A Comparison of the Bow-Tie and STAMP Approaches to Reduce the Risk of Surgical Instrument Retention

Although relatively rare, surgical instrument retention inside a patient following Central Venous Catheterisation still presents a significant risk. The research presented here compared two approaches to help reduce retention risk: Bow-Tie Analysis and Systems- Theoretic Accident Model and Processes. Each method was undertaken separately and then the results of the two approaches were compared and combined. Both approaches produced beneficial results that added to existing domain knowledge, and a combination of the two methods was found to be beneficial. For example, the bow-tie analysis gave an overview of which activities keep controls working and who is responsible for each control, and the Systems-Theoretic Accident Model and Processes revealed the safety constraints that were not enforced by the supervisor of the controlled process. Such two-way feedback between both methods is potentially helpful for improving patient safety. Further methodology ideas to minimise surgical instrument retention risks are also described.This research was part-funded by the National Institute for Health Research (NIHR) Collaboration for Leadership in Applied Health Research and Care East of England (CLAHRC EoE) at Cambridge and Peterborough NHS Foundation Trust. The views expressed are those of the author(s) and not necessarily those of the NHS, the NIHR, or the Department of Health. Additional funding was provided by Cambridge University Hospitals NHS Foundation Trust. Cambridge University Hospitals NHS Foundation Trus

Leading safety indicators: Towards determining the enhancement or degradation of the level of patient safety in healthcare

A leading safety indicator is “a warning sign that can be used in monitoring a safety-critical process to detect when a safety-related assumption is broken or dangerously weak and that action is required to prevent an accident. Alternatively, a leading indicator is a warning signal that the validity or vulnerability of an assumption is changing” (Leveson 2015). The NHS defines a “patient safety incident” as “any unintended or unexpected incident which could have or did lead to harm for one or more patients receiving NHS care”. The Health Foundation (2013) notes that fifteen years after the establishment of the National Patient Safety Agency, it is still difficult to know whether patients are safer in the NHS than they were. Thus, the question is: can leading safety indicators monitor and assess the level of patient safety

A Comparison of the Bow-Tie and STAMP Approaches to Reduce the Risk of Surgical Instrument Retention

Although relatively rare, surgical instrument retention inside a patient following Central Venous Catheterisation still presents a significant risk. The research presented here compared two approaches to help reduce retention risk: Bow-Tie Analysis and Systems- Theoretic Accident Model and Processes. Each method was undertaken separately and then the results of the two approaches were compared and combined. Both approaches produced beneficial results that added to existing domain knowledge, and a combination of the two methods was found to be beneficial. For example, the bow-tie analysis gave an overview of which activities keep controls working and who is responsible for each control, and the Systems-Theoretic Accident Model and Processes revealed the safety constraints that were not enforced by the supervisor of the controlled process. Such two-way feedback between both methods is potentially helpful for improving patient safety. Further methodology ideas to minimise surgical instrument retention risks are also described

Guidewire Retention after Central Venous Catheterisation: Prevention and Mitigation using Bow-Tie Analysis

Never events are typically rare but serious incidents in healthcare. They are perceived to be preventable, and include the retention of a surgical instrument in a patient's body. One such instrument is a "guidewire", which is used to help introduce a catheter tube into the venous system of a patient. Following a number of guidewire retentions, these authors investigated contributing factors and examined mechanisms to reduce the risk of further occurrences. This paper presents the results in the form of a bow-tie analysis, which was found to provide an effective way to graphically display and examine the issue

Conceptualizing the key features of cyber-physical systems in a multi-layered representation for safety and security analysis

Many safety‐related systems are evolving into cyber‐physical systems (CPSs), integrating information technologies in their control architectures and modifying the interactions among automation and human operators. Particularly, a promising potential exists for enhanced efficiency and safety in applications such as autonomous transportation systems, control systems in critical infrastructures, smart manufacturing and process plants, robotics, and smart medical devices, among others. However, the modern features of CPSs are ambiguous for system designers and risk analysts, especially considering the role of humans and the interactions between safety and security. The sources of safety risks are not restricted to accidental failures and errors anymore. Indeed, cybersecurity attacks can now cascade into safety risks leading to physical harm to the system and its environment. These new challenges demand system engineers and risk analysts to understand the security vulnerabilities existing in CPS features and their dependencies with physical processes. Therefore, this paper (a) examines the key features of CPSs and their relation with other system types; (b) defines the dependencies between levels of automation and human roles in CPSs from a systems engineering perspective; and (c) applies systems thinking to describe a multi‐layered diagrammatic representation of CPSs for combined safety and security risk analysis, demonstrating an application in the maritime sector to analyze an autonomous surface vehicle