Described is a 67-year-old man whose initial symptoms evoked an obesity-hypoventilation syndrome. Polysomnography showed hypopneas associated with O2 desaturation episodes, and no apnea; maximal changes were noted during REM sleep. A few months later, in spite of marked weight loss, acute alveolar hypoventilation occurred and necessitated mechanical ventilatory support. Tracheostomy was perform...

Oxygen (O2) desaturation may occur in patients affected by respiratory diseases during daily activities, although most of these activities, e.g. walking, washing and cooking, can be avoided or eventually performed with an external aid. In this prospective study, the respiratory changes induced by the mandatory effort of defecation were assessed in patients with chronic respiratory insufficiency...

In a group of 37 heavy snorers with obstructive sleep apnoea (OSA, Group 1) and a group of 23 heavy snorers without OSA (Group 2) cephalometric indices, ENT indices related to upper airway collapsibility, and nocturnal O2 desaturation indices were related to variables from maximal expiratory and inspiratory flow-volume (MEFV and MIFV) curves. The cephalometric indices used were the length and d...

The effect of transtracheal oxygen administration by means of a 9-French (2.7 mm) percutaneous catheter was assessed in five patients with severe obstructive sleep apnea. We hypothesized that the delivery of oxygen below the site of airway obstruction should reduce the arterial oxygen desaturation during apneas and hypopneas, thereby increasing respiratory stability. Standard sleep and respirat...

Nielsen, H. B., R. Boushel, P. Madsen, and N. H. Secher. Cerebral desaturation during exercise reversed by O2 supplementation. Am. J. Physiol. 277 (Heart Circ. Physiol. 46): H1045–H1052, 1999.—The combined effects of hyperventilation and arterial desaturation on cerebral oxygenation (ScO2) were determined using near-infrared spectroscopy. Eleven competitive oarsmen were evaluated during a 6-min...

It has been hypothesized but not firmly established that sleep-related hypoxaemia could favour the development of pulmonary hypertension in chronic obstructive pulmonary disease (COPD) patients without marked daytime hypoxaemia. We have investigated the relationships between pulmonary function data, sleep-related desaturation and daytime pulmonary haemodynamics in a group of 94 COPD patients no...

The combined effects of hyperventilation and arterial desaturation on cerebral oxygenation ([Formula: see text]) were determined using near-infrared spectroscopy. Eleven competitive oarsmen were evaluated during a 6-min maximal ergometer row. The study was randomized in a double-blind fashion with an inspired O2 fraction of 0.21 or 0.30 in a crossover design. During exercise with an inspired O2...

This study was attempted to observe the rate of oxygen desaturation after full oxygenation in six parturients scheduled for Cesarean sections and six patients scheduled for transabdominal hysterectomies. We calculated the mean rate of fall of arterial saturation (slope of desaturation: less than SaO2 (t2)-SaO2(t1) greater than/t2-t1) and changes in arterial blood gases were observed. All subjec...