Decrease in functional residual capacity during sleep in normal humans

1984 ◽  
Vol 57 (5) ◽  
pp. 1319-1322 ◽  
Author(s):  
D. W. Hudgel ◽  
P. Devadatta
Keyword(s):  
Functional Residual Capacity ◽  
Closed System ◽  
Rem Sleep ◽  
Airflow Limitation ◽  
Ventilation Distribution ◽  
Stage 2 Sleep ◽  
Residual Capacity ◽  
Helium Dilution ◽  
Normal Humans ◽  
Healthy Males

A decrease in functional residual capacity (FRC) during sleep could result in worsening of ventilation distribution contributing to sleep hypoxemia. Therefore the purpose of this study was to determine whether FRC does decrease and to what extent it decreases in normal humans during sleep. Using helium dilution in a closed system we measured FRC in 10 healthy males during wakefulness, stage 2, stages 3–4, and rapid-eye-movement (REM) sleep. Mean FRC decreased from 3.14 +/- 0.01 (SE) liters during wakefulness to 2.95 +/- 0.01 liters in stage 2 sleep. Lowest sleep values were 2.86 +/- 0.01 liters in stages 3–4 and 2.83 +/- 0.01 liters in REM sleep (P less than 0.05 from wakefulness). Although the amount of the decrease in FRC identified during sleep was surely not large enough to impair ventilation distribution in normal humans, this degree of decrease might contribute to the hypoxemia seen in patients with severe airflow limitation.

A deeper level of ketamine anesthesia does not affect functional residual capacity and ventilation distribution in healthy preschool children

2007 ◽  
Vol 17 (12) ◽  
pp. 1150-1155 ◽  
Author(s):  
BRITTA S VON UNGERN-STERNBERG ◽  
ADRIAN REGLI ◽  
FRANZ J. FREI ◽  
EVA-MARIA JORDI RITZ ◽  
JÜRG HAMMER ◽  
...  
Keyword(s):  
Preschool Children ◽  
Functional Residual Capacity ◽  
Ventilation Distribution ◽  
Ketamine Anesthesia ◽  
Residual Capacity

scholarly journals Effect of cardiopulmonary bypass and aortic clamping on functional residual capacity and ventilation distribution in children

2007 ◽  
Vol 134 (5) ◽  
pp. 1193-1198 ◽  
Author(s):  
Britta S. von Ungern-Sternberg ◽  
Ferenc Petak ◽  
Sonja Saudan ◽  
Michel Pellegrini ◽  
Thomas O. Erb ◽  
...  
Keyword(s):  
Cardiopulmonary Bypass ◽  
Functional Residual Capacity ◽  
Ventilation Distribution ◽  
Aortic Clamping ◽  
Residual Capacity

Hydrostatic weighing at residual volume and functional residual capacity

1980 ◽  
Vol 49 (1) ◽  
pp. 157-159 ◽  
Author(s):  
T. R. Thomas ◽  
G. L. Etheridge
Keyword(s):  
Prone Position ◽  
Functional Residual Capacity ◽  
Lung Volume ◽  
Residual Volume ◽  
Body Density ◽  
Residual Capacity ◽  
Hydrostatic Weighing ◽  
Helium Dilution ◽  
The Subject ◽  
The Difference

Hydrostatic weighing (HW) was performed at both residual volume (RV) and functional residual capacity (FRC) to determine if underwater weighing at different lung volumes affected the measurement of body density. Subjects were 43 males, 18-25 yr. Subjects were submerged in the prone position, and the lung volume was measured by helium dilution at the time of the underwater weighing. Underwater weight was first assessed at FRC followed by assessment at RV. Changes in lung volume were accurately reflected in the underwater weight. Body density (D) was not different with the use of the FRC (mean D = 1.0778) or RV (mean D = 1.0781) data. Percent fat values for the FRC and RV data were 9.3 ± 5.4 and 9.2 ± 5.1%, respectively, and were not statistically different. The results indicate that the difference between percent fat determinations by HW in the prone position at FRC and RV is negligible. Because measurement of underwater weight at FRC is more comfortable for the subject, this may be the method of choice when the lung volume can be measured during the underwater weighing.

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