***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: To comprehend the results of a r and omised controlled trial ( RCT ) , readers must underst and its design , conduct , analysis , and interpretation . That goal can be achieved only through total transparency from authors . Despite several decades of educational efforts , the reporting of RCTs needs improvement . Investigators and editors developed the original CONSORT ( Consoli date d St and ards of Reporting Trials ) statement to help authors improve reporting by use of a checklist and flow diagram . The revised CONSORT statement presented here incorporates new evidence and addresses some criticisms of the original statement . The checklist items pertain to the content of the Title , Abstract , Introduction , Methods , Results , and Discussion . The revised checklist includes 22 items selected because empirical evidence indicates that not reporting this information is associated with biased estimates of treatment effect , or because the information is essential to judge the reliability or relevance of the findings . We intended the flow diagram to depict the passage of participants through an RCT . The revised flow diagram depicts information from four stages of a trial ( enrolment , intervention allocation , follow- up , and analysis ) . The diagram explicitly shows the number of participants , for each intervention group , included in the primary data analysis . Inclusion of these numbers allows the reader to judge whether the authors have done an intention- to-treat analysis . In sum , the CONSORT statement is intended to improve the reporting of an RCT , enabling readers to underst and a trial 's conduct and to assess the validity of its results OBJECTIVE To assess the effects of metoprolol on perioperative cardiovascular events in patients with risk or at high risk for coronary artery disease ( CAD ) who were to undergo non-cardiac surgery . METHODS 102 patients with definite CAD or at high risk for CAD who were to undergo selective non-cardiac surgery were r and omized to 2 equal groups : Group A ( blank control group ) and Group B given metoprolol orally or intravenously from 2 h before surgery to 30 days after surgery . The dosage of metoprolol was adjusted according to the blood pressure and heart rate . The changes of peri-operative heart rate ( HR ) , level of creatine kinase (CK)-MB , cardiac events such as unstable angina pectoris ( UAP ) and myocardial infa rct ion ( MI ) , death , and stroke were recorded . RESULTS The HR values , intra-operative and 6 h , 1 d , and 2 d after operation of Group B were all significantly lower than those of Group A ( all P < 0.05 ) . One patient from each group had MI . One case of death and two cases of strokes occurred in Group A. The occurrence rate of at least one cardiovascular event were 9.8 % in Group A ( 5/51 ) and 2.0 % in Group B ( 1/51 ) without significant difference between these 2 groups ( P > 0.05 ) . CONCLUSIONS Metoprolol reduces the incidence of postoperative severe cardiovascular episodes in patients with risk of or at high risk for CAD undergoing non-cardiac surgery Background Perioperative opioid administration results in postoperative nausea and vomiting ( PONV ) and acute opioid tolerance that manifests in increased postoperative pain . Esmolol is an ultra short acting cardioselective β1-adrenergic receptor antagonist , and it has been successfully used for perioperative sympatholysis and it reduces the opioid requirement during total intravenous anesthesia . We tested the hypothesis that perioperative esmolol administration results in decreased PONV and postoperative pain . Methods Sixty patients undergoing laparoscopic appendectomy were r and omly assigned to two groups ( Group E and Group C ) . The Group E patients were administered 5 - 10 µg/kg/min esmolol with remifentanil that was titrated to the autonomic response . The Group C patients received normal saline that was of the same volume as the esmolol in Group E , and the remifentanil was also titrated to the vital sign . Before intubation and extubation , the Group E patients were administered 1.0 mg/kg esmolol , and the Group C patients were administered normal saline of the same volume . The incidence and severity of PONV , the pain score , the rescue antiemetics and the rescue analgesics were assessed 30 min , 6 h and 24 h after surgery . The mean arterial pressure and heart rate under anesthesia were also recorded . Results PONV and postoperative pain were significantly increased