***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: BACKGROUND patients with dementia are almost invariably unable to use any form of inhaler . Some elderly patients are unable to learn to use a metered dose inhaler or Turbohaler despite a normal abbreviated mental test score . Studies have shown that in many people this is due to unrecognised cognitive impairment and /or dyspraxia . The executive domains of cognition are particularly important in planning and sequencing ; it might be expected therefore that disordered frontal ( executive ) function could be a predictor of poor inhaler technique in subjects with no overt features of dementia . OBJECTIVE to explore the relationship between cognitive , and executive , function and the ability to acquire metered dose inhaler and Turbohaler technique in old age . DESIGN a prospect i ve r and omised observational study with blinded evaluation . SUBJECTS 30 inhaler-naive in patients ( 21 female ) with a mean age of 85 ( range 75 - 94 ) and having a normal ( 8 - 10 ) abbreviated mental test score . METHODS subjects received st and ardised metered dose inhaler and Turbohaler training and were scored on an analogue scale ( for metered dose inhaler ) or for competence ( Turbohaler ) the following day . The Mini-Mental State Examination and EXIT25 ( for executive function ) were performed by separate observers . RESULTS significant correlation was found between the metered dose inhaler score and Mini-Mental State Examination ( r 0.540 , P<0.002 ) and EXIT25 ( r -0.702 , P<0.0001 ) . Threshold effects emerged for the metered dose inhaler in that 18/19 with a competent score compared to 2/11 scored as incompetent had a Mini-Mental State Examination of > 23 ( P<0.01 ) and 19/19 compared to 0/11 had an EXIT25 of < 15 ( P<0.01 ) . Similarly , for the Turbohaler 21/21 of the competent subjects had a Mini-Mental State Examination of > 23 compared with 3/9 incompetent subjects ( P<0.01 ) , with 21/21 competent compared with 0/9 incompetent having an EXIT25 < 15 ( P<0.01 ) . CONCLUSION acquisition and short-term retention of metered dose inhaler and Turbohaler techniques is unlikely to be successful in frail elderly people who have an abnormal Mini-Mental State Examination and /or EXIT25 test . The latter test , when abnormal , is probably the superior predictor of inability to learn inhaler techniques Background — It has been suggested that the risk of cerebral dysfunction is less with off-pump coronary artery bypass grafting ( OPCAB ) than with conventional coronary artery bypass grafting ( CCAB ) . However , evidence for this statement is preliminary , and additional insight is needed . Methods and Results — The study was a sub study of the r and omized Best Bypass Surgery trial that compared OPCAB with CCAB treatment with respect to intraoperative and postoperative mortality and morbidity in patients with a moderate to high level of predicted preoperative risk . The outcome was cognitive function .  A total of 120 elderly patients ( mean age 76 years , SD 4.5 years ) underwent  psychometric testing  before surgery and at a mean of 103 ( SD 15 ) days postoperatively with a  neuropsychological test battery that included 7 parameters from 4 tests .  Cognitive dysfunction was defined as the occurrence of at least 2 of the 7 possible deficits . Secondary analysis was performed on the basis of the definition of a 20 % decline in cognitive scores compared with baseline , and with z score analysis . Cognitive dysfunction was identified in 4 of the 54 patients ( 7.4 % , 95 % confidence interval [ CI ] 2.1 % to 17.9 % ) in the OPCAB group and 5 of the 51 patients ( 9.8 % , 95 % CI 3.3 % to 21.4 % ) in the CCAB group . We found no difference in incidence of cognitive dysfunction between the groups regardless of the definition applied . Conclusions — In elderly high-risk patients , no significant difference was found in the incidence of cognitive dysfunction 3 months after either OPCAB or CCAB Objectives To clarify cerebral perfusion distribution and cognitive functions in patients with chronic obstructive pulmonary disease ( COPD ) according to the hypoxia levels and to assess if there is a relationship between cognitive impairment and cerebral perfusion index . Patients and Methods Eight patients with stable hypoxemic COPD ( HC ) , 10 patients with stable nonhypoxemic COPD ( NHC ) , and 10 age-matched healthy volunteers participated in the study . All subjects underwent a complete neuropsychological assessment with the mental deterioration battery ( MDB ) , Wechsler memory scale-revised ( WMS-R ) , color trail test ( CCT ) , and grooved pegboard test ( GPT ) . SPECT examination with Tc-99 m HMPAO was performed in all patients and controls . Quantitative analysis was performed by a region of interest (ROI)-based method . Results The scores of verbal memory , delayed recall and attention were significantly lower in COPD patients ( p < 0.01 ) . The scores of other subtests were similar in patients and controls . Comparing NHC patients to HC groups showed that verbal memory was impaired in both groups , but delayed recall and attention scores were significantly worse in HC patients than NHC patients . Perfusion indexes on frontal ROIs in NHC patients and frontal and parietal ROIs in HC patients showed significant decreases . Our scintigraphic findings were correlated with the results of neuropsychological tests . Conclusions Our results demonstrate that cerebral perfusion is significantly altered in COPD patients . Hypoxemic patients showed more deterioration in cerebral perfusion and cognitive performance than nonhypoxemic patients . The relationship between decreased perfusion and cognitive impairment and the clinical significance of these results require further studies in larger population Cognitive dysfunction is common and clinical ly important in severe chronic obstructive pulmonary disease ( COPD ) . We investigated the diagnostic accuracy of the  Mini Mental State Examination ( MMSE ) and Instrumental Activities of Daily Living ( IADL ) scale in screening severe cognitive  dysfunction in 149 patients with COPD , mean age 69.3 ± 8.5 years , forced expiratory