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Effects of prone position and positive end-expiratory pressure on lung perfusion and ventilation.
Crit Care Med. 2008 Aug; 36(8):2373-80.CC

Abstract

OBJECTIVES

Prone positioning is frequently used during acute respiratory distress syndrome. However, mechanisms by which it improves oxygenation are poorly understood, as well as its interaction with positive end-expiratory pressure. This study was conducted to decipher the respective effects of positive end-expiratory pressure and posture during lung injury on regional lung ventilation, perfusion and recruitment assessed by positron emission tomography.

DESIGN

Experimental study.

SETTING

Research laboratory of a university hospital.

SUBJECTS

Six female piglets.

INTERVENTIONS

After oleic acid-induced lung injury, all animals were studied in supine and prone position at both positive end-expiratory pressure 0 and positive end-expiratory pressure 10 cm H2O.

MEASUREMENTS AND MAIN RESULTS

In each experimental condition, regional lung perfusion and ventilation were assessed with positron emission tomograph using intravenous 15O-labeled water and inhaled nitrogen-13. Nonaerated lung weight was assessed with positron emission tomograph, and alveolar recruitment was defined as the difference of nonaerated lung weight between conditions. Positive end-expiratory pressure was associated with significant alveolar recruitment (130 +/- 85 and 65 +/- 29 g of lung in supine and prone position, respectively [p < 0.05 vs. 0]), whereas recruitment induced by posture was not statistically significant (77 +/- 97 g with positive end-expiratory pressure 0 and 13 +/- 19 g with positive end-expiratory pressure 10 [p > 0.05 vs. 0]). Regardless the posture, positive end-expiratory pressure redistributed both perfusion and ventilation toward dependent regions. Recruitment by positive end-expiratory pressure was restricted to dorsal regions in supine position, but extended diffusely along the ventral-to-dorsal dimension in prone position. Prone position was associated with recruitment in dorsal regions with concomitant derecruitment in ventral regions, magnitude of this being reduced by positive end-expiratory pressure. Prone position redistributed ventilation toward dorsal and ventral regions at positive end-expiratory pressure 0 and positive end-expiratory pressure, respectively. Finally, prone position redistributed perfusion toward ventral regions, to an extent amplified by positive end-expiratory pressure.

CONCLUSIONS

Positive end-expiratory pressure and posture act synergistically by redistributing lung regional perfusion toward ventral regions, but have antagonistic effects on regional ventilation.

Authors+Show Affiliations

Hospices civils de Lyon, Service de Réanimation Médicale et d'Assistance Respiratoire, Hôpital de la Croix Rousse, Lyon, France.No affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info available

Pub Type(s)

Journal Article
Research Support, Non-U.S. Gov't

Language

eng

PubMed ID

18596639

Citation

Richard, Jean-Christophe, et al. "Effects of Prone Position and Positive End-expiratory Pressure On Lung Perfusion and Ventilation." Critical Care Medicine, vol. 36, no. 8, 2008, pp. 2373-80.
Richard JC, Bregeon F, Costes N, et al. Effects of prone position and positive end-expiratory pressure on lung perfusion and ventilation. Crit Care Med. 2008;36(8):2373-80.
Richard, J. C., Bregeon, F., Costes, N., Bars, D. L., Tourvieille, C., Lavenne, F., Janier, M., Bourdin, G., Gimenez, G., & Guerin, C. (2008). Effects of prone position and positive end-expiratory pressure on lung perfusion and ventilation. Critical Care Medicine, 36(8), 2373-80. https://doi.org/10.1097/CCM.0b013e31818094a9
Richard JC, et al. Effects of Prone Position and Positive End-expiratory Pressure On Lung Perfusion and Ventilation. Crit Care Med. 2008;36(8):2373-80. PubMed PMID: 18596639.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Effects of prone position and positive end-expiratory pressure on lung perfusion and ventilation. AU - Richard,Jean-Christophe, AU - Bregeon,Fabienne, AU - Costes,Nicolas, AU - Bars,Didier L E, AU - Tourvieille,Christian, AU - Lavenne,Franck, AU - Janier,Marc, AU - Bourdin,Gaël, AU - Gimenez,Gérard, AU - Guerin,Claude, PY - 2008/7/4/pubmed PY - 2008/8/30/medline PY - 2008/7/4/entrez SP - 2373 EP - 80 JF - Critical care medicine JO - Crit Care Med VL - 36 IS - 8 N2 - OBJECTIVES: Prone positioning is frequently used during acute respiratory distress syndrome. However, mechanisms by which it improves oxygenation are poorly understood, as well as its interaction with positive end-expiratory pressure. This study was conducted to decipher the respective effects of positive end-expiratory pressure and posture during lung injury on regional lung ventilation, perfusion and recruitment assessed by positron emission tomography. DESIGN: Experimental study. SETTING: Research laboratory of a university hospital. SUBJECTS: Six female piglets. INTERVENTIONS: After oleic acid-induced lung injury, all animals were studied in supine and prone position at both positive end-expiratory pressure 0 and positive end-expiratory pressure 10 cm H2O. MEASUREMENTS AND MAIN RESULTS: In each experimental condition, regional lung perfusion and ventilation were assessed with positron emission tomograph using intravenous 15O-labeled water and inhaled nitrogen-13. Nonaerated lung weight was assessed with positron emission tomograph, and alveolar recruitment was defined as the difference of nonaerated lung weight between conditions. Positive end-expiratory pressure was associated with significant alveolar recruitment (130 +/- 85 and 65 +/- 29 g of lung in supine and prone position, respectively [p < 0.05 vs. 0]), whereas recruitment induced by posture was not statistically significant (77 +/- 97 g with positive end-expiratory pressure 0 and 13 +/- 19 g with positive end-expiratory pressure 10 [p > 0.05 vs. 0]). Regardless the posture, positive end-expiratory pressure redistributed both perfusion and ventilation toward dependent regions. Recruitment by positive end-expiratory pressure was restricted to dorsal regions in supine position, but extended diffusely along the ventral-to-dorsal dimension in prone position. Prone position was associated with recruitment in dorsal regions with concomitant derecruitment in ventral regions, magnitude of this being reduced by positive end-expiratory pressure. Prone position redistributed ventilation toward dorsal and ventral regions at positive end-expiratory pressure 0 and positive end-expiratory pressure, respectively. Finally, prone position redistributed perfusion toward ventral regions, to an extent amplified by positive end-expiratory pressure. CONCLUSIONS: Positive end-expiratory pressure and posture act synergistically by redistributing lung regional perfusion toward ventral regions, but have antagonistic effects on regional ventilation. SN - 1530-0293 UR - https://www.unboundmedicine.com/medline/citation/18596639/Effects_of_prone_position_and_positive_end_expiratory_pressure_on_lung_perfusion_and_ventilation_ L2 - https://dx.doi.org/10.1097/CCM.0b013e31818094a9 DB - PRIME DP - Unbound Medicine ER -