Responsiveness of patient-reported breathlessness during exercise in persistent asthma

Activity limitation and exertional dyspnea in adult asthmatic patients: What do we know?

Limitation of activity is the most cited symptom described by uncontrolled asthma patients. Assessment of activity limitation can be undertaken through several ways, more or less complex, subjective or objective. Yet little is known about the link between patients sensations and objective measurements. The present review reports the current knowledge regarding activity limitation and symptom perception (i.e., exertional dyspnea) in adult patients with asthma. This work is based on references indexed by PubMed, irrespective of the year of publication. Overall, patients with stable asthma do not have a more sedentary lifestyle than healthy subjects. However, during a cycle ergometric test, the maximal load is reduced when FEV1, FVC and muscle strengths are decreased. Additionally, during the six-minute walking test, mild asthma patients walk less than healthy subjects even if the minimal clinically important difference is not reached. The major complaint of asthma patients when exercising is dyspnea that is mainly related to the inspiratory effort and also to dynamic hyperinflation in some circumstances. Finally, the administration of bronchodilator does not improve the ventilatory pattern and the exercise capacity of asthma patients and little is known on its effect on exertional dyspnea. The present review allows to conclude that until now there is no gold standard test allowing the objective assessment of "activity limitation and exertional dyspnea" in asthma patients.

Breathlessness in everyday life from a patient perspective: A qualitative study using diaries

Objective:

Breathlessness is a subjective symptom, which makes it difficult to define and understand. The aim of the present study was to illuminate how patients suffering from breathlessness experience their everyday life.

Method:

The study was a qualitative study, and the focus of the analysis was the patients' descriptions of their experiences of breathlessness using a diary with two unstructured questions for a period of 7 consecutive days. Sixteen participants: 7 men, mean age 65 ± 7 (range 55–73 years old), and 9 women, mean age 65 ± 9 (range 50–72 years old) participated in the study.

Results:

Two themes emerged from the analysis: 1) Impaired quality of life and 2) symptom tolerance and adaptation. The theme “impaired quality of life” included the categories limited physical ability, psychological burdens, and social life barriers. The theme “symptom tolerance and adaptation” included importance of health care, social support, hobbies and leisure activities, and coping strategies.

Significance of results:

The findings in our study showed that patients, in spite of considerable difficulties with shortness of breath, found relief in several types of activities, in addition to drug therapy. The result indicates that the “biopsychosocial model” is an appealing approach that should be discussed further to gain a better understanding of breathlessness.

Perceptual and physiologic responses during treadmill and cycle exercise in patients with COPD

BACKGROUND

Although the cycle ergometer is the traditional mode for exercise testing in patients with respiratory disease, this preference over the treadmill does not consider perceptual responses. Our hypotheses were as follows: (1) the regression slope between breathlessness and oxygen consumption (Vo(2)) is greater on the treadmill than on the cycle ergometer; and (2) the regression slope between leg discomfort and Vo(2) is greater on the cycle ergometer than on the treadmill.

METHODS

Twenty patients (10 men/10 women) with COPD (mean +/- SD postbronchodilator FEV(1), 50 +/- 15% of predicted) used a continuous method to report changes in breathlessness and in leg discomfort during cycle and treadmill exercise.

RESULTS

Patients reported an earlier onset of breathlessness and leg discomfort during cycling. Peak ratings of breathlessness were higher on the treadmill, whereas peak ratings of leg discomfort were higher on the cycle ergometer. The regression slopes for breathlessness as a function of Vo(2) and of minute ventilation (Ve) were higher on the treadmill. The regression slopes between leg discomfort and Vo(2) were similar for treadmill and cycle exercise. Peak Vo(2) was significantly higher with treadmill exercise (mean Delta = 8%; p = 0.002).

CONCLUSIONS

Patients with COPD exhibit different perceptual and physiologic responses during treadmill walking and cycling. Although ratings of breathlessness are initially higher with cycling at equivalent levels of Vo(2), the changes in breathlessness as a function of physiologic stimuli (Vo(2) and Ve) are greater during treadmill exercise. Leg discomfort is the predominant symptom throughout cycling.