Document Detail


Variations in flows and pressures during jet ventilation in the infant: a model study.
MedLine Citation:
PMID:  8196999     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
Ventilatory flow rates with either He-O2 (heliox) or N2-O2 (nitrox) mixtures during high frequency jet ventilation (HFJV) were calculated using a mathematical model, and were measured in a physical monoalveolar model of the infant lung. A constant flow was delivered to the model (Vd) drawing with it an entrained flow (Ve). When the inspiratory time (Tl) was long, a back flow (Vr) was generated that increased progressively as the alveolar pressure increased. In order to reduce Vr, the reflux time (Tr), i.e., the time needed for the injected gas to reflux, was measured (Trm) and calculated (Trc) with the model. The Tr depends on both chest-lung compliance and resistance to reflux as well as on the Ve/Vd ratio. For a given setting of the ventilator, values of Trm and Trc were significantly lower with heliox than nitrox (P < 0.01), and the correlation between Trm and Trc were fair with both gases. Tidal volume (VT) was calculated when the Tl was interrupted at Tr. The values of VT were significantly higher with helix than nitrox (P < 0.05). It is concluded that the evaluation of Tr during HFJV may provide useful information for setting the ventilator.
Authors:
A Belaguid; H Guenard
Related Documents :
7189349 - Gas viscosity effects in anesthesia.
3131069 - Total parenteral nutrition-induced cyclic hypercapnia.
18276899 - The effect of conductive ventilation heterogeneity on diffusing capacity measurement.
1649429 - Aerosol delivery in neonatal ventilator circuits: a rabbit lung model.
16809999 - Biologically variable ventilation improves oxygenation and respiratory mechanics during...
18205899 - Pulse pressure variation and stroke volume variation during different loading condition...
24656889 - Flow transport and gas mixing during invasive high frequency oscillatory ventilation.
9475239 - Efficacy of newly developed pressure swing adsorption type oxygen concentrator with mem...
7295919 - Telemetry of cardiac left ventricular pressure in conscious dogs.
Publication Detail:
Type:  Journal Article    
Journal Detail:
Title:  Pediatric pulmonology     Volume:  17     ISSN:  8755-6863     ISO Abbreviation:  Pediatr. Pulmonol.     Publication Date:  1994 Mar 
Date Detail:
Created Date:  1994-06-30     Completed Date:  1994-06-30     Revised Date:  2008-11-21    
Medline Journal Info:
Nlm Unique ID:  8510590     Medline TA:  Pediatr Pulmonol     Country:  UNITED STATES    
Other Details:
Languages:  eng     Pagination:  183-8     Citation Subset:  IM    
Affiliation:
Physiology Laboratory, Victor Pachon Faculty, University of Bordeaux, France.
Export Citation:
APA/MLA Format     Download EndNote     Download BibTex
MeSH Terms
Descriptor/Qualifier:
Airway Resistance / drug effects,  physiology
Helium / pharmacology*
High-Frequency Jet Ventilation*
Humans
Infant, Newborn
Lung / drug effects*,  physiology*
Lung Compliance / drug effects,  physiology
Mathematics
Models, Theoretical
Nitrogen / pharmacology*
Oxygen / pharmacology*
Physical Phenomena
Physics
Pressure
Pulmonary Alveoli / drug effects,  physiology
Pulmonary Ventilation / drug effects,  physiology
Tidal Volume / drug effects,  physiology
Time Factors
Chemical
Reg. No./Substance:
37291-87-5/nitrox; 58933-55-4/heliox; 7440-59-7/Helium; 7727-37-9/Nitrogen; 7782-44-7/Oxygen

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


Previous Document:  Disease severity and optimum mean airway pressure level on transfer to high frequency oscillation.
Next Document:  Infrared end-tidal CO2 measurement does not accurately predict arterial CO2 values or end-tidal to a...