Högskolan i Skövde

Background: Early detection of bacteria and their antibiotic susceptibility patterns are critical to guide therapeutic decision-making for optimal care of septic patients. The current gold standard, blood culturing followed by subculture on agar plates for subsequent identification, is too slow leading to excessive use of broad-spectrum antibiotic with harmful consequences for the patient and, in the long run, the public health. The aim of the present study was to assess the performance of two commercial assays, QuickFISH® (OpGen) and Maldi Sepsityper™ (Bruker Daltonics) for early and accurate identification of microorganisms directly from positive blood cultures.

Materials and methods: During two substudies of positive blood cultures, the two commercial assays were assessed against the routine method used at the clinical microbiology laboratory, Unilabs AB, at Skaraborg Hospital, Sweden.

Results: The Maldi Sepsityper™ assay enabled earlier microorganism identification. Using the cut-off for definite species identification according to the reference method (>2.0), sufficiently accurate species identification was achieved, but only among Gram-negative bacteria. The QuickFISH®assay was time-saving and showed high concordance with the reference method, 94.8% (95% CI 88.4–98.3), when the causative agent was covered by the QuickFISH® assay.

Conclusions: The use of the commercial assays may shorten the time to identification of causative agents in bloodstream infections and can be a good complement to the current clinical routine diagnostics. Nevertheless, the performance of the commercial assays is considerably affected by the characteristics of the causative agents.

Healthcare facilities, and especially emergency departments (ED), are usually characterized by its complexity due to the variability and stochastic nature of the processes involved in the system. The combination of different flows of patients, staff and resources also increments the complexity of this kind of facilities. In order to increase its efficiency, many researchers have proposed discrete-event simulation (DES) as a powerful improvement tool. However, DES can be a limited approach in the case a simulation model has too many combinations of input parameters, complex correlations between the input and output parameters and different objective functions. Hence, to find the best configuration of a complex system, an approach combining DES and meta-heuristic optimization becomes an even more powerful improvement technique. Simulation-based multiobjective-optimization (SMO) is a promising approach to generate multiple trade-off solutions particularly when multiple conflicting objectives exist within a complex system. The generated solutions provide decision makers with feasible and optimal alternatives to improve, modify or design healthcare systems. The aim of this paper is to present the work done at the ED of the regional Hospital of Skövde in Sweden, where SMO implemented in modeFromtier has been successfully applied. The result and methodology present a successful approach for decision makers in healthcare systems to reduce the waiting time of patients saving considerable time, money and resources.

Emergency departments in Sweden are usually struggling with long waiting times, delays and bottlenecks in the system. The National Board of Health and Welfare and the County Council of Västra Götaland have established to decrease the average time a patient stays in an emergency department as important priority as well as the waiting time to be seen by a nurse and by a physician.

Healthcare systems are usually characterized by its complexity because of the variability and stochastic nature of the different processes involved in the flow of patients, staff and resources. In order to increase the use of the existing resources and to reduce the waiting times of patients, a system improvement methodology involving discrete-event simulation and process analysis has been used. In this project a computer-based simulation tool was applied at the emergency department of the hospital Kärnsjukhuset in Skövde, which belongs to Skaraborgs Sjukhus and is one of the largest emergency departments in the region of Västra Götaland. A three-dimensional model was created to help visualize and understand the problems, as well as to identify improvements by the different stakeholders involved. Continually, the simulation model was modified to test possible improved scenarios with the aim to increase the service level of the system. 

The design, implementation and analysis of these scenarios have provided decision makers of the emergency department with the necessary information to implement or reject the ideas of the different improved scenarios. Some of these scenarios had a significant impact with small changes so they were implemented in the real system; some others had non-significant impact in the results so they were not implemented. The main result of this project has been to identify which system changes will lead to a reduction of the different waiting times of patients. In addition, the simulation and experiments of future solutions show a more efficient use of the existing resources. This design of a better configuration of the system gives Kärnsjukhuset the possibility to increase the service level of the system and to meet some of the requirements established by the County Council. This project shows that the use of simulation tools provides enormous benefits for healthcare system analysis and improvement; new ideas and scenarios can be designed without disturbing the normal activities of the hospital, saving considerable time, money and resources.