| |
 | The
same sensations |
Incorrect
|
Table
8.1: Values represent the percentage of trials (n=72
for external resistors, n=26 for bronchoconstriction)
under the conditions of external resistive loading
and bronchoconstriction
|
|---|
| External
Resistors
| Methacholine
Bronchoconstriction
|
|---|
| Chest
tightness or constriction |
3%
|
92%
|
| Work
or effort |
92%
|
54%
|
| Official
journal of the American Thoracic Society. © American
Lung Association. Reprinted with permission.
|
|
With
the external loads, subjects describe primarily a sense of increased
work or effort (Moy et al., 2000). During methacholine inhalation
trials, a sequence of sensations was noted ranging from chest
tightness to a sense of increased effort of breathing, to a sense
of air hunger. Although the sense of effort was present under
both conditions, the sense of chest tightness clearly distinguished
bronchoconstriction from the experimental model. Furthermore,
as previously noted, patients with asthma typically associate
their breathing discomfort with the inspiratory phase of the breathing
cycle despite the fact that airway resistance is increased both
during inspiration and expiration.
|