Contrast media extravasations in patients undergoing computerized tomography scanning: a systematic review and meta-analysis of risk factors and interventions.

To identify risk factors and interventions preventing or reducing contrast medium extravasation. Computed tomography (CT) is a radiological examination essential for the diagnosis and monitoring of many diseases. It is often performed with the intravenous (IV) injection of contrast agents. Use of these products can result in a significant complication, extravasation, which is the accidental leakage of IV material into the surrounding tissue. Patients may feel a sharp pain and skin ulceration or necrosis may develop. This review considered studies that included patients (adults and children) undergoing a CT with IV administration of contrast media. The risk factors considered were patient demographics, comorbidities and medication history. This review also investigated any strategies related to: contrast agent, injection per se, material used for injection, apparatus used, healthcare professionals involved, and patient risk assessment performed by the radiology personnel. The comparators were other interventions or usual care. This review investigated randomized controlled trials and non-randomized controlled trials. When neither of these were available, other study designs, such as prospective and retrospective cohort studies, case-control studies and case series, were considered for inclusion. Primary outcomes considered were: extravasation frequency, volume, severity and complications. The databases PubMed, CINAHL, Embase, the Cochrane Register of Controlled Trials, Web of Science PsycINFO, ProQuest Dissertations and Theses A&I, TRIP Database and ClinicalTrials.gov were searched to find both published and unpublished studies from 1980 to September 2016. Papers were assessed by two independent reviewers for methodological validity using the Joanna Briggs Institute System for the Unified Management, Assessment and Review of Information (JBI SUMARI). Data were extracted using the standardized data extraction tool from JBI SUMARI. In one case, quantitative data from two cohort studies were pooled in a statistical meta-analysis. However, generally, statistical pooling was not possible due to heterogeneity of the interventions, populations of interest or outcomes. Accordingly, the findings have been presented in narrative form. Fifteen articles were selected from a total of 2151 unique studies identified. Two were randomized controlled trials and 13 were quasi-experimental and observational studies. The quality of these studies was judged to be low to moderate. Some patient characteristics, such as female sex and inpatient status, appeared to be risk factors for extravasation. Additionally, injection rate, venous access site and catheter dwelling time could affect the volume extravasated. Preliminary studies seemed to indicate the potential of extravasation detection accessories to identify extravasation and reduce the volume extravasated. The other interventions either did not result in significant reduction in the frequency/volume of extravasation, or the results were mixed across the studies. The majority of the studies included in this review evaluated the outcomes of extravasation frequency and volume. Given the quality of the primary studies, this systematic review identified only potential risk factors and interventions. It further highlighted the research gap in this area and the importance of conducting trials with solid methodological designs

Descriptional Complexity of Formal Systems

The proceedings contain 24 papers. The special focus in this conference is on Descriptional Complexity of Formal Systems. The topics include: Sensing as a complexity measure; avoiding overlaps in pictures; on the degree of nondeterminism of tree adjoining languages and head grammar languages; on the average complexity of strong star normal form; most complex non-returning regular languages; uncountable realtime probabilistic classes; a parametrized analysis of algorithms on hierarchical graphs; graph-controlled insertion-deletion systems generating language classes beyond linearity; computational completeness of networks of evolutionary processors with elementary polarizations and a small number of processors; self-attraction removal from oritatami systems; one-time nondeterministic computations; branching measures and nearly acyclic NFAS; a pumping lemma for ordered restarting automata; concise representations of reversible automata; reset complexity of ideal languages over a binary alphabet; state complexity of suffix distance and the quotient operation on input driven pushdown automata

Operation Characteristics Optimization of Low Power Three-Phase Asynchronous Motors

Most published papers on low power asynchronous motors were aimed to achieve better operational performances in different operating conditions. The optimal design of the general-purpose motors requires searching and selecting an electric machine to meet minimum operating costs criterion and certain customer imposed restrictive conditions. In this paper, there are many significant simulations providing qualitative and quantitative information on reducing active and reactive energy losses in motors, and on parameters and constructive solution. The optimization study applied the minimal operating costs criterion, and it took into account the starting restrictive conditions. Thirteen variables regarding electromagnetic stresses and main constructive dimensions were considered. The operating costs of the optimized motor decreased with 25.6%, as compared to the existing solution. This paper can be a practical and theoretical support for the development and implementation of modern design methods, based on theoretical and experimental study of stationary and transient processes in low power motors, to increase efficiency and power factor

Noise and Vibration Monitoring for Premium Efficiency IE 3 Three-Phase Induction Motors

The paper presents the original SV-100 platform that enables low-cost and very high accuracy determinations of noise and vibration levels. The aim of the proposed platform is to achieve an effective integration of the two topics of this analysis: vibrations and noises. To the best of our knowledge, no low price, dedicated compact platform with embedded measuring instruments exists. For proving the practical utility of the proposed platform, two induction motors of 7.5 kW and 11 kW, respectively, in single-layer winding, at 1000 rpm, with IE3 premium efficiency were analyzed. This analysis is required because, according to IEC60034-30 standard, the IE3 efficiency standard has become mandatory for induction motors of rated power greater than 7.5 kW. Therefore, in order to improve the motor operating efficiency, the power losses caused by noises and vibrations have to be reduced. Several variants of supply were studied, i.e., by the three-phase 50 Hz network and by a three-phase inverter at 40, 50 and 60 Hz, respectively. The experimental determinations of noises are presented comparatively, by using a Bruel&Kjaer sonometer and by using the new platform SV-100. The results are compared with the IEC60034 standard