in Group C. These patients needed more antiemetics and analgesics in the first 24 postoperative hours . The mean arterial pressure and heart rate were significantly higher in Group C at the time of intubation and extubation . Conclusions Perioperative esmolol administration contributes to the significant decrease in PONV and postoperative pain , and so this facilitates earlier discharge Objectives : Atrial fibrillation after cardiac surgery is associated with increases in the risk of complications , length of intensive care unit stay , and cost of care . Beta blockers are effective for controlling myocardial ischemia and arrhythmia and suppressing inflammatory cytokines . The purpose of this study was to examine the effect of administrating a short-acting beta-adrenoceptor antagonist , l and iolol , on postoperative atrial fibrillation . Methods : 136 patients undergoing off-pump coronary artery bypass grafting were single-blindly assigned r and omly to l and iolol ( n = 68 ) and non-l and iolol ( control , n = 68 ) groups . In the l and iolol group , the beta blocker was administered from the beginning of the operation until postoperative day 2 . The primary endpoint was the incidence of atrial fibrillation until postoperative day 7 , and the secondary endpoints were the postoperative levels of troponin I , creatine kinase MB-isoenzyme , and C-reactive protein . Results : The incidence of atrial fibrillation was significantly lower in the l and iolol group compared to the control group ( 13/68 , 19 % vs. 25/68 , 37 % , p = 0.02 , logrank test ) . L and iolol also significantly reduced the postoperative peak C-reactive protein level compared to the control group ( 132 ± 55.4 vs. 161 ± 50.9 mgċL−1 , p = 0.004 ) . Conclusion : Low-dose continuous infusion of l and iolol reduced the incidence of postoperative atrial fibrillation , and significantly suppressed inflammation BACKGROUND Trials of beta blockers in patients undergoing non-cardiac surgery have reported conflicting results . This r and omised controlled trial , done in 190 hospitals in 23 countries , was design ed to investigate the effects of perioperative beta blockers . METHODS We r and omly assigned 8351 patients with , or at risk of , atherosclerotic disease who were undergoing non-cardiac surgery to receive extended-release metoprolol succinate ( n=4174 ) or placebo ( n=4177 ) , by a computerised r and omisation phone service . Study treatment was started 2 - 4 h before surgery and continued for 30 days . Patients , health-care providers , data collectors , and outcome adjudicators were masked to treatment allocation . The primary endpoint was a composite of cardiovascular death , non-fatal myocardial infa rct ion , and non-fatal cardiac arrest . Analyses were by intention to treat . This trial is registered with Clinical Trials.gov , number NCT00182039 . FINDINGS All 8351 patients were included in analyses ; 8331 ( 99.8 % ) patients completed the 30-day follow-up . Fewer patients in the metoprolol group than in the placebo group reached the primary endpoint ( 244 [ 5.8 % ] patients in the metoprolol group vs 290 [ 6.9 % ] in the placebo group ; hazard ratio 0.84 , 95 % CI 0.70 - 0.99 ; p=0.0399 ) . Fewer patients in the metoprolol group than in the placebo group had a myocardial infa rct ion ( 176 [ 4.2 % ] vs 239 [ 5.7 % ] patients ; 0.73 , 0.60 - 0.89 ; p=0.0017 ) . However , there were more deaths in the metoprolol group than in the placebo group ( 129 [ 3.1 % ] vs 97 [ 2.3 % ] patients ; 1.33 , 1.03 - 1.74 ; p=0.0317 ) . More patients in the metoprolol group than in the placebo group had a stroke ( 41 [ 1.0 % ] vs 19 [ 0.5 % ] patients ; 2.17 , 1.26 - 3.74 ; p=0.0053 ) . INTERPRETATION Our results highlight the risk in assuming a perioperative beta-blocker regimen has benefit without substantial harm , and the importance and need for large r and omised trials in the perioperative setting . Patients are unlikely to accept the risks associated with perioperative extended-release metoprolol Background : Increased sympathetic activity perioperatively and associated cardiovascular effects play a central role in cardiovascular complications . High thoracic epidural blockade attenuates the sympathetic response , but even with complete pain relief , haemodynamic and endocrine responses are still present . Beta – adrenoceptor blockade is effective in situations with increased sympathetic activity . This study was design ed to evaluate the perioperative haemodynamic effect of preoperative βblockade and its