Weinberg J, Borg J, Bevegård S, Sinderby C
Division of Neurology, Karolinska Institute, Huddinge University Hospital, Sweden.
Arch Phys Med Rehabil. 1999 Sep;80(9):1095-100. doi: 10.1016/s0003-9993(99)90067-9.
To evaluate the limiting factors of exercise performance and to analyze the respiratory strategies adopted during exercise in postpolio patients with severe inspiratory muscle dysfunction.
Five patients with prior poliomyelitis associated with scoliosis and with respiratory muscle dysfunction (mean vital capacity, 1.74L [range, 1.1 to 2.4]) were studied at rest and during leg or arm cycle exercise.
Gas exchange was examined by arterial blood gases and mass spectrometry of expired air. Ventilatory mechanics were studied by measurement of esophageal and gastric pressures.
Blood gases at rest were normal, except for subnormal PO2 levels in three patients. In all but one patient, ventilatory insufficiency was the limiting factor for exercise. A compensatory breathing pattern with abdominal muscle recruitment during expiration was present already at rest in three of the patients. The pressures generated by the diaphragm were below fatiguing margins, ie, levels that in healthy subjects can be sustained for at least 45 minutes.
The extent of ventilatory dysfunction was not evident in blood gas values at rest; however, it was revealed by blood gas values during the exercise test. Diaphragm fatigue seems to be avoided at the cost of impaired blood gases.
评估运动能力的限制因素，并分析患有严重吸气肌无力的小儿麻痹后遗症患者在运动过程中所采用的呼吸策略。
五名既往患有小儿麻痹症并伴有脊柱侧弯及呼吸肌无力的患者（平均肺活量为1.74升[范围为1.1至2.4升]），在静息状态以及腿部或手臂自行车运动期间接受了研究。
通过动脉血气分析和呼出气体质谱法检测气体交换情况。通过测量食管和胃内压力来研究通气力学。
除三名患者的动脉血氧分压水平低于正常外，静息状态下的血气指标均正常。除一名患者外，所有患者的通气不足均为运动的限制因素。三名患者在静息状态下即已出现呼气时募集腹肌的代偿性呼吸模式。横膈膜产生的压力低于疲劳阈值，即在健康受试者中可维持至少45分钟的水平。
通气功能障碍的程度在静息状态下的血气值中并不明显；然而，在运动试验期间的血气值中得以显现。横膈膜疲劳似乎是以血气受损为代价而得以避免的。
