The frequency and correlates of dyspnea in patients with advanced cancer

Dyspnea is a devastating symptom in patients with advanced cancer. Unfortun ately, very limited research has been done on the frequency and correlates of dyspnea in this particular patient population. The purpose of this prosp ective study was to assess the frequent of moderate to severe dyspnea and t he correlates of dyspnea in a population of ambulatory terminally ill cance r patients. One hundred thirty-five consecutive patients attending a multid isciplinary pain clinic were tested for respiratory function (vital capacit y, peak flow, maximal inspiratory pressure, and oxygen saturation). All pat ients gave their rating of dyspnea, anxiety, and fatigue/tiredness using vi sual analogue scales (VAS). Lung involvement by the tumor (primary or metas tatic ) was determined from the patient's chart. Moderate dyspnea occurred in 74/135 (55%) patients with terminal cancer. Lung involvement (r = 0.285, P = 0.0009), anxiety (r = 0.306, P = 0.0003), fatigue/tiredness (r = 0.211 , P = 0.0146), and vital capacity (r = -0.189, P = 0.0444) were significant ly correlated with the intensity of dyspnea. Multivariate analysis demonstr ated that lung involvement (P = 0.0016) and anxiety (P = 0.0027) were indep endently correlated with the intensity found anxiety (P = 0.0318) and maxim al inspiratory pressure (P = 0.0187) to be independent correlates of the in tensity of dyspnea. Dyspnea is a frequent symptom in patients with advanced cancer. The presence of cancer in the lungs, anxiety, and maximal inspirat ory pressure are correlates of the intensity of dyspnea on this patient pop ulation. Possible treatments addressing low maximal inspiratory pressure an d anxiety are needed, as well as further research in finding new correlates of dyspnea in advanced cancer patients. (C) U.S. Cancer Pain Relief Commit tee, 2000.