Comparison of prone positioning and high-frequency oscillatory ventilation in patients with acute respiratory distress syndrome.
OBJECTIVE
Both prone position and high-frequency oscillatory ventilation (HFOV) have the potential to facilitate lung recruitment, and their combined use could thus be synergetic on gas exchange. Keeping the lung open could also potentially be lung protective. The aim of this study was to compare physiologic and proinflammatory effects of HFOV, prone positioning, or their combination in severe acute respiratory distress syndrome (ARDS).


METHODS
: Prospective, comparative randomized study.


METHODS
A medical intensive care unit.


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


METHODS
After 12 hrs on conventional lung-protective mechanical ventilation (tidal volume 6 mL/kg of ideal body weight, plateau pressure not exceeding the upper inflection point, and a maximum of 35 cm H2O; supine-CV), 39 patients were randomized to receive one of the following 12-hr periods: conventional lung-protective mechanical ventilation in prone position (prone-CV), HFOV in supine position (supine-HFOV), or HFOV in prone position (prone-HFOV).


RESULTS
Prone-CV (from 138 +/- 58 mm Hg to 217 +/- 110 mm Hg, p < .0001) and prone-HFOV (from 126 +/- 40 mm Hg to 227 +/- 64 mm Hg, p < 0.0001) improved the Pao2/Fio2 ratio whereas supine-HFOV did not alter the Pao2/Fio2 ratio (from 134 +/- 57 mm Hg to 138 +/- 48 mm Hg). The oxygenation index ({mean airway pressure x Fio2 x 100}/Pao2) decreased in the prone-CV and prone-HFOV groups and was lower than in the supine-HFOV group. Interleukin-8 increased significantly in the bronchoalveolar lavage fluid (BALF) in supine-HFOV and prone-HFOV groups compared with prone-CV and supine-CV. Neutrophil counts were higher in the supine-HFOV group than in the prone-CV group.


CONCLUSIONS
Although HFOV in the supine position does not improve oxygenation or lung inflammation, the prone position increases oxygenation and reduces lung inflammation in ARDS patients. Prone-HFOV produced similar improvement in oxygenation like prone-CV but was associated with higher BALF indexes of inflammation. In contrast, supine-HFOV did not improve gas exchange and was associated with enhanced lung inflammation.
Papazian
Laurent
L
Service de Réanimation Médicale, Hôpital Sainte-Marguerite, Faculté de Médecine de Marseille, Université de la Méditerranée, Marseille, France.
Gainnier
Marc
M
Marin
Valérie
V
Donati
Stéphane
S
Arnal
Jean-Michel
JM
Demory
Didier
D
Roch
Antoine
A
Forel
Jean-Marie
JM
Bongrand
Pierre
P
Brégeon
Fabienne
F
Sainty
Jean-Marie
JM
D000328:Adult; D001784:Blood Gas Analysis; D001992:Bronchoalveolar Lavage Fluid / Q000737:chemistry; D005260:Female; D006612:High-Frequency Ventilation; D006801:Humans; D018836:Inflammation Mediators / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D016684:Prone Position; D011446:Prospective Studies; D011659:Pulmonary Gas Exchange / Q000502:physiology*; D012128:Respiratory Distress Syndrome / Q000378:metabolism / Q000503:physiopathology* / Q000628:therapy*; D015656:Respiratory Mechanics; D016683:Supine Position
D018836:Inflammation Mediators