Move With Air: Physiological Response Assessment

Move With Air: Can a Fan Reduce Exertional Breathlessness During a 3-minute Constant Rate Walking Test in Adults With Cardiopulmonary Disease?

A fan blowing cool air to the face has been shown to alleviate breathlessness in malignant and non-malignant disease at rest and during exercise, however the underlying physiological mechanisms remain unknown. This random order, three-condition design study will explore physiological mechanisms of breathlessness relief with fan-to-face therapy during constant-rate exercise in people with cardiorespiratory disease.

Constant work rate tests are viewed as the most suitable and sensitive method to assess exertional breathlessness. The 3-minute constant rate treadmill test (3-min CRTT) is a validated test wherein participants exercise at an intensity determined by an incremental test. For the purpose of this study, participants will perform three 3-min CRTT at 75% of peak power output, achieved during an incremental treadmill exercise test, under three experimental conditions: (i) fan to the face; (ii) fan to the leg; (iii) no fan. The order of the experimental conditions will be random for each participant. Cardiac and dynamic respiratory parameters will be collected breath-by-breath at rest and during exercise using the Hexokin Smart Shirt. In order to target the intranasal pathway located on the trigeminal nerve that is hypothesized to modulate the mechanisms governing the potential effectiveness of a fan to the face, a metabolic cart will be omitted due to the use of the facemask or mouthpiece and nasal clip that would block this pathway. Using the Borg 0-10 scale, perceptions of breathlessness intensity, unpleasantness and leg fatigue will be assessed at rest, within the last 15-seconds of each minute of exercise, and at end exercise or the symptom limited peak of exercise. Two areas of facial skin temperature, one at the forehead to target the ophthalmic branch of the trigeminal nerve and the other at the cheek to target the maxillary branch of the trigeminal nerve, will be measured prior to exercise, within the last 15-seconds of each minute of exercise, at end exercise, and following exercise using a medical grade non-contact infrared forehead thermometer. The model number of the forehead thermometer that will be used is THERMOPROPCV2 and is licensed by Health Canada and approved by the U.S. Food and Drug Administration (FDA), CE approved with European health, safety, and environmental protection standards, and approved by the Restriction of Hazardous Substances Directive (RoHS).

Breathlessness, Dyspnea, Exercise, Fan-to-face therapy, Physiological Mechanisms, Constant work rate exercise

Each participant will complete the same constant work rate exercise test under three different conditions.

It is impossible to mask the participants or the investigator since they will be aware if the fan is pointed to the face, to the leg, or there is no fan. However, participants will not be informed of which interventional arm is suspected to be beneficial.

The participants will complete a 3-minute constant work rate treadmill test at 75% of peak power output achieved on an incremental treadmill test with a basic, portable fan placed in front of the face. The fan will be placed at a location to target the second and third branches of the trigeminal nerve and will be placed a distance so that the maximum airflow speed at the face is 4.3 meters/second.

The participants will complete a 3-minute constant work rate treadmill test at 75% of peak power output achieved on an incremental treadmill test with a basic, portable fan placed facing the side of the lower left leg (side calf area). The fan will be placed a distance so that the maximum airflow speed at the face is 4.3 meters/second.

The participants will complete a 3-minute constant work rate treadmill test at 75% of peak power achieved on an incremental treadmill test with no fan.

Borg modified 0-10 category ratio scale will be used to assess breathlessness intensity at end-exercise of each 3-minute constant rate treadmill test under three conditions: (i) fan to the face; (ii) fan to the leg (sham) and; (iii) no fan (control). A higher score is indicative of greater breathlessness, while a lower score is indicative of lesser breathlessness.

Mean ventilation (Liters/minute) will be compared across the 3-minute constant rate treadmill tests under the three different conditions: (i) fan to the face; (ii) fan to the leg (sham) and; (iii) no fan (control). A greater mean ventilation is indicative of a less efficient respiratory system, whereas a lower mean ventilation is indicative of a more efficient respiratory system.

Cardiopulmonary exercise test (3-minute constant rate) physiological response (operating lung volumes)

Mean operating lung volumes (i.e., inspiratory capacity in liters) will be compared across the 3-minute constant rate treadmill tests under the three different conditions: (i) fan to the face; (ii) fan to the leg (sham) and; (iii) no fan (control). A greater operating lung volume (i.e., greater inspiratory capacity) is indicative of a better and more efficient breathing pattern, while a lower operating lung volume (i.e., smaller inspiratory capacity) is indicative of a worse and less efficient breathing pattern.

Mean heart rate (beats per minute) will be compared across the 3-minute constant rate treadmill tests under the three different conditions: (i) fan to the face; (ii) fan to the leg (sham) and; (iii) no fan (control). A lower heart rate is indicative of better cardiovascular fitness, while a higher heart rate is indicative of worse cardiovascular fitness.

Mean oxygen saturation (in percentage) will be compared across the 3-minute constant rate treadmill tests under the three different conditions: (i) fan to the face; (ii) fan to the leg (sham) and; (iii) no fan (control). A lower oxygen saturation is indicative of worse health status, while a higher oxygen saturation is indicative of better health status.

Inclusion Criteria: have a physician diagnosis of cardiopulmonary disease (e.g., chronic obstructive pulmonary disease, interstitial lung disease, heart failure) must report breathlessness on exertion, defined as modified Medical Research Council dyspnea scale rating ≥2 despite optimal treatment of their underlying cardiopulmonary pathophysiology according to established clinical practice guidelines have a body mass index of >18.5 kg/m2 and <35 kg/m2 must be cleared by a physician to perform physical activity/exercise following the completion of the 'Medical Clearance Form for Cardiopulmonary Exercise Testing'. Exclusion Criteria: have changed their respiratory or cardiac medication dosage and/or frequency of administration in preceding two weeks have had a disease exacerbation/hospitalization in preceding six weeks have important contraindication(s) to exercise (e.g., significant musculoskeletal or neurological disease) or pulmonary function testing (e.g., eye, chest or stomach surgery, or any history of coughing up significant amounts of blood in the previous 3 months).