The objective of the present study was to evaluate the effect of morphine on exertional breathlessness and exercise endurance in advanced chronic obstructive pulmonary disease (COPD). In a randomised crossover trial, we compared the acute effect of immediate-release oral morphine versus placebo on physiological and perceptual responses during constant-load cardiopulmonary cycle exercise testing (CPET) in 20 adults with advanced COPD and chronic breathlessness syndrome. Compared with placebo, morphine reduced exertional breathlessness at isotime by 1.2±0.4 Borg units and increased exercise endurance time by 2.5±0.9 min (both p≤0.014). During exercise at isotime, morphine decreased ventilation by 1.3±0.5 L·min−1 and breathing frequency by 2.0±0.9 breaths·min−1 (both p≤0.041). Compared with placebo, morphine decreased exertional breathlessness at isotime by ≥1 Borg unit in 11 participants (responders) and by <1 Borg unit in nine participants (non-responders). Baseline participant characteristics, including pulmonary function and cardiorespiratory fitness, were similar between responders and non-responders. A higher percentage of responders versus non-responders stopped incremental CPET due to intolerable breathlessness: 82 versus 33% (p=0.028). Immediate-release oral morphine improved exertional breathlessness and exercise endurance in some, but not all, adults with advanced COPD. The locus of symptom-limitation on laboratory-based CPET may help to identify patients most likely to benefit from morphine. Immediate-release oral morphine decreased exertional breathlessness and improved exercise endurance in advanced COPD http://ow.ly/mrHQ30dS2qS

中文翻译：

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吗啡对晚期 COPD 患者呼吸困难和运动耐力的影响：一项随机交叉试验

本研究的目的是评估吗啡对晚期慢性阻塞性肺疾病 (COPD) 劳力性呼吸困难和运动耐力的影响。在一项随机交叉试验中，我们比较了 20 名患有晚期 COPD 和慢性呼吸困难综合征的成人在恒定负荷心肺循环运动测试 (CPET) 期间立即释放口服吗啡与安慰剂对生理和知觉反应的急性影响。与安慰剂相比，吗啡在等时减少劳力性呼吸困难 1.2±0.4 Borg 单位，增加运动耐力时间 2.5±0.9 分钟（均 p≤0.014）。在等时运动期间，吗啡使通气量减少 1.3±0.5 L·min−1，呼吸频率减少 2.0±0.9 次呼吸·min−1（均 p≤0.041）。与安慰剂相比，吗啡使 11 名参与者（响应者）在等时的劳力性呼吸困难减少 ≥ 1 Borg 单位，9 名参与者（无响应者）减少 <1 Borg 单位。响应者和无响应者的基线参与者特征，包括肺功能和心肺健康，相似。由于无法忍受的呼吸困难，有反应者与无反应者相比停止增量 CPET 的比例更高：82% 对 33% (p=0.028)。速释口服吗啡改善了一些（但不是全部）晚期 COPD 成人的劳力性呼吸困难和运动耐力。基于实验室的 CPET 症状限制的位置可能有助于识别最有可能从吗啡中受益的患者。速释口服吗啡可减少晚期 COPD 患者的劳力性呼吸困难并提高运动耐力 http://ow.