Neuropsychologic findings in hypoxemic chronic obstructive pulmonary disease

Abstract

As part of a 6-center clinical trial of the effectiveness of continuous vs. nocturnal O2 in the management of hypoxemic chronic obstructive pulmonary disease (COPD), detailed neuropsychologic assessments of these patients prior to their beginning treatment were performed. The 203 patients (age, 65 yr; PaO2 [arterial partial pressure of O2], 51 mm Hg; forced expiratory volume in 1 s, 0.74 l) performed significantly worse than controls on virtually all neuropsychologic tests. Moderate to severe test impairment suggestive of cerebral dysfunction was found in 42% of the patients, as compared with 14% of controls. Higher cognitive functions (abstracting ability, complex perceptual-motor integration) were most severely affected, although half of the patients showed decrements in motor speed, strength and coordination. Low-order significantly inverse correlations were found between neuropsychologic impairment and PaO2, resting arterial O2 saturation and Hb levels and maximum work. Cerebral disturbance is common in hypoxemic COPD and may be related in part to decreased availability of O2 to the brain.