Attentional distraction reduces the affective but not the sensory dimension of perceived dyspnea

The perception of dyspnea shows many similarities to the perception of pain. Both are multidimensional processes, which are not only influenced by sensory input but also by nonsensory factors like attention. Recent research has suggested that attentional distraction might reduce the perception of dyspnea but results are conflicting. Furthermore, the specific impact of attentional distraction on the distinct dimensions of perceived dyspnea has not been studied yet. Therefore, the present study examined the specific impact of changes in the attentional focus on the sensory and affective dimension of perceived dyspnea. Dyspnea was induced in forty-four healthy volunteers (mean age: 27.7 years, range: 18-47 years) by breathing through an inspiratory resistive load (3.57kPa/L/s), while attention was directed either to breathing or distracted by reading texts. Inspiratory time (Ti) and breathing frequency (f) were measured continuously. After each condition the experienced intensity (i.e., sensory dimension) and unpleasantness (i.e., affective dimension) of dyspnea were rated on separate visual analog scales (VAS), presented in randomized order. ANOVAs showed that attentional distraction during loaded breathing reduced the perceived unpleasantness of dyspnea (P < 0.05), while the perceived intensity of dyspnea as well as Ti and f remained unchanged. The results show that attentional distraction reduces the affective, but not the sensory dimension of induced dyspnea in healthy volunteers. Future studies are needed to clarify whether attentional. distraction can effectively be used as intervention technique for reducing the unpleasant aspects of dyspnea in different patients groups. (c) 2006 Elsevier Ltd. All rights reserved.