Background. Cognitive deterioration may impair COPD patient’s ability to perform tasks like driving vehicles. We investigated: (a) whether subclinical neuropsychological deficits occur in stable COPD patients with mild hypoxemia (PaO2 > 55？mmHg), and (b) whether these deficits affect their driving performance. Methods. We recruited 35 stable COPD patients and 10 normal subjects matched for age, IQ, and level of education. All subjects underwent an attention/alertness battery of tests for assessing driving performance based on the Vienna Test System. Pulmonary function tests, arterial blood gases, and dyspnea severity were also recorded. Results. COPD patients performed significantly worse than normal subjects on tests suitable for evaluating driving ability. Therefore, many (22/35) COPD patients were classified as having inadequate driving ability (failure at least in one of the tests), whereas most (8/10) healthy individuals were classified as safe drivers ( ). PaO2 and FEV1 were correlated with almost all neuropsychological tests. Conclusions. COPD patients should be warned of the potential danger and risk they face when they drive any kind of vehicle, even when they do not exhibit overt symptoms related to driving inability. This is due to the fact that stable COPD patients may manifest impaired information processing operations. 1. Introduction It is increasingly recognized that chronic obstructive pulmonary disease (COPD) is a multicomponent disease, but relatively little attention has been paid to its impact on neuropsychological function. Several studies have identified neuropsychological deficits in COPD patients [1–3]. The extent of this dysfunction appears to be related to the level of hypoxemia [4–8]. Subclinical cognitive deficits can even be detected in COPD patients with mild hypoxemia ( ？mm？Hg) [9, 10]. Neuropsychological tests aim to provide standardized and objective measurements is the function of specific cognitive domains. The tasks, performed as part of the neuropsychological testing, often closely resemble mental challenges encountered in everyday life. One of the commonest mental challenges in everyday life is driving performance. The latter is a complex task highly dependent on the cognitive function, involving perceptual, motor, and decision making skills. Therefore, our hypothesis was that driving ability may be impaired even in stable COPD patients with mild hypoxemia. Road testing per se is the gold standard for assessing driving ability [11], but it is time consuming, expensive, and potentially hazardous. Simulators, which
References
[1]
R. A. Incalzi, A. Gemma, C. Marra, R. Muzzolon, O. Capparella, and P. Carbonin, “Chronic obstructive pulmonary disease: an original model of cognitive decline,” American Review of Respiratory Disease, vol. 148, no. 2, pp. 418–424, 1993.
[2]
M. Klein, S. Gauggel, G. Sachs, and W. Pohl, “Impact of chronic obstructive pulmonary disease (COPD) on attention functions,” Respiratory Medicine, vol. 104, no. 1, pp. 52–60, 2010.
[3]
W. W. Hung, J. P. Wisnivesky, A. L. Siu, and J. S. Ross, “Cognitive decline among patients with chronic obstructive pulmonary disease,” American Journal of Respiratory and Critical Care Medicine, vol. 180, no. 2, pp. 134–137, 2009.
[4]
A. J. Fix, C. J. Golden, and D. Daughton, “Neuropsychological deficits among patients with chronic obstructivepulmonary disease,” International Journal of Neuroscience, vol. 16, no. 2, pp. 99–105, 1982.
[5]
I. Grant, R. K. Heaton, and A. J. McSweeney, “Neuropsychologic findings in hypoxemic chronic obstructive pulmonary disease,” Archives of Internal Medicine, vol. 142, no. 8, pp. 1470–1476, 1982.
[6]
I. Grant, G. P. Prigatano, R. K. Heaton, A. J. McSweeny, E. C. Wright, and K. M. Adams, “Progressive neuropsychologic impairment and hypoxemia. Relationship in chronic obstructive pulmonary disease,” Archives of General Psychiatry, vol. 44, no. 11, pp. 999–1006, 1987.
[7]
H. D. Krop, A. J. Block, and E. Cohen, “Neuropsychologic effects of continuous oxygen therapy in chronic obstructive pulmonary disease,” Chest, vol. 64, no. 3, pp. 317–322, 1973.
[8]
R. K. Heaton, I. Grant, and A. J. McSweeny, “Psychologic effects of continuous and nocturnal oxygen therapy in hypoxemic chronic obstructive pulmonary disease,” Archives of Internal Medicine, vol. 143, no. 10, pp. 1941–1947, 1983.
[9]
G. P. Prigatano and A. et, “Neuropsychological test performance in mildly hypoxemic patients with chronic obstructive pulmonary disease,” Journal of Consulting and Clinical Psychology, vol. 51, no. 1, pp. 108–116, 1983.
[10]
J. J. W. Liesker, D. S. Postma, R. J. Beukema et al., “Cognitive performance in patients with COPD,” Respiratory Medicine, vol. 98, no. 4, pp. 351–356, 2004.
[11]
S. Mazza, J.-L. Pepin, B. Naegele et al., “Driving ability in sleep apnoea patients before and after CPAP treatment: evaluation on a road safety platform,” European Respiratory Journal, vol. 28, no. 5, pp. 1020–1028, 2006.
[12]
M. Juniper, M. A. Hack, C. F. George, R. J. O. Davies, and J. R. Stradling, “Steering simulation performance in patients with obstructive sleep apnoea and matched control subjects,” European Respiratory Journal, vol. 15, no. 3, pp. 590–595, 2000.
[13]
M. Orth, H.-W. Duchna, M. Leidag, et al., “Driving simulator and neuropsychological testing in OSAS before and under CPAP therapy,” European Respiratory Journal, vol. 26, no. 5, pp. 898–903, 2005.
[14]
Gold Report, Global Strategy for Diagnosis, Management, and Prevention of COPD, http;//www.goldcopd.org/, 2011.
[15]
J. C. Raven, J. H. Court, and J. Raven, Manual for Raven's Progressive Matrices, HK Lewis, London, UK, 1976.
[16]
“Directive 2007/59/EC of the European Parliament and the council on the certification of train drivers operating locomotives and trains on the railway system in the Community,” Official Journal of the European Union, vol. L 315, pp. 51–78, 2007.
[17]
M. R. Miller, J. Hankinson, V. Brusasco, et al., “Series “ATS/ERS TASK FORCE: standardisation of lung function testing” standardisation of spirometry,” European Respiratory Journal, vol. 26, no. 2, pp. 319–338, 2005.
[18]
J. Wanger, J. L. Clausen, A. Coates, et al., “Series “ATS/ERS TASK FORCE: standardisation of lung function testing” Standardisation of the measurement of lung volumes,” European Respiratory Journal, vol. 26, no. 3, pp. 511–522, 2005.
[19]
N. Maclntyre, R. O. Crapo, G. Viegi, et al., “Series “ATS/ERS TASK FORCE: standardisation of lung function testing” Standardisation of the single-breath determination of carbon monoxide uptake in the lung,” European Respiratory Journal, vol. 26, no. 4, pp. 720–735, 2005.
[20]
Ph. H. Quanjer, Ed., “Standardized lung function testing. Report Working Party “Standardization of Lung Function Tests”, European Community for Coal and Steel,” European Respiratory Journal, vol. 6, supplement 16, pp. C1–C100, 1993.
[21]
J. C. Bestall, E. A. Paul, R. Garrod, R. Garnham, P. W. Jones, and J. A. Wedzicha, “Usefulness of the Medical Research Council (MRC) dyspnoea scale as a measure of disability in patients with chronic obstructive pulmonary disease,” Thorax, vol. 54, no. 7, pp. 581–586, 1999.
[22]
G. Schuhfried, Computer-Aided Procedures for Ability and Personality Diagnostics. Catalogue, Modling, Vienna, Austria, 2001.
[23]
M. Alchanatis, N. Zias, N. Deligiorgis, A. Amfilochiou, G. Dionellis, and D. Orphanidou, “Sleep apnea-related cognitive deficits and intelligence: an implication of cognitive reserve theory,” Journal of Sleep Research, vol. 14, no. 1, pp. 69–75, 2005.
[24]
K. M. J. Hynninen, M. H. Breitve, A. B. Wiborg, S. Pallesen, and I. H. Nordhus, “Psychological characteristics of patients with chronic obstructive pulmonary disease: a review,” Journal of Psychosomatic Research, vol. 59, no. 6, pp. 429–443, 2005.
[25]
A. R. Incalzi, F. Chiappini, L. Fuso, M. P. Torrice, A. Gemma, and R. Pistelli, “Predicting cognitive decline in patients with hypoxaemic COPD,” Respiratory Medicine, vol. 92, no. 3, pp. 527–533, 1998.
[26]
R. A. Incalzi, “Verbal memory impairment in COPD: its mechanisms and clinical relevance,” Chest, vol. 112, no. 6, pp. 1506–1513, 1997.
[27]
M. Orth, C. Diekmann, B. Suchan et al., “Driving performance in patients with chronic obstructive pulmonary disease,” Journal of Physiology and Pharmacology, vol. 59, no. 6, pp. 539–547, 2008.
[28]
P. M. A. Calverley, V. Brezinova, and N. J. Douglas, “The effect of oxygenation on sleep quality in chronic bronchitis and emphysema,” American Review of Respiratory Disease, vol. 126, no. 2, pp. 206–210, 1982.
[29]
W. Cormick, L. G. Olson, M. J. Hensley, and N. A. Saunders, “Nocturnal hypoxaemia and quality of sleep in patients with chronic obstructive lung disease,” Thorax, vol. 41, no. 11, pp. 846–854, 1986.
[30]
G. E. Gibson, W. Pulsinell, J. P. Blass, and T. E. Duffy, “Brain dysfunction in mild to moderate hypoxia,” American Journal of Medicine, vol. 70, no. 6, pp. 1247–1254, 1981.
