Ventilatory muscle function during exercise in air and oxygen in patients with chronic air-flow limitation.

摘要: Ventilatory muscle function was examined at rest and during exercise on a cycle ergometer in 8 patients with moderate to severe chronic air-flow limitation (FEV1, 32 ± 4% predicted) air oxygen. The diaphragmatic electromyogram (EMG) measured using an esophageal electrode. In addition, measurements of (Pes), gastric (Pga), transdiaphragmatic (Pdi) pressures abdominal wall movements were made. Patients exercised exhaustion constant submaximal workload (80% maximal power output) inspiring or 40% O2 random order separate days. At end-exercise air, tidal inspiratory Pes swings 36 static Pes, Pdi 45 7% the Pdi. Arterial oxygen saturation decreased from 91 2% 80 5% air. During 5 demonstrated persistent greater than 20% fall ratio high frequency (150 350 Hz) low (20 46 (H/L)...