Department of Pediatrics, Division of Pediatric Intensive Care, Beatrix Children's Hospital, University Medical Center Groningen, Groningen, the Netherlands.
Respir Care. 2012 Sep;57(9):1496-504. doi: 10.4187/respcare.01571. Epub 2012 Feb 17.
Mechanical ventilation using low tidal volumes has become universally accepted to prevent ventilator-induced lung injury. High-frequency oscillatory ventilation (HFOV) allows pulmonary gas exchange using very small tidal volume (1-2 mL/kg) with concomitant decreased risk of atelectrauma. However, its use in pediatric critical care varies between only 3% and 30% of all ventilated children. This might be explained by the fact that the beneficial effect of HFOV on patient outcome has not been ascertained. Alternatively, in contrast with present recommendations, one can ask if HFOV has been employed in its most optimal fashion related especially to the indications for and timing of HFOV, as well as to using the best oscillator settings. The first was addressed in one small randomized study showing that early use of HFOV, instead of rescue use, was associated with improved survival. From a physiologic perspective, the oscillator settings could be refined. Lung volume is the main determinant of oxygenation in diffuse alveolar disease, suggesting using an open-lung strategy by recruitment maneuvers, although this is in practice not custom. Using such an approach, the patient can be oscillated on the deflation limb of the pressure-volume (P-V) curve, allowing less pressure required to maintain a certain amount of lung volume. Gas exchange is determined by the frequency and the oscillatory power setting, controlling the magnitude of the membrane displacement. Experimental work as well as preliminary human data have shown that it is possible to achieve the smallest tidal volume with concomitant adequate gas exchange when oscillating at high frequency and high fixed power setting. Future studies are needed to validate these novel approaches and to evaluate their effect on patient outcome.
机械通气采用小潮气量已被普遍接受，以防止呼吸机引起的肺损伤。高频振荡通气（HFOV）允许使用非常小的潮气量（1-2ml/kg）进行肺气体交换，同时降低了肺不张损伤的风险。然而，它在儿科重症监护中的使用比例仅为所有接受通气治疗的儿童的 3%至 30%。这可能是因为高频振荡通气对患者预后的有益影响尚未确定。或者，与目前的建议相反，可以询问高频振荡通气是否以最优化的方式使用，特别是与高频振荡通气的适应证和时机有关，以及使用最佳的振荡器设置。第一项研究在一项小型随机研究中得到了证实，该研究表明，早期使用高频振荡通气（而不是抢救使用）与存活率的提高有关。从生理学的角度来看，振荡器的设置可以进一步优化。在弥漫性肺泡疾病中，肺容量是氧合的主要决定因素，这表明可以通过募集手法采用开肺策略，尽管在实践中并非如此。采用这种方法，患者可以在压力-容积（P-V）曲线的呼气支上进行振荡，允许使用较低的压力来维持一定量的肺容量。气体交换取决于频率和振荡功率设置，控制膜位移的幅度。实验工作和初步的人体数据表明，当以高频和固定高功率设置振荡时，有可能实现最小的潮气量，并同时进行足够的气体交换。需要进一步的研究来验证这些新方法，并评估它们对患者预后的影响。
