Thammanomai Apiradee, Hueser Lauren E, Majumdar Arnab, Bartolák-Suki Erzsébet, Suki Béla
Department of Biomedical Engineering, Boston University, Boston, MA 02215, USA.
J Appl Physiol (1985). 2008 May;104(5):1329-40. doi: 10.1152/japplphysiol.01002.2007. Epub 2008 Mar 13.
Variable ventilation (VV), characterized by breath-to-breath variation of tidal volume (Vt) and breathing rate (f), has been shown to improve lung mechanics and blood oxygenation during acute lung injury in many species compared with conventional ventilation (CV), characterized by constant Vt and f. During CV as well as VV, the lungs of mice tend to collapse over time; therefore, the goal of this study was to develop a new VV mode (VV(N)) with an optimized distribution of Vt to maximize recruitment. Groups of normal and HCl-injured mice were subjected to 1 h of CV, original VV (VV(O)), CV with periodic large breaths (CV(LB)), and VV(N), and the effects of ventilation modes on respiratory mechanics, airway pressure, blood oxygenation, and IL-1beta were assessed. During CV and VV(O), normal and injured mice showed regional lung collapse with increased airway pressures and poor oxygenation. CV(LB) and VV(N) resulted in a stable dynamic equilibrium with significantly improved respiratory mechanics and oxygenation. Nevertheless, VV(N) provided a consistently better physiological response. In injured mice, VV(O) and VV(N), but not CV(LB), were able to reduce the IL-1beta-related inflammatory response compared with CV. In conclusion, our results suggest that application of higher Vt values than the single Vt currently used in clinical situations helps stabilize lung function. In addition, variable stretch patterns delivered to the lung by VV can reduce the progression of lung injury due to ventilation in injured mice.
可变通气（VV）的特征是潮气量（Vt）和呼吸频率（f）在呼吸周期中不断变化，与传统通气（CV，其特征为Vt和f恒定）相比，已证明可变通气在许多物种的急性肺损伤期间可改善肺力学和血液氧合。在CV以及VV过程中，小鼠的肺随着时间推移往往会塌陷；因此，本研究的目的是开发一种新的VV模式（VV(N)），通过优化Vt分布来实现最大程度的肺复张。将正常小鼠和盐酸损伤小鼠分组，分别接受1小时的CV、原始VV（VV(O)）、周期性大呼吸的CV（CV(LB)）和VV(N)，并评估通气模式对呼吸力学、气道压力、血液氧合和IL-1β的影响。在CV和VV(O)期间，正常小鼠和损伤小鼠均出现局部肺塌陷，气道压力升高且氧合不佳。CV(LB)和VV(N)实现了稳定的动态平衡，呼吸力学和氧合显著改善。然而，VV(N)产生的生理反应始终更佳。在损伤小鼠中，与CV相比，VV(O)和VV(N)而非CV(LB)能够减轻与IL-1β相关的炎症反应。总之，我们的结果表明，应用高于目前临床使用的单一Vt值有助于稳定肺功能。此外，VV传递至肺的可变拉伸模式可减轻损伤小鼠因通气导致的肺损伤进展。
