***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: Hypertension following coronary artery bypass grafting is not uncommon , especially in patients having good left ventricular function . It is often accompanied by tachycardia . The purpose of this study is to determine the efficacy of esmolol in the treatment of tachycardia and hypertension immediately following cardiopulmonary bypass and to study other haemodynamic effects of esmolol . Thirty patients undergoing elective [ corrected ] coronary artery bypass grafting were included in this prospect i ve study . Morphine-based anaesthetic technique along-with st and ard bypass techniques were used in all the patients . The study was performed in the operating room about 30 - 45 minutes after the termination of cardiopulmonary bypass . Patients having a heart rate of more than 90 bpm and systolic blood pressure of more than 130 mm Hg without any inotropic support were included and r and omly assigned to esmolol or control group . Esmolol was administered in a bolus dose of 500 micrograms/kg followed by infusion of upto 100 micrograms/kg/min . The patients in the control group were administered comparable volumes of normal saline .  Baseline haemodynamic measurements were obtained just before the administration of esmolol or normal saline and were repeated after 5 , 10 , 15 , 30 and 45 min . The baseline measurement in both the groups showed that patients were maintaining a state of hyperdynamic circulation with high systolic blood pressure  ( esmolol group 148 + /- 15 mm Hg , control group 140 + /- 8 mm Hg ; p = NS ) , heart rate ( esmolol group 128 + /- 17 bpm , control group 127 + /- 17 bpm ; p = NS ) and cardiac index ( esmolol group 3.1 + /- 1 L/min/m2 , control group 3.3 + /- 0.5 L/min/m2 ; p = NS ) . Esmolol decreased systolic blood pressure ( p < 0.001 ) , heart rate ( p < 0.01 ) and cardiac index ( p < 0.05 ) at five minutes . These changes persisted throughout the study period . The left ventricular stroke work index decreased at five minutes ( p < 0.05 ) and remained so till 30 minutes . The maximum fall in heart rate ( 15 % ) and systolic blood pressure ( 16 % ) was observed at 45 minutes . There were no haemodynamic changes in the control group except that cardiac index , stroke volume and left ventricular stroke work index increased at five minutes . We conclude that esmolol lowers the indices of cardiovascular work in patients who demonstrated hyperdynamic circulation . This was achieved by decreasing the heart rate and systolic blood pressure which was accompanied by decrease in cardiac index and left ventricular stroke work index 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 The safety and efficacy of esmolol during high-dose fentanyl anesthesia were studied in 37 patients undergoing coronary artery bypass grafting ( CABG ) . The anesthetic management consisted of fentanyl 75 μg/kg , pancuronium 0.15 mg/kg , and O2 . To assess the safety of esmolol , it was administered in a double-blind manner to 17 anesthetized patients prior to surgical incision . Infusion of the drug was increased in stepwise fashion to obtain administration rates between 100 and 300 μg · kg−1 ' min−1 . Esmolol produced smail but significant increases in pulmonary capillary wedge pressure ( PCWP ) ( 8.3 ± 1.7 to 13.2 ± 2.0 mmHg ) when compared with placebo ( 10.9 ± 1.0 to 12.1 ± 0.6 mmHg ) ( P < 0.05 ) . For the other studied parameters ( heart rate , mean arterial pressure , central venous pressure , cardiac index , stroke index , left ventricular stroke work index , systemic vascular resistance , and peripheral vascular resistance ) , no significant differences were observed between esmolol and placebo . To evaluate the efficacy of esmolol , 20 patients were r and omly assigned to an esmolol group ( n = 11 ) or a placebo group ( n = 9 ) . The study medication was infused from 5 min before induction through initiation of cardiopulmonary bypass . Infusion of esmolol at 200 μg · kg−1 · min−1 prevented tachycardia in response to intubation . In the esmolol group the heart rate increased from 63.4 ± 2.7 to 67.6 ± 2.9 beats/min after intubation , while in the placebo group it increased from 61.4 ± 4.3 to 72.4 ± 3.4 beats/min ( P < 0.05 ) . Furthermore , the increases in mean pulmonary artery pressure and PCWP observed in unstimulated , anesthetized