***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: OBJECTIVE To determine if adding frailty measures to the EuroSCORE II improves model performance in predicting postoperative delirium . METHODS In a prospect i ve observational study in elective cardiac surgery patients , frailty was defined using the Modified Fried Criteria ( MFC ) , the Short Physical Performance Battery ( SPPB ) and a 35-item Frailty Index ( FI ) . The primary outcome was postoperative delirium , assessed using the Confusion Assessment Method ( CAM ) . RESULTS Seventy-two ( 54.1 % ) of the 133 participants met the MFC definition for frailty and 69 ( 51.9 % ) met the SPPB definition . Eighty-eight ( 66.2 % ) participants had an FI score ≥ 0.2 , and 47 ( 35.3 % ) had a score ≥ 0.3 . After adjusting for the EuroSCORE II , frail patients as identified by the MFC were at increased risk of postoperative delirium ( adjusted odds ratio [ OR ] , 5.05 , 95 % confidence interval [ CI ] , 1.58 - 16.13 ) . Patients in the " high risk frailty " SPPB category had even greater risk ( adjusted OR , 8.26 , 95 % CI , 2.23 - 30.64 ) . FI scores ≥ 0.3 were also associated with higher risk of delirium ( adjusted OR , 3.72 , 95 % CI , 1.39 - 9.92 ) . The inclusion of any of these definitions of frailty improved the discrimination of the EuroSCORE II in predicting postoperative delirium . CONCLUSIONS Frailty results in a 3- to 8-fold increase in risk of postoperative delirium , independent of the EuroSCORE II . " Frail " and " fit " may be considered 2 ends of a continuum , and the risk of postoperative delirium grows as one becomes increasingly frail . The addition of frailty improves the ability of the EuroSCORE II to predict postoperative delirium , pointing to opportunities for improved prevention and management Background : The aim of this r and omized , parallel-arm trial was to study the effect of treating subsyndromal delirium with risperidone on the incidence of clinical delirium in elderly patients who underwent on-pump cardiac surgery . Methods : One hundred one patients aged 65 yr or older who experienced subsyndromal delirium after on-pump cardiac surgery were r and omized using a computer-generated list to receive 0.5 mg risperidone ( n = 51 ) or placebo ( n = 50 ) every 12 h by mouth . Patients were assessed at 8 h by a blinded observer using the Intensive Care Delirium Screening Checklist , and those scoring more than 3 were evaluated by a blinded psychiatrist to confirm delirium . Patients in either group who experienced delirium were treated according to the same algorithm . Initially , risperidone was administered and if symptoms were not controlled , haloperidol was administered . The primary outcome was the proportion of patients who experienced delirium in either group . Results : Seven ( 13.7 % ) patients in the risperidone group experienced delirium versus 17 ( 34 % ) in the placebo group ( P = 0.031 ) Competing-risks regression analysis showed that failure to treat subsyndromal delirium with risperidone was an independent risk factor for delirium ( subhazard ratio , 3.83 ; 95 % CI , 1.63–8.98 ; P = 0.002 ) . Two ( 3.9 % ) patients in the risperidone group experienced extrapyramidal manifestations versus one ( 2 % ) in the placebo group ( P = 1.0 ) . Conclusion : Administration of risperidone to elderly patients who experienced subsyndromal delirium after on-pump cardiac surgery was associated with significantly lower incidence of delirium . Larger studies are required to determine whether early administration of risperidone during the subsyndromal phase of delirium would influence the clinical course of such patients Delirium is an acute change in cognition which occurs frequently after coronary artery bypass graft ( CABG ) surgery . Cerebral microemboli , from plaque , air , or thrombus , have been hypothesized to contribute to delirium and cognitive decline after CABG . The purpose of this study was to determine if there was an association between cerebral microemboli and delirium after cardiac surgery . Non-delirious patients ( n=68 ) were prospect ively enrolled and underwent intraoperative monitoring of the middle cerebral arteries with transcranial Doppler ( TCD ) . TCD signals were saved and analyzed postoperatively for microemboli manually , according to established criteria . Postoperatively , patients were assessed for delirium with a st and ardized battery . Thirty-three patients ( 48.5 % ) developed delirium after surgery . Microemboli counts ( mean ± SD ) were not significantly different in those with and without delirium ( 303 ± 449 vs. 299 ± 350 ; p=0.97 ) . While intraoperative