Postoperative prophylactic administration of beta-adrenergic blockers in patients at risk for myocardial ischemia

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. Implications: 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.     

Reorganizing the system of care surrounding laparoscopic surgery: a cost-effectiveness analysis using discrete-event simulation.

PURPOSE: To determine the cost-effectiveness of a proposed reorganization of surgical and anesthesia care to balance patient volume and safety. METHODS: Discrete-event simulation methods were used to compare current surgical practice with a new modular system in which patient care is handed off between 2 anesthesiologists. A health care system's perspective, using hospital and professional costs, was chosen for the cost-effectiveness analysis. Outcomes were patient throughput, flow time, wait time, and resource use. Sensitivity analyses were performed on staffing levels, mortality rates, process times, and scheduled patient volume. RESULTS: The new strategy was more effective (average 4.41 patients/d [median = 5] v. 4.29 [median = 4]) and had similar costs (average cost/ patient/d = 5327 dollars v. 5289 dollars) to the current strategy with an incremental cost-effectiveness of 318 dollars/additional patient treated/d. Surgical mortality rate must be >4% or hand-off delay >15 min before the new strategy is no longer more effective. CONCLUSION: The proposed system is more cost-effective relative to current practice over a wide range of mortality rates, hand-off times, and scheduled patient volumes.     

Weaning from mechanical support in a patient with acute heart failure and multiple sclerosis

We describe a 19-year-old woman developing acute left ventricular heart failure during her first exacerbation of multiple sclerosis. Histopathologic examination of myocardial tissue showed extensive myocytolysis. A left ventricular assist device was implanted. Three months later the cardiac function was restored and the left ventricular assist device was explanted. After 1 year the patient still remains well and her cardiac function is normal.