***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: 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 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 Dexmedetomidine ( DEX ) has sedative , sympatholytic and analgesic effects and might be beneficial if used as an adjuvant to : improve analgesia ; modulate haemodynamic responses to intubation and pneumoperitoneum and ; reduce the number of opioid-associated adverse events . The aim of this study was to evaluate the efficacy and safety of DEX infusion during elective laparoscopic cholecystectomy ( LC ) . Methods A r and omized , single-centre , parallel-group , placebo-controlled study was carried out between May 2016 and June 2017 . Adult patients ( 18–79 years ) with American Society of Anesthesiology ( ASA ) physical status I – II were r and omly assigned to 0.5 μg/kg/h DEX infusion from induction of anaesthesia to extubation ( Group D ; n = 30 ) or normal saline infusion ( Group C ; n = 30 ) . The primary efficacy outcomes were postoperative morphine consumption . Secondary efficacy outcomes included : time to first use of rescue analgesia ; postoperative morphine consumption ; intraoperative fentanyl consumption ; time from end of surgery to extubation ; lengths of intensive care unit ( ICU ) and general ward stay ; degree of postoperative pain 3 , 6 , 12 and 24 h after surgery ; incidence of persistent post-surgical pain . Results DEX infusion was associated with a decrease in postoperative morphine consumption ( p = 0.001 ) , lower incidence of severe postoperative pain ( odds ratio [ OR ] 9 , 95 % confidence interval [ CI ] 1.1–77 , p = 0.04 ) and significantly longer time to first use of rescue analgesia ( p = 0.001 ) . Group D also had significantly lower fentanyl consumption both intraoperatively ( p = 0.001 ) and in the time from end of surgery to extubation ( p = 0.001 ) plus decreased incidence of persistent post-surgical pain ( OR 14.5 , 95 % CI 1.7–122 , p = 0.005 ) . The incidence of postoperative nausea and vomiting was lower in Group D than Group C ( OR 5 , 95 % CI 1.1–26 , p = 0.005 ) . Median pain intensity did not differ between the groups 3 , 6 , 12 or 24 h after surgery and there were no inter-group differences in the lengths of ICU stay or overall hospital stay between groups . The incidence of hypertension was significantly higher in Group C ( OR 13.8 , 95 % CI 4–48 , p < 0.0001 ) ; there were no inter-group differences in incidences of hypotension and bradycardia . Conclusions Intraoperative DEX infusion is safe and effective for improving analgesia during and after elective LC . DEX appears to significantly reduce the number of patients with severe postoperative pain , postoperative morphine consumption and prolong time to first use of rescue analgesia . Trial registration Clinical Trials.gov : Retrospectively registered on July 7 , 2017 , NCT03211871 Introduction Delirium , which is prevalent in postcardiac surgical patients , is an acute brain dysfunction characterised by disturbances in attention , awareness and cognition not explained by a pre-existing neurocognitive disorder . The pathophysiology of delirium remains poorly understood . However , basic science and clinical studies suggest that sleep disturbance may be a modifiable risk factor for the development of delirium . Dexmedetomidine is a α-2A adrenergic receptor agonist medication that patterns the activity of various arousal nuclei similar to sleep . A single night-time loading dose of dexmedetomidine promotes non-rapid eye movement sleep stages N2 and N3 sleep . This trial hypothesises dexmedetomidine-induced sleep as pre-emptive therapy for postoperative delirium . Methods and analysis The MINDDS ( Minimizing ICU Neurological Dysfunction with Dexmedetomidine-induced  Sleep ) trial is a 370-patient block-r and omised , placebo-controlled , double-blinded , single-site , parallel-arm superiority trial . Patients over 60 years old , undergoing cardiac surgery with planned cardiopulmonary bypass , will be r and omised to receive a sleep-inducing dose of dexmedetomidine or placebo . The primary outcome is the incidence of delirium on postoperative day 1 , assessed with the Confusion Assessment Method by staff blinded to the treatment assignment . To ensure that the study is appropriately powered for the primary outcome measure , patients will be recruited and r and omised into the study until 370 patients receive the study intervention on postoperative day 0 . Secondary outcomes will be evaluated by in-person assessment s and medical record review for in-hospital end points , and by telephone interview for 30-day , 90-day and 180-day end points . All trial outcomes will be evaluated using an intention-to-treat analysis plan . Hypothesis testing will be performed using a two-sided significance level ( type I error ) of α=0.05 . Sensitivity analyses using the actual treatment received will be performed and compared with the intention-to-treat analysis results . Additional sensitivity analyses will assess the potential impact of missing data due to loss of follow-up . Ethics and dissemination The Partners Human Research Committee approved the MINDDS trial . Recruitment began in March 2017 . Dissemination plans include presentations at scientific conferences , scientific publications and popular media . Trial registration number NCT02856594 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 
    Output:
    
The trial sequential analyses for the incidence of delirium , bradycardia and hypotension was conclusive but not for the incidence of agitation and mortality .
In summary , this meta- analysis suggests that dexmedetomidine reduces the incidence of delirium and agitation in intensive care patients .