The longitudinal pattern of response when morphine is used to treat chronic refractory dyspnea

Background: While evidence supports using sustained release morphine for chronic refractory breathlessness, little is known about the longitudinal pattern of breathlessness intensity as people achieve symptomatic benefit. The aim of this study is to describe this pattern. Methods: This secondary analysis used breathlessness intensity scores (100 mm visual analogue scale (VAS)) from a prospective, dose increment study of once daily (morning) sustained release morphine for chronic refractory breathlessness. Participants who achieved 10 mg: 13 participants (20 mg) and 4 (30 mg), contributing 634 VAS observations. In the week leading to a response, average VAS scores worsened by 0.3 mm/day (p=0.16); the average improvement in the first 24 hours of response was 10.9 mm (7.0 to 14.7; p<0.0001), with continued improvement of 2.2 mm/day (p