The Ritchie Centre, Monash Institute for Medical Research, Monash University, Melbourne, Australia.
Pediatr Res. 2013 Jun;73(6):734-41. doi: 10.1038/pr.2013.48. Epub 2013 Mar 11.
We investigated the effects of positive end-expiratory pressure (PEEP) and tidal volume (VT) on lung aeration, pulmonary mechanics, and the distribution of ventilation immediately after birth using a preterm rabbit model.
Sixty preterm rabbits (27 d) received volume-targeted positive pressure ventilation from birth, with one of the 12 combinations of PEEP (0, 5, 8, or 10 cm H2O) and VT (4, 8, or 12 ml/kg). Outcomes included functional residual capacity (FRC), peak inflating pressure (PIP), dynamic compliance (Cd), and distribution of ventilation.
Increasing PEEP from 0 to 10 cm H2O increased FRC by 4 ml/kg, increased Cd by 0.2 ml/kg/cm H2O, and reduced PIP by 5 cm H2O. Increasing VT from 4 to 12 ml/kg increased FRC by 2 ml/kg, increased Cd by 0.3 ml/kg/cm H2O, and increased PIP by 4 cmH2O. No effect of VT on FRC occurred at 0 or 5 PEEP, and no effect of PEEP occurred at VT = 4 ml/kg. At 0 PEEP, increasing VT increased the proportion of gas entering the smaller apical regions, whereas at 10 PEEP, increasing VT increased the proportion of gas entering basal regions, from 47% to 63%.
Both PEEP and VT have independent, additive effects on FRC, lung mechanics, and the distribution of ventilation during the immediate newborn period.
我们通过使用早产兔模型，研究了呼气末正压（PEEP）和潮气量（VT）对出生后即刻肺充气、肺力学和通气分布的影响。
60 只早产兔（27 日龄）从出生起接受容量目标性正压通气，使用 4、8 或 12ml/kg 这三种 VT 中的一种，以及 0、5、8 或 10cmH2O 这四种 PEEP 中的一种。研究结果包括功能残气量（FRC）、峰压（PIP）、动态顺应性（Cd）和通气分布。
与 0cmH2O 的 PEEP 相比，将 PEEP 增加到 10cmH2O 使 FRC 增加了 4ml/kg，使 Cd 增加了 0.2ml/kg/cmH2O，使 PIP 降低了 5cmH2O。与 4ml/kg 的 VT 相比，将 VT 增加到 12ml/kg 使 FRC 增加了 2ml/kg，使 Cd 增加了 0.3ml/kg/cmH2O，使 PIP 增加了 4cmH2O。在 0 或 5cmH2O 的 PEEP 下，VT 对 FRC 没有影响，在 VT = 4ml/kg 时，PEEP 没有影响。在 0cmH2O 的 PEEP 下，增加 VT 会增加气体进入较小的肺尖区域的比例，而在 10cmH2O 的 PEEP 下，增加 VT 会增加气体进入基底区域的比例，从 47%增加到 63%。
PEEP 和 VT 对出生后即刻的 FRC、肺力学和通气分布均有独立的、相加的影响。
