It may be of interest that patients with COPD in a randomized controlled six-week trial of inspiratory muscle endurance training sustained an improvement of similar magnitude (approximately seven minutes). One might therefore speculate that inspiratory muscle endurance could be further increased with a combination of rest and exercise, but to our knowledge, possible clinical benefits of such an approach have not been evaluated. buy cheap antibiotics
Although it is conceivable that the inspiratory muscles recovered from a state of chronic fatigue, we have not provided conclusive evidence of the existence of such fatigue. It is possible that the inspiratory muscles benefited from the improvement in Sa02 and pH that resulted from the improved nocturnal gas exchange (Tables 3 and 4). In addition to the beneficial effects of rest and better gases on inspiratory muscle function, nocturnal mechanical ventilation may reduce the daytime work of breathing by preventing peripheral atelectasis and the consequent decrease in lung compliance. Another consequence of improved nocturnal gas values may be a resetting of central control to increase chemosensitivity and a reduction in body bicarbonate pool. Such changes are difficult to measure and in three of our subjects, we found both the peripheral and the central chemoreflexes to remain well below the normal range at 14 months despite the improvement in daytime ABC values.