***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: Cardiopulmonary bypass ( CPB ) with extracorporeal circulation produces changes in the immune system accompanied by an increase in proinflammatory cytokines and a decrease in anti-inflammatory cytokines . We hypothesize that dexmedetomidine ( DEX ) as an anesthetic adjuvant modulates the inflammatory response after coronary artery bypass graft surgery with mini-CPB . In a prospect i ve , r and omized , blind study , 12 patients ( 4 females and 8 males , age range 42 - 72 ) were assigned to  DEX group and compared with a conventional total intravenous anesthesia ( TIVA ) group of 11 patients ( 4 females and 7 males ) . The endpoints used to assess inflammatory and biochemical responses to mini-CPB  were plasma interleukin (IL)-1 , IL-6 , IL-10 , interferon (INF)-γ , tumor necrosis factor (TNF)-α , C-reactive protein , creatine phosphokinase , creatine phosphokinase-MB , cardiac troponin I , cortisol , and glucose levels . These variables were determined before anesthesia , 90 min after beginning CPB , 5 h after beginning CPB , and 24 h after the end of surgery . Endpoints of oxidative stress , including thiobarbituric acid reactive species and delta-aminolevulinate dehydratase activity in erythrocytes were also determined . DEX+TIVA use was associated with a significant reduction in IL-1 , IL-6 , TNF-α , and INF-γ ( P<0.0001 ) levels compared with TIVA ( two-way ANOVA ) . In contrast , the surgery-induced increase in thiobarbituric acid reactive species was higher in the DEX+TIVA group than in the TIVA group ( P<0.01 ; two-way ANOVA ) . Delta-aminolevulinate dehydratase activity was decreased after CPB ( P<0.001 ) , but there was no difference between the two groups . DEX as an adjuvant in anesthesia reduced circulating IL-1 , IL-6 , TNF-α , and INF-γ levels after mini-CPB . These findings indicate an interesting anti-inflammatory effect of DEX , which should be studied in different types of surgical interventions 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 OBJECTIVE The purpose of this pilot study was to evaluate whether dexmedetomidine has a cardioprotective effect during coronary artery bypass graft surgery with cardiopulmonary bypass ( CPB ) . DESIGN A prospect i ve , double-blind , r and omized controlled trial . SETTING A university hospital . PARTICIPANTS Thirty-eight patients undergoing coronary artery bypass graft surgery . INTERVENTIONS Patients were r and omized into 2 groups : dexmedetomidine and placebo groups . In the dexmedetomidine group , dexmedetomidine infusion was started by a loading dose of 0.5 μg/kg/10 min , followed by a continuous infusion of 0.5 μg/kg/h . The placebo group received the same volume of saline .  Measurements of central venous pressure , mean pulmonary artery pressure ( MPAP ) and cardiac index were performed before and after dexmedetomidine loading dose and 2 , 24 and 48 hours after CPB . Simultaneously , arterial blood was sample d for CK-MB , cardiac troponin T , and N-terminal probrain natriuretic peptide . MEASUREMENTS AND MAIN RESULTS CK-MB , cardiac troponin T and N-terminal probrain natriuretic peptide values were elevated in the periods after CPB in both groups ( p<0.05 ) and there were no statistically significant differences between groups . MPAP was decreased in the dexmedetomidine group at the 2nd , 24th and 48th hour after CPB ( p<0.001 , p<0.001 , p = 0.002 , respectively ) . Higher cardiac index values were seen earlier in the dexmedetomidine group than in the placebo group ( p < 0.05 ) . CONCLUSIONS Myocardial damage was not reduced by administration of 0.5 μg/kg loading dose and 0.5 μg/kg/h infusion of dexmedetomidine . However MPAP tended to be lower in the dexmedetomidine group . Large-scale clinical outcome studies are indicated to confirm the effect of dexmedetomidine The aim of this study was to observe the impact of dexmedetomidine on postoperative myocardial injury in patients undergoing off-pump coronary artery bypass ( OPCAB ) grafting . One hundred and sixty-two patients who were undergoing OPCAB surgery were r and omly divided into control and dexmedetomidine groups ( groups C and Dex , respectively ) . Following the first vascular anastomosis grafting , the patients in group Dex received a continuous intravenous infusion of 0.2–0.5 μg/kg/h dexmedetomidine , until they were transferred to the Cardiac Surgery intensive care unit ( ICU ) for 12 h. Patients in group C received physiological saline intraoperatively and an intravenous infusion of 2–4 mg/kg/h isopropylphenol for postoperative sedation . Invasive arterial pressure and heart rate were continuously monitored for 5 min subsequent to entry into the operating theatre ( T0 ) , immediately following surgery ( T1 ) , 12 h post-surgery ( T2 ) , 24 h post-surgery(T3 ) , 48 h post-surgery(T4 ) and 72 h post-surgery ( T5 ) . Blood sample s were taken to determine the plasma levels of cardiac troponin I ( cTnI ) and creatine kinase-MB ( CK-MB ) at each time point . At 72 h post-surgery , a dynamic electrocardiogram was monitored . The blood pressure , heart rate , levels of cTnI , CK-MB , norepinephrine and cortisol , and postoperative arrhythmic events in the patients in