Using laboratory models to test treatment: morphine reduces dyspnea and hypercapnic ventilatory response.

Rationale: Opioids are commonly used to relieve dyspnea, but clinical data are mixed and practice varies widely.

Objectives: Evaluate the effect of morphine on dyspnea and ventilatory drive under well-controlled laboratory conditions.

Methods: Six healthy volunteers received morphine (0.

Physiologic changes and clinical correlates of advanced dyspnea.

Purpose Of Review: To discuss the pathophysiology of dyspnea as it relates to patients suffering with chronic respiratory illness or end-stage disease.

Recent Findings: There are several publications highlighting important new concepts in this field including a new multidimensional model of dyspnea, similar to that developed for pain, that sheds new insight into the pathophysiology. Research in pulmonary rehabilitation, exercise testing and distractive auditory stimulation has also contributed to our understanding.