ABSTRACT

Dyspnea is a complex symptom and multifaceted sensory experience, the neurophysiological bases of which remains obscure. Unfortunately the mechanisms to provoke it are multifactorials. Within the most important mechanisms responsible of the dyspnea perception are the increased of the intrinsic mechanic load of the inspiratory muscles, increased in ventilatory demand, gas exchange anomalies, dynamic airway compression, and cardiovascular factors. For exercising patients with COPD, these conditions apply. In contrast to healthy subjects, patients with COPD who have substantial lung hyperinflation at rest undergo further dynamic increases in thoracic gas volume as exercise progress. In this chapter we will review the different physiological mechanisms that produce dyspnea and modify its intensity. We will then focus in the different stimulus wish provokes the symptom and the different instrument used for its evaluation.

KEYWORDS

Dyspnea, exercise, pulmonary hyperinflation, measurement scales.

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