Effect of gradually increasing carboxyhaemoglobin saturation on visual perception and psychomotor performance of smoking and nonsmoking subjects
Seppänen, A.; Häkkinen, V.; Tenkku, M.
Annals of Clinical Research 9(5): 314-319
1977
ISSN/ISBN: 0003-4762 PMID: 616218 Document Number: 112740
The effect of gradually increasing Hb CO saturation on human visuoperceptual and psychomotor performance was studied in 22 nonsmokers and 22 smokers. Each subject performed 2 sessions in randomized order, 1 during air breathing and the other during CO breathing on 2 separate days. Testing and Hb CO saturation measurement were repeated 6 times during each session. Gas breathing was between the test periods. The increase of Hb CO saturation up to 12-13% units had no effect (P > 0.05) on perceptual speed and accuracy as measured by the Bourdon-Wiersma test. Finger tapping speed was also unaffected. Visual perception measured with critical flicker frequency (CFF) was sensitive to CO. The gradual increase in Hb CO saturation caused a linear decrease in CFF in the both groups. An increase of 1% unit in Hb CO saturation caused significant decrease in CFF (P < 0.001), when intraindividual changes were taken into account. During acute exposure to CO there was no difference in any test performance between the groups. During air breathing there was no difference in performance although there was a significant difference (P < 0.001) in the Hb CO saturation levels. This negative finding might be due to adaptation of smokers to chronic exposure of CO because of smoking.