High-frequency oscillatory ventilation following prone positioning prevents a further impairment in oxygenation.
OBJECTIVE
The improvement in oxygenation with prone positioning is not persistent when patients with acute respiratory distress syndrome (ARDS) are turned supine. High-frequency oscillatory ventilation (HFOV) aims to maintain an open lung volume by the application of a constant mean airway pressure. The aim of this study was to show that HFOV is able to prevent the impairment in oxygenation when ARDS patients are turned back from the prone to the supine position.


METHODS
Prospective, comparative randomized study.


METHODS
A medical intensive care unit.


METHODS
Forty-three ARDS patients with a Pao2/Fio2 ratio <150 at positive end-expiratory pressure > or =5 cm H2O.


METHODS
After an optimization period, the patients were assigned to one of three groups: a) conventional lung-protective mechanical ventilation in the prone position (12 hrs) followed by a 12-hr period of conventional lung-protective mechanical ventilation in the supine position (CV(prone)-CV(supine)); b) conventional lung-protective mechanical ventilation in the supine position (12 hrs) followed by HFOV in the supine position (12 hrs) (CV(supine)-HFOV(supine)); or c) conventional lung-protective mechanical ventilation in the prone position (12 hrs) followed by HFOV in the supine position (CV(prone)-HFOV(supine) group).


RESULTS
Pao2/Fio2 ratio was higher at the end of the study period in the CV(prone)-HFOV(supine) group than in the CV(prone)-CV(supine) group (p < .02). Venous admixture at the end of the study period was lower in the CV(prone)-HFOV(supine) group than in the two other groups.


CONCLUSIONS
HFOV maintained the improvement in oxygenation related to prone positioning when ARDS patients were returned to the supine position.
Demory
Didier
D
Service de Réanimation Médicale, Hôpital Sainte-Marguerite, Université de la Méditerranée, Marseille, France.
Michelet
Pierre
P
Arnal
Jean-Michel
JM
Donati
Stéphane
S
Forel
Jean-Marie
JM
Gainnier
Marc
M
Brégeon
Fabienne
F
Papazian
Laurent
L
D000368:Aged; D000704:Analysis of Variance; D001784:Blood Gas Analysis; D003422:Critical Care / Q000379:methods; D005260:Female; D005602:France; D006612:High-Frequency Ventilation / Q000379:methods*; D006785:Hospitals, University; D006801:Humans; D008297:Male; D008875:Middle Aged; D016684:Prone Position; D011446:Prospective Studies; D011659:Pulmonary Gas Exchange; D012121:Respiration, Artificial / Q000379:methods; D012128:Respiratory Distress Syndrome / Q000175:diagnosis / Q000378:metabolism / Q000503:physiopathology / Q000628:therapy*; D016683:Supine Position; D013990:Tidal Volume; D013997:Time Factors; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome