Sánchez Luna Manuel, Santos González Martín, Tendillo Cortijo Francisco
Neonatology Division, Instituto de Investigación Sanitaria Gregorio Marañón, Hospital General Universitario "Gregorio Marañón", C/ Dr. Esquerdo 46, 28007 Madrid, Spain.
Crit Care Res Pract. 2013;2013:593915. doi: 10.1155/2013/593915. Epub 2013 Jul 18.
Objective. To assess volume guarantee (VG) ventilation combined with high-frequency oscillatory ventilation (HFOV) strategy on PaCO2 regulation in an experimental model of neonatal distress syndrome. Methods. Six 2-day-old piglets weighing 2.57 ± 0.26 kg were used for this interventional experimental study. Animals were ventilated during physiologic lung conditions and after depletion of lung surfactant by bronchoalveolar lavage (BAL). The effect of HFOV combined with VG on PaCO2 was evaluated at different high-frequency expired tidal volume (VThf) at constant frequency (f R ) and mean airway pressure (mPaw). Fluctuations of the pressure (ΔPhf) around the mPaw and PaCO2 were analyzed before and after lung surfactant depletion. Results. PaCO2 levels were inversely proportional to VThf. In the physiological lung condition, an increase in VThf caused a significant decrease in PaCO2 and an increase in ΔPhf. After BAL, PaCO2 did not change as compared with pre-BAL situation as the VThf remained constant by the ventilator. Conclusions. In this animal model, using HFOV combined with VG, changes in the VThf settings induced significant modifications in PaCO2. After changing the lung condition by depletion of surfactant, PaCO2 remained unchanged, as the VThf setting was maintained constant by modifications in the ΔPhf done by the ventilator.
目的。在新生儿呼吸窘迫综合征实验模型中评估容量保证（VG）通气联合高频振荡通气（HFOV）策略对二氧化碳分压（PaCO₂）的调节作用。方法。选用6头2日龄、体重2.57±0.26千克的仔猪进行这项干预性实验研究。在生理肺条件下以及通过支气管肺泡灌洗（BAL）耗竭肺表面活性物质后对动物进行通气。在恒定频率（fR）和平均气道压（mPaw）条件下，评估不同高频呼出潮气量（VThf）时HFOV联合VG对PaCO₂的影响。分析肺表面活性物质耗竭前后mPaw和PaCO₂周围压力的波动（ΔPhf）。结果。PaCO₂水平与VThf成反比。在生理肺条件下，VThf增加导致PaCO₂显著降低且ΔPhf增加。BAL后，由于呼吸机使VThf保持恒定，PaCO₂与BAL前相比未发生变化。结论。在该动物模型中，使用HFOV联合VG时，VThf设置的改变会引起PaCO₂的显著变化。通过耗竭表面活性物质改变肺条件后，由于呼吸机通过改变ΔPhf使VThf设置保持恒定，PaCO₂保持不变。
