Ear oximetry studies during sleep in patients with severe chronic obstructive pulmonary disease in a stable state

Changes in ear oxygen saturation (SaO2) during the night were measured in 12 elderly patients (mean age = 63.4 +/- 6.7 years) with stable severe chronic obstructive pulmonary disease. The mean FEV1 was 0.84 L (range = 0.45 to 1.30 L) and the mean SaO2 daytime value was 94.4% (range = 93% to 96%). The mean maximal decrease in SaO2 from daytime to sleep was 2.3% (range = 0% to 4%). There was no correlation between the decrease in SaO2 during sleep and the degree of airways obstruction, or the daytime SaO2. In contrast to published data, our 12 patients did not have a significantly lower mean minimum SaO2 than those without chronic obstructive pulmonary disease.