Abstract
Objective: To investigate changes in pulmonary
function when postural changes are made in sitting
position.
Methodology: This cross sectional study enrolled 500
students of Riphah International University using nonprobability convenience sampling technique. They
performed spirometry in five different positions
without nebulization out of which, three were done in
sitting positions i.e. upright sitting, lordotic sitting and
kyphotic sitting and standing and supine position.
Subjects were allowed to take rest for 5 minutes
between each successive position. The FEV1, FVC,
PEFR and FVC/FEV1 were recorded for each position.
Results: Mean FEV1/FVC were 91 ± 16.0 for
standing, 86 ± 15.4 for upright sitting, 84 ± 19.7 for
kyphotic sitting, 88 ± 29.7 for lordotic sitting and 80 ±
23.3 for supine positions, respectively. The change in
the dynamic lung volumes was highly significant
amongst these positions (p < 0.28). There was
statistical difference in dynamic lung volumes of
males and females (p < 0.001).
Conclusion: In healthy males and females, changes
from the standing to sitting and supine position causes
statistically significant changes in all the spirometry
values owing to the changes in the respiratory pattern.
The spirometry values of males and females were also
profoundly different. There was no profoundly
different change between different sitting positions.
Keywords: FEV1, FVC, FEV1/FVC, gender
differences, PFTs, spirometry.
