Theoretical modelling and experimental investigation of a thermal energy storage refrigerator

Numerical simulations using the computational fluid dynamics (CFD) software ANSYS Fluent were undertaken to characterize the airflow and temperature distribution in a natural convection thermal energy storage refrigerator. The model compared the household refrigerator temperature stability with different phase change materials (PCM) incorporated into the storage compartment. Scenarios investigated included the PCM orientation (vertical or horizontal), PCM temperature (use of water or eutectics) and compartment designs (conventional or drawer type appliance). The results suggested that a horizontal PCM configuration produces lower compartment temperatures than a vertical configuration. The temperature distribution with a horizontal PCM was tested experimentally and the results were in agreement with the CFD predictions. Both the simulation and the experimental results suggest that a eutectic with a phase change temperature below 0 °C must be employed to maintain the compartment temperature within acceptable limits. The model indicated that combining horizontal and vertical PCMs in a full height compartment or dividing the same compartment into two drawers with a horizontal PCM configuration for each drawer are feasible design options for the household thermal storage refrigerator

Efficacy of Memantine for Agitation in Alzheimer’s Dementia: A Randomised Double-Blind Placebo Controlled Trial

Agitation in Alzheimer's disease (AD) is common and associated with poor patient life-quality and carer distress. The best evidence-based pharmacological treatments are antipsychotics which have limited benefits with increased morbidity and mortality. There are no memantine trials in clinically significant agitation but post-hoc analyses in other populations found reduced agitation. We tested the primary hypothesis, memantine is superior to placebo for clinically significant agitation, in patients with moderate-to-severe AD

Evaluation of drug administration errors in a teaching hospital

<p>Abstract</p> <p>Background</p> <p>Medication errors can occur at any of the three steps of the medication use process: prescribing, dispensing and administration. We aimed to determine the incidence, type and clinical importance of drug administration errors and to identify risk factors.</p> <p>Methods</p> <p>Prospective study based on disguised observation technique in four wards in a teaching hospital in Paris, France (800 beds). A pharmacist accompanied nurses and witnessed the preparation and administration of drugs to all patients during the three drug rounds on each of six days per ward. Main outcomes were number, type and clinical importance of errors and associated risk factors. Drug administration error rate was calculated with and without wrong time errors. Relationship between the occurrence of errors and potential risk factors were investigated using logistic regression models with random effects.</p> <p>Results</p> <p>Twenty-eight nurses caring for 108 patients were observed. Among 1501 opportunities for error, 415 administrations (430 errors) with one or more errors were detected (27.6%). There were 312 wrong time errors, ten simultaneously with another type of error, resulting in an error rate without wrong time error of 7.5% (113/1501). The most frequently administered drugs were the cardiovascular drugs (425/1501, 28.3%). The highest risks of error in a drug administration were for dermatological drugs. No potentially life-threatening errors were witnessed and 6% of errors were classified as having a serious or significant impact on patients (mainly omission). In multivariate analysis, the occurrence of errors was associated with drug administration route, drug classification (ATC) and the number of patient under the nurse's care.</p> <p>Conclusion</p> <p>Medication administration errors are frequent. The identification of its determinants helps to undertake designed interventions.</p

A review of studies describing the use of acetyl cholinesterase inhibitors in Parkinson's disease dementia

Objective: To review the literature relating to the use of acetyl cholinesterase inhibitors in Parkinson's disease dementia (PDD). Method: MEDLINE (1966 - December 2004), PsychINFO (1972 December 2004), EMBASE (1980 - December 2004), CINHAL (1982 - December 2004), and the Cochrane Collaboration were searched in December 2004. Results: Three controlled trials and seven open studies were identified. Efficacy was assessed in three key domains: cognitive, neuropsychiatric and parkinsonian symptoms. Conclusion: Cholinesterase inhibitors have a moderate effect against cognitive symptoms. There is no clear evidence of a noticeable clinical effect against neuropsychiatric symptoms. Tolerability including exacerbation of motor symptoms - in particular tremor - may limit the utility of cholinesterase inhibitors

The use of phase change materials in domestic refrigerator applications

This paper presents a study on the application of PCMs to domestic refrigerators. It is the result of a 4 year Industrial Case Award PhD supported by the EPSRC and Adande Refrigeration. The research focused on the design and operation of the thermal storage refrigerator aiming to improve the appliance efficiency, temperature stability and energetic autonomy. To achieve the project goals first the performance of a conventional refrigerator was analysed, in particular the size and efficiency of the compressor and its impact on the overall system performance. The operation of the thermal storage refrigerator was investigated by estimating the PCM melting and freezing time. A computational fluid dynamics (CFD) model was used to predict the airflow and temperature distribution within the thermal storage refrigerator. Several design options were