title: Postoperative prophylactic administration of beta-adrenergic blockers in patients at risk for myocardial ischemia.
abstract: Perioperative myocardial ischemia (MI) is associated with postoperative cardiac morbidity. Postoperative sympatholysis may reduce the incidence of MI. This study evaluated such a reduction postoperatively with the administration of prophylactic beta-blockers in patients undergoing elective total knee arthroplasty with epidural anesthesia and postoperative epidural analgesia. One hundred seven patients were preoperatively randomized into two groups, control and beta-blockers, who received postoperative esmolol infusions on the day of surgery and metoprolol for the next 48 h to maintain a heart rate less than 80 bpm. Patients were followed for ST segment depression by using a Holter monitor and adverse cardiac outcomes. Postoperative electrocardiographic ischemia was significantly more prevalent in the control group compared with the beta-blocker group during esmolol blockade (0 of 52 vs 4 of 55; P = 0.04) and tended to be more common in the control group the next two days (8 of 55 vs 3 of 52; P = 0.135). In addition, the number of ischemic events (control, 50; beta-blockers, 16) and total ischemic time (control, 709 min; beta-blocker, 236 min) were also significantly different from the control group. Myocardial infarctions and cardiac events were more common in the control group, but these differences were not significant. Our results suggest that the use of prophylactic beta-blocker therapy may reduce the incidence of postoperative MI.
  
  
  CONCLUSIONS
  Prophylactic beta adrenergic blockade administered after elective total knee arthroplasty was associated with a reduced prevalence and duration of postoperative myocardial ischemia detected with Holter monitoring.
authors.affiliation: Department of Anesthesiology, Hospital for Special Surgery-Weill Medical College of Cornell University, New York, New York 10021, USA.
authors.forename: M K
authors.initials: MK
authors.lastname: Urban
authors.forename: S M
authors.initials: SM
authors.lastname: Markowitz
authors.forename: M A
authors.initials: MA
authors.lastname: Gordon
authors.forename: B L
authors.initials: BL
authors.lastname: Urquhart
authors.forename: P
authors.initials: P
authors.lastname: Kligfield
mesh_terms: D000319:Adrenergic beta-Antagonists / Q000008:administration & dosage / Q000627:therapeutic use*; D000368:Aged; D000369:Aged, 80 and over; D016058:Analgesia, Patient-Controlled; D019645:Arthroplasty, Replacement, Knee; D004562:Electrocardiography; D015716:Electrocardiography, Ambulatory; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D017202:Myocardial Ischemia / Q000453:epidemiology / Q000209:etiology / Q000517:prevention & control*; D011183:Postoperative Complications / Q000517:prevention & control*; D011184:Postoperative Period; D012306:Risk
chemical_list: D000319:Adrenergic beta-Antagonists