Pulmonary Rehabilitation in Patients with COPD: Discussion (3)
It is not clear which target pressure, expressed as a percentage of PImax, is the most effective. Other investigators used 30, 50, or 60 percent of PImax. We used a target-pressure of 70 percent of PImax, combined with an inspiration of 3 s and an expiration of 4 s. This training method results in a tension-time index of 0.3 (Pl/PImax 0.7, Ti/Ttot 0.43). Bellamare and Grassino showed that a tension-time index of 0.3 resulted in fatigue of the diaphragm in about 10 to 15 minutes. Therefore, on theoretic grounds, we believed that this was a reasonable training intensity. Practically, the training sessions were fairly well tolerated by the patients.
The endurance of the diaphragm was improved in the PR as well as in the PR+IMT group, although significantly more in the latter group. It seems, therefore, that exercise as such may result in a training stimulus for the diaphragm, presumably by increasing minute ventilation during the training sessions. buy birth control online
In conclusion, adding TF-IMT to a PR program is useful in patients with COPD with ventilatory limitation, and it results in significantly more improvement in inspiratory muscle strength and diaphragm endur-nace as well as general exercise endurance than PR alone.