Document Detail

Comparison of patient-ventilator interfaces based on their computerized effective dead space.
MedLine Citation:
PMID:  21063677     Owner:  NLM     Status:  MEDLINE    
PURPOSE: Non-invasive ventilation is largely used to treat acute and chronic respiratory failure. This ventilation encounters a non-negligible rate of failure related to the used interface/mask, but the reasons for this failure remain unclear. In order to shed light on this issue and to better understand the effects of the geometrical design of interfaces, we aimed to quantify flow, pressure and gas composition in terms of CO(2) and O(2) at the passage through different types of interface (oronasal mask, integral mask and helmet). In particular, we postulated that due to specific gas flow passing throughout the interface, the effective dead space added by the interface is not always related to the whole gas volume included in the interface.
METHODS: Numerical simulations, using computational fluid dynamics, were used to describe pressure, flow and gas composition during ventilation with the different interfaces.
RESULTS: Between the different interfaces the effective dead spaces differed only modestly (110-370 ml), whereas their internal volumes were markedly different (110-10,000 ml). Effective dead space was limited to half the tidal volume for the most voluminous interface, whereas it was close to the interface gas volume for the less voluminous interfaces. Pressure variations induced by the flow ventilation throughout the interface were negligible.
CONCLUSIONS: Effective dead space is not related to the internal gas volume included in the interface, suggesting that this internal volume should not be considered as a limiting factor for their efficacy during non-invasive ventilation. Patient's comfort and synchrony have also to be taken into account.
R Fodil; F Lellouche; J Mancebo; G Sbirlea-Apiou; D Isabey; L Brochard; B Louis
Related Documents :
6789717 - Pulmonary gas exchange effects of nitroglycerin in canine edematous lungs.
15081177 - Arterial blood gases with 700 ml tidal volumes during out-of-hospital cpr.
12205407 - Controlled versus assisted mechanical ventilation.
2773287 - An unusual cause of increasing airway pressure during anesthesia.
20640137 - Comparison of clinical performance of i-gel with lma-proseal in elective surgeries.
9756567 - Evidence for increased cardiac compliance during exposure to simulated microgravity.
Publication Detail:
Type:  Comparative Study; Journal Article     Date:  2010-11-10
Journal Detail:
Title:  Intensive care medicine     Volume:  37     ISSN:  1432-1238     ISO Abbreviation:  Intensive Care Med     Publication Date:  2011 Feb 
Date Detail:
Created Date:  2011-01-28     Completed Date:  2011-05-03     Revised Date:  2013-07-03    
Medline Journal Info:
Nlm Unique ID:  7704851     Medline TA:  Intensive Care Med     Country:  United States    
Other Details:
Languages:  eng     Pagination:  257-62     Citation Subset:  IM    
Inserm Unite U955, Cell and Respiratory Biomechanics Group, 94010 Créteil, France.
Export Citation:
APA/MLA Format     Download EndNote     Download BibTex
MeSH Terms
Computer Simulation*
Equipment Design*
Face / anatomy & histology
Positive-Pressure Respiration / instrumentation*
Respiratory Dead Space*
Comment In:
Intensive Care Med. 2011 Feb;37(2):193-5   [PMID:  21063675 ]

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

Previous Document:  Severe hyperkalemia induced by a short interruption of barbiturate coma.
Next Document:  No impact of severe varus deformity on clinical outcome after posterior stabilized total knee arthro...