DISABLING DYSPNEA IN PATIENTS WITH ADVANCED DISEASE - TACK OF EFFECT OF NEBULIZED MORPHINE

The purpose of this placebo-controlled, double-blind, randomized study was to assess the effect of nebulized morphine on dyspnoea perceived at rest by patients with advanced disease. Seventeen hospital in-patie nts with disabling dyspnoea received isotonic saline or morphine via n ebulization for 10 min through a mouthpiece, combined with oxygen via nasal prongs, On four consecutive days, they were given one of the fou r following treatments in random order: saline with 2 L.min(-1) oxygen ; 10 mg morphine with 2 L.min(-1) oxygen; 20 mg morphine with 2 L.min( -1) oxygen; and 10 mg morphine without oxygen (prongs fixed, no flow). Dyspnoea was assessed on a bipolar visual analogue scale (VAS) (-100 % much more short of breath, +100 % much less short of breath), and ar terial oxygen saturation (Sa,O-2) and respiratory frequency (fR) were recorded at the end of nebulization and 10 min later. In 14 subjects w ho completed the study, mean VAS ratings 10 min after the end of nebul ization ranged +30 to +43%, with no significant difference between the four study days (VAS 20 mg morphine minus VAS saline, 95% confidence interval (95% CI) a to +8%). Sa,O-2 significantly increased on the 3 d ays with supplemental oxygen, and remained stable on the zero flow day . Respiratory frequency significantly decreased on the 4 days, with a trend to correlation between VAS rating and parallel change in respira tory frequency (Spearman's rank correlation coefficient (r(s))=-0.46; p=0.09). We conclude that the subjects benefited from saline or morphi ne via a placebo effect and/or a nonspecific effect, and that nebulize d morphine had no specific effect on dyspnoea.