High-frequency Percussive Ventilation Improves Oxygenation in Patients With ARDS: Conclusion
Although it is highly unlikely that this course could have been reversed without HFPV, this possibility has not been tested and therefore cannot be excluded. The absence of a control group managed without HFPV does not allow conclusions on outcome differences. This is the reason we elected to report only the short-term ventilatory and hemodynamic changes that we believed might have been directly associated with the change in mechanical ventilation strategies. Conclusions derived from analysis of recordings of these parameters for longer periods of time would be obscured by the multiple variables that interfere with the progression of the disease in such critically ill patients. Similarly, attempts to correlate these data with clinical outcome would be senseless in the absence of a control group. It is appropriate that we reserved this method of ventilation for only very sick patients. The mortality rate of 59% attests to this necessity. As with every mode of therapy, HFPV may be more useful when used before full-blown organ failure is established. Identification of patients at risk of ARDS before frank clinical manifestation of the disease may result in appropriate selection of subgroups most likely to benefit by this mode of ventilation. The diverse nature of disease profiles of the patients included in this study diminishes our ability to generalize from our data. Although we documented significant improvements in the respiratory function of all subgroups examined, we have not yet clearly identified the ideal patients for implementation of this method. We believe that trauma patients constitute a fairly uniform group with little likelihood of previous respiratory disease that could confound the clinical picture. For this reason, we are planning to evaluate the efficacy of HFPV with a prospective randomized study in critically injured patients. Source
In summary, it appears that in selected patients, HFPV can improve oxygenation with reduced peak airway pressures, potentially reducing the risk of barotrauma. This improvement can be achieved without elevations of CO2 or deterioration of hemodynamic parameter values. The improved clearance of pulmonary secretions may reduce the risk of intrathoracic infection. Further studies are justified to define the population that can be maximally benefited by this method.