microemboli were not associated with delirium after CABG , further investigation into the source and composition of microemboli can further eluci date the long-term clinical impact of microemboli OBJECTIVE To develop and vali date a new st and ardized confusion assessment method ( CAM ) that enables nonpsychiatric clinicians to detect delirium quickly in high-risk setting s. DESIGN Prospect i ve validation study . SETTING Conducted in general medicine wards and in an outpatient geriatric assessment center at Yale University ( site 1 ) and in general medicine wards at the University of Chicago ( site 2 ) . PATIENTS The study included 56 subjects , ranging in age from 65 to 98 years . At site 1 , 10 patients with and 20 without delirium participated ; at site 2 , 16 patients with and 10 without delirium participated . MEASUREMENTS AND MAIN RESULTS An expert panel developed the CAM through a consensus building process . The CAM instrument , which can be completed in less than 5 minutes , consists of nine operationalized criteria from the Diagnostic and Statistical Manual of Mental Disorders ( DSM-III-R ) . An a priori hypothesis was established for the diagnostic value of four criteria : acute onset and fluctuating course , inattention , disorganized thinking , and altered level of consciousness . The CAM algorithm for diagnosis of delirium required the presence of both the first and the second criteria and of either the third or the fourth criterion . At both sites , the diagnoses made by the CAM were concurrently vali date d against the diagnoses made by psychiatrists . At sites 1 and 2 values for sensitivity were 100 % and 94 % , respectively ; values for specificity were 95 % and 90 % ; values for positive predictive accuracy were 91 % and 94 % ; and values for negative predictive accuracy were 100 % and 90 % . The CAM algorithm had the highest predictive accuracy for all possible combinations of the nine features of delirium . The CAM was shown to have convergent agreement with four other mental status tests , including the Mini-Mental State Examination . The interobserver reliability of the CAM was high ( kappa = 0.81 - 1.0 ) . CONCLUSIONS The CAM is sensitive , specific , reliable , and easy to use for identification of delirium Introduction Postoperative delirium is an important problem in patients undergoing major surgery .  Cerebral oximetry is a non-invasive method to detect imbalances in the cerebral oxygen supply/dem and -ratio . Low preoperative cerebral oxygen saturation ( ScO2 ) levels have been associated with postoperative delirium in non-cardiac surgery patients . The present prospect i ve observational study determines the relationship between pre- and intra-operative ScO2 levels and postoperative delirium in patients undergoing on-pump cardiac surgery . Methods After approval of the local ethical committee and written informed consent , N = 231 patients scheduled for elective/urgent cardiac surgery were enrolled .  Delirium was assessed by the confusion- assessment - method for the intensive care unit ( CAM-ICU ) on the first three days after surgery .  ScO2 was obtained on the day before surgery , immediately before surgery and throughout the surgical procedure . Preoperative cognitive function , demographic , surgery related , and intra- and post-operative physiological data were registered . Results Patients with delirium had lower pre- and intra-operative ScO2 readings , were older , had lower mini-mental-status-examination(MMSE ) scores , higher additive EuroScore and lower preoperative haemoglobin-levels . The binary logistic regression identified older age , lower MMSE , neurological or psychiatric disease and lower preoperative ScO2 as independent predictors of postoperative delirium . Conclusions The presented study shows that a low preoperative ScO2 is associated with postoperative delirium after on-pump cardiac surgery OBJECTIVES Delirium is a common complication in elderly patients after cardiac surgery and is associated with adverse outcomes including prolonged hospital stay and increased mortality . Therefore , prevention or early detection of delirium is indicated . Our objective was to identify preoperative and operative characteristics that could predict delirium after cardiac surgery in elderly patients . METHODS We conducted a prospect i ve cohort study in which we analysed 201 patients of 70 years and older who underwent cardiac surgery , for developing a delirium . Patients were assessed daily using the Confusion Assessment Method -Intensive Care Unit . RESULTS Sixty-three patients ( 31 % ) developed a delirium after cardiac surgery . The