Document Detail


Positive end-expiratory pressure redistributes regional blood flow and ventilation differently in supine and prone humans.
MedLine Citation:
PMID:  21068656     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
BACKGROUND: Animal studies have demonstrated an interaction between posture and the effect of positive end-expiratory pressure (PEEP) on regional ventilation and lung blood flow. The aim of this study was to explore this interaction in humans.
METHODS: Regional lung blood flow and ventilation were compared between mechanical ventilation with and without PEEP in the supine and prone postures. Six normal subjects were studied in each posture. Regional lung blood flow was marked with In-labeled macroaggregates and ventilation with Technegas (Tc). Radiotracer distributions were mapped using quantitative single-photon emission computed tomography.
RESULTS: In supine subjects, PEEP caused a similar redistribution of both ventilation and blood flow toward dependent (dorsal) lung regions, resulting in little change in the V/Q correlation. In contrast, in prone subjects, the redistribution toward dependent (ventral) regions was much greater for blood flow than for ventilation, causing increased V/Q mismatch. Without PEEP, the vertical ventilation-to-perfusion gradient was less in prone postures than in supine, but with PEEP, the gradient was similar.
CONCLUSIONS: During mechanical ventilation of healthy volunteers, the addition of PEEP, 10 cm H2O, causes redistribution of both lung blood flow and ventilation, and the effect is different between the supine and prone postures. Our results suggest that the addition of PEEP in prone might be less beneficial than in supine and that optimal use of the prone posture requires reevaluation of the applied PEEP.
Authors:
Johan Petersson; Malin Ax; Joana Frey; Alejandro Sánchez-Crespo; Sten G E Lindahl; Margareta Mure
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Publication Detail:
Type:  Comparative Study; Journal Article; Research Support, Non-U.S. Gov't    
Journal Detail:
Title:  Anesthesiology     Volume:  113     ISSN:  1528-1175     ISO Abbreviation:  Anesthesiology     Publication Date:  2010 Dec 
Date Detail:
Created Date:  2010-11-24     Completed Date:  2010-12-22     Revised Date:  -    
Medline Journal Info:
Nlm Unique ID:  1300217     Medline TA:  Anesthesiology     Country:  United States    
Other Details:
Languages:  eng     Pagination:  1361-9     Citation Subset:  AIM; IM    
Affiliation:
Department of Anesthesiology and Intensive Care, Karolinska University Hospital Solna, Stockholm, Sweden. johan.petersson@karolinska.se
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MeSH Terms
Descriptor/Qualifier:
Adult
Anesthesia, General
Carbon Dioxide / blood
Female
Hemodynamics / physiology
Humans
Indium Radioisotopes / diagnostic use
Lung / radionuclide imaging
Male
Middle Aged
Monitoring, Physiologic
Oxygen / blood
Positive-Pressure Respiration*
Prone Position / physiology*
Pulmonary Circulation / physiology*
Pulmonary Gas Exchange / physiology
Regional Blood Flow / physiology
Respiratory Mechanics / physiology*
Supine Position / physiology*
Technetium Compounds / diagnostic use
Tomography, Emission-Computed, Single-Photon
Young Adult
Chemical
Reg. No./Substance:
0/Indium Radioisotopes; 0/Technetium Compounds; 124-38-9/Carbon Dioxide; 7782-44-7/Oxygen
Comments/Corrections
Comment In:
Anesthesiology. 2010 Dec;113(6):1262-4   [PMID:  21042196 ]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


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