HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:
Guest Access | Sign In via User Name/Password

This Article Full Text Free Full Text (PDF) Free Submit a response Alert me when this article is cited Alert me when eLetters are posted Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in ISI Web of Science Similar articles in PubMed Alert me to new issues of the journal Add to My Personal Article Archive Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via ISI Web of Science (10) Citing Articles via Google Scholar Google Scholar Articles by Richard, J.-C. Articles by Guérin, C. Search for Related Content PubMed PubMed Citation Articles by Richard, J.-C. Articles by Guérin, C.

Effects of Positive End-Expiratory Pressure and Body Position on Pulmonary Blood Flow Redistribution in Mechanically Ventilated Normal Pigs^*

^* From the Centre Etude et de Recherches en Tomographie par Emission de Positrons (Drs. Richard and Janier), Hôpital Neuro-Cardiologique, Lyon, France; Equipe d’Accueil Universitaire 1896 (Drs. Decailliot, Annat, and Guérin), Université Claude Bernard Lyon I, Lyon, France.

Correspondence to: Claude Guérin, MD, Service de Réanimation Médicale et Assistance Respiratoire, 103 Grande Rue de la Croix-Rousse, Lyon 69004, France; e-mail claude.guerin{at}chu-lyon.fr

Study objectives: To assess the respective effects of position and positive end-expiratory pressure (PEEP) on the distribution of regional pulmonary blood flow (PBF).

Design: Prospective randomized animal study.

Setting: Animal research facility in a university hospital.

Participants: Normal pigs that were tracheostomized, anesthetized, and mechanically ventilated.

Interventions: PBF was measured in seven pigs in the supine position (SP) and the prone position (PP) at both zero end-expiratory pressure (ZEEP) and 10 cm H₂O of PEEP. The regional PBF was assessed by the radioactive microsphere method. The lungs from each pig were sliced into 90 samples. The heterogeneity of PBF was estimated from its coefficient of variation.

Measurements and results: The lung samples had a mean (± SD) weight of 1.60 ± 0.39 g. Changing position from SP to PP at ZEEP redistributed PBF toward the anterior, superior, and peripheral regions and did not significantly reduce the coefficient of variation for regional PBF (reduction, 44.7 ± 7% to 42.2 ± 8%). Changing from the SP to PP position at PEEP induced a similar, but more marked, redistribution of PBF and a significant reduction in the coefficient of variation from 53 ± 13% to 30.4 ± 7% (p < 0.001). In the SP, PEEP redistributed PBF toward the posterior, inferior, and central regions without changing the heterogeneity of PBF. In the PP, PEEP had little effect on the PBF redistribution but significantly reduced the coefficient of variation of PBF from 42.2 ± 8% to 30.4 ± 7% (p < 0.05).

Conclusions: Pigs in the PP had altered gravitational dependence of PBF compared to that observed when pigs were in the SP. This effect was enhanced by using a PEEP of 10 cm H₂O.

Key Words: mechanical ventilation • positive end-expiratory pressure • prone positioning • pulmonary blood flow • radioactive microspheres

This article has been cited by other articles:

				G. R. Polglase, C. J. Morley, K. J. Crossley, P. Dargaville, R. Harding, D. L. Morgan, and S. B. Hooper Positive end-expiratory pressure differentially alters pulmonary hemodynamics and oxygenation in ventilated, very premature lambs J Appl Physiol, October 1, 2005; 99(4): 1453 - 1461. [Abstract] [Full Text] [PDF]

				S. M. Walther, M. J. Johansson, T. Flatebo, A. Nicolaysen, and G. Nicolaysen Marked differences between prone and supine sheep in effect of PEEP on perfusion distribution in zone II lung J Appl Physiol, September 1, 2005; 99(3): 909 - 914. [Abstract] [Full Text] [PDF]

				F.-C. Lin, Y.-C. Chen, H.-I. Chang, and S.-C. Chang Effect of Body Position on Gas Exchange in Patients With Idiopathic Pulmonary Alveolar Proteinosis: No Benefit of Prone Positioning Chest, March 1, 2005; 127(3): 1058 - 1064. [Abstract] [Full Text] [PDF]