Morphine for chronic breathlessness in COPD: improvement predictors-cross-sectional study

Abstract

Objective Morphine is used as palliative treatment of chronic breathlessness in patients with chronic obstructive pulmonary disease (COPD). Part of the patients does not experience a clinically meaningful improvement of breathlessness and it is unclear which characteristics are related to a clinically meaningful improvement of breathlessness after morphine. Therefore, this study assessed whether sensory breathlessness description, demographic and clinical characteristics are related with this improvement. Methods Cross-sectional secondary analysis of the intervention arm of a randomised controlled trial. 45 patients with COPD and moderate-to-very severe chronic breathlessness despite optimal treatment received 20-30 mg oral sustained-release morphine daily for 4 weeks. Using binary logistic regression, the relationship between a clinically meaningful improvement in breathlessness (≥1 point on 0-10 numeric rating scale) and the baseline variables sensory breathlessness descriptors, age, breathlessness and body mass index (BMI) was assessed. Results Twenty-one participants (42%) showed a clinically meaningful improvement. Baseline breathlessness (OR 1.51, 95% CI 1.04 to 2.21, p=0.03) and BMI (OR 1.13, 95% 1.02-1.28, p=0.02) were significant associated to a clinically meaningful improvement of breathlessness, while age and sensory breathlessness descriptors were not. Conclusions Worse baseline breathlessness and higher BMI are associated to a clinically meaningful improvement of breathlessness in patients using 20-30 mg oral sustained-release morphine. Opioid treatment should be considered in patients with COPD with severe breathlessness, taking into account the patient's BMI.