Department of Clinical Sciences Lund, Respiratory Medicine and Allergology, Faculty of Medicine, Lund University, Lund, Sweden.
Curr Opin Support Palliat Care. 2019 Sep;13(3):179-183. doi: 10.1097/SPC.0000000000000444.
Treatments for chronic breathlessness, including opioids and oxygen, have shown efficacy in the controlled laboratory setting, whereas effects have been inconsistent or absent in trials in daily life. This review discusses the lack of standardized exertion as a potential cause of false negative findings for breathlessness in daily life.
The level of breathlessness can be modified by patients by changing their level of physical activity. Effects of opioids and oxygen have been shown at standardized level of exertion (iso-time) but not at the end of symptom-limited (peak) exertion. Trials in daily life reporting no effects on breathlessness did not standardize the exertion or employed insensitive methods, such as the 6-min walk test that should not be used for measuring breathlessness. Novel tests - the 3-min walk and stepping tests have been validated in chronic obstructive pulmonary disease and are responsive for measuring change in breathlessness.
Breathlessness should be measured at standardized exertion, otherwise treatment effects may be biased or overlooked. Tests for valid measurement of breathlessness in clinical practice and daily life are available and emerging.
治疗慢性呼吸困难的方法，包括阿片类药物和氧气，在受控的实验室环境中已显示出疗效，而在日常生活中的试验中，其效果不一致或不存在。本文讨论了缺乏标准化的用力作为日常生活中呼吸困难出现假阴性结果的潜在原因。
患者可以通过改变体力活动水平来改变呼吸困难的程度。阿片类药物和氧气的作用已在标准化的用力水平（等时）下显示，但不在症状限制（峰值）用力的终点下显示。在日常生活中报告对呼吸困难没有影响的试验没有标准化用力，也没有使用敏感的方法，如不应用于测量呼吸困难的 6 分钟步行试验。在慢性阻塞性肺疾病中已经验证了新的测试——3 分钟步行和踏步测试，并且可以用于测量呼吸困难的变化。
如果不进行标准化用力测量，否则可能会产生治疗效果的偏差或被忽视。在临床实践和日常生活中，有一些可用于测量呼吸困难的有效测试，并且还在不断涌现。
