- Poster presentation
- Open Access
High-frequency oscillatory ventilation: a better tool for lung protection?
© BioMed Central Ltd. 2004
- Published: 15 March 2004
- Acute Respiratory Distress Syndrome
- Hemodynamic Parameter
- Ventilatory Setting
- Recruitment Maneuver
- Conventional Mechanical Ventilation
This study was performed to compare the efficacy of high-frequency oscillatory ventilation (HFOV) with conventional mechanical ventilation (CV) in patients with acute respiratory distress syndrome (ARDS).
Ten patients with ARDS were enrolled to the study. Gas exchange and hemodynamic parameters were measured during initial phase of the mechanical ventilation (tidal volume [TV] ≤ 6–8 ml/kg, positive end expiratory pressure [PEEP] = 10 cmH2O, f = 12/min, I/E = 0.5, FIO2 = 1). Then patients were randomized into CV or HFOV groups. The upper inflection point (UIP) and closing pressures (CP) were approximated according to blood gases response to PEEP/continuous distending pressure (CDP) titration. The lung protective ventilation strategy was followed for both groups. Ventilatory settings were CDP = CP + 5 cmH2O, f = 5 Hz, bias flow = 20 l/min for HFOV and PEEP = CP + 2 cmH2O, f = 12/min, TV ≤ 6–8 ml/kg for CV. FIO2 was set to keep on the SaO2 over 90%. After 3 hours ventilation with each setting, groups were switched from HFOV to CMV or vice versa. For each group, the recruitment maneuver was applied with a pressure of 2 cmH2O below the UIP for 40–60 s at the beginning and after all disconnections. Gas exchange and hemodynamic parameters in addition to ventilatory settings were recorded at 10, 60 and 120 min of each setting. Results were mentioned as the median. The Mann–Whitney U test was used for the comparisons.
CO2 removal capacity of HFOV may not only be related with its active expiration feature, but also related with its capability to prevent derecruitment better than CV ventilation, as shown with an improvement in PaO2/FIO2 ratios. Therefore, HFOV may be a better tool to follow lung protective ventilation.