Use of ultrahigh frequency ventilation in patients with ARDS. A preliminary report
STUDY OBJECTIVE: Our objective was to compare the efficacy of ultrahigh frequency ventilation (UHFV) (frequencies > 3 Hz) with respect to oxygenation, airway pressures, and hemodynamic parameters in patients with adult respiratory distress syndrome (ARDS) who were not responding to conventional ventilation.
DESIGN: We used a prospective, multicenter, nonrandomized study design in which each patient served as his own control. SETTING: Three university-affiliated, tertiary-care medical centers participated.
PATIENTS: Persons aged 16 to 79 years old with ARDS and unresponsive to conventional ventilation, as defined by a Food and Drug Administration (FDA) approved protocol, were included.
INTERVENTIONS: Ninety patients who were not responding to conventional ventilation were changed to UHFV using a microcomputer-controlled device.
MEASUREMENTS AND RESULTS: The patient's blood gas, hemodynamic, and airway pressure variables were measured just before, and at 1 and 24 h after the switch to UHFV. We demonstrated clinically significant improvements in arterial oxygen tension (PaO2) and reductions in peak and mean inspiratory pressures.
CONCLUSIONS: In a multicenter study, UHFV improved respiratory gas exchange and reduced airway pressure variables at both 1 h and 24 h after the onset of UHFV when compared with conventional ventilation just prior to the change and without hemodynamic deterioration, in patients with severe ARDS.