The EventIndex is the complete catalogue of all ATLAS events, keeping the references to all files that contain a given event in any processing stage. It replaces the TAG database, which had been in ...use during LHC Run 1. For each event it contains its identifiers, the trigger pattern and the GUIDs of the files containing it. Major use cases are event picking, feeding the Event Service used on some production sites, and technical checks of the completion and consistency of processing campaigns. The system design is highly modular so that its components (data collection system, storage system based on Hadoop, query web service and interfaces to other ATLAS systems) could be developed separately and in parallel during LSI. The EventIndex is in operation for the start of LHC Run 2. This paper describes the high-level system architecture, the technical design choices and the deployment process and issues. The performance of the data collection and storage systems, as well as the query services, are also reported.
Background. The Laryngeal Tube Sonda® (LTS) is a supraglottic airway which, like the ProSeal® Laryngeal Mask Airway (PLMA), incorporates a drain tube. We compared the performances of LTS and PLMA ...during controlled ventilation anaesthesia. Methods. The devices were studied in 32 ventilated patients by randomized crossover trial. Primary outcome was airway seal pressure. Secondary outcomes included insertion success and time, manipulations required, ventilation quality, peak and plateau airway pressures, ability to pass a gastric tube and fibreoptic laryngeal view. Results. The PLMA produced a higher seal pressure (median values, PLMA 26 cm H2O and LTS 24 cm H2O, P<0.01). First-attempt insertion succeeded with PLMA 28 times and LTS 22 times (P>0.05). The PLMA required fewer manipulations (P<0.05) in fewer patients (P<0.05) and took less time to insert (P<0.01). All PLMA patients and 22 LTS patients achieved optimal ventilation (P<0.01). Peak airway pressure was lower with the PLMA than with the LTS (P<0.01). The vocal cords were visible through the PLMA in 32 patients and through the LTS in nine patients (P<0.001). The laryngeal view was superior through the PLMA (P<0.001). Conclusion. The difference in seal pressure between devices was clinically unimportant. However, the LTS had an unexpectedly high failure rate. PLMA performance exceeded LTS performance in many clinically useful measures. The PLMA has greater clinical utility than the LTS during controlled ventilation.
Summary
Ninety‐three claims (total cost £4 915 450) filed under ‘anaesthesia’ in the NHS Litigation Authority database between 1995 and 2007, alleging patient harm directly by drug administration ...error or by an allergic reaction, were analysed. Alleged errors were categorised using systems employed by the National Coordinating Council for Medication Error Reporting and Prevention, the American Society of Anesthesiologists Closed Claims Project and the UK Health and Safety Executive. The severity of outcome in each claim was categorised using adapted National Patient Safety Agency definitions. Sixty‐two claims involved alleged drug administration errors (total cost £4 283 677) and 15 resulted in severe harm or death. Half alleged the administration of the wrong drug, in most (16) a neuromuscular blocker. Of the claims alleging the wrong dose had been given (25), nine alleged opioid overdose including by neuraxial routes. The most frequently recorded adverse outcomes were awake paralysis (19 claims; total cost £182 347) and respiratory depression requiring intensive care treatment (13 claims; total cost £2 752 853). Thirty‐one claims involved allergic reactions (total cost £631 773). In 20 claims, the patient allegedly received a drug to which they were known to be allergic (total cost £130 794). All claims in which it was possible to categorise the nature of the error involved human error. Fewer than half the claims appeared likely to have been preventable by an ‘ideal double checking process’.
