One of the objectives of a study by Mulloy and McNicholas (A-26) was to compare ventilation and gas exchange during sleep and exercise in chronic obstructive pulmonary disease (COPD). The investigators wished also to determine whether exercise studies could aid in the prediction of nocturnal desaturation in COPD. Subjects (13 male, 6 female) were ambulatory patients attending an outpatient respiratory clinic. The mean age of the patients, all of whom had severe, stable COPD, was 64.8 years with a standard deviation of 5.2. Among the data collected were measurements on the following variables:

Age

(years) BMI PaO2

(mm Hg)

PaCO2

(mm Hg)

FEV1

(% Predicted)

Lowest Ex.

Sao2 a

Mean Sleep Sao2 a

Lowest Sleep Sao2 a

Fall Sleep Sao2 a

67 23.46 52.5 54 22 74 70.6 56 29.6 62 25.31 57.75 49.575 19 82 85.49 76 11.66 68 23.11 72 43.8 41 95 88.72 82 11.1 61 25.15 72 47.4 38 88 91.11 76 18.45 70 24.54 78 40.05 40 88 92.86 92 0.8 71 25.47 63.75 45.375 31 85 88.95 80 13 60 19.49 80.25 42.15 28 91 94.78 90 4 57 21.37 84.75 40.2 20 91 93.72 89 5.8 69 25.78 68.25 43.8 32 85 90.91 79 13 57 22.13 83.25 43.725 20 88 94.39 86 9.5 74 26.74 57.75 51 33 75 89.89 80 14.11 63 19.07 78 44.175 36 81 93.95 82 13 64 19.61 90.75 40.35 27 90 95.07 92 4 73 30.30 69.75 38.85 53 87 90 76 18