Effect of Nasal CPAP on Human Diaphragm Position and Lung Volume
The cephalic margin of the zone of apposition (ZOA) was observed with ultrasonography at ambient pressure and during nasal continuous positive airway pressure (nasal CPAP) in nine awake healthy males in a supine position. In a relaxed state at ambient pressure, there was a significant (p< 0.001)...
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Published in | Nihon Kyōbu Shikkan Gakkai zasshi Vol. 32; no. 11; pp. 1043 - 1048 |
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Main Authors | , , , |
Format | Journal Article |
Language | English Japanese |
Published |
Japan
The Japanese Respiratory Society
01.11.1994
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Subjects | |
Online Access | Get full text |
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Summary: | The cephalic margin of the zone of apposition (ZOA) was observed with ultrasonography at ambient pressure and during nasal continuous positive airway pressure (nasal CPAP) in nine awake healthy males in a supine position. In a relaxed state at ambient pressure, there was a significant (p< 0.001) linear relationship between lung volume and the movement of the cephalic margin of the ZOA over the range from maximum expiratory position (MEP) to maximum inspiratory position (MIP). With nasal CPAP, functional residual capacity increased significantly (p< 0.01) in proportion to the increase in CPAP. At 20cmH2O CPAP, the mean increase in volume at end expiration was 36% of the vital capacity measured at ambient pressure. The cephalic margin of the ZOA moved significantly (p< 0.01) in a caudal direction as CPAP was increased. At 20cmH2O CPAP, the cephalic margin of the ZOA at end expiratory position (EEP) had moved 55% of the difference from MIP to MEP measured at ambient pressure. The end expiratory diaphragm position during nasal CPAP was lower than the diaphragm position at ambient pressure when lung volumes were equal. These results suggest that during nasal CPAP the chest wall is distorted from its relaxed configuration, with a decrease in rib cage expansion and an increase in outward displacement of the abdominal wall. |
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Bibliography: | ObjectType-Article-2 SourceType-Scholarly Journals-1 ObjectType-Feature-1 content type line 23 |
ISSN: | 0301-1542 1883-471X |
DOI: | 10.11389/jjrs1963.32.1043 |