Document Detail

Reliable time to estimate subglottal pressure.
MedLine Citation:
PMID:  18207358     Owner:  NLM     Status:  MEDLINE    
Measuring subglottal pressure (P(s)) with complete interruption can be problematic due to unsteady plateaus in supraglottal pressure data traces during balloon valve interruption. Subjectively determining when the graph plateaus neglect the effects of laryngeal, auditory, and other physical reflexes may alter patient effort and glottal configuration. If the P(s) estimation was made at a consistent time before the onset of reflexes, the recorded pressure would not be dependent on subjective analysis by a clinician, and intrasubject data would be more precise. Previously collected data using the airflow interruption system have shown consistency at approximately 150 milliseconds after balloon valve inflation. To evaluate the validity of estimating P(s) at this point, a theoretical and a physical model were applied. A theoretical ideal gas model of capacitance calculated the time necessary for supraglottal pressure to equilibrate with P(s). Using a mechanical pseudolung which served as a constant pressure source, known subresistor pressures were compared to the pressure measured by the interruption device. Both models confirmed the validity of measuring P(s) consistently at 150 milliseconds into the 500-millisecond interruption. In human trials testing 25 subjects, mean intrasubject standard deviation using this optimal time constant was 0.66+/-0.37cm H(2)O, and 1.11+/-0.48cm H(2)O when performing plateau analysis (P<0.0005). This novel modification to the clinically feasible interruption model for P(s) estimation demonstrates a marked improvement in the reliability of balloon valve interruption while maintaining the validity demonstrated in previous studies.
Matthew R Hoffman; Christopher D Baggott; Jack Jiang
Related Documents :
3298358 - Quantitative assessment of the hemodynamic consequences of aortic regurgitation by mean...
6489308 - Observations on structure and function of the equine mitral valve.
18692658 - A prospective randomized comparison of the medtronic advantage supra and st jude medica...
15908258 - Determination of the pressure required to cause mitral valve failure.
20362438 - Comparison of atmospheric pressure effects on the anaerobic digestion of municipal soli...
6385958 - Physiological interpretation of the skewness of indicator-dilution curves; theoretical ...
Publication Detail:
Type:  Journal Article; Research Support, N.I.H., Extramural     Date:  2008-01-22
Journal Detail:
Title:  Journal of voice : official journal of the Voice Foundation     Volume:  23     ISSN:  1873-4588     ISO Abbreviation:  J Voice     Publication Date:  2009 Mar 
Date Detail:
Created Date:  2009-03-09     Completed Date:  2009-07-16     Revised Date:  2014-09-14    
Medline Journal Info:
Nlm Unique ID:  8712262     Medline TA:  J Voice     Country:  United States    
Other Details:
Languages:  eng     Pagination:  169-74     Citation Subset:  IM    
Export Citation:
APA/MLA Format     Download EndNote     Download BibTex
MeSH Terms
Glottis / physiology*
Models, Biological
Pulmonary Ventilation
Time Factors
Grant Support

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

Previous Document:  Utility of polyclonal antibodies targeted toward unique tryptic peptides in the proteomic analysis o...
Next Document:  Muscle tension dysphonia in Vietnamese female teachers.