***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 research was to perform a feasibility study of prophylactic coronary revascularization in patients with preoperative extensive stress-induced ischemia . BACKGROUND Prophylactic coronary revascularization in vascular surgery patients with coronary artery disease does not improve postoperative outcome . If a beneficial effect is to be expected , then at least those with extensive coronary artery disease should benefit from this strategy . METHODS One thous and eight hundred eighty patients were screened , and those with > or =3 risk factors underwent cardiac testing using dobutamine echocardiography ( 17-segment model ) or stress nuclear imaging ( 6-wall model ) . Those with extensive stress-induced ischemia ( > or = 5 segments or > or =3 walls ) were r and omly assigned for additional revascularization . All received beta-blockers aim ing at a heart rate of 60 to 65 beats/min , and antiplatelet therapy was continued during surgery . The end points were the composite of all-cause death or myocardial infa rct ion at 30 days and during 1-year follow-up . RESULTS Of 430 high-risk patients , 101 ( 23 % ) showed extensive ischemia  and were r and omly assigned to revascularization ( n = 49 ) or no revascularization . Coronary angiography showed 2-vessel disease in 12 ( 24 % ) , 3-vessel disease in 33 ( 67 % ) , and left main in 4 ( 8 % ) . Two patients died after revascularization , but before operation , because of a ruptured aneurysm . Revascularization did not improve 30-day outcome ; the incidence of the composite end point was 43 % versus 33 % ( odds ratio 1.4 , 95 % confidence interval 0.7 to 2.8 ; p = 0.30 ) . Also , no benefit during 1-year follow-up was observed after coronary revascularization ( 49 % vs. 44 % , odds ratio 1.2 , 95 % confidence interval 0.7 to 2.3 ; p = 0.48 ) . CONCLUSIONS In this r and omized pilot study , design ed to obtain efficacy and safety estimates , preoperative  coronary revascularization  in high-risk patients was not associated with an improved outcome Forty-five patients of ASA physical status 1 and II undergoing a variety of non-cardiac surgical procedures were studied to determine the effect of bolus administration of esmolol , a new short-acting beta blocking drug , on heart rate and blood pressure responses to induction of anaesthesia and tracheal intubation . Subjects were allocated r and omly to receive placebo , 100 mg or 200 mg of esmolol IV as part of an anaesthetic induction technique . The differences in heart rate between the placebo group and both the 100 mg and 200 mg groups were significant prior to intubation ( 95 ± 7.9 , 82 ± 9.7 , 80 ± 7.3 beats per min respectively ) , and also at 0.5 min and 1.5 min following intubation for the 200 mg group . In the 200 mg group there was a significant decrease , compared with placebo , in systolic blood pressure at 0.5 min ( 144 ± 32.1 vs 165 ± 18.7 mmHg ) and 1.5 min ( 154 ± 25.0 vs 170 ± 19.5 mmHg ) after intubation . In this study , adequate haemodynamic control was obtained following administration of 200 mg of esmolol . RésuméQuarante-cinq patients ASA classe I et II devant subir une variété de procédures chirurgicales non-cardiaques ont été étudiés afin de déterminer l’effet de l’administration de l’esmolol en bolus sur la fréquence cardiaque et la tension artérielle lors de l’induction de l’anesthesie et l’intubation endotrachéale . Les sujets ont été r and omisés afin de recevoir soit du placebo , soit 100 mg ou 200 mg d’esmolol lors de l’induction . Les différences dans la fréquence cardiaque entre le groupe placebo et les deux groupes de 100 mg et 200 mg etaient significatives avant l’intubation ( 95 ± 7,9 , 82 ± 9,7 , 80 ± 7,3 battlminute respectivement ) , et aussi à 0,5 minutes et 1,5 minutes après l ’ intubation pour le groupe de 200 mg . Pour le groupe 200 mg , il y avait une diminution significative ( comparativement au placebo ) dans la pression artérielle systolique à 0,5 minutes ( 144 ± 32,1 versus 165 ± 18,7 mmHg ) et à 1,5 minutes ( 154 ± 25,0 versus 170 ± 19,5 mmHg ) après intubation . Dans cette etude , un contrôle hémodynamique adéquat était obtenu aprés administration de 200 mg d’esmolol Background : Carbon dioxide ( CO2 ) pneumoperitoneum for laparoscopic surgery increases arterial pressures , systemic vascular resistance and heart rate and decreases urine output The goal of this study was to compare the efficacy of esmolol and sodium nitroprusside ( SNP ) as primary drugs for producing controlled hypotension and limiting blood loss during