Brederlau Joerg, Muellenbach Ralf, Kredel Markus, Greim Clemens, Roewer Norbert
Klinik und Poliklinik für Anästhesiologie, Universitätsklinikum Würzburg, Oberdürrbacher Str, 6, 97080 Würzburg, Germany.
BMC Anesthesiol. 2006 Apr 3;6:4. doi: 10.1186/1471-2253-6-4.
This animal study was conducted to assess the combined effects of high frequency oscillatory ventilation (HFOV) and prone positioning on pulmonary gas exchange and hemodynamics.
Saline lung lavage was performed in 14 healthy pigs (54 +/- 3.1 kg, mean +/- SD) until the arterial oxygen partial pressure (PaO2) decreased to 55 +/- 7 mmHg. The animals were ventilated in the pressure controlled mode (PCV) with a positive endexpiratory pressure (PEEP) of 5 cmH2O and a tidal volume (VT) of 6 ml/kg body weight. After a stabilisation period of 60 minutes, the animals were randomly assigned to 2 groups. Group 1: HFOV in supine position; group 2: HFOV in prone position. After evaluation of prone positioning in group 2, the mean airway pressure (Pmean) was increased by 3 cmH2O from 16 to 34 cmH2O every 20 minutes in both groups accompanied by measurements of respiratory and hemodynamic variables. Finally all animals were ventilated supine with PCV, PEEP = 5 cm H2O, VT = 6 ml/kg.
Combination of HFOV with prone positioning improves oxygenation and results in normalisation of cardiac output and considerable reduction of pulmonary shunt fraction at a significant (p < 0.05) lower Pmean than HFOV and supine positioning.
If ventilator induced lung injury is ameliorated by a lower Pmean, a combined treatment approach using HFOV and prone positioning might result in further lung protection.
本动物研究旨在评估高频振荡通气（HFOV）与俯卧位通气对肺气体交换和血流动力学的联合影响。
对14头健康猪（体重54±3.1千克，均值±标准差）进行生理盐水肺灌洗，直至动脉血氧分压（PaO2）降至55±7 mmHg。动物采用压力控制通气模式（PCV），呼气末正压（PEEP）为5 cmH2O，潮气量（VT）为6 ml/kg体重。在60分钟的稳定期后，将动物随机分为2组。第1组：仰卧位HFOV；第2组：俯卧位HFOV。在评估第2组的俯卧位通气后，两组均每20分钟将平均气道压（Pmean）从16 cmH2O提高3 cmH2O至34 cmH2O，同时测量呼吸和血流动力学变量。最后所有动物均采用PCV仰卧位通气，PEEP = 5 cmH2O，VT = 6 ml/kg。
HFOV与俯卧位通气相结合可改善氧合，使心输出量恢复正常，并使肺分流分数显著降低（p < 0.05），且所需的Pmean显著低于HFOV与仰卧位通气。
如果较低的Pmean可减轻呼吸机诱导的肺损伤，那么采用HFOV与俯卧位通气的联合治疗方法可能会进一步保护肺脏。
