Document Detail


Static pressure volume curves and body posture in acute respiratory failure.
MedLine Citation:
PMID:  16249926     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
OBJECTIVE: In acute respiratory distress syndrome the body posture effects on pressure-volume (PV) curves are still unclear. We examined the effects of prone position on inflation PV curves and their potential relationships with postural alterations in gas exchange. DESIGN AND SETTING: Prospective study with patients serving as their own controls in a university-affiliated 30-bed intensive care unit. PATIENTS AND PARTICIPANTS: Thirteen anesthetized, paralyzed, semirecumbent, mechanically ventilated patients with early/severe/diffuse ARDS. INTERVENTIONS: Sequential body posture changes: preprone semirecumbent, prone, and postprone semirecumbent. MEASUREMENTS AND RESULTS: In each posture hemodynamics, gas exchange, and lung volumes were determined before/during removal and after restoration of positive end-expiratory pressure (PEEP=10.2+/-0.6 cmH2O). At zero PEEP PV curves of respiratory system, lung, and chest wall were constructed. Prone position vs. preprone semirecumbent resulted in significantly reduced pressure at lower inflection point of lung PV curve (2.2+/-0.2 vs. 3.7+/-0.5 cmH2O) and increased volume at upper inflection point (0.87+/-0.03 vs. 0.69+/-0.05 l). Postural reduction in lower inflection point pressure of lung PV curve was the sole independent predictor of pronation-induced increases in PaO2/FIO2 (R2=0.76). PaO2/FIO2 increases were also significantly related with increases in functional residual capacity (R2=0.60). CONCLUSIONS: In early/severe/diffuse ARDS prone position reduces lower inflection point pressure and increases upper inflection point UIP volume of the lung PV curve. Lower inflection point pressure reductions explain oxygenation improvements, which are also associated with a postural increase in functional residual capacity.
Authors:
Spyros D Mentzelopoulos; Charis Roussos; Spyros G Zakynthinos
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Publication Detail:
Type:  Clinical Trial; Journal Article; Research Support, Non-U.S. Gov't     Date:  2005-10-26
Journal Detail:
Title:  Intensive care medicine     Volume:  31     ISSN:  0342-4642     ISO Abbreviation:  Intensive Care Med     Publication Date:  2005 Dec 
Date Detail:
Created Date:  2005-12-05     Completed Date:  2006-03-17     Revised Date:  2007-11-15    
Medline Journal Info:
Nlm Unique ID:  7704851     Medline TA:  Intensive Care Med     Country:  United States    
Other Details:
Languages:  eng     Pagination:  1683-92     Citation Subset:  IM    
Affiliation:
sdm@hol.gr
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MeSH Terms
Descriptor/Qualifier:
Adult
Catheterization, Swan-Ganz
Female
Functional Residual Capacity
Hemodynamics
Humans
Linear Models
Male
Middle Aged
Multivariate Analysis
Positive-Pressure Respiration / methods*
Posture*
Prone Position
Prospective Studies
Pulmonary Gas Exchange*
Respiratory Distress Syndrome, Adult / therapy*
Respiratory Mechanics*

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


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