Biomaterial Database

Effect of inspired volume on closing volume. 1976

B Holtz, and B Bake, and H Oxhöj

Closing volume (CV) was ?EASURED WITH THE RESIDENT GAS TECHNIQUE IN 12 HEALTHY SEATED SUBJECTS AGE 22-70 YR, AND IN 8 SUBJECTS WITH THE BOLUS TECHNIQUE. Various volumes were inspired (Vi range: 20-100% vital capacity) from residual volume and CV was assessed on the subsequent recording of expired volume versus gas concentration. The results indicate that the resident gas technique may erroneously underestimate CV at reduced Vi in conformity with calculations which predict that during expiration, after a certain reduced VI, the nitrogen concentration is identical in the most basal lung region and at the mouth. CV obtained with the bolus technique decreased linearly with reduced Vi and the effect appeared to be age dependent according to the equation CV50/CV100=0.0078 X age +1.18, where CV50 and CV100 denote the bolus CV corresponding to Vi=50% and 100% of vital capacity. Therefore, in older subjects, during tidal breathing, airways appear to close at substantially lower lung volume than previously considered.

UI	MeSH Term	Description	Entries
D007321	Inspiratory Reserve Volume	The extra volume of air that can be inspired with maximal effort after reaching the end of a normal, quiet inspiration. Common abbreviation is IRV.	Inspiratory Reserve Volumes,Reserve Volume, Inspiratory,Reserve Volumes, Inspiratory,Volume, Inspiratory Reserve,Volumes, Inspiratory Reserve
D008176	Lung Volume Measurements	Measurement of the amount of air that the lungs may contain at various points in the respiratory cycle.	Lung Capacities,Lung Volumes,Capacity, Lung,Lung Capacity,Lung Volume,Lung Volume Measurement,Measurement, Lung Volume,Volume, Lung
D008875	Middle Aged	An adult aged 45 - 64 years.	Middle Age
D011653	Pulmonary Diffusing Capacity	The amount of a gas taken up, by the pulmonary capillary blood from the alveolar gas, per minute per unit of average pressure of the gradient of the gas across the BLOOD-AIR BARRIER.	Capacity, Pulmonary Diffusing,Diffusing Capacity, Pulmonary
D012115	Residual Volume	The volume of air remaining in the LUNGS at the end of a maximal expiration. Common abbreviation is RV.	Residual Volumes,Volume, Residual,Volumes, Residual
D005652	Functional Residual Capacity	The volume of air remaining in the LUNGS at the end of a normal, quiet expiration. It is the sum of the RESIDUAL VOLUME and the EXPIRATORY RESERVE VOLUME. Common abbreviation is FRC.	Capacities, Functional Residual,Capacity, Functional Residual,Functional Residual Capacities,Residual Capacities, Functional,Residual Capacity, Functional
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D000328	Adult	A person having attained full growth or maturity. Adults are of 19 through 44 years of age. For a person between 19 and 24 years of age, YOUNG ADULT is available.	Adults
D000368	Aged	A person 65 years of age or older. For a person older than 79 years, AGED, 80 AND OVER is available.	Elderly
D014109	Total Lung Capacity	The volume of air contained in the lungs at the end of a maximal inspiration. It is the equivalent to each of the following sums: VITAL CAPACITY plus RESIDUAL VOLUME; INSPIRATORY CAPACITY plus FUNCTIONAL RESIDUAL CAPACITY; TIDAL VOLUME plus INSPIRATORY RESERVE VOLUME plus functional residual capacity; or tidal volume plus inspiratory reserve volume plus EXPIRATORY RESERVE VOLUME plus residual volume.	Lung Capacity, Total,Capacities, Total Lung,Capacity, Total Lung,Lung Capacities, Total,Total Lung Capacities