Huddleston, Jeanne M.

Spine surgeries tend to be lengthy (mean time of 4 hours) and highly variable (with some surgeries lasting 18 hours or more). This variability along with patient preferences driving scheduling decisions resulted in both low operating room (OR) utilization and significant overtime for surgical teams at Mayo Clinic. In this paper we discuss the development of an improved scheduling approach for spine surgeries over a rolling planning horizon. First, data mining and statistical analysis was performed using a large data set to identify categories of surgeries that could be grouped together based on surgical time distributions and could be categorized at the time of case scheduling. These surgical categories are then used in a hierarchical optimization approach with the objective of maximizing a weighted combination of OR utilization and net profit. The optimization model is explored to consider trade-offs and relationships among utilization levels, financial performance, overtime allowance, and case mix. The new scheduling approach was implemented via a custom Web-based application that allowed the surgeons and schedulers to interactively identify best surgical days with patients. A pilot implementation resulted in a utilization increase of 19% and a reduction in overtime by 10%.

Objectives To determine the incidence and 1‐year outcomes of an elderly population with perioperative atrial arrhythmia (PAA) within 7 days of hip fracture surgery. Design Retrospective cohort study. Setting The Rochester Epidemiology Project (REP). Participants Elderly adults consecutive undergoing hip fracture repair from 1988 to 2002 in Olmsted County, Minnesota (N = 1,088, mean age 84.0 ± 7.4, 80.2% female). Measurements Baseline clinical variables were analyzed in relation to survival using Cox proportional hazards methods for comparison. Results Sixty‐one participants (5.6%) developed PAA within the first 7 days. During 1 year of follow‐up, 239 (22%) participants died. PAA was associated with greater mortality (45% vs 21%; hazard ratio (HR) = 2.8, 95% confidence interval (CI) = 1.9–4.2). Other mortality risk factors were male sex (HR = 2.0, 95% CI = 1.5–2.6), congestive heart failure (HR = 2.1, 95% CI = 1.7–2.8), chronic renal insufficiency (HR = 2.0, 95% CI = 1.5–2.8), dementia (HR = 2.9, 95% CI = 2.2–3.7), and American Society of Anesthesiologists risk Class III, IV, or V (HR = 3.3, 95% CI = 1.9–5.9). Conclusion Elderly adults undergoing hip fracture surgery who develop PAA within 7 days have significantly higher 1‐year mortality than those who do not. Further studies are indicated to determine whether prevention of PAA will reduce mortality in this population.

Objectives To quantify the occurrence of myocardial infarction ( MI ) occurring in the early postoperative period after surgical hip fracture repair and estimate the effect on 1‐year mortality. Design A population‐based, historical cohort study of individuals who underwent surgical repair of a hip fracture that used the computerized medical record linkage system of the R ochester E pidemiology P roject. Setting Academic and community hospitals, outpatient offices, and nursing homes in O lmsted C ounty, M innesota. Participants Over the 15‐year study period (1988–2002), 1,116 elderly adults underwent surgical repair of a hip fracture. Measurements At the end of the first 7 days after hip fracture repair, participants were classified into one of three groups: clinically verified MI (cv‐ MI ), subclinical myocardial ischemia, and no myocardial ischemia. One‐year mortality was compared between these groups. Multivariate models assessed risk factors for early postoperative cv‐ MI and 1‐year mortality. Results Within the first 7 days after hip fracture repair, 116 (10.4%) participants experienced cv‐ MI and 41 (3.7%) subclinical myocardial ischemia. Overall 1‐year mortality was 22%, with no difference between those with subclinical myocardial ischemia and those with no myocardial ischemia. One‐year mortality for those with cv‐ MI (35.8%) was significantly higher than for the other two groups. Occurrence of early postoperative cv‐ MI , male sex, and history of heart failure or dementia were independently associated with greater 1‐year mortality, whereas prefracture home residence and preoperative higher hemoglobin were protective. Conclusion Rates of early postoperative, cv‐ MI after hip fracture repair exceed rates after other major orthopedic surgeries and are independently associated with greater 1‐year mortality.

ABSTRACT We investigated the effect of multiple freeze-thaw cycles on mumps, measles, and rubella virus serum antibody levels with whole-virus immunoglobulin G enzyme-linked immunoassays. Fresh serum samples from nine healthy adult volunteers were divided into six sets of five aliquots each. Samples were taken through a total of 10 freeze-thaw cycles and stored at 4°C until assayed. Each assay measurement was done in replicates of five, and the mean value was reported. After completing 10 freeze-thaw cycles, we found no clinically or statistically significant effect on measured antibody levels and found no discernible detrimental effect on the ability to measure these antibodies by enzyme-linked immunoassays.