***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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    ***EXAMPLES*** 
    Input: BACKGROUND Both dopamine and norepinephrine are recommended as first-line vasopressor agents in the treatment of shock . There is a continuing controversy about whether one agent is superior to the other . METHODS In this multicenter , r and omized trial , we assigned patients with shock to receive either dopamine or norepinephrine as first-line vasopressor therapy to restore and maintain blood pressure . When blood pressure could not be maintained with a dose of 20 microg per kilogram of body weight per minute for dopamine or a dose of 0.19 microg per kilogram per minute for norepinephrine , open-label norepinephrine , epinephrine , or vasopressin could be added . The primary outcome was the rate of death at 28 days after r and omization ; secondary end points included the number of days without need for organ support and the occurrence of adverse events . RESULTS The trial included 1679 patients , of whom 858 were assigned to dopamine and 821 to norepinephrine . The baseline characteristics of the groups were similar . There was no significant between-group difference in the rate of death at 28 days ( 52.5 % in the dopamine group and 48.5 % in the norepinephrine group ; odds ratio with dopamine , 1.17 ; 95 % confidence interval , 0.97 to 1.42 ; P=0.10 ) . However , there were more arrhythmic events among the patients treated with dopamine than among those treated with norepinephrine ( 207 events [ 24.1 % ] vs. 102 events [ 12.4 % ] , P<0.001 ) . A subgroup analysis showed that dopamine , as compared with norepinephrine , was associated with an increased rate of death at 28 days among the 280 patients with cardiogenic shock but not among the 1044 patients with septic shock or the 263 with hypovolemic shock ( P=0.03 for cardiogenic shock , P=0.19 for septic shock , and P=0.84 for hypovolemic shock , in Kaplan-Meier analyses ) . CONCLUSIONS Although there was no significant difference in the rate of death between patients with shock who were treated with dopamine as the first-line vasopressor agent and those who were treated with norepinephrine , the use of dopamine was associated with a greater number of adverse events . ( Clinical Trials.gov number , NCT00314704 . AIMS The aim of this study was to assess long-term safety of intravenous cardiovascular agents-vasodilators , inotropes and /or vasopressors-in  acute heart failure ( AHF ) . METHODS AND RESULTS The European Society of Cardiology Heart Failure Long-Term ( ESC-HF-LT ) registry was a prospect i ve , observational registry conducted in 21 countries . Patients with unscheduled hospitalizations for AHF ( n = 6926 ) were included : 1304 ( 18.8 % ) patients received a combination of intravenous ( i.v . ) vasodilators and diuretics , 833 ( 12 % ) patients received i.v . inotropes and /or vasopressors . Primary endpoint was long-term all-cause mortality . Main secondary endpoints were in-hospital and post-discharge mortality . Adjusted hazard ratio ( HR ) showed no association between the use of i.v . vasodilator and diuretic and long-term mortality [ HR 0.784 , 95 % confidence interval ( CI ) 0.596 - 1.032 ] nor in-hospital mortality ( HR 1.049 , 95 % CI 0.592 - 1.857 ) in the matched cohort ( n = 976 paired patients ) . By contrast , adjusted HR demonstrated a detrimental association between the use of i.v . inotrope and /or  vasopressor  and long-term all-cause mortality ( HR 1.434 , 95 % CI 1.128 - 1.823 ) , as well as in-hospital mortality ( HR 1.873 , 95 % CI 1.151 - 3.048 ) in the matched cohort ( n = 606 paired patients ) . No association was found between the use of i.v . inotropes and /or  vasopressors  and long-term mortality in patients discharged alive ( HR 1.078 , 95 % CI 0.769 - 1.512 ) . A detrimental association with inotropes and /or vasopressors was seen in all geographic regions and , among catecholamines , dopamine was associated with the highest risk of death ( HR 1.628 , 95 % CI 1.031 - 2.572 vs. no inotropes ) . CONCLUSIONS Vasodilators did not demonstrate any association with long-term