Skip to Content
Interactive Textbook on Clinical Symptom Research Logo


Home Button

 

Clinical Research on Dyspnea
Author Bios
What is Dyspnea?
What Provokes Dyspnea?
The Nature of Dyspnea
Currently selected section: Language of Dyspnea
Clinical Application
Research Application
Variability in Sensations
Challenges in Study
Mechanical Loads and Sense of Effort
Chemoreceptors
Mechanoreceptors
Neuro-Mechanical Dissociation
Phase of Respiration and Dyspnea
Physiology of Dyspnea
Respiratory System
Cardiovascular System
Measuring Dyspnea
Scaling Issues
Qualitative Aspects
Reliability and Validity Overview
Reliability and Validity
Sensitivity and Specificity
Scales
Sensation vs. Perception vs. Symptom
Treating Dyspnea
Why Measure?
Cluster Analysis
Statistical vs. Clinical Significance
Standard Error of Measurement
Measuring Fatigue
Measuring Depression
Measuring Anxiety and Hyperventilation
Measuring Quality of Life
Conclusion

 

 

Chapter 23: Dyspnea: Research Application of the Language of Dyspnea
        

Now imagine that you are investigating the effect of mechanical ventilation on the sensation of dyspnea in subjects with mild asthma, but normal lung function at baseline, who are given methacholine to induce bronchoconstriction. The protocol requires you to have the subjects rate dyspnea both on the ventilator (passive breathing) and when breathing spontaneously off the ventilator (active breathing). You are aware that patients with asthma describe multiple sensations, including "chest tightness" and increased "effort and work of breathing" (Simon et al., 1990; Moy et al., 2000).

Question 6.3

In designing your study, you should ask the subjects to rate:

Selection ABreathing discomfort
Selection BChest tightness
Selection CEffort or work of breathing
Selection DChest tightness and the effort or work of breathing
Selection E"A" or "D"

Question 6.4

Consider the data summarized in the two charts below. What do you notice about the effect of mechanical ventilation on the sensation of chest tightness as compared to the sensation of effort of breathing? The sensations are affected:

Selection ASimilarly
Selection BDifferently

Figure 6.2: Sensations of tightness (left panel) and effort to breathe (right panel) made during mechanical and spontaneous ventilation with the highest level of bronchoconstriction.
Graphic demonstrates that although the sensation of 'effort' of breathing was reduced on the ventilator, the sensation of 'chest tightness' did not change. If one had asked the subjects to rate only 'breathlessness,' we likely would have seen a decrease in discomfort on the ventilator and missed the important information that chest tightness persisted despite the reduction in the mechanical work of breathing.
Offical Journal of the American Thoracic Society. © American Thoracic Society.
Reprinted with permission.


Page 12 of 47
      Previous Page