Villafranca C, Borzone G, Leiva A, Lisboa C
Departamento de Enfermedades Respiratorias, Pontificia Universidad Católica de Chile, Santiago.
Eur Respir J. 1998 Jan;11(1):28-33. doi: 10.1183/09031936.98.11010028.
There is very little information about the effect of inspiratory muscle training on inspiratory flow (V'I) and thus on power output (PO) in patients with chronic obstructive pulmonary disease (COPD). In this study we aimed to evaluate the changes induced by training on the determinants of PO. Thirty one patients with severe COPD were randomly divided into: Group 1, trained with 30% maximal inspiratory pressure (PI,max); Group 2, with 10% PI,max; and Group 3 also trained with 30% PI,max, but the breathing pattern was evaluated while performing the training manoeuvres along inspiratory muscle training (IMT). All groups used a threshold device for 10 weeks. The PO for each of the loads during an incremental threshold test was evaluated prior to and after training. Maximal PO (POmax) increased in all groups, but the increment was higher in groups trained with 30% PI,max (p<0.005), mainly due to an increase in V'I. Group 3 showed a progressive increase in V'I (p<0.001) during the training manoeuvres in spite of an increase in load along IMT. In addition, the load after IMT was overcome with a shorter inspiratory time (tI) (p<0.02), a smaller tI/total duration of the respiratory cycle (t(tot)), (p<0.001) with no change in tidal volume or t(tot). The increment in POmax in this group correlated with the V'I generated while training (r=0.85; p<0.0001). We conclude that in patients with chronic obstructive pulmonary disease, the use of an intermediate threshold load for training improves power output mainly by increasing inspiratory flow, an effect consistent with an increase in shortening velocity of inspiratory muscles.
关于吸气肌训练对慢性阻塞性肺疾病（COPD）患者吸气流量（V'I）以及由此对功率输出（PO）的影响，相关信息非常少。在本研究中，我们旨在评估训练对PO决定因素所引起的变化。31例重度COPD患者被随机分为：第1组，采用30%最大吸气压力（PI,max）进行训练；第2组，采用10%PI,max进行训练；第3组同样采用30%PI,max进行训练，但在进行吸气肌训练（IMT）的训练动作时评估呼吸模式。所有组均使用阈值装置进行10周训练。在递增阈值测试期间，对训练前后每种负荷的PO进行评估。所有组的最大PO（POmax）均增加，但采用30%PI,max训练的组增加幅度更高（p<0.005），主要是由于V'I增加。尽管在IMT过程中负荷增加，但第3组在训练动作期间V'I呈逐渐增加趋势（p<0.001）。此外，IMT后的负荷在吸气时间（tI）更短的情况下被克服（p<0.02），tI/呼吸周期总时长（t(tot)）更小（p<0.001），而潮气量或t(tot)无变化。该组POmax的增加与训练时产生的V'I相关（r=0.85；p<0.0001）。我们得出结论，在慢性阻塞性肺疾病患者中，使用中等阈值负荷进行训练主要通过增加吸气流量来提高功率输出，这一效应与吸气肌缩短速度增加一致。