group Dex all decreased compared with those in group C. The duration of mechanical ventilation and ICU residence time were also shorter than those in the control group ( P<0.05 ) . Dexmedetomidine reduced post-surgical myocardial injury in patients who had undergone OPCAB surgery Objective : The aim of the study was to assess the effect of dexmedetomidine in high-risk patients undergoing aortic vascular surgery . Design : A r and omized prospect i ve study . Setting : Cairo University , Egypt . Material s and Methods : The study included 150 patients undergoing aortic vascular surgery . Intervention : The patients were classified into two groups ( n = 75 ) . Group D : The patients received a loading dose of 1 μg/kg dexmedetomidine over 15 min before induction and maintained as an infusion of 0.3 μg/kg/h to the end of the procedure . Group C : The patients received an equal volume of normal saline . The medication was prepared by the nursing staff and given to anesthetist blindly . Measurements : The monitors included the heart rate , mean arterial blood pressure , central venous pressure , electrocardiogram ( ECG ) , serum troponin I level , end-tidal sevoflurane , and total dose of morphine in addition transthoracic echocardiography to the postoperative in cases with elevated serum troponin I level . Main Results : The dexmedetomidine  decreased heart rate and minimized the changes in blood pressure compared to control group ( P < 0.05 ) . Furthermore , it decreased the incidence of myocardial ischemia reflected by troponin I level , ECG changes , and the development of new regional wall motion abnormalities ( P < 0.05 ) . Dexmedetomidine decreased the requirement for nitroglycerin and norepinephrine compared to control group ( P < 0.05 ) . The incidence of hypotension and bradycardia was significantly higher with dexmedetomidine ( P < 0.05 ) . Conclusion : The dexmedetomidine is safe and effective in patients undergoing aortic vascular surgery . It decreases the changes in heart rate and blood pressure during the procedures . It provides cardiac protection in high-risk patients reflected by decreasing the incidence of myocardial ischemia and serum level of troponin . The main side effects of dexmedetomidine  were hypotension and bradycardia OBJECTIVE To investigate the cardioprotective effect of the continuous administration of dexmedetomidine using serum cardiac troponin I ( cTnI ) and creatine kinase MB ( CK-MB ) concentrations as biomarkers during off-pump coronary artery bypass grafting ( OPCAB ) surgery . DESIGN A prospect i ve , r and omized , parallel-group controlled study . SETTING A university hospital . PARTICIPANTS One hundred sixteen patients undergoing OPCAB surgery . INTERVENTIONS Patients were divided r and omly into 3 experimental groups that were separated by the dexmedetomidine administration protocol : a high-dose group ( loading dose , 1 μg/kg ; maintenance dose , 0.6 μg/kg/h ) ; low-dose group ( loading dose , 0.6 μg/kg ; maintenance dose , 0.3 μg/kg/h ) ; and control group ( the same amount of 0.9 % saline as placebo ) . Serum cTnI and CK-MB levels were measured before surgery and 24 hours and 48 hours after surgery . MEASUREMENTS AND MAIN RESULTS Serum cTnI and CK-MB levels in patients of the high-dose group were less than those of the other 2 groups 48 hours after surgery . The administration of dexmedetomidine significantly decreased the heart rate . Compared with the control group , there was a significantly reduced requirement of sevoflurane in the other 2 groups ( p<0.05 ) . The intraoperative and postoperative cumulative volumes of urine output in the high-dose group were greater than those of the other 2 groups ( p<0.05 ) . The authors also found that the extubation time and length of stay in the intensive care unit were prolonged in the high-dose group . CONCLUSIONS Myocardial damage was reduced by the administration of a 1 μg/kg loading dose and a 0.6 μg/kg/h infusion dose of dexmedetomidine . However , further studies are needed to underst and the underlying mechanism and to confirm that high doses of dexmedetomidine could be administered safely in patients undergoing OPCAB surgery Background Postoperative junctional ectopic tachycardia is one of the most serious arrhythmias that occur after pediatric cardiac surgery , difficult to treat and better to be prevented . Our aim was to assess the efficacy of prophylactic dexmedetomidine in preventing junctional ectopic tachycardia after pediatric cardiac surgery . Methods and Results A prospect i ve controlled study was carried out on 90 children who underwent elective cardiac surgery for congenital heart diseases . Patients were r and omized into 2 groups . Group I ( dexmedetomidine group ) : 60 patients received dexmedetomidine ; Group II ( Placebo group ) : 30 patients received the same amount of normal saline intravenously . The primary outcome was the incidence of postoperative junctional 
    Output:
    
In addition , dexmedetomidine could reduce time of surgery and stay in intensive care units , improve delirium with good safety .
Our study shows clinical application of dexmedetomidine in cardiac surgery patients can reduce risks of abnormal hemodynamics with good safety