The Effect of Aerosol Saline on Laboratory-Induced Dyspnea.
The Effect of Aerosol Saline on Laboratory-Induced Dyspnea.
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DOI：
10.1007/s00408-016-9971-3
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发表时间：
2017-02
期刊：
影响因子：
5
通讯作者：
Banzett R
中科院分区：
文献类型：
--
作者：
O'Donnell CR;Lansing RW;Schwartzstein RM;Banzett R
在最近的一项研究的“安慰剂组”中，我们发现盐水气雾剂（假治疗）在近一半的受试者中显著缓解了实验室诱导的呼吸困难（呼吸不适- BD）。假干预包括生理变化，对受试者的说明可能会产生呼吸困难缓解的预期。在本研究中，我们试图发现对假气雾剂的反应是否是由干预的行为或生理方面驱动的。在分级高碳酸血症期间，通过限制潮气量诱发呼吸困难（空气饥饿）。我们测量了雾化盐水前后Petco 2与BD的关系。为了尽量减少受试者对呼吸困难缓解的期望，明确指示参与者我们将只提供盐水气雾剂。在方案1中，我们使用呼吸机输送盐水气雾剂（模仿我们之前的研究）;在方案2中，我们在没有呼吸机的情况下输送气雾剂。盐水气雾剂给药对该组受试者的BD几乎没有影响，但有一个例外：方案1中1例受试者的BD明显降低。方案2中的治疗效果较低。两种最可能的解释是：a）尽管受试者知道没有给予药物，但呼吸机气雾剂给药程序产生了心理安慰剂治疗效应，B）呼吸流量和呼吸量测量未检测到呼吸行为变化，这改变了受试者的舒适度。当治疗效果的预期最小化时，生理盐水安慰剂引起的呼吸困难显著减轻并不常见，但并非不可能。
In the ‘placebo arm’ of a recent study we found that aerosol saline (sham treatment) produced substantial relief of laboratory-induced dyspnea (Breathing Discomfort – BD) in nearly half the subjects. The sham intervention included a physiological change, and instructions to subjects could have produced expectation of dyspnea relief. In the present study we attempted to discover whether the response to sham aerosol was driven by behavioral or physiological aspects of the intervention. Dyspnea (air hunger) was evoked by constraining tidal volume during graded hypercapnia. We measured Petco2 vs BD relationship before and after aerosol saline. To minimize subjects’ expectations of dyspnea relief, participants in were clearly instructed that we would only deliver saline aerosol. In Protocol 1, we delivered aerosol saline with a ventilator (mimicking our prior study); in Protocol 2, we delivered aerosol without a ventilator. Administration of aerosol saline had little effect on BD in this group of subjects with one exception: one subject experienced appreciable reduction in BD in Protocol 1. This treatment effect was less in Protocol 2. The two most likely explanations are a) that procedures surrounding ventilator administration of aerosol produced a psychological placebo treatment effect even though the subject knew a drug was not given, b) there were behavioral changes in breathing undetected by our measurements of respiratory flow and volume that altered the subjects comfort. When the expectation of treatment effect is minimized, a significant reduction in dyspnea in response to saline placebo is uncommon but not impossible.