Dyspnée en soins palliatifs : épidémiologie, neurophysiologie et évaluation

Dyspnea is a common symptom, which prevalence increases in later life, affecting 40% of patients in palliative care units. It is especially common in cancer, particularly in patients with primary or secondary thoracic involvement. There is probably exclusively terminal dyspnea, independent of the underlying pathology, and should be distinguished from earlier dyspnea: their pathophysiology and management could be different. Dyspnea is a complex multidimensional symptom, causing physical, mental, social and spiritual suffering that can be called “total dyspnea”. Although particularly disabling, this symptom is often underestimated by caregivers and is difficult to alleviate, especially because of complex and intricate pathophysiological mechanisms. A systematic evaluation of this symptom seems necessary to improve practices. When it is possible, self-report should be preferred; however, altered consciousness and confusion are frequent in later life and warrant the use of third-party assessment. The Respiratory Distress Observation Scale (RDOS) is useful in such situations. The American Thoracic Society insists on the multidimensional nature of dyspnea and recommends its objective and systematic assessment in patients with chronic respiratory or cardiac failure. The frequency of dyspnea at end of life and its impact on quality of life encourages extending this recommendation to all patients with terminal illness.