Ventilation Increases with Lower Extremity Venous Occlusion in Young Adults.
BACKGROUND
Venous distention via subsystolic occlusion of the lower limbs may augment ventilation via stimulation of group III/IV afferent neurons.


OBJECTIVE
The purpose of this study was to examine the ventilatory response to graded lower extremity venous occlusion during exercise in healthy adults.


METHODS
Nineteen adults (9 men, 25 ± 5 yr) completed two visits. Visit 1 included a maximal cycle ergometry exercise test. Visit 2 included a 30% peak workload cycle exercise with randomized inflations of bilateral thigh pressure tourniquets to 20, 40, 60, 80, and 100 mm Hg for 2 min each, separated by 2 min of deflation. Three minutes of cycling occurred before cuffing (control [CTL]). Expired minute ventilation (V˙E), whole body gas exchange, rating of perceived exertion, and dyspnea were measured during each session.


RESULTS
V˙E increased significantly from the control condition (exercise only, CTL) to each occlusion pressure (P < 0.05) with the greatest increase at 100 mm Hg (CTL to 100 mm Hg: 31.5 ± 6.6 to 40.1 ± 10.7 L·min). Respiratory rate (RR) increased as well (CTL to 100 mm Hg: 24.8 ± 6.0 to 30.9 ± 11.5 breaths per minute, P < 0.05, condition effect) with no change in tidal volume (P > 0.05). Tidal volume to inspiratory time (VT/TI) increased significantly from the CTL condition to each occlusion pressure (CTL to 100 mm Hg: 1.5 ± 0.3 to 1.8 ± 0.4 L·min, P < 0.05, all pressures). Dyspnea and RPE increased with all occlusion pressures from CTL exercise (P < 0.05, all pressures).


CONCLUSIONS
Our findings suggest that mild-to-moderate venous occlusion of the lower extremity evokes a tachypneic breathing pattern which, in turn, augments V˙E and perceived breathing effort during exercise.
1Program in Physical Therapy, University of Minnesota, Minneapolis, MN; and 2Internal Medicine, Mayo Clinic College of Medicine, Rochester, MN.
Manda L
ML
Keller-Ross
Andrielle L
AL
Sarkinen
Troy
T
Cross
Bruce D
BD
Johnson
Thomas P
TP
Olson
D000328:Adult; D002245:Carbon Dioxide / Q000032:analysis; D003251:Constriction, Pathologic; D005080:Exercise Test; D005260:Female; D006801:Humans; D007866:Leg / Q000503:physiopathology*; D008297:Male; D052097:Quadriceps Muscle / Q000503:physiopathology*; D012039:Regional Blood Flow; D056152:Respiratory Rate; D013990:Tidal Volume; D014111:Tourniquets; D055815:Young Adult
D002245:Carbon Dioxide