***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 
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    Input: Background : Peripheral nerve block is a preferable method for elderly patients receiving hip arthroplasty . Sedation with dexmedetomidine may reduce postoperative delirium ( POD ) . The aim of this study was to investigate whether intraoperative sedation with dexmedetomidine , as a supplementary to peripheral nerve block for elderly patients receiving total hip arthroplasty , can decrease the prevalence of POD . Methods : A prospect i ve , r and omized controlled study was conducted with patients 65 years of age or older who underwent total hip arthroplasty between June 2016 and June 2017 . The patients were r and omly assigned to receive a lumbosacral plexus plus T12 paravertebral block supplemented with propofol or dexmedetomidine for sedation . Incidence of POD was the primary endpoint and was determined with the confusion assessment method , and incidence of postoperative cognitive dysfunction ( POCD ) was assessed with the mini-mental state examination . The time of ambulation , discharge time , and complications over a 30-day postsurgery period were also recorded . Results : A total of 296 patients were r and omly assigned to 2 groups . The patients se date d with dexmedetomidine had lower incidences of POD and POCD and were out of bed and discharged sooner than the patients se date d with propofol . There was no difference in complications between the 2 groups . Conclusions : As a supplementary to peripheral nerve block , intraoperative sedation with dexmedetomidine could be associated with a lower incidence of POD , which may have benefits on reducing the incidence of early POCD and offering a better short-term recovery for elderly patients receiving hip arthroplasty Objective : To investigate the effect of dexmedetomidine adding to ropivacaine for continuous femoral nerve block on the improvement of postoperative sleep quality in elderly patients after total knee arthroplasty . Methods : One hundred and sixty patients aged 60 years or older in Jishuitan Hospital scheduled for single total knee arthroplasty between Nov. 2016 and Jun. 2017 were recruited . All patients received  spinal anesthesia and were r and omized to receive either combined ropivacaine and dexmedetomidine ( 0.2 % ropivacaine 250 ml and 5 μg/kg dexmedetomidine , at a rate of 5 ml/h or 0.1 μg·kg-1·h-1 dexmedetomidine , dexmedetomidine group ) or only ropivacaine ( 0.2 % ropivacaine , at a rate of 5 ml/h , controlled group ) for continuous femoral nerve block as postoperative analgesia after surgery . The severity of postoperative pain was assessed with numeric rating scale at 4 , 24 , and 48 hours after surgery both at rest and with movement . Subjective sleep quality and delirium were evaluated daily during the first 3 days postoperatively . Results : The subjective sleep quality scores were 2(1 - 4 ) , 2(1 - 4 ) and 4(2 - 8 ) , 4(2 - 7 ) in dexmedetomidine group and controlled group respectively on the 1st and 2nd days after surgery . The scores of dexmedetomidine group were much better than those of controlled group ( Z=-4.597 , -4.183 , both P<0.05 ) . The difference was statistically significant . The NRS pain scores at rest were 2(1 - 2 ) , 2(1 - 4 ) , and 3(2 - 5 ) , 3(2 - 6 ) in dexmedetomidine group and controlled group respectively at 24 and 48 hours after surgery . The scores of dexmedetomidine group were lower than those of controlled group ( Z=-6.671 , -4.010 , both P<0.05 ) . The difference was statistically significant . The NRS pain scores with movement were 1(1 - 2 ) , 3(2 - 4 ) , 3(2 - 3 ) and 3(2 - 4 ) , 5(3 - 6 ) , 5(4 - 7)in dexmedetomidine group and controlled group respectively at 4 , 24 and 48 hours after surgery . The scores of dexmedetomidine group were lower than those of controlled group ( Z=-7.167 , -6.824 , -7.473 , all P<0.05 ) . The difference was statistically significant . The incidence of 3-day delirium was lower in dexmedetomidine group ( 5 % ) than that in controlled group ( 15 % ) ( χ2=4.444 , P<0.05 ) . The difference was statistically significant . There were no significant differences between groups regarding the incidences of adverse events . Conclusion : Dexmedetomidine combined with ropivacaine for continuous femoral nerve block may improve subjective sleep quality , postoperative analgesia , and reduce delirium in the elderly after total knee arthroplasty BACKGROUND Delirium is a postoperative complication that occurs frequently in patients older than 65 years , and presages adverse outcomes . We investigated whether prophylactic low-dose dexmedetomidine , a highly selective α2 adrenoceptor agonist , could safely decrease the incidence of delirium in elderly patients after non-cardiac surgery . METHODS We did this r and omised , double-blind , placebo-controlled trial in two tertiary-care hospitals in Beijing , China . We enrolled patients aged 65 years or older , who were admitted to intensive care units after non-cardiac surgery , with informed consent . We used a computer-generated r and omisation sequence ( in a 1:1 ratio ) to r and omly assign patients to receive either intravenous dexmedetomidine ( 0·1 μg/kg per h , from intensive care unit admission on the day of surgery until 0800 h on postoperative day 1 ) , or placebo ( intravenous normal saline ) . Participants , care providers , and investigators were all masked to group assignment . The primary endpoint was the incidence of delirium , assessed twice daily with the Confusion Assessment Method for intensive care units during the first 7 postoperative days . Analyses were done by intention-to-treat and safety population s. This study is registered with Chinese Clinical Trial Registry , www.chictr.org.cn , number ChiCTR-TRC-10000802 . FINDINGS Between Aug 17 , 2011 , and Nov 20 , 2013 , of 2016 patients assessed , 700 were r and omly assigned to receive either placebo ( n=350 ) or dexmedetomidine ( n=350 ) . The incidence of postoperative delirium was significantly lower in the dexmedetomidine group ( 32 [ 9 % ] of 350 patients ) than in the placebo group ( 79 [ 23 % ] of 350 patients ; odds ratio [ OR ] 0·35 , 95 % CI 0·22 - 0·54 ; p<0·0001 ) . Regarding safety , the incidence of hypertension was higher with placebo ( 62 [ 18 % ] of 350 patients ) than with dexmedetomidine ( 34 [ 10 % ] of 350 patients ; 0·50 , 0·32 - 0·78 ; p=0·002 ) . Tachycardia was also higher in patients given placebo ( 48 [ 14 % ] of 350 patients ) than in patients given dexmedetomidine ( 23 [ 7 % ] of 350 patients ; 0·44 , 0·26 - 0·75 ; p=0·002 ) . Occurrence of hypotension and bradycardia did not differ between groups . INTERPRETATION For patients aged over 65 years who are admitted to the intensive care unit after non-cardiac surgery , prophylactic low-dose dexmedetomidine significantly decreases the occurrence of delirium during the first 7 days after surgery . The therapy is safe . FUNDING Braun Anaesthesia Scientific Research Fund and Wu Jieping Medical Foundation , Beijing , China . Study drugs were manufactured and supplied by Jiangsu Hengrui Medicine Co , Ltd , Jiangsu , China Background Delirium is a frequent complication after cardiac surgery and its occurrence is associated with poor outcomes . The purpose of this study was to investigate the impact of perioperative dexmedetomidine administration on the incidence of delirium in elderly patients after cardiac surgery . Methods This r and omized , double-blinded , and placebo-controlled trial was conducted in two tertiary hospitals in Beijing between December 1 , 2014 and July 19 , 2015 . Eligible patients were r and omized into two groups .  Dexmedetomidine ( DEX ) was administered during anesthesia and early postoperative period for patients in the DEX group , whereas normal saline was administered in the same rate for the same duration for patients in the control ( CTRL ) group . The primary endpoint was the incidence of delirium during the first five days after surgery . Secondary endpoints included the cognitive function assessed on postoperative days 6 and 30 , the overall incidence of non-delirium complications within 30 days after surgery , and the all-cause 30-day mortality . Results Two hundred eighty-five patients were enrolled and r and omized . Dexmedetomidine did not decrease the incidence of delirium ( 4.9 % [ 7/142 ] in the DEX group vs 7.7 % [ 11/143 ] in the CTRL group ; OR 0.62 , 95 % CI 0.23 to 1.65 , p = 0.341 ) . Secondary endpoints were similar between the two groups ; however , the incidence of pulmonary complications was slightly decreased ( OR 0.51 , 95 % CI 0.26 to 1.00 , p = 0.050 ) and the percentage of early extubation was significantly increased ( OR 3.32 , 95 % CI 1.36 to 8.08 , p = 0.008 ) in the DEX group . Dexmedetomidine decreased the required treatment for intraoperative tachycardia ( 21.1 % [ 30/142 ] in the DEX group vs 33.6 % [ 48/143 ] in the CTRL group , p = 0.019 ) , but increased the required treatment for postoperative hypotension ( 84.5 % [ 120/142 ] in the DEX group vs 69.9 % [ 100/143 ] in the CTRL group , p = 0.003 ) . Conclusions Dexmedetomidine administered during anesthesia and early postoperative period did not decrease the incidence of postoperative delirium in elderly patients undergoing elective cardiac surgery . However , considering the low delirium incidence , the trial might have been underpowered . Trial Registration Clinical Trials.gov BACKGROUND This study evaluates the incidence of delirium and risk factors associated with delirium in elderly patients admitted to a general surgical ward . METHODS Patients aged over 60 years who were admitted with an acute or elective general surgical diagnosis were eligible for this prospect i ve cohort study . Risk factors associated with delirium were analyzed using univariate and multivariate analysis to identify those independently associated with delirium . RESULTS A total of 209 patients were included in the study . The incidence of delirium was 16.9 % ( 23.2 % for acute admission , P < .001 ) . Variables associated with delirium were dementia , presence of an urinary catheter , cognitive decline at admission measured with the mini-mental state examination , white blood cell count > 10.0 × 10(9)/L , and urea > 7.5 mmol/L. Median length of hospital stay was 13 days ( range 3 - 85 ) for patients with delirium versus 7 ( range 1 - 54 ) for patients without ( P = .002 ) . CONCLUSIONS The incidence of delirium is high in elderly patients , especially after an acute admission , leading to an increase in length of hospital stay . To minimize delirium , associated risk factors must be identified and , if possible , treated Background Postoperative nausea and vomiting ( PONV ) are common following laparoscopic cholecystectomy ( LC ) .  Dexamethasone has been reported to reduce PONV . However , there is insufficient evidence regarding the effect of dexmedetomidine in decreasing PONV . This study was design ed to compare the effects of a single dose of dexmedetomidine to dexamethasone for reducing PONV after LC . Methods Eighty-six adult patients scheduled for LC were r and omized to receive either single dose 1 µg/kg of dexmedetomidine ( Dexmed group , N = 43 ) or 8 mg dexamethasone ( Dexa group , N = 43 ) before skin incision . During the first 24 h postoperatively , the incidence and severity of PONV were assessed . Pain and sedation scores were assessed on arrival in the recovery room and early postoperatively . Analgesic and antiemetic consumption during the 24 h after surgery were calculated . Intra-operative and postoperative hemodynamics were recorded . Results Twenty-one percent of the patients in the Dexmed group developed 
    Output:
    
Dexmedetomidine therapy seems to be an effective treatment for pain control and postoperative delirium in patients undergoing TKA/THA .
However , the incidence of bradycardia is markedly increased in patients undergoing TKA .