clinical outcomes , while inotropes and /or vasopressors were associated with increased risk of all-cause death , mostly related to excess of in-hospital mortality in AHF Background Clinical evidence continues to exp and and is increasingly difficult to overview . We aim ed at conceptualizing a visual assessment tool , i.e. , a matrix for overviewing studies and their data in order to assess the clinical evidence at a glance . Methods A four-step matrix was constructed using the three dimensions of systematic error , r and om error , and design error . Matrix step I ranks the identified studies according to the dimensions of systematic errors and r and om errors . Matrix step II orders the studies according to the design errors . Matrix step III assesses the three dimensions of errors in studies . Matrix step IV assesses the size and direction of the intervention effect . Results The application of this four-step matrix is illustrated with two examples : peri-operative beta-blockade initialized in relation to surgery versus placebo for major non-cardiac surgery , and antiarrhythmics for maintaining sinus rhythm after cardioversion of atrial fibrillation .  When clinical evidence is deemed both internally and externally valid , the size of the intervention effect is to be assessed . Conclusion The error matrix provides an overview of the validity of the available evidence at a glance , and may assist in deciding which interventions to use in clinical practice BACKGROUND Worsening renal function ( WRF ) and hypokalemia related to diuretic use for acute decompensated heart failure ( ADHF ) are common and associated with poor prognosis . Low-dose dopamine infusion improves renal perfusion ; its effect on diuresis or renal function specifically in ADHF is not known . METHODS AND RESULTS Sixty consecutive ADHF patients ( age 75.7 ± 11.2 years ; 51.7 % female ; left ventricular ejection fraction 35.3 ± 12.1 % ) were r and omized , after receiving a 40 mg intravenous furosemide bolus , to either high-dose furosemide ( HDF , 20 mg/h continuous infusion for 8 hours ) or low-dose furosemide combined with low-dose dopamine ( LDFD , furosemide 5 mg/h plus dopamine 5 μg kg(-1 ) min(-1 ) continuous infusion for 8 hours ) . Both strategies were compared for total diuresis , WRF ( defined as a rise in serum creatinine of > 0.3 mg/dL from baseline to 24 hours ) , electrolyte balance , and 60-day postdischarge outcomes . Mean hourly excreted urine volume ( 272 ± 149 mL in HDF vs 278 ± 186 mL in LDFD group ; P = .965 ) and changes in dyspnea score ( Borg index : -4.4 ± 2.1 in HDF group vs -4.7 ± 2.0 in LDFD group ; P = .575 ) during the 8 hours of protocol treatment were similar in the two groups . WRF was more frequent in the HDF ( n = 9 ; 30 % ) than in the LDFD group ( n = 2 ; 6.7 % ; P = .042 ) . Serum potassium changed from 4.3 ± 0.5 to 3.9 ± 0.4 mEq/L at 24 hours ( P = .003 ) in the HDF group and from 4.4 ± 0.5 to 4.2 ± 0.5 mEq/L at 24 hours ( P = .07 ) in the LDFD group . Length of stay and 60-day mortality or rehospitalization rates ( all-cause , cardiovascular , and worsening HF ) were similar in the two groups . CONCLUSIONS In ADHF patients , the combination of low-dose furosemide and low-dose dopamine is equally effective as high-dose furosemide but associated with improved renal function profile and potassium homeostasis Thirty-six patients with preoperative renal dysfunction were studied to evaluate the effects of dopamine ( D ) and dopamine-nitroprusside ( DN ) on renal function during cardiopulmonary bypass ( CPB ) . No differences from the control group ( C ) were found in creatinine clearance , fractional sodium excretion , osmolarity and free-water clearance . Sodium output/intake ratio during CPB was higher in group D than in groups C and DN ( P less than 0.05 ) ; water output/intake ratio was higher in group D than in group C ( P less than 0.05 ) . Urine lysozime levels and alpha-glycosidase/creatinine ratios increased similarly in the three groups , suggesting ischemic tubular cell damage . No patients showed acute postoperative renal failure or a worsening of their renal dysfunction . The data