***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: Objectives : The purpose of this study was to determine analgesic efficacy of dexmedetomidine used as a continuous infusion without loading dose in postcardiac surgery patients . Setting s and Design : A prospect i ve , r and omized , double-blind clinical study in a single tertiary care hospital on patients posted for elective cardiac surgery under cardiopulmonary bypass . Interventions : Sixty-four patients who underwent elective cardiac surgery under general anesthesia were shifted to intensive care unit ( ICU ) and r and omly divided into two groups . Group A ( n = 32 ) received a 12 h infusion of normal saline and group B ( n = 32 ) received a 12 h infusion of dexmedetomidine 0.4 μg/kg/h . Postoperative pain was managed with bolus intravenous fentanyl . Total fentanyl consumption , hemodynamic monitoring , Visual Analogue Scale ( VAS ) pain ratings , Ramsay Sedation Scale were charted every 6 th hourly for 24 h postoperatively and followed-up till recovery from ICU . Student′s t-test , Chi-square/Fisher′s exact test has been used to find the significance of study parameters between the groups . Results : Dexmedetomidine treated patients had significantly less VAS score at each level ( P < 0.001 ) . Total fentanyl consumption  in dexmedetomidine group was 128.13 ± 35.78 μg versus 201.56 ± 36.99 μg in saline group ( P < 0.001 ) . A statistically significant but clinical ly unimportant sedation was noted at 6 and 12 h ( P < 0.001 , and P = 0.046 respectively ) . Incidence of delirium was less in dexmedetomidine group ( P = 0.086 + ) . Hemodynamic parameters were statistically insignificant . Conclusions : Dexmedetomidine infusion even without loading dose provides safe , effective adjunct analgesia , reduces narcotic consumption , and showed a reduced trend of delirium incidence without undesirable hemodynamic effects in the cardiac surgery patients Rationale : Dexmedetomidine is associated with less delirium than benzodiazepines and better sleep architecture than either benzodiazepines or propofol ; its effect on delirium and sleep when administered at night to patients requiring sedation remains unclear . Objectives : To determine if nocturnal dexmedetomidine prevents delirium and improves sleep in critically ill adults . Methods : This two‐center , double‐blind , placebo‐controlled trial r and omized 100 delirium‐free critically ill adults receiving sedatives to receive nocturnal ( 9:30 p.m. to 6:15 a.m. )  intravenous dexmedetomidine ( 0.2 & mgr;g/kg/h , titrated by 0.1 & mgr;g /kg/h every 15 min until a goal Richmond Agitation and Sedation Scale score of −1 or maximum rate of 0.7 & mgr;g/kg/h was reached ) or placebo until ICU discharge . During study infusions , all sedatives were halved ; opioids were unchanged . Delirium was assessed using the Intensive Care Delirium Screening Checklist every 12 hours throughout the ICU admission . Sleep was evaluated each morning by the Leeds Sleep Evaluation Question naire . Measurements and Main Results : Nocturnal dexmedetomidine ( vs. placebo ) was associated with a greater proportion of patients who remained delirium‐free  during the ICU stay ( dexmedetomidine [ 40 ( 80 % ) of 50 patients ] vs. placebo [ 27 ( 54 % ) of 50 patients ] ; relative risk , 0.44 ; 95 % confidence interval , 0.23‐0.82 ; P = 0.006 ) . The average Leeds Sleep Evaluation Question naire score was similar ( mean difference , 0.02 ; 95 % confidence interval , 0.42‐1.92 ) between the 34 dexmedetomidine ( average seven assessment s per patient ) and 30 placebo ( six per patient ) group patients able to provide one or more assessment s. Incidence of hypotension , bradycardia , or both did not differ significantly between groups . Conclusions : Nocturnal administration of low‐dose dexmedetomidine in critically ill adults reduces the incidence of delirium during the ICU stay ; patient‐reported sleep quality appears unchanged . Clinical trial registered with www . clinical trials.gov ( NCT01791296 ) 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 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 PURPOSE To determine whether dexmedetomidine sedation in the postanesthesia care unit ( PACU ) could decrease agitation and delirium after free flap surgery . MATERIAL S AND METHODS Eighty patients were r and omly divided into 2 groups . In the experimental group , dexmedetomidine was given at an hourly infusion rate of 0.5 μg/kg for 1 hour before the operation was completed and continued in the PACU at 0.2 to 0.7 μg/kg continuously until the next morning . In the control group , normal saline was given during the same periods . Patients in the 2 groups received sufentanil and midazolam for sedation and pain relief when necessary . Agitation was monitored with the Riker Sedation-Agitation Scale in the PACU and delirium was monitored with the Confusion Assessment Method for the Intensive Care Unit for 5 days postoperatively . RESULTS The overall incidence of agitation was similar between the 2 groups . However , when the influence of patient shifting was excluded , the incidence of agitation in the dexmedetomidine group was apparently lower than that in the control group ( 10. 
    Output:
    
Use of dexmedetomidine significantly increased the risks of bradycardia and hypotension .
Conclusion Findings suggest that dexmedetomidine  reduces incidence and duration of ICU delirium .
Furthermore , our systematic search es show that there is limited evidence if a delirium shall be treated with dexmedetomidine