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Incorrect
| Figure
10.1: Air Hunger Ratings from a Single Subject During
Neuromuscular Paralysis.
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The figure
here is from a study in which normal subjects were paralyzed with
a neuromuscular blocker and subsequently developed respiratory
distress in association with acute hypercapnia despite receiving
adequate mechanical ventilation. These data confirm that acute
hypercapnia can produce a sensation of air hunger independent
of changes in muscle activity and ventilation. As with hypercapnia,
the breathlessness associated with acute hypoxia has been attributed
to the resulting increases in ventilation. Changes in dyspnea
ratings, however, precede changes in ventilation (Chronos
et al., 1988). Furthermore, the administration of oxygen to hypoxic patients
with COPD during exercise reduced dyspnea out of proportion to
changes in ventilation (Lane
et al., 1987).
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