Yoga-derived breathing has been reported to improve gas exchange in patients with chronic heart failure and in participants exposed to high-altitude hypoxia. We investigated the tolerability and effect of yoga breathing on ventilatory pattern and oxygenation in patients with chronic obstructive pulmonary disease (COPD). METHODS: Patients with COPD (N = 11, 3 women) without previous yoga practice and taking only short-acting ß2-adrenergic blocking drugs were enrolled. Ventilatory pattern and oxygen saturation were monitored by means of inductive plethysmography during 30-minute spontaneous breathing at rest (sb) and during a 30-minute yoga lesson (y). During the yoga lesson, the patients were requested to mobilize in sequence the diaphragm, lower chest, and upper chest adopting a slower and deeper breathing. We evaluated oxygen saturation (SaO2%), tidal volume (VT), minute ventilation (E), respiratory rate (i>f), inspiratory time, total breath time, fractional inspiratory time, an index of thoracoabdominal coordination, and an index of rapid shallow breathing. Changes in dyspnea during the yoga lesson were assessed with the Borg scale.
The oxygen saturation values reported in the high altitude literature are usually taken during a few minutes of measurement either at rest or during exercise. We aimed to investigate the daily hypoxic profile by monitoring oxygen saturation for 24h in 8 lowlanders (4 females, ages 26 to 59) during trekking from Lukla (2850m) to the Pyramid Laboratory (5050m). Oxygen saturation was measured (1) daily at each altitude (sm), (2) for 24-h during ascent to 3500m, 4200m, and on day 1 at 5050m (lm), and (3) during a standardized exercise (em). Results: (1) the sm and lm values were 90.9% (±0.5) and 86.4% (±1.1) at 3500m; 85.2%(±1.1), and 80% (±1.9) at 4200m; 83.8%(±1) and 77% (±1.7) at 5050m (p<0.05); (2) the daily time spent with oxygen saturation <90% was 56.5% at 3500m, 81% at 4200m, and 95.5% at 5050m; (3) during exercise, oxygen saturation decreased by 10.58%, 13.43%, and 11.24% at 3500, 4200, and 5050?m, respectively. In conclusion, our data show that the level of hypoxemia during trekking at altitude is more severe than expected on the basis of a short evaluation at rest and should be taken into account.