Mini-Mental State Examination ( MMSE ) score prior to surgery was lower in the delirious patients when compared with the non-delirious patients ( 27 vs. 28 , P = 0.026 ) , creatinine level was higher ( 98 vs. 88 μmol/l , P = 0.003 ) and extracorporeal circulation ( ECC ) time was longer ( 145 vs. 113 min , P < 0.001 ) . Mortality during the first 30 days after surgery in patients with delirium was significantly higher than that in the non-delirious patients ( 14 vs. 0 % , P < 0.001 ) . CONCLUSIONS Low MMSE score and high creatinine level prior to surgery as well as increased ECC time are important independent predictors of delirium . In addition , delirium is an important predictor of 30-day mortality . Patients with a substantial risk for delirium should be c and i date s for interventions to reduce postoperative delirium and to potentially improve overall surgical outcomes OBJECTIVES To determine the extent to which preoperative performance on tests of executive function and memory was associated with delirium after coronary artery bypass graft ( CABG ) surgery .  DESIGN Prospect i ve observational cohort study . SETTING Two academic medical centers and one Department of Veterans Affairs medical center in Massachusetts . PARTICIPANTS Eighty subjects without preoperative delirium undergoing CABG or CABG-valve surgery  completed baseline neuropsychological assessment s with vali date d measures of memory and executive function . MEASUREMENTS Beginning on postoperative Day 2 , a battery to diagnose delirium was administered daily . Confirmatory factor analysis ( CFA ) was used to define two cognitive domain composites ( memory and executive function ) . The loading pattern of neuropsychological measures onto the latent cognitive domains was determined a priori . Poisson regression was used to model the association between neuropsychological performance and cognitive domain composite scores and risk of postoperative delirium . The association was expressed as the difference between impaired ( 0.5 st and ard deviations ( SDs ) below mean ) and nonimpaired ( 0.5 SDs above mean ) performers . RESULTS Forty subjects ( 50 % ) developed delirium . Measures of memory function were not significantly related to delirium . Of the executive function measures , verbal fluency , category fluency , Hopkins Verbal Learning Test learning , and backward recounting of days and months were significantly related to delirium . Preoperative mental status was a strong predictor of postoperative delirium . After controlling for age , sex , education , medical comorbidity , mental status , and the other cognitive domain , CFA cognitive domain composites suggest that risk for delirium is specific for executive functioning impairment ( relative risk ( RR ) = 2.77 , 95 % confidence interval ( CI ) = 1.12 - 6.87 ) but not for memory impairment ( RR = 0.49 , 95 % CI = 0.19 - 1.25 ) . CONCLUSION Worse preoperative performance in executive function was independently associated with greater risk of developing delirium after CABG Introduction Delirium is a frequent complication after cardiac surgery . Although various risk factors for postoperative delirium have been identified , the relationship between nocturnal breathing disorders and delirium has not yet been eluci date d. This study evaluated the relationship between sleep-disordered breathing ( SDB ) and postoperative delirium in cardiac surgery patients without a previous diagnosis of obstructive sleep apnea . Methods In this prospect i ve cohort study , 92 patients undergoing elective cardiac surgery with extracorporeal circulation  were evaluated for both SDB and postoperative delirium . Polygraphic recordings were used to calculate the  apnea-hypopnea index ( AHI ; mean number of apneas and hypopneas per hour recorded ) of all patients preoperatively . Delirium was assessed during the first four postoperative days using the Confusion Assessment Method . Clinical differences between individuals with and without postoperative delirium were determined 
    Output:
    
A strong level of evidence for an association with the occurrence of postoperative delirium was found for age , previous psychiatric conditions , cerebrovascular disease , pre-existent cognitive impairment , type of surgery , peri-operative blood product transfusion , administration of risperidone , postoperative atrial fibrillation and mechanical ventilation time .
Postoperative oxygen saturation and renal insufficiency were supported by a moderate level of evidence , and there is no evidence that gender , education , CPB duration , pre-existent cardiac disease or heart failure are risk factors .