An alternate method for the determination of functional residual capacity in a plethysmograph

The American Review of Respiratory Disease
K J DesmondA L Coates

Abstract

The validity of measuring thoracic gas volume using a single inspiratory effort against an occlusion (Vtginsp) was determined in children and young adults (8 normal control subjects and 17 patients with cystic fibrosis [CF] or asthma). In addition, the validity of the measurement of Vtg at FRC in children at a low panting frequency (Vtgpant) was also determined. During both the panting (encouraged to be about 1 Hz) and inspiratory maneuvers, mouth pressure (Pm) and esophageal pressure (Pes) were measured simultaneously. Hence, Vtgpant and Vtginsp were determined using both delta Pm and delta Pes. Vtginsp using delta Pm was found to be similar to Vtginsp using delta Pes. Values for Vtgpant using either delta Pm or delta Pes were also found to be similar. The percent difference between Vtginsp (using delta Pm) and the average of Vtgpant and Vtginsp (using delta Pes for both) was calculated as an indication of the error of the inspiratory method. The error ranged from -13 to +13% and did not correlate with indices of air-flow limitation or hyperinflation. We have found that Vtginsp can be used to determine FRC in normal children and young adults as well as in those with CF or asthma. In addition, we have also validated the use of ...Continue Reading

References

Oct 1, 1975·Thorax·J Hruby, J Butler
Dec 1, 1984·Journal of Applied Physiology: Respiratory, Environmental and Exercise Physiology·R Brown, A S Slutsky

Citations

Jun 1, 1992·Pediatric Pulmonology·L LandsA L Coates
Mar 21, 2000·Journal of Aerosol Medicine : the Official Journal of the International Society for Aerosols in Medicine·A L CoatesL Lands
Mar 1, 1993·The Journal of Pediatrics·P PianosiA L Coates
Oct 8, 1999·Chronobiology International·R D Ballard
Apr 1, 1993·The American Review of Respiratory Disease·R D BallardD P White
Jan 22, 2005·Clinical Physiology and Functional Imaging·Thomas HalvorsenEinar Thorsen

Related Concepts

Airway Resistance
Asthma
Pulmonary Cystic Fibrosis
Forced Expiratory Volume Function
Functional Residual Capacity
Lung
Maximal Midexpiratory Flow Rate
Plethysmography, Whole Body

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