RESUMO
Background and study aims: The projected increased demand for health services obligates healthcare organizations to operate efficiently. Discrete event simulation (DES) is a modeling method that allows for optimization of systems through virtual testing of different configurations before implementation. The objective of this study was to identify strategies to improve the daily efficiencies of an endoscopy center with the use of DES. Methods: We built a DES model of a five procedure room endoscopy unit at a tertiary-care university medical center. After validating the baseline model, we tested alternate configurations to run the endoscopy suite and evaluated outcomes associated with each change. The main outcome measures included adequate number of preparation and recovery rooms, blocked inflow, delay times, blocked outflows, and patient cycle time. Results: Based on a sensitivity analysis, the adequate number of preparation rooms is eight and recovery rooms is nine for a five procedure room unit (total 3.4 preparation and recovery rooms per procedure room). Simple changes to procedure scheduling and patient arrival times led to a modest improvement in efficiency. Increasing the preparation/recovery rooms based on the sensitivity analysis led to significant improvements in efficiency. Conclusions: By applying tools such as DES, we can model changes in an environment with complex interactions and find ways to improve the medical care we provide. DES is applicable to any endoscopy unit and would be particularly valuable to those who are trying to improve on the efficiency of care and patient experience.
RESUMO
Previous studies suggest baicalein, in addition to its antioxidant effects, protects against hypoxia/reoxygenation injury via its pro-oxidant properties. We hypothesize that a brief period of baicalein treatment prior to ischemia/reperfusion (I/R) may trigger preconditioning protection via a mitochondrial pro-oxidant mechanism. Using an established chick cardiomyocyte model of I/R, cells were preconditioned with baicalein (10 µM) for 10 min followed by 10-min wash prior to I/R. Intracellular oxidants were measured using 2', 7'-dichlorofluorescin diacetate (DCFH/DA). Cell viability was assessed by propidium iodide and apoptosis determined by DNA fragmentation. Baicalein induced a transient but significant increase of DCF fluorescence within the 10-min preconditioning period, and led to significant reduction of cell death (38.9 ± 1.8% vs. 58.7 ± 1.2% in I/R control, n = 6, p < 0.001) and DNA fragmentation after I/R. Cotreatment with N-acetylcysteine (500 µM), mitochondrial complex III electron transport chain inhibitor myxothiazol (1 µM), mitochondrial KATP channel blocker 5-hydroxydecanoate-Na (5-HD, 500 µM) or anion channel inhibitor 4', 4'-diisothiocyanato-stilbene-2, 2'-disulfonic acid (DIDS, 200 µM) resulted in significant abrogation of oxidant increase during induction as well as the protection conferred by baicalein preconditioning. These results suggest that baicalein preconditioning exhibits significant anti-apoptotic protection against cardiomyocyte I/R injury by mitochondrial oxidant signaling, which was in part mediated by mitochondrial KATP channel and anion channel opening.
