Reducing adverse drug events: lessons from a breakthrough series collaborative

BACKGROUND: In January 1996, 38 hospitals and health care organizations (for a total of 40 hospitals) in the United States came together in an Institute for Healthcare Improvement (IHI; Boston) Breakthrough Series collaborative to reduce adverse drug events-injuries related to the use or nonuse of medications. METHODS: The participants were taught the Model for Improvement, a method for rapid-cycle change and evaluation, and were then coached on how to identify their own problem areas and develop changes in practice for rapid-cycle testing. These changes could be implementation of one or more known medication error prevention practices or new practices developed. RESULTS: During a 15-month period the 40 hospitals conducted a total of 739 tests of changes. Process changes accounted for 63% of the cycles; the remainder consisted of preliminary data gathering, consensus-building, or education cycles. Eight types of changes were implemented by seven or more hospitals, with a success rate of 70%. These changes included non-punitive reporting, ensuring documentation of allergy information, standardizing medication administration times, and implementing chemotherapy protocols. DISCUSSION: Success in making significant changes was associated with strong leadership, effective processes, and appropriate choice of intervention. Successful teams were able to define, clearly state, and relentlessly pursue their aims, and then chose practical interventions and moved early into changing a process. They did not spend months collecting data before beginning a change. Changes that were most successful were those that attempted to change processes, not people. Health care organizations committed to patient safety need not regard current performance limits as inevitable.     

Kinetics of human erythrocyte acetylcholinesterase inhibition by a novel derivative of physostigmine: phenserine

The elastic properties of carotid arteries of spontaneously hypertensive rats (SHR) and normotensive controls (Wistar-Kyoto rats [WKY]) were examined in vivo, in situ, and in vitro. The changes of internal diameter were measured with a high-resolution A-mode echo-tracking device simultaneously with the intra-arterial pressure at the carotid. The internal diameter at mean arterial blood pressure (MBP) was substantially smaller in vitro than in vivo in SHR (-33.8%) and WKY (-48.3%). The arterial distensibility was lower in vitro in all arteries compared with in vivo conditions (SHR, -30.1%; WKY, -60.4%; at MBP) despite a reduced incremental elastic modulus in vitro (SHR, -56.9%; WKY, -45.1%; at MBP). However, the in vitro and in vivo measurements show consistent elastic behavior of the carotid arteries between both strains of rats. Carotid arteries from WKY were also examined in situ. Although no significant reduction in internal diameter could be observed in situ, distensibility was dramatically decreased (-87% at MBP). These results emphasize the importance of considering the original vascular geometry when determining elastic properties of arteries. We conclude that experimental conditions are likely to be a critical determinant for the assessment of the mechanical properties of conduit vessels.     

Analysis of the semisynchronous carrier sense multiple access onthe bus topology

Consider an arbitrary number of stations equally spaced on a channel configured as a bus topology. The stations access the channel according to the nonpersistent CSMA protocol, which may be with or without collision detection. Users are synchronized to the propagation delay between two adjacent users, and are thus semisynchronized. Such a system with single-buffered users and an exponential backoff strategy, is modeled. The system throughput and the mean delay are evaluated, and it is shown how to obtain the distribution of the packet interdeparture time as well as the packet delay. It is shown that the rescheduling strategy has a profound effect on the station performance, and that it can be used to eliminate the difference between the performance of different stations at any given offered load. The model is also used to accommodate finer synchronization steps, as well as arbitrary topologies     

The computer-aided design of modular fixturing systems

The flexibility of modular fixturing systems can be exploited to significantly enhance the productivity of computer integrated manufacturing facilities. A major impediment to the implementation of this philosophy is the absence of viable methodologies for the automated design and assembly of these fixturing systems. This paper addresses this technological void by proposing a CAD/CAM tool for the automated design and robotic assembly of modular fixturing systems which can form the basis for a fully automated design system. The development of automated flexible fixturing technologies that transcend the traditional time-consuming and expensive practice of manual assembly would significantly contribute to the evolution to the factory-of-the-future.     

A monoclonal antibody-based enzyme immunoassay for detecting parasite antigenaemia and antigenuria in Schistosomiasis mansoni

Both specific polycolonal antibody and monoclonal antibody against the microsomal antigen of adult S. mansoni were used to detect antigenaemia and antigenuria by antigen-capture sandwich ELISA in the sera and urine of patients infected with S. mansoni and other parasites. Antigenaemia was detected in 22 sera out of 100 of patients infected with S. mansoni but no antigenuria was detected. None of the sera of S. mansoni free patients were positive for microsomal antigen. More standardization of the technique and more refining of the reagents used is required to improve the sensitivity of the test.     

A Study of Users' Buffer Variations in Random Access Satellite Channels

A novel approach to modeling the slotted-ALOHA random access channel is presented. The objectives of the model are threefold: (1) to identify the channel's stability boundaries analytically as a function of the system's independent input parameters; (2) to investigate the impact of buffer-control on the channel's behavior; and (3) to facilitate the structuring of individual users' buffer-control as the focus of a dynamic control scheme. The significance of maintaining channel stability via buffer-control lies in its conceptual simplicity and implementability. Simulation runs of a finite-population model have clearly revealed the variation in individual users' buffer sizes and their sensitivity to the retransmission procedure.     

