Carlos Chagas Filho Institute of Biophysics, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil.
Respiration. 2012;84(5):369-76. doi: 10.1159/000334403. Epub 2011 Dec 28.
Hypoxemia in acute lung injury/acute respiratory distress syndrome (ALI/ARDS) patients represents a common finding in the intensive care unit (ICU) and frequently does not respond to standard ventilatory techniques.
To study whether the early short-term application of high-frequency percussive ventilation (HFPV) can improve gas exchange in hypoxemic patients with ALI/ARDS or many other conditions in comparison to conventional ventilation (CV) using the same mean airway pressure (P(aw)), representing the main determinant of oxygenation and hemodynamics, irrespective of the mode of ventilation.
Thirty-five patients not responding to CV were studied. During the first 12 h after admission to the ICU the patients underwent CV. Thereafter HFPV was applied for 12 h with P(aw) kept constant. They were then returned to CV. Gas exchange was measured at: 12 h after admission, every 4 h during the HFPV trial, 1 h after the end of HFPV, and 12 h after HFPV. Thirty-five matched patients ventilated with CV served as the control group (CTRL).
PaO(2)/FiO(2) and the arterial alveolar ratio (a/A PO(2)) increased during HFPV treatment and a PaO(2)/FiO(2) steady state was reached during the last 12 h of CV, whereas both did not change in CTRL. PaCO(2) decreased during the first 4 h of HFPV, but thereafter it remained unaltered; PaCO(2) did not vary in CTRL. Respiratory system compliance increased after HFPV.
HFPV improved gas exchange in patients who did not respond to conventional treatment. This improvement remained unaltered until 12 h after the end of HFPV.
急性肺损伤/急性呼吸窘迫综合征（ALI/ARDS）患者的低氧血症在重症监护病房（ICU）中很常见，且通常对标准通气技术没有反应。
研究高频脉冲通气（HFPV）在早期短期应用时是否可以改善低氧血症ALI/ARDS 患者的气体交换，与使用相同平均气道压（P（aw））的常规通气（CV）相比，HFPV 可以改善低氧血症 ALI/ARDS 患者的气体交换，而不论通气模式如何，P（aw）是氧合和血液动力学的主要决定因素。
研究了 35 名对 CV 无反应的患者。在入住 ICU 的头 12 小时内，患者接受 CV 治疗。此后，以保持恒定的 P（aw）的方式对患者进行 12 小时的 HFPV 治疗。然后，患者再次接受 CV 治疗。在以下时间点测量气体交换：入住后 12 小时、HFPV 试验期间每 4 小时、HFPV 结束后 1 小时和 HFPV 后 12 小时。35 名接受 CV 通气的匹配患者作为对照组（CTRL）。
在 HFPV 治疗期间，PaO（2）/FiO（2）和肺泡动脉比值（a/A PO（2））增加，并且在 CV 的最后 12 小时达到 PaO（2）/FiO（2）稳定状态，而在 CTRL 中两者均未改变。在 HFPV 的前 4 小时，PaCO（2）下降，但此后保持不变；在 CTRL 中，PaCO（2）没有变化。在 HFPV 后，呼吸系统顺应性增加。
HFPV 改善了对常规治疗无反应的患者的气体交换。这种改善在 HFPV 结束后 12 小时内保持不变。
