OBJECTIVE: We tested the hypothesis that ventilation in the prone position might improve homogenization of tidal ventilation by reducing time-constant inequalities, and thus improving alveolar ventilation. We have recently reported in ARDS patients that these inequalities are responsible for the presence of a "slow compartment," excluded from tidal ventilation at supportive respiratory rate. DESIGN: In 11 ARDS patients treated by ventilation in the prone position because of a major oxygenation impairment (PaO(2)/FIO(2)</=100 mm Hg) we studied mechanical and blood gas changes produced by a low PEEP (6+/-1 cm H(2)O), ventilation in the prone position, and the two combined. RESULTS: Ventilation in the prone position significantly reduced the expiratory time constant from 1.98+/-0.53 s at baseline with ZEEP to 1.53+/-0.34 s, and significantly decreased PaCO(2) from 55+/-11 mm Hg at baseline with ZEEP to 50+/-7 mm Hg. This improvement in alveolar ventilation was accompanied by a significant improvement in respiratory system mechanics, and in arterial oxygenation, the latter being markedly increased by application of a low PEEP (PaO(2)/FIO(2) increasing from 64+/-19 mm Hg in supine position with ZEEP to 137+/-88 mm Hg in prone with a low PEEP). CONCLUSION: In severely hypoxemic patients, prone position was able to improve alveolar ventilation significantly by reducing the expiratory time constant.
OBJECTIVE: We tested the hypothesis that ventilation in the prone position might improve homogenization of tidal ventilation by reducing time-constant inequalities, and thus improving alveolar ventilation. We have recently reported in ARDSpatients that these inequalities are responsible for the presence of a "slow compartment," excluded from tidal ventilation at supportive respiratory rate. DESIGN: In 11 ARDSpatients treated by ventilation in the prone position because of a major oxygenation impairment (PaO(2)/FIO(2)</=100 mm Hg) we studied mechanical and blood gas changes produced by a low PEEP (6+/-1 cm H(2)O), ventilation in the prone position, and the two combined. RESULTS: Ventilation in the prone position significantly reduced the expiratory time constant from 1.98+/-0.53 s at baseline with ZEEP to 1.53+/-0.34 s, and significantly decreased PaCO(2) from 55+/-11 mm Hg at baseline with ZEEP to 50+/-7 mm Hg. This improvement in alveolar ventilation was accompanied by a significant improvement in respiratory system mechanics, and in arterial oxygenation, the latter being markedly increased by application of a low PEEP (PaO(2)/FIO(2) increasing from 64+/-19 mm Hg in supine position with ZEEP to 137+/-88 mm Hg in prone with a low PEEP). CONCLUSION: In severely hypoxemic patients, prone position was able to improve alveolar ventilation significantly by reducing the expiratory time constant.
Authors: C Guerin; M Badet; S Rosselli; L Heyer; J M Sab; B Langevin; F Philit; G Fournier; D Robert Journal: Intensive Care Med Date: 1999-11 Impact factor: 17.440
Authors: P Pelosi; D Tubiolo; D Mascheroni; P Vicardi; S Crotti; F Valenza; L Gattinoni Journal: Am J Respir Crit Care Med Date: 1998-02 Impact factor: 21.405
Authors: Antoine Vieillard-Baron; Sebastien Prin; Jean-Marie Schmitt; Roch Augarde; Bernard Page; Alain Beauchet; François Jardin Journal: Am J Respir Crit Care Med Date: 2002-04-15 Impact factor: 21.405
Authors: Marc Gainnier; Pierre Michelet; Xavier Thirion; Jean-Michel Arnal; Jean-Marie Sainty; Laurent Papazian Journal: Crit Care Med Date: 2003-12 Impact factor: 7.598
Authors: Peter Andrews; Elie Azoulay; Massimo Antonelli; Laurent Brochard; Christian Brun-Buisson; Daniel de Backer; Geoffrey Dobb; Jean-Yves Fagon; Herwig Gerlach; Johan Groeneveld; Jordi Mancebo; Philipp Metnitz; Stefano Nava; Jerome Pugin; Michael Pinsky; Peter Radermacher; Christian Richard; Robert Tasker Journal: Intensive Care Med Date: 2006-02-01 Impact factor: 17.440
Authors: Cyril Charron; Koceila Bouferrache; Vincent Caille; Samuel Castro; Philippe Aegerter; Bernard Page; François Jardin; Antoine Vieillard-Baron Journal: Intensive Care Med Date: 2011-03-02 Impact factor: 17.440