orthognathic surgery . Thirty ASA physical status I and II patients ( mean age 22 yr ) undergoing LeFort I maxillary osteotomies were r and omly assigned to receive either esmolol ( n = 15 ) or SNP ( n = 15 ) as the primary drug to induce hypotension . All patients received a balanced anesthetic technique including isoflurane , with controlled hypotension during the down fracture of the maxilla . Patients assigned to the esmolol treatment group received boluses of 500 μg/kg of esmolol , followed by a continuous infusion of 100–300 μkg−1 · min−1 , and the SNP treatment group received a continuous infusion of SNP at 0.25 - -4.00 μkg−1 · min−1 ; both infusions were nitrated to obtain a mean arterial blood pressure within the target range of 55 - -65 mm Hg . The mean arterial blood pressure during the hypotensive period was 58.7 ±0.7 ( mean ± SEM ) and 61.8 ± 0.4 mm Hg for esmolol and SNP , respectively ( P < 0.001 ) . In addition , 40 % ± 4 % of the observed values in the esmolol group and 53 % ± 3 % in the SNP group were outside the target range for mean arterial blood pressure ( difference significant at P < 0.05 ) , and a greater proportion of the deviations were above 65 mm Hg in the SNP group than in the esmolol group ( 0.64 vs 0.46 , respectively , P < 0.05 ) . The mean heart rate was 70 Rekha 3 beats/min ( esmolol ) and 100 ± 3 beats/min ( SNP ) ( P < 0.001 ) , and the mean blood loss was 436 ± 65 mL ( esmolol ) and 895 ± 101 mL ( SNP ) ( P < 0.001 ) . The surgical field was judged to be drier with esmolol than with SNP ( P < 0.05 ) . Plasma renin activity decreased slightly in the esmolol group , whereas in the SNP group it increased 267 % ( P < 0.001 ) . The absence of the renin release may have facilitated the stability of controlled hypotension with esmolol . The advantages of esmolol over SNP for controlled hypotension during orthognathic surgery include greater control of blood pressure , reduction in blood loss , and a drier surgical field . These advantages must be weighed against the possibility of significant myocardial depression produced by intense β1-adrenergic blockade 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 In a double‐blind study the effect of esmolol and alfentanil on the QT interval of the ECG corrected by the heart rate ( QTc ) , heart rate and arterial pressure during anaesthetic induction was studied in 59 oxycodone‐ and atropine‐premedicated ASA class I‐(II ) patients with a mean age of 26 yr ( range 15–50 yr ) . The patients were r and omly allocated to one of the four groups : saline , esmolol 2 mg · kg‐1 , esmolol 3 mg · kg‐1 or alfentanil 0.03 mg·kg‐1 . Both doses of esmolol prevented the prolongation of the QTc interval after thiopental and suxamethonium , but not after laryngoscopy and intubation . Alfentanil prevented the prolongation of the QTc interval following thiopental , suxamethonium and laryngoscopy but not after intubation . Esmolol did not prevent the increase in the heart rate and arterial pressure in response to laryngoscopy and intubation . No cardiovascular responses to laryngoscopy and intubation occurred in the patients treated with alfentanil . No cardiac arrhythmias occurred in the esmolol 3 mg·kg‐1 group , whereas the frequency of ventricular ectopic beats was 40 % in the saline group and 13–20 % m the other groups BACKGROUND Beta-adrenergic agonists enhance behavioural and electroencephalographic arousal reactions . We explored whether adding esmolol , a short-acting beta(1)-adrenoceptor antagonist , to propofol anaesthesia modified the bispectral index ( BIS ) during induction of anaesthesia and orotracheal intubation . METHODS Fifty patients were r and omly allocated , in a double-blind fashion , to receive esmolol 1 mg kg(-1 ) followed by 250 micro g kg(-1 ) min(-1 ) or saline ( control ) . Esmolol or saline was started 6 min after a target-controlled infusion ( TCI ) of propofol ( effect-site concentration 4 micro g ml(-1 ) ) . After loss of consciousness , and before administration of vecuronium 0.1 mg kg(-1 ) , a tourniquet was applied to one arm and inflated to 150 mm Hg greater than systolic pressure . Eleven minutes after the TCI began , the trachea was intubated ; gross movement within the first min after orotracheal intubation was recorded . BIS was recorded at 10-s intervals . Mean arterial pressure ( MAP ) and heart rate 
    Output:
    
Dose titration was shown to influence both the change in arterial blood pressure and heart rate .
: This review suggests that titration of esmolol to a hemodynamic end point can be safe and effective .