influence on the haemodynamic aspects of the surgical stress response This double-blind , r and omized , placebocontrolled study evaluated the sparing effect of esmolol on sevoflurane during laparoscopic gynaecological surgery in 54 patients between December 2009 and May 2010 . The concentration of sevoflurane required to maintain adequate anaesthesia was determined . Patients received either a 0.5 mg/kg esmolol intravenous loading dose followed by infusion of 30 μg/kg per min or an identical volume of normal saline ( placebo ) . During surgery the input concentration of sevoflurane was adjusted every 5 min to maintain systolic blood pressure within 15 % of baseline and bispectral index at 50–60 . Infusion of esmolol result ed in an 18.2 % decrease in mean sevoflurane input concentration .  Patients receiving esmolol had an earlier discharge from the postanaesthetic care unit and a lower mean fentanyl dose . In conclusion , intraoperative esmolol infusion decreased both the requirement for sevoflurane and postoperative administration of fentanyl Sotalol is a beta-adrenergic blocking drug with the additional property of lengthening the cardiac action potential . These electrophysiologic properties render the drug attractive for use in the prevention of postoperative supraventricular arrhythmias ( SVA ) , and previous studies have suggested that it was indeed effective . The hemodynamic response to sotalol and its safety early after coronary artery bypass graft ( CABG ) surgery were therefore studied . Forty-two patients undergoing CABG were r and omly assigned either to receive sotalol to prevent postoperative SVA ( 25 patients ) or to serve as controls ( 17 patients ) . Sotalol was started 6 hours after surgery if patients had a cardiac index > 2.8 L/min/m2 with a pulmonary capillary wedge pressure < 15 mmHg , and if they had no contraindications to the use of beta-blockers . The drug was given as a loading infusion of 1 mg/kg over 2 hours , followed by a maintenance infusion of 0.15 mg/kg/h for 24 hours . Three hours later , patients received the first oral dose of 80 mg to be repeated every 8 or 12 hours . Adverse effects necessitating discontinuation of the drug ( bradycardia < 50 beats/min , systolic blood pressure < 90 mmHg , or cardiac index < 2.2 L/min/m2 ) occurred in six patients ( 24 % ) and were mainly related to the loading infusion . The hemodynamic data for patients who completed the study were characterized by a significant fall of the cardiac index caused by a lower heart rate without significant change of the stroke volume index . The incidence of supraventricular arrhythmias was not significantly different in the two groups ( 3/19 in the sotalol group , 5/17 in the control group ) . ( ABSTRACT TRUNCATED AT 250 WORDS OBJECTIVE Supraventricular tachyarrhythmias ( SVT ) complicate postoperative management after coronary bypass surgery in about 30 % of all patients . Though a prophylactic treatment both with beta-adrenergic blocking agents and the calcium antagonist diltiazem has been used for the prevention of post-operative SVT , no study yet has performed a prospect i ve comparison of the efficacy of these therapies . METHODS To investigate the prophylactic effect of either a calcium antagonist ( diltiazem , 0.1 mg/kg per h i.v . ) or a beta-adrenergic blocking agent ( propranolol , 10 mg every 6 h postoperatively ) , we r and omized prospect ively 103 consecutive patients into three groups , the third one serving as a control group . Anti-arrhythmic medication was started with the procedure and was continued until the 3rd postoperative day . RESULTS Preoperative conditions were the same for the three groups concerning age , extent of coronary heart disease , ventricular function and heart-related medication . There were no differences in intraoperative parameters or post 
    Output:
    
According to our findings , perioperative application of beta-blockers still plays a pivotal role in cardiac surgery , as they can substantially reduce the high burden of supraventricular and ventricular arrhythmias in the aftermath of surgery .
Their influence on mortality , AMI , stroke , congestive heart failure , hypotension and bradycardia in this setting remains unclear .
In non-cardiac surgery , evidence from low risk of bias trials shows an increase in all-cause mortality and stroke with the use of beta-blockers .
The substantial reduction in supraventricular arrhythmias and AMI in this setting seems to be offset by the potential increase in mortality and stroke