Document Detail


Positive end-expiratory pressure increases capillary pressure relative to wedge pressure in the closed and open chest.
MedLine Citation:
PMID:  8343866     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
The pulmonary arterial wedge pressure is used as a measure of left atrial pressure and frequently as an estimate of pulmonary capillary pressure. The arterial occlusion concept has recently been used to derive a pressure that is thought to be more representative of capillary pressure (Pcap) than wedge pressure (Pw). The object of this study was to measure the arterial occlusion Pcap at different positive end-expiratory pressure (PEEP) levels and to compare it with Pw. Anesthetized, paralyzed, supine, and mechanically ventilated dogs were instrumented with a Swan-Ganz balloon tip catheter (7F) for monitoring pulmonary arterial pressure (Pa), for measuring cardiac output (CO; thermodilution technique), and for performing the arterial occlusions. The postocclusion tracings were analyzed for Pcap in a conventional manner: exponential fitting of the data during the 2 seconds immediately postocclusion and back extrapolating to the instant of occlusion. Instant of occlusion was defined as the time when the Pa tracing began to deviate from the normal tracing. Pw was averaged from the data between 8 to 10 seconds after the occlusion. Increasing PEEP between 0 to 15 mm Hg caused a gradual decline in cardiac output in the closed and open chest conditions. Despite this decline, all three pressures (Pa, Pcap, and Pw) rose gradually in the closed chest. However, in the open chest, increasing PEEP from 0 to 4.7 mm Hg had no effect on the pressures, but between 4.7 and 13.4 mm Hg of PEEP, Pa and Pcap increased markedly with minimal change in Pw.(ABSTRACT TRUNCATED AT 250 WORDS)
Authors:
T S Hakim; E Gilbert; E Camporesi
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Publication Detail:
Type:  Comparative Study; Journal Article; Research Support, Non-U.S. Gov't    
Journal Detail:
Title:  Journal of critical care     Volume:  8     ISSN:  0883-9441     ISO Abbreviation:  J Crit Care     Publication Date:  1993 Jun 
Date Detail:
Created Date:  1993-09-08     Completed Date:  1993-09-08     Revised Date:  2006-11-15    
Medline Journal Info:
Nlm Unique ID:  8610642     Medline TA:  J Crit Care     Country:  UNITED STATES    
Other Details:
Languages:  eng     Pagination:  80-6     Citation Subset:  IM    
Affiliation:
Department of Surgery, SUNY Health Science Center, Syracuse 13210.
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MeSH Terms
Descriptor/Qualifier:
Animals
Capillaries / physiology
Carbon Dioxide / blood
Cardiac Output
Dogs
Oxygen / blood
Positive-Pressure Respiration*
Pulmonary Artery / physiology
Pulmonary Wedge Pressure*
Thoracotomy
Vascular Resistance
Chemical
Reg. No./Substance:
124-38-9/Carbon Dioxide; 7782-44-7/Oxygen

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


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