ORTHOGONAL RANGE SKYLINE QUERIES

Given a set of points P, we often need to report the ones that lie within a certain query range Q. This is referred to as orthogonal range reporting. We can also go further, reporting only the dominant points within that query. In 2 dimensions, a point p1 = (x1, y1) dominates a point p2 = (x2, y2) iff x1 ≥ x2 and y1 \u3e y2 or x1 \u3e x2 and y1 ≥ y2. The set of all dominant points within a query range is called the skyline of that query. There are several different variants of skyline queries. For example, we can consider each point in P to be colored. Given a query range Q, can we efficiently count the number of points of each color in the skyline? In this thesis, we will present a new O( log n log log n + D log log n) method for doing so. The method is possible thanks to a new reduction from skyline queries to orthogonal range queries. We will also explore novel algorithms for answering skyline query variants in the I/O model of computation, making use of techniques such as Ganguly et al.’s [2] double-chaining method and Alstrup et al.’s [14] grid approach. By applying these existing techniques in new ways, we can not only derive our own efficient algorithms for skyline queries, but also explore potential avenues for future researc

Reminding staff of diligence during the medication process is not enough to ensure safety : Learning from wrong fluid product selection incidents in the care of critically ill patients

Background and objectives: Wrong fluid product selection may cause harm to patients. This study aimed to describe voluntarily reported wrong fluid product selection incidents, including their consequences, the reported latent conditions and active failures leading to these and the suggested safeguards to prevent their occurrence, and to compare the suggested and literature-based safeguards to improve the fluid therapy safety within the intensive care (ICU) environment. Methods: All voluntarily and anonymously reported wrong fluid product selection incidents in all Finnish ICUs during 2007–2017 were reviewed. The incident reports included categorized data that were analyzed quantitatively, and narratives that were analyzed qualitatively, using content analysis. The results were reported as frequencies and percentages and described by using Reason's model of human error. Results: Over the eleven years, one wrong fluid product selection incident was reported every six days (n=663; 584 errors, 79 near misses); most were reported to have occurred during the dispensing/preparing phase (92%). Of the 584 reported selection errors, a quarter (26%) was reported to have caused consequences to patients, and one third (35%) to have required corrective or monitoring actions. The main reported latent conditions to the incidents were Working environment and resources (e.g. workload and time pressure) (29%), Similar-looking and -sounding names or shared features of the product containers (i.e. the LASA phenomenon) (28%) and Working methods (22%); and the main reported active failures were a lack of concentration, or forgetfulness (26%). Some usable suggestions of safeguards were made, e.g. optimizing fluid storage (15%) or utilizing checking practices (21%). While requiring accuracy, i.e. reminding staff of diligence and to be more attentive to detail during the whole medication process, was emphasized in most reports (71%), involving manufacturers in redesigning labels of fluid products, utilizing technology and strengthening pharmacy services are advocated existing literature. Conclusions: Wrong fluid product selection incidents with various latent conditions and active failures were reported more than once a week. To minimize the serious LASA phenomenon,multi-professional collaboration, coordinated international discussion and agreements of solutions with manufacturers, regulators and end-users, are needed. However, work is also needed to reduce the other latent factors, such as Working environment and resources as well as cognitive biases in daily work that may contribute to the occurrence of LASA related errors.Peer reviewe

Describing voluntarily reported fluid therapy incidents in the care of critically ill patients: Identifying, and learning from, points of risk at the national level

Background:Fluid therapy is a common intervention in critically ill patients. Fluid therapy errors may cause harm to patients. Thus, understanding of reported fluid therapy incidents is required in order to learn from them and develop protective measures, including utilizing expertise of pharmacists and technology to improve patient safety at the national level. Objectives:To describe fluid therapy incidents voluntarily reported in intensive care and high dependency units (ICUs) to a national incident reporting system, by investigating the error types,fluid products, consequences to patients and actions taken to alleviate them, and to identify at which phase of the medication process the incidents had occurred and had been detected. Methods:Medication related voluntarily reported incident (n= 7623) reports were obtained from all ICUs in2007–2017. Incidents concerning fluid therapy (n= 2201) were selected. The retrospective analysis utilized categorized data and narrative descriptions of the incidents. The results were expressed as frequencies and percentages. Results:Most voluntarily reported incidents had occurred during the dispensing/preparing phase(n= 1306, 59%) of the medication process: a point of risk. Most incidents (n= 1975, 90%) had reached the patient and passed through many phases in the medication process and nursing shift change checks before detection. One third of the errors (n=596,30%) were reported to have caused consequences to patients. One quarter (n= 492, 25%) of the errors were reported to have required an additional procedure to alleviate or monitor the consequences. Conclusions:Utilizing national incident report data enabled identifying systemic points of risk in the medication process and learning to improve patient safety. To prevent similar incidents, initial interventions should focus on the dispensing/preparing phase before implementing active medication identification procedures at each phase of the medication process and nursing shift changes. Strengthening clinical pharmacy services, utilizing technology, co-ordinated by IV Fluid Coordinators and Medication Safety Officers, could improve patient safety in the ICUs.Peer reviewe