INCREMENTAL THRESHOLD LOADING IN PATIENTS WITH CHRONIC OBSTRUCTIVE PULMONARY-DISEASE

The purpose of this research was to study the reproducibility of incre mental threshold loading, a test of inspiratory muscle endurance, in p atients with mild to severe chronic obstructive pulmonary disease. Twe nty-seven patients completed four weekly visits. A significant differe nce was noted between the first visit and subsequent visits for the ma ximum absolute load that patients could tolerate, but no difference wa s noted in the load relative to inspiratory strength. Breathing patter n did not change significantly among visits to account for the differe nces in absolute load. Patients had a tendency to use rapid shallow br eathing at the end of the test, suggesting that they approached the li mits of their endurance and thus fatigued their inspiratory muscles.