suggest an increased water and sodium excretion during CPB with a dopamine infusion , possibly result ing from a renal vasodilator effect that was abolished by simultaneous nitroprusside administration Objective : To compare the efficacy and safety of dopexamine with dopamine in the treatment of low cardiac output syndrome after cardiac surgery . Design : This was a multicentre , double-blind , r and omised , parallel-group study conducted in intensive care units at centres in Holl and and Belgium . Patients were r and omised to receive dopexamine ( up to 2.0 μg/kg per min ) or dopamine ( up to 6.0 μg/kg per min ) for 6 h after low cardiac output syndrome was confirmed . Results : 70 patients were enrolled ( 35/group ) and there was no significant difference in the operative procedures or haemodynamics at entry into the study . Clinical efficacy , defined as a cardiac index > 2.5 l/min per m2 with urine production > 0.5 ml/kg per h and stable haemodynamics for two consecutive readings 1 h apart , was achieved by 90 and 87 % of patients in the dopexamine and dopamine groups , respectively . However , more patients maintained clinical efficacy over the 6-h period in the dopexamine group , which was statistically significant at 1–2 h and approached significance at all other time points . Safety was assessed by comparing the adverse events and concomitant medication . Fewer patients on dopexamine  had cardiac events compared with dopamine-treated patients ( 25 vs 38 events ) , although there was no difference in the pattern of rhythm disturbance . Fewer patients in the dopexamine group required concomitant vasodilating drugs ( 18 vs 30 ) . Conclusion : Taking the proportion of patients achieving clinical efficacy , the time to achieve it and the maintenance of it along with the adverse event profile , dopexamine was shown to be an effective and safe drug to use in the management of low cardiac output syndrome after coronary artery bypass graft surgery and may be superior to dopamine Background —Acute renal failure is a serious complication of cardiac surgery causing high morbidity and mortality . The aim of this study was to evaluate the usefulness of fenoldopam , a specific agonist of the dopamine-1 receptor , in patients at high risk of perioperative renal dysfunction . Methods and Results —A prospect i ve single-center , r and omized , double-blind trial was performed after local ethical committee approval and after written consent was obtained from 80 patients undergoing cardiac surgery . Patients received either fenoldopam at 0.05 & mgr;g/kg per minute or dopamine at 2.5 & mgr;g/kg per minute after the induction of anesthesia for a 24-hour period . All these patients were at high risk of perioperative renal dysfunction as indicated by Continuous Improvement in Cardiac Surgery Program score > 10 . Primary end point was defined as 25 % creatinine increase from baseline levels after cardiac surgery . The 2 groups ( fenoldopam versus dopamine ) were homogeneous cohorts , and no difference in outcome was observed . Acute renal failure was similar : 17 of 40 ( 42.5 % ) in the fenoldopam group and 16 of 40 ( 40 % ) in the dopamine group ( P=0.9 ) . Peak postoperative serum creatinine level , intensive care unit and hospital stay , and mortality were also similar in the 2 groups . Conclusions —Despite an increasing number of reports of renal protective properties from fenoldopam , we observed no difference in the clinical outcome compared with dopamine in a high-risk population undergoing cardiac surgery Mitral valve surgery may be complicated by a post-operative low output state requiring inotropic support , and a wide variety of factors may influence the choice of agents used to treat this condition . The authors have examined and compared the haemodynamic effects of the highly specific phosphodiesterase inhibitor en 
    Output:
    
There were also no statistically significant associations for any of the outcomes in subgroup analyses by type of comparator ( inactive compared to potentially active ) , dopamine dose ( low compared to moderate dose ) , or setting ( cardiac surgery compared to heart failure ) .