patients were absent during surgical stimulation . Thus , in CABG patients anesthetized with fentanyl , esmolol appears safe and effective in preventing increases in heart rate during stimulation OBJECTIVE To assess the effectiveness of labetalol vs dexmedetomidine for attenuation of hemodynamic stress response to laryngoscopy and endotracheal intubation . DESIGN Prospect i ve , r and omized , controlled , observer-blinded study . SETTING This study was carried out in Tanta University Hospital . PATIENTS Ninety patients of both sexes ; American Society of Anesthesiologists physical status I and II ; age range from 20 to 60 years ; scheduled for elective surgery under general anesthesia . INTERVENTIONS Patients were divided into 3 groups ( 30 each ) . Group A received 1 μg/kg of dexmedetomidine as intravenous ( IV ) infusion , group B received labetalol 0.25mg/kg IV , and group C received 10mL saline IV . MEASUREMENTS The groups were compared for heart rate ( HR ) , mean arterial pressure ( MAP ) , and rate pressure product ( RPP ) . Hemodynamic parameters were recorded during the preinduction ; after induction ; at intubation ; and at 1 , 3 , 5 , 10 , and 15minutes . The primary outcomes were hemodynamic changes ( HR , MBP , and RPP ) , and the secondary outcome was propofol dose requirement for induction of general anaesthesia . RESULTS Significant decrease ( P < .05 ) in HR , MBP , and RPP in groups A and B in comparison with group C and in group A in comparison with group B. Just before intubation , there was a significant decrease ( P < .05 ) in HR , MBP , and RPP in groups A and B in comparison with group C. In group C , there was a significant increase in HR , MBP , and RPP at all points when compared with the baseline . In group A , the mean propofol induction dose ( mg ) was statistically significantly low as compared with that in groups B and C. CONCLUSION Dexmedetomidine attenuates the hemodynamic stress response to laryngoscopy and intubation more effectively compared with labetalol without any deleterious effects . Furthermore , dexmedetomidine decreases dose of propofol for induction of anesthesia as guided by bispectral index OBJECTIVES We previously conducted a prospect i ve study of l and iolol hydrochloride ( INN l and iolol ) , an ultrashort-acting β-blocker , and reported that it could prevent atrial fibrillation after cardiac surgery . This trial was performed to investigate the safety and efficacy of l and iolol hydrochloride in patients with left ventricular dysfunction undergoing cardiac surgery . METHODS Sixty patients with a preoperative left ventricular ejection fraction of less than 35 % were r and omly assigned to 2 groups before cardiac surgery and then received intravenous infusion with l and iolol hydrochloride ( l and iolol group ) or without l and iolol ( control group ) . The primary end point was occurrence of atrial fibrillation as much as 1 week postoperatively . The secondary end points were blood pressure , heart rate , intensive care unit and hospital stays , ventilation time , ejection fraction , biomarkers of ischemia , and brain natriuretic peptide . RESULTS Atrial fibrillation occurred in 3 patients ( 10 % ) in the l and iolol group versus 12 ( 40 % ) in the control group , and its frequency was significantly lower in the l and iolol group ( P = .002 ) . During the early postoperative period , levels of brain natriuretic peptide and ischemic biomarkers were significantly lower in the l and iolol group than the control group . The l and iolol group also had a significantly shorter hospital stay ( P = .019 ) . Intravenous infusion was not discontinued for hypotension or bradycardia in either group . CONCLUSIONS Low-dose infusion of l and iolol hydrochloride prevented atrial fibrillation after cardiac surgery in patients with cardiac dysfunction and was safe , with no effect on blood pressure . This intravenous β-blocker seems useful for perioperative management of cardiac surgical patients with left ventricular dysfunction 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 Tri 
    Output:
    
We found no evidence of a difference in early all-cause mortality , myocardial infa rct ion , cerebrovascular events , hypotension and bradycardia .
However , there may be a reduction in atrial fibrillation and ventricular arrhythmias when beta-blockers are used .