Does spirometry predict dyspnoea in advanced cancer?

This study explores the similarities and differences between subjective assessments of dyspnoea and objective spirometric indices of respiratory function in advanced cancer. Of 155 patients investigated, 71 (46%) were dyspnoeic and 108 (70%) had spirometry (94 post-salbutamol). Of the 94, 84 had height and weight measured to calculate predicted spirometry. Average dyspnoea levels over 24 h were measured by patient visual analogue scales (VASMe 24). Forced expiratory volume after 1 s (FEV1) and forced vital capacity (FVC) were almost always lower than predicted, indicating frequent impaired respiratory function. Mean spirometric increase post-salbutamol was 21% for FEV1 and 12% for FVC. Correlations between VAS dyspnoea scores and spirometry were low; hence, the latter cannot be relied upon as a measure of the former. Respiratory impairment tended to be obstructive (mean FEV1/FVC = 65%).