immediately after TLV initiation. Three blocks of measurements were first performed: one during initial respiratory system adaptation to TLV, followed by two other series during steady-state conditions. Lambs were then divided into two groups before undergoing another three blocks of measurements: the first group received a 10-min intravenous infusion of salbutamol (1.5 microg x kg(-1) x min(-1)) after continuous infusion of methacholine (9 microg x kg(-1) x min(-1)), while the second group of lambs was chest strapped. Respiratory impedance was measured using serial single-frequency tests at frequencies ranging between 0.05 and 2 Hz and then fitted with a constant-phase model. Harmonic test signals of 0.2 Hz were also launched every 10 min throughout the measurement protocol. Airway resistance and inertance were starkly increased in TLV compared with gas ventilation, with a resonant frequency < or = 1.2 Hz. Resistance of 0.2 Hz and reactance were sensitive to bronchoconstriction and dilation, as well as during compliance reduction. We report successful implementation of LFFOT to neonatal TLV and present the first insight into respiratory impedance under this new modality of ventilation. We show that LFFOT is an effective tool to track respiratory mechanics under TLV.
本研究旨在将低频强迫振荡技术（LFFOT）应用于新生儿全液体通气（TLV），并首次深入了解这种新通气模式下的呼吸阻抗。13只新生羔羊，体重2.5±0.4 kg（平均±标准差），进行术前用药、插管、麻醉，然后使用专门设计的液体通气机和全氟化碳进行TLV。在TLV开始后立即启动呼吸力学测量方案。首先进行三组测量：一组在呼吸系统对TLV的初始适应期，随后在稳态条件下进行另外两组测量。然后将羔羊分为两组，再进行三组测量：第一组在持续输注乙酰甲胆碱（9μg·kg⁻¹·min⁻¹）后静脉输注沙丁胺醇10分钟（1.5μg·kg⁻¹·min⁻¹），而第二组羔羊进行胸部束缚。使用频率范围在0.05至2 Hz之间的系列单频测试测量呼吸阻抗，然后用恒相模型拟合。在整个测量方案中，每隔10分钟还会发出0.2 Hz的谐波测试信号。与气体通气相比，TLV时气道阻力和惯性明显增加，共振频率≤1.2 Hz。0.2 Hz时的阻力和电抗对支气管收缩和扩张以及顺应性降低敏感。我们报告了LFFOT在新生儿TLV中的成功应用，并首次深入了解了这种新通气模式下的呼吸阻抗。我们表明LFFOT是跟踪TLV下呼吸力学的有效工具。
