Coordinated Design of Phase Measurement Unit and Power System Stabilisers in Large Scale Power System

This paper presents a case-study of a PMU application with PSS support in a real large scale Chinese power system to suppress inter-area oscillations. The paper uses PMU measured feedback signals from a PSS input signal for dynamic torque analysis (DTA). In the paper, a mathematical model of multi-machine power system is described, followed by formation of the residue and DTA indices. Simulations of the model are used with a large-scale power system model to demonstrate the role of PSS and the equivalence of DTA residue indices.

Prospective clinical audit of chloral hydrate administration practices in a neonatal unit

Aim: Chloral hydrate is generally considered a safe and effective single dosing procedural sedative for neonates in the clinical setting. However, its safety profile as a repetitive dosing maintenance sedative is largely unknown. This study aimed to document current administration practices of chloral hydrate in the Neonatal Unit, Royal Children's Hospital, Melbourne, Australia, over a 6-month period.

Methods: Patients who had been prescribed chloral hydrate during the specified audit period were recruited into the study and prospectively followed for a period of 28 days, or until they were discharged from the unit. Demographic data were collected on recruitment, and daily documentation of chloral hydrate administration was recorded.

Results: A total of 238 doses of chloral hydrate were administered to a cohort of 32 patients during the study period. The majority of the audited doses (84%) were ordered as repeating doses. Doses were more likely to be given at night than during the day, and the median dosage for repetitive dosing was found to be above the study site's recommended dosing range. Pre-dose and/or post-dose assessment of distress/agitation accompanied dosage approximately half of the time. The audit did not reveal any recognisable pattern of sedation maintenance or weaning process for patients who received multiple doses.

Conclusions: Health-care professionals caring for hospitalised infants should be made aware of the potential risks of chloral hydrate as a repetitive dosing sedative, and of the importance of systematically evaluating the appropriateness and effectiveness of utilising such pharmacological intervention for managing and treating distress.

Implementing change in the neonatal unit: Part 1 – The evidence base

Pain management in premature and sick babies has long been recognised as a vital component of neonatal care; however practices pertaining to pain assessment and administration of analgesia remain variable in Neonatal Units (NNU). Sucrose has been identified as an effective agent in reducing pain during minor painful procedures in premature babies but the uptake has been modest.This article is the first of two, and will describe the rationale for implementation of sucrose administration as a measure for pain relief for minor procedures in one neonatal unit in Northern Ireland. Current literature relating to use of sucrose willbe utilised in generating debate and discussion around the implementation of Clinical Practice Guidelines (CPG) for Sucrose use.

Loss-of-Mains Protection System by Application of Phasor Measurement Unit Technology with Experimentally Assessed Threshold Settings

Loss-of-mains protection is an important component of the protection systems of embedded generation. The role of loss-of-mains is to disconnect the embedded generator from the utility grid in the event that connection to utility dispatched generation is lost. This is necessary for a number of reasons, including the safety of personnel during fault restoration and the protection of plant against out-of-synchronism reclosure to the mains supply. The incumbent methods of loss-of-mains protection were designed when the installed capacity of embedded generation was low, and known problems with nuisance tripping of the devices were considered acceptable because of the insignificant consequence to system operation. With the dramatic increase in the installed capacity of embedded generation over the last decade, the limitations of current islanding detection methods are no longer acceptable. This study describes a new method of loss-of-mains protection based on phasor measurement unit (PMU) technology, specifically using a low cost PMU device of the authors' design which has been developed for distribution network applications. The proposed method addresses the limitations of the incumbent methods, providing a solution that is free of nuisance tripping and has a zero non-detection zone. This system has been tested experimentally and is shown to be practical, feasible and effective. Threshold settings for the new method are recommended based on data acquired from both the Great Britain and Ireland power systems.

Synergy Between an Improved Covariate Unit Root Test and Cross-sectionally Dependent Panel Data Unit Root Tests, with two Applications

This paper proposes the use of an improved covariate unit root test which exploits the cross-sectional dependence information when the panel data null hypothesis of a unit root is rejected. More explicitly, to increase the power of the test, we suggest the utilization of more than one covariate and offer several ways to select the ‘best’ covariates from the set of potential covariates represented by the individuals in the panel. Employing our methods, we investigate the Prebish-Singer hypothesis for nine commodity prices. Our results show that this hypothesis holds for all but the price of petroleum.

Development of a Short Stay Unit in an Emergency Department

In 2009, the Royal Victoria Hospital, Belfast, established a nine-bed, short-stay unit in its emergency department. This article explains the rationale for the model of care delivery adopted, and the importance of developing and working with integrated care pathways. It also discusses four areas essential to the effective running of the unit: interdisciplinary collaboration, training for clinical nurse leaders, management of change and leadership.

Genomovar diversity amongst Burkholderia cepacia complex isolates from an Australian adult cystic fibrosis unit

In this study, a combination of recA-based PCR assays and 16S rDNA restriction fragment length polymorphism (RFLP) analysis was used to determine the genomovar diversity of clinical Burkholderia cepacia complex isolates. Twenty-eight isolates were prospectively collected from patients attending a large Australian adult cystic fibrosis (CF) unit, 22 isolates were referred from other Australian CF units and a further eight isolates originated from patients without CF. The 28 prospectively collected isolates were distributed amongst the following genomovars: Burkholderia cepacia genomovar I (28.6%), Burkholderia multivorans (21.4%), Burkholderia cepacia genomovar III (39.3%), Burkholderia vietnamiensis(3.6%) and Burkholderia ambifaria (7.1%). The results of this study highlight the usefulness of 16S rDNA RFLP typing for the identification of other Burkholderia spp. and non-fermenting gram-negative bacteria.

