Inspiratory Muscle Training in Patients With Duchenne Muscular Dystrophy: Analisys
At the beginning of the study the Pesmax and Pdimax values were not significantly different in the two groups (Fig 1, Table 2). After the 6-month training period, however, the ten patients who completed the training had significantly higher Pesmax and Pdimax values than the 12 control subjects without severe functional impairment (p < 0.001) (Fig 1, Table 2). At the end of training the mean Pesmax and Pdimax values were 5.59 ± 0.98 kPa and 6.61 ±1.16 kPa, respectively, for the 10 training patients; 3.38 ± 1.18 kPa and 4.12 ± 1.11 kPa, respectively, for the 12 controls. The 12 controls without severe pulmonary function impairment, the 5 training, and the 3 control patients with severe impairment showed no significant change of Pesmax and Pdimax values during the observation period (Fig 1, Table 2). The effects of training on inspiratory muscle endurance are shown in Table 3. In the ten patients who completed the training, the endurance time increased significantly (Table 3). The reasons for terminating the test are also listed in Table 3. It should be noted that in the ten patients who completed the training, the target pressure during the resistive breathing tests increased during the training period. This means that the inspiratory task which could be sustained increased. In these ten patients, a pressure/endurance-time product was calculated by multiplying the created Pdi by Те to compare the work capacity of the inspiratory muscles before and at the end of training. The mean pressure-time product increased from 2678 kPa«s to 5500 kPa«s (p < 0.001) (Fig 2). sildenafil citrate pink
In the ten patients who completed the training, no relationship existed between the degree of improvement in respiratory muscle strength and endurance following training and the baseline levels of VC. The number of incorrect exercises did not significantly differ in the five training patients with severe pulmonary function impairment from that of the remaining ten training patients. Within the 1-month training period, the number of incorrect resistive breathing trials and static inspiratory effort maneuvers were 38.3 ± 21.6 and 40.1 ± 18.5, respectively, for the five training patients with severe pulmonary function impairment; 32.9 ± 11.7 and 35.2 ± 12.5, respectively, for the remaining ten training patients. None of the patients finished the training prematurely so that the prescribed number of correctly performed exercises was reached by all patients. The sniff maneuvers were performed by all patients without difficulties. In all patients, a plateau of peak sniff Pdi was reached within four to six sniffs. No further increase in Pdimax was observed during the remaining four to six sniff maneuvers.
The individual maximal variation was not more than 2.0 kPa for Pdi performed during all ten sniff maneuvers and less than 0.4 kPa for Pdi performed during the last four to six of the ten sniff maneuvers. The contribution of esophageal and gastric pressure to sniff Pdi varied among patients, though none had a negative Pga at peak Pdi. A trend toward higher blood creatine kinase levels could not be detected in any patient during the observation period.
Figure 1. Maximal sniff assessed esophageal (Pesmax) and transdiaphragmatic (Pdimax) pressure values before, during, and after the training period in the 10 patients who completed the training (T), in the 5 patients with severe pulmonary function impairment who interrupted the training after 1 month (T), in the 12 controls without (C), and in the 3 controls with (O’) severe pulmonary (unction impairment. In both the T group and the Cf group, one patient had to be excluded from the last examination because they needed ventilatory support.
Figure 2. Changes of the pressure-time product (Pdi.T) during the training period in the ten patients who completed the training.
Table 2—Maximal Sniff Assessed Esophageal (Pesmax) and Transdiaphragmatic (Pdimax) Pressure Values in the DMD Patients
3 mo Before Training | Begin of Training | End of Training | 6 mo After Training | |
Pesmax | ||||
T | 3.20 ± 0.90 | 3.23 ± 0.93 | 5.59 ± 0.98t | 5.30 ± 1.141 |
r | 1.51 ±0.67 | 1.39 ±0.62 | 1.36 ±0.74 | 1.32 ±0.60 |
С | 3.43 ± 1.14 | 3.51 ± 1.25 | 3.38 ± 1.18 | 3.22 ± 1.05 |
С’ | 1.55 ±0.81 | 1.64 ±0.90 | 1.47 ±0.85 | 1.41 ± 0.77 |
Pdimax | ||||
T | 3.85 ± 1.11 | 3.94 ± 1.05 | 6.61 ± 1.16 | 6.33 ± 1.06 |
r | 1.92 ±0.88 | 1.74 ±0.83 | 1.70 ±0.95 | 1.66 ±0.85 |
С | 4.08 ± 1.27 | 4.28 ± 1.20 | 4.12 ± 1.11 | 3.85 ± 1.02 |
С’ | 2.03 ± 1.01 | 2.20 ± 1.16 | 1.88 ± 1.06 | 1.80 ±0.95 |
Table 3—-Endurance Time (Те) and Reasons for Terminating the Endurance Test in the DMD Patients
Months | -3 | 0 | 1 | 3 | 6 | +6 |
Те, min | ||||||
T | 14.514.5 | 14.913.8 | 16.813.0 | 16.512.7 | 17.813.4t | 17.012.9 |
r | 12.813.4 | 13.713.4 | 13.31 3.7 | 12.613.1 | 14.213.9 | 14.114.3 |
С | 14.115.9 | 14.515.2 | 13.714.6 | 14.014.8 | 14.415.3 | 15.115.5 |
С’ | 13.213.1 | 13.713.6 | 13.313.5 | 14.014.0 | 13.813.7 | 13.113.3 |
Reasons for terminating the endurance test; No. of patients | ||||||
Target pressure not generated during 3 consecutive breaths | ||||||
T 9 9 8 | 7 | 7 | 7 | |||
V | 5 | 5 | 5 | 5 | 5 | 4 |
С | 10 | 10 | 10 | 10 | 10 | 9 |
С’ | 3 | 3 | 3 | 3 | 3 | 2 |
Duration = 20 cycles | ||||||
T | 1 | 1 | 2 | 3 | 3 | 3 |
T’ | 0 | 0 | 0 | 0 | 0 | 0 |
С | 2 | 2 | 2 | 2 | 2 | 1 |
С’ | 0 | 0 | 0 | 0 | 0 | 0 |