From low-tidal-volume ventilation to lowest-tidal-volume ventilation
© BioMed Central Ltd 2008
Published: 13 March 2008
The therapeutic measures of lung-protective mechanical ventilation used in treatment of acute lung injury (ALI) and acute respiratory distress syndrome (ARDS) have revived the interest in high-frequency ventilation (HFV). The reduction of the tidal volume during the conventional ventilation (CV) in terms of low-tidal-volume ventilation is not unboundedly feasible. However, HFV allows a further reduction of tidal volume. Established HFV techniques are high-frequency oscillation (HFO), high-frequency percussive ventilation (HFPV) and superimposed high-frequency jet ventilation (SHFJV). The aim of this study was to evaluate the amelioration of the oxygenation index (OI).
Twenty-four patients with ALI/ARDS admitted to an ICU were involved. Haemodynamic parameters, blood gas analysis, ventilation pressures (positive end-expiratory pressure (PEEP), plateau and mean airway pressures) were measured. The use of HFV was indicated if the OI was still lower than 200 under CV. The initial parameters (plateau and mean airway pressure, PEEP, I:E ratio, ventilation frequency and FiO2) were chosen as the latest setups of the CV. We randomly used one of the abovementioned techniques to treat patients with ALI/ARDS. The clinically relevant parameters were proved every 4 hours and ventilation was adopted.
We achieved a significant amelioration of the OI using HFV rather than with CV. Each of the HFV techniques, however, needs a period of a few hours to predict that the technique is responding or nonresponding.
This article is published under license to BioMed Central Ltd.