Exercise rehabilitation following intensive care unit discharge for recovery from critical illness

Background: Skeletal muscle wasting and weakness are significant complications of critical illness, associated with the degree of illness severity and periods of reduced mobility during mechanical ventilation. They contribute to the profound physical and functional deficits observed in survivors. These impairments may persist for many years following discharge from the intensive care unit (ICU) and may markedly influence health-related quality of life. Rehabilitation is a key strategy in the recovery of patients following critical illness. Exercise based interventions are aimed at targeting this muscle wasting and weakness. Physical rehabilitation delivered during ICU admission has been systematically evaluated and shown to be beneficial. However its effectiveness when initiated after ICU discharge has yet to be established. Objectives: To assess the effectiveness of exercise rehabilitation programmes, initiated after ICU discharge, on functional exercise capacity and health-related quality of life in adult ICU survivors who have been mechanically ventilated for more than 24 hours. Search methods:We searched the following databases: the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library), OvidSP MEDLINE, Ovid SP EMBASE, and CINAHL via EBSCO host to 15th May 2014. We used a specific search strategy for each database. This included synonyms for ICU and critical illness, exercise training and rehabilitation. We searched the reference lists of included studies and contacted primary authors to obtain further information regarding potentially eligible studies. We also searched major clinical trials registries (Clinical Trials and Current Controlled Trials) and the personal libraries of the review authors. We applied no language or publication restriction. We reran the search in February 2015. We will deal with any studies of interest when we update the review.  Selection criteria:We included randomized controlled trials (RCTs), quasi-RCTs, and controlled clinical trials (CCTs) that compared an exercise interventioninitiated after ICU discharge to any other intervention or a control or ‘usual care’ programme in adult (≥18years) survivors ofcritical illness. Data collection and analysis:We used standard methodological procedures expected by The Cochrane Collaboration. Main results:We included six trials (483 adult ICU participants). Exercise-based interventions were delivered on the ward in two studies; both onthe ward and in the community in one study; and in the community in three studies. The duration of the intervention varied according to the length of stay in hospital following ICU discharge (up to a fixed duration of 12 weeks).Risk of bias was variable for all domains across all trials. High risk of bias was evident in all studies for performance bias, although blinding of participants and personnel in therapeutic rehabilitation trials can be pragmatically challenging. Low risk of bias was at least 50% for all other domains across all trials, although high risk of bias was present in one study for random sequence generation (selection bias), incomplete outcome data (attrition bias) and other sources. Risk of bias was unclear for remaining studies across the domains.All six studies measured effect on the primary outcome of functional exercise capacity, although there was wide variability in natureof intervention, outcome measures and associated metrics, and data reporting. Overall quality of the evidence was very low. Only two studies using the same outcome measure for functional exercise capacity, had the potential for pooling of data and assessment of heterogeneity. On statistical advice, this was considered inappropriate to perform this analysis and study findings were therefore qualitatively described. Individually, three studies reported positive results in favour of the intervention. A small benefit (versus. control)was evident in anaerobic threshold in one study (mean difference, MD (95% confidence interval, CI), 1.8 mlO2/kg/min (0.4 to 3.2),P value = 0.02), although this effect was short-term, and in a second study, both incremental (MD 4.7 (95% CI 1.69 to 7.75) Watts, P value = 0.003) and endurance (MD 4.12 (95% CI 0.68 to 7.56) minutes, P value = 0.021) exercise testing demonstrated improvement.Finally self-reported physical function increased significantly following a rehabilitation manual (P value = 0.006). Remaining studies found no effect of the intervention.Similar variability in with regard findings for the primary outcome of health-related quality of life were also evident. Only two studies evaluated this outcome. Following statistical advice, these data again were considered inappropriate for pooling to determine overall effect and assessment of heterogeneity. Qualitative description of findings was therefore undertaken. Individually, neither study reported differences between intervention and control groups for health-related quality of life as a result of the intervention. Overall quality of the evidence was very low.Mortality was reported by all studies, ranging from 0% to 18.8%. Only one non-mortality adverse event was reported across all patients in all studies (a minor musculoskeletal injury). Withdrawals, reported in four studies, ranged from 0% to 26.5% in control groups,and 8.2% to 27.6% in intervention groups. Loss to follow-up, reported in all studies, ranged from 0% to 14% in control groups, and 0% to 12.5% in intervention groups. Authors’ conclusions:We are unable, at this time, to determine an overall effect on functional exercise capacity, or health-related quality of life, of an exercise based intervention initiated after ICU discharge in survivors of critical illness. Meta-analysis of findings was not appropriate. This was due to insufficient study number and data. Individual study findings were inconsistent. Some studies reported a beneficial effect of the intervention on functional exercise capacity, and others not. No effect was reported on health-related quality of life. Methodological rigour was lacking across a number of domains influencing quality of the evidence. There was also wide variability in the characteristics of interventions, outcome measures and associated metrics, and data reporting.If further trials are identified, we may be able to determine the effect of exercise-based interventions following ICU discharge, on functional exercise capacity and health-related quality of life in survivors of critical illness.