1998 OPEN FORUM Abstracts
HIGH FREQUENCY OSCILLATORY VENTILATION (HFOV): RESCUE THERAPY FOR SEVERE OXYGENATION FAILURE IN ADULTS.
R MacDonald RRT, AB Cooper MD, TE Stewart MD, RJ Groll BsC.. The Wellesley Central Hospital, University of Toronto, Critical Care Medicine Program, Toronto, Canada.
High Frequency Oscillatory Ventilation(HFOV) has many potential advantages in patients with ARDS, however, largely due to equipment problems, it has been infrequently used in adults. More recently these difficulties have been overcome. We evaluated the physiologic impact of HFOV in the first 5 patients who received it as rescue therapy for severe oxygenation failure (All values Mean±S.D.). Five adults (2M, 3F: age 57.8 ± 15.2 years, weight 62.3 ± 16.5 kg., Apache II score 25.2 ± 6.0) with severe ARDS (LISS=3.55 ± 0.33, PaO2/FiO2= 91.4 ± 39.2 and oxygenation index (OI)=38.9 ± 24.5) who were considered to be failing conventional ventilation were given a trial of HFOV (initial settings: frequency=5 Hz, PAW=4cmH2O greater than conventional mean PAW, I:E=33%, FiO2+1.0, power=6). We report grouped observations of the study cohort over small intervals of elapsed time (0.2.8 hrs.) for a 72 hour period for the following oxygenation and hemodynamic endpoints: PaO2/FiO2 ratio, O1 (FiO2 x PAW x 100 / PaO2), estimated shunt fraction (Qs / Qt% = (Cc'O2 - CaO2) / (3.5 + (Cc'O2 - CaO2))).
Parameter Ohrs. 48hrs. 72hrs.
O1 33.2 ± 7.9 19.6 ± 6.5 15.8 ± 13.0
PaO2/FiO2 109.2 ± 25.9 135.2 ± 45.3 245.6 ± 134.6
Qs/Qt 34.9 ± 4.9 32.2 ± 7.5 22.3 ± 15.7
HFOV appears to be an effective rescue therapy for patients failing conventional ventilation. The impact of these physiological benefits on patient outcome needs to be assessed.
The 44th International Respiratory Congress Abstracts-On-Disk®, November 7 - 10, 1998, Atlanta, Georgia.