Document Detail


Effects of inverse ratio ventilation and positive end-expiratory pressure in oleic acid-induced lung injury.
MedLine Citation:
PMID:  10806151     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
Continuous as well as cyclic (with each expiration) lung collapse in acute respiratory failure can be reduced by positive end-expiratory pressure (PEEP) or short expiration times, as in inverse ratio ventilation (IRV). In 20 pigs with oleic acid-induced lung edema, we compared the effects of a PEEP of 20 cm H(2)O with IRV, using an inspiratory-to-expiratory ratio of 3:1 without external PEEP. During IRV, expiration times of 0.5 or 1.0 s were obtained with respiratory rates of 30 breaths/min or 15 breaths/min, respectively. In 15 animals, ventilation-perfusion relationships were studied through the multiple inert gas elimination technique, and lung morphology was studied with computed tomography. In another five pigs, blood flow distribution was studied with perfusion scintigraphy. All three ventilatory modes had similar effects on mean arterial blood pressure, cardiac output, oxygen delivery, and mean airway pressure. PEEP reduced shunt and improved oxygenation to a greater extent than the two modes of IRV, although there was a large variation within each group. The improvement, irrespective of which ventilatory mode was superior in a particular pig, was caused by greater and more even aeration of the lung, whereas the perfusion distribution with PEEP was the same as with IRV. Thus, the strategy of stabilizing the lungs through short expiration times, as in IRV, did not offer any advantages in our lung injury model.
Authors:
P Neumann; J E Berglund; L G Andersson; E Maripu; A Magnusson; G Hedenstierna
Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't    
Journal Detail:
Title:  American journal of respiratory and critical care medicine     Volume:  161     ISSN:  1073-449X     ISO Abbreviation:  Am. J. Respir. Crit. Care Med.     Publication Date:  2000 May 
Date Detail:
Created Date:  2000-06-21     Completed Date:  2000-06-21     Revised Date:  2007-11-15    
Medline Journal Info:
Nlm Unique ID:  9421642     Medline TA:  Am J Respir Crit Care Med     Country:  UNITED STATES    
Other Details:
Languages:  eng     Pagination:  1537-45     Citation Subset:  AIM; IM    
Affiliation:
Department of Clinical Physiology, University of Uppsala, Uppsala, Sweden.
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MeSH Terms
Descriptor/Qualifier:
Animals
Hemodynamics
Lung / radiography,  radionuclide imaging
Oleic Acid
Oxygen / blood
Positive-Pressure Respiration / methods
Pulmonary Circulation
Pulmonary Gas Exchange
Respiration, Artificial / methods*
Respiratory Distress Syndrome, Adult / chemically induced,  physiopathology*,  radiography,  therapy
Swine
Ventilation-Perfusion Ratio
Chemical
Reg. No./Substance:
112-80-1/Oleic Acid; 7782-44-7/Oxygen

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


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