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To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.ejor.2006.10.003 Byline: Xiuli Qu (a), Ronald L. Rardin (a), Julie Ann S. Williams (b), Deanna R. Willis (c) Keywords: OR in health service; Appointment scheduling; Advanced access; No-show rate Abstract: Advanced access scheduling, introduced in the early 1990s, is reported to significantly improve the performance of outpatient clinics. The successful implementation of advanced access scheduling requires the match of daily healthcare provider capacity with patient demand. In this paper, for the first time a closed-form approach is presented to determine the optimal percentage of open-access appointments to match daily provider capacity to demand. This paper introduces the conditions for the optimal percentage of open-access appointments and the procedure to find the optimal percentage. Furthermore, the sensitivity of the optimal percentage of open-access appointments to provider capacity, no-show rates, and demand distribution is investigated. Our results demonstrate that the optimal percentage of open-access appointments mainly depends on the ratio of the average demand for open-access appointments to provider capacity and the ratio of the show-up rates for prescheduled and open-access appointments. Author Affiliation: (a) Purdue University, School of Industrial Engineering, 315 N. Grant Street, West Lafayette, IN 47907-2023, United States (b) University of West Florida, Department of Management and MIS, 11000 University Parkway, Bldg 76/128, Pensacola, FL 32514-5752, United States (c) Indiana University, Department of Family Medicine, 1110 W Michigan Street, Indianapolis, IN 46202, United States Article History: Received 17 December 2005; Accepted 25 October 2006

Background: Transaminase elevations can occur from liver injury or in the setting of rhabdomyolysis. The goal of this study is to evaluate indices that could differentiate acetaminophen toxicity from muscle injury in the setting of transaminase elevations.Methods: A retrospective chart review of consecutive cases reported to our regional poison center. Patients with transaminase (AST and ALT) elevation were grouped as those with acetaminophen exposure (AT) and those with elevated creatine phosphokinase (CPK) without evidence of acetaminophen exposure (RHB).Results: Of the 345 patients included in the study, elevated AST/ALT levels were attributed to rhabdomyolysis in 168 patients and attributed to acetaminophen toxicity in 177 patients. The median AST: ALT values also differed between groups, with patients in the RHB group had higher median ratios (p < 0.001). Using an AST: ALT value of 2.02 as a diagnostic cutoff produced a specificity of 0.52 (95% CI: 0.37, 0.64) and sensitivity of 0.84 (95% CI: 0.73, 0.94) for acetaminophen detection in the test dataset (N = 104).Conclusions: Elevated transaminases due to liver injury from acetaminophen ingestion had a different pattern than elevated transaminases due to rhabdomyolysis. Lower AST:ALT ratios were found in acetaminophen cases, however, the specificity using a ratio threshold of ≤1 would be 83%. [ABSTRACT FROM AUTHOR]

Bacterial meningitis is a serious, acute infection of the meninges. Definitive diagnosis is made by analysis of cerebral spinal fluid (CSF) culture. Diagnostic clues of bacterial meningitis on the CSF include pleocytosis, an elevation in the white blood cell (WBC) count. We report a 3-year-old white male who presented to the emergency department (ED) secondary to two febrile seizures. He was ultimately diagnosed with fulminant bacterial meningitis secondary to CSF culture confirmed Neiserria meningitidis. The patient's CSF obtained on admission to the ED did not have pleocytosis. Within 5 hours of initial presentation, he became hypotensive, altered and went into disseminated intravascular coagulation. He expired within 24 hours of presentation. Bacterial meningitis without CSF pleocytosis, later determined to be culture positive, has been reported in both adult and pediatric patients but is extremely rare. However, these patients are more likely to have poorer outcomes. If bacterial meningitis is suspected, empiric antibiotics should be administered regardless of initial WBC count on lumbar puncture. [ABSTRACT FROM AUTHOR]