On the use of pressure‐volume‐temperature data of polyethylene liquids for the determination of their solubility and interaction parameters

Specific volumes of high‐density and low‐density polyethylene liquids at several elevated temperatures and pressures were measured. The measured specific volumes were then used to estimate the thermal expansion coefficients $\left( {{\rm \alpha = }\frac{{\rm 1}}{v}\left( {\frac{{\partial v}}{{\partial T}}} \right)_P } \right)$ and isothermal compressibility $\left( {{\rm \beta = } - \frac{{\rm 1}}{v}\left( {\frac{{\partial v}}{{\partial P}}} \right)_T } \right)$ of the polymers. Two different approaches were used in which one was simply to fit the raw data by second order polynomials to obtain (?v/?T)_P and (?v/?P)_T, while the other by the Sanchez‐Lacombe (S‐L) equation of state. It was found that the resultant α and β obtained from the above methods differ significantly, indicating that the S‐L equation of state may not be suitable for determining α and β at elevated temperatures. When these two sets of α and β were used to calculate the corresponding solubility parameters and then the Flory‐Huggins interaction parameters (χ) of the polymers, the results also differ considerably. Nonetheless, χ obtained from the first method agrees well with the results obtained from small angle neutron scattering measurements while the S‐L equation of state method does not. The current results suggest that solubility and interaction parameters obtained from pressure‐volume‐temperature experiments depend critically on the manner by which the data analysis is performed. Polym. Eng. Sci. 44:853–860, 2004. © 2004 Society of Plastics Engineers.     

Patient safety and computerized medication ordering at Brigham and Women's Hospital

BACKGROUND: Medications are important therapeutic tools in health care, yet creating safe medication processes is challenging for many reasons. Computerized physician order entry (CPOE), one important way that technology can be used to improve the medication process, has been in place at Brigham and Women's Hospital (BWH; Boston) since 1993. CPOE AT BWH: The CPOE application, designed and developed internally by the BWH information systems team, allows physicians and other clinicians to enter all patient orders into the computer. Physicians enter 85% of orders, with the remainder entered electronically by other clinicians. CPOE AND SAFE MEDICATION USE: The CPOE application at BWH includes several features designed to improve medication safety--structural features (for example, required fields, use of pick lists), enhanced workflow features (order sets, standard scales for insulin and potassium), alerts and reminders (drug-drug and drug-allergy interaction checking), and adjunct features (the pharmacy system, access to online reference information). RESULTS AT BWH: Studies of the impact of CPOE on physician decision making and patient safety at BWH include assessment of CPOE's impact on the serious medication error and the preventable adverse drug event rate, the impact of computer guidelines on the use of vancomycin, the impact of guidelines on the use of heparin in patients at bed rest, and the impact of dosing suggestions on excessive dosing. CONCLUSION: CPOE and several forms of clinical decision support targeted at increasing patient safety have substantially decreased the frequency of serious medication errors and have had an even bigger impact on the overall medication error rate.     

Person tracking and reidentification: Introducing Panoramic Appearance Map (PAM) for feature representation

This paper develops a concept of Panoramic Appearance Map (PAM) for performing person reidentification in a multi-camera setup. Each person is tracked in multiple cameras and the position on the floor plan is determined using triangulation. Using the geometry of the cameras and the person location, a panoramic map centered at the person’s location is created with the horizontal axis representing the azimuth angle and vertical axis representing the height. Each pixel in the map image gets color information from the cameras which can observe it. The maps between different tracks are compared using a distance measure based on weighted SSD in order to select the best match. Temporalintegration by registering multiple maps over the tracking period improves the matching performance. Experimental results of matching persons between two camera sets show the effectiveness of the approach. This work has been sponsored by the Technical Support Working Group (TSWG) of US Department of Defence (DoD).     

Behavior of Stone Columns Based on Experimental and FEM Analysis

A detailed experimental study on behavior of single column and group of seven columns is carried out by varying parameters like spacing between the columns, shear strength of soft clay, and loading condition. Laboratory tests are carried out on a column of 100?mm diameter surrounded by soft clay of different consistency. The tests are carried out either with an entire equivalent area loaded to estimate the stiffness of improved ground or only a column loaded to estimate the limiting axial capacity. During the group experiments, the actual stress on column and clay were measured by fixing pressure cells in the loading plate. Finite-element analyses have also been performed using 15-noded triangular elements with the software package PLAXIS. A drained analysis was carried out using Mohr-Coulomb’s criterion for soft clay, stones, and sand. The numerical results from the FEM are compared with the experimental results which showed good agreement between the results. Columns arranged with spacings more than 3 times the diameter of the column does not give any significant improvement. Based on the results, design charts are developed and a design procedure is suggested.