Larson J L, Kim M J, Sharp J T, Larson D A
College of Nursing, University of Illinois, Chicago 60612.
Am Rev Respir Dis. 1988 Sep;138(3):689-96. doi: 10.1164/ajrccm/138.3.689.
The inspiratory pressure load is an important variable in inspiratory muscle training (IMT), but previous studies with chronic obstructive pulmonary disease (COPD) patients have not controlled for this variable. We compared the effects of two months of IMT with a pressure threshold breathing device at inspiratory pressure loads equal to either 15 or 30% of each patient's maximal inspiratory pressure (Plmax). This study was double blind and patients were randomly assigned to the treatment groups, 12 in the 15% group and ten in the 30% group. Dependent variables were measured at baseline, and after one and two months of IMT. Patients who exercised with the 30% load improved the following: Plmax by a mean of -12 +/- 9 cm H2O (p less than 0.01), endurance time while breathing against an inspiratory pressure load equal to 66% of Plmax by 5 +/- 9 min (p less than 0.01), and 12-min distance walk (12MD) by 199 +/- 90 feet (p less than 0.01). Patients who exercised with the 15% load demonstrated no improvements in Plmax, endurance time, and 12MD. There were no changes in patients' report of functional impairment (Sickness Impact Profile), mood (Profile of Mood States), health status (Health Perceptions Questionnaire), and pulmonary symptoms (respiratory symptom log). We conclude that the 30% load was more effective than the 15% load in this sample.
吸气压力负荷是吸气肌训练（IMT）中的一个重要变量，但之前针对慢性阻塞性肺疾病（COPD）患者的研究并未对该变量进行控制。我们比较了使用压力阈值呼吸装置进行两个月IMT在吸气压力负荷分别等于每位患者最大吸气压力（Plmax）的15%或30%时的效果。本研究为双盲研究，患者被随机分配到治疗组，15%组有12名患者，30%组有10名患者。在基线以及IMT进行1个月和2个月后测量相关变量。在30%负荷下进行锻炼的患者有以下改善：Plmax平均提高-12±9 cm H2O（p<0.01），在对抗等于Plmax 66%的吸气压力负荷时的耐力时间增加5±9分钟（p<0.01），12分钟步行距离（12MD）增加199±90英尺（p<0.01）。在15%负荷下进行锻炼的患者在Plmax、耐力时间和12MD方面没有改善。患者在功能障碍报告（疾病影响概况）、情绪（情绪状态概况）、健康状况（健康认知问卷）和肺部症状（呼吸症状记录）方面没有变化。我们得出结论，在该样本中，30%的负荷比15%的负荷更有效。