ATLAS developed and employed for Run 1 of the Large Hadron Collider a sophisticated infrastructure for metadata handling in event processing jobs. This infrastructure profits from a rich feature set ...provided by the ATLAS execution control framework, including standardized interfaces and invocation mechanisms for tools and services, segregation of transient data stores with concomitant object lifetime management, and mechanisms for handling occurrences asynchronous to the control framework's state machine transitions. This metadata infrastructure is evolving and being extended for Run 2 to allow its use and reuse in downstream physics analyses, analyses that may or may not utilize the ATLAS control framework. At the same time, multiprocessing versions of the control framework and the requirements of future multithreaded frameworks are leading to redesign of components that use an incident-handling approach to asynchrony. The increased use of scatter-gather architectures, both local and distributed, requires further enhancement of metadata infrastructure in order to ensure semantic coherence and robust bookkeeping. This paper describes the evolution of ATLAS metadata infrastructure for Run 2 and beyond, including the transition to dual-use tools-tools that can operate inside or outside the ATLAS control framework-and the implications thereof. It further examines how the design of this infrastructure is changing to accommodate the requirements of future frameworks and emerging event processing architectures.
The Event Index project consists in the development and deployment of a complete catalogue of events for experiments with large amounts of data, such as the ATLAS experiment at the LHC accelerator at ...CERN. Data to be stored in the EventIndex are produced by all production jobs that run at CERN or the GRID; for every permanent output file, a snippet of information, containing the file unique identifier and the relevant attributes for each event, is sent to the central catalogue. The estimated insertion rate during the LHC Run 2 is about 80 Hz of file records containing ∼15 kHz of event records. This contribution describes the system design, the initial performance tests of the full data collection and cataloguing chain, and the project evolution towards the full deployment and operation by the end of 2014.
The ATLAS event-level metadata infrastructure supports applications that range from data quality monitoring, anomaly detection, and fast physics monitoring to event-level selection and navigation to ...file-resident event data at any processing stage, from raw through analysis object data, in globally distributed analysis. A central component of the infrastructure is a distributed TAG database, which contains event-level metadata records for all ATLAS events, real and simulated. This resource offers a unique global view of ATLAS data, and provides an opportunity, not only for stream-style mining of event data, but also for an examination of data across streams, across runs, and across (re)processings. The TAG database serves as a natural locus for run-level and processing-level integrity checks, for investigations of event duplication and other issues in the trigger and offline systems, for questions about stream overlap, for queries about interesting but out-of-stream events, for statistics, and more. In early ATLAS running, such database queries were largely ad hoc, and were handled manually. In this paper, we describe an extensible infrastructure for addressing these and other use cases during upload and post-upload processing, and discuss some of the uses to which this infrastructure has been applied.
Modern scientific experiments collect vast amounts of data that must be catalogued to meet multiple use cases and search criteria. In particular, high-energy physics experiments currently in ...operation produce several billion events per year. A database with the references to the files including each event in every stage of processing is necessary in order to retrieve the selected events from data storage systems. The ATLAS EventIndex project is studying the best way to store the necessary information using modern data storage technologies (Hadoop, HBase etc.) that allow saving in memory key-value pairs and select the best tools to support this application from the point of view of performance, robustness and ease of use. This paper describes the initial design and performance tests and the project evolution towards deployment and operation during 2014.
Summary
We report the management of a patient requiring surgical laryngoscopy with a view to laser resection of an epiglottic recurrence of laryngeal cancer. Previous attempts at tracheal intubation ...and awake nasal fibreoptic intubation had failed. During a previous anaesthetic the patient had been both ‘impossible to intubate and to ventilate’. Neck scarring potentially complicated access for transtracheal jet ventilation. Nevertheless, a cricothyroid catheter was placed and surgery performed during low frequency ‘volume’ jet ventilation. Upper airway obstruction developed during the procedure, preventing exhalation, which led to raised intrathoracic pressure, cardiovascular collapse and barotrauma. The airway was re‐established by insertion of an LMA Proseal™. Fibreoptic placement of an Aintree intubation catheter® through this allowed re‐oxygenation and exchange for a cuffed tracheal tube. Some hours after the procedure, re‐intubation was necessary. This was achieved using the Aintree intubation catheter as an aid to nasal fibreoptic intubation and as a tube exchanger. Novel roles of the Aintree intubation catheter and LMA Proseal in this case are discussed. Complications of transtracheal jet ventilation as well as possible methods for avoiding them are also reviewed.
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