volume in 1 s = 36.6 ± 17.8 % of the predicted . Patients underwent the MMSE and an in-depth neuropsychological assessment based upon the Mental Deterioration Battery ( MDB ) . The 5-item IADL scale was assessed . The sample was r and omly divided into a training ( n = 73 ) and a testing ( n = 76 ) population . The diagnostic accuracy of MMSE , IADL scale or both versus cognitive dysfunction corresponding to abnormal performance in 3 or more MDB tests was assessed in the training population and the model obtained was tested in the testing population . The combination of MMSE < 24 and dependence in at least 1 IADL had better diagnostic accuracy than either MMSE or IADL , with sensitivity = 52.4 , specificity = 82.7 , positive predictive value = 55.0 % and negative predictive value = 81.1 % in the testing population . MMSE and the 5-item IADL scale can be used to exclude , but not to detect cognitive dysfunction in COPD patients . A confirmatory cognitive test should be administered to patients with an MMSE score of < 24 and who are dependent in at least 1 IADL BACKGROUND  Cognitive impairment  frequently occurs in elderly COPD patients , but little is known about its prognostic implication s. We aim ed at evaluating the prognostic role of cognitive impairment in patients with severe COPD . METHODS Our series consisted of 149 stable patients ( mean [ + /- SD ] age , 68.7 + /- 8.5 years ) with COPD and a Pao(2 ) of < 57 mm Hg at rest ( n = 97 ) or at the end of the 6-min walking test ( n = 37 ) who were enrolled in a prospect i ve observational study . After a multidimensional baseline assessment , patients were followed up by telephone calls for a mean duration of 32.5 + /- 9.2 months ( minimal follow-up duration , 24 months ) ; 134 patients were successfully tracked . We used multivariable Cox proportional hazard analysis to identify predictors of death among clinical /functional variables that previously were shown to have prognostic implication s and among neuropsychological indexes selected on the basis of univariate analysis . RESULTS We observed 29 deaths over a median follow-up time of 32 months . Only the two following variables were independently associated with the outcome : an abnormal score on the copy with l and mark test ( hazard ratio [ HR ] , 2.93 ; 95 % confidence interval [ CI ] , 1.34 to 6.39 ) ; and a 6-min walk distance of < 300 m ( HR , 3.46 ; 95 % CI , 1.15 to 10.5 ) . A Pao(2 ) of < 57 mm Hg at rest ( HR , 2.19 ; 95 % CI , 0.93 to 5.18 ) and an FEV(1 ) of < 40 % predicted ( HR , 2.74 ; 95 % CI , 0.99 to 7.57 ) were nearly significantly associated with the outcome , while Paco(2 ) , body mass index , physical dependence , comorbid diseases , and the impairment of cognitive domains other than drawing impairment were unrelated to the outcome . CONCLUSIONS Drawing impairment is a risk factor for mortality and might improve the assessment of hypoxemic COPD patients BACKGROUND Hypoxemic patients with Chronic Obstructive Pulmonary Disease ( COPD ) have impaired cognitive performance . These neuropsychological impairments are related to the degree of hypoxemia . So far , cognitive performance has not been tested in non-hypoxemic patients with COPD . METHODS We recruited patients with stable COPD and PaO2 > 8.0 kPa ( 60 mmHg ) , as well as healthy subjects , who were matched for age , intelligence quotient ( IQ ) , and level of education .  Cognitive performance was studied by  Stroop Colour Word Test , Trailmaking , digit-symbol of the Wechsler Adult Intelligence Scale , addition subtest of the Groningen Intelligence Test , and Story Recall .  RESULTS Thirty patients with COPD ( FEV1 49.8 % pred , mean age 64.8 yr ) and 20 healthy volunteers ( 65.6 yr ) were enrolled . COPD patients performed significantly worse on trailmaking B , the digit-symbol test , and on the addition subtest . There was no significant correlation between the tests of cognitive performance and disease specific health status ( Chronic Respiratory Question naire ) . CONCLUSIONS We conclude that even non-hypoxemic patients with COPD show significant impairments in cognitive performance . These impairments are not associated with deteriorations in health related quality of life . Prospect i ve evaluation of the impact of treatment on cognitive performance in non-hypoxemic patients with COPD would be a logical subsequent study Eighteen patients with chronic obstructive pulmonary disease ( COPD ) were administered a series of pulmonary , neurological , and neuropsychological measures to test if there was an effect of COPD on neurological and cognitive functioning . Overall , there was no evidence of general dementia in this sample . Measures of immediate and delayed memory , complex attention , and speed of information processing correlated highly with arterial carbon dioxide partial pressure and , to a lesser extent , with oxygen partial pressure . Measures of language abilities , perceptual-motor functioning , and simple attention generally were not related to arterial gas pressures . A similar pattern of findings was obtained when group differences were examined between participants classified as severely hypoxic or mildly hypoxic , although group differences were mitigated by premorbid IQ differences . Hypoxia in COPD results in a relatively focused pattern of impairment in measures of memory function and tasks requiring attention allocation . The memory dysfunction may be related to involvement of limbic memory regions necessary for explicit memory . The attentional deficits were attributed to diffuse brain involvement result ing in reduced re source allocation . Early diagnosis and treatment of the hypoxia is essential 
    Output:
    
Cognitive function was impaired in COPD patients as compared to healthy controls , but the level of functioning was better than in patients with Alzheimer 's disease .
There was a significant association between severity of COPD , as measured by lung function and blood gases , and cognitive dysfunction , but only in patients with severe COPD .
Cognitive impairment can be detected in severe COPD patients , but the clinical relevance of the cognitive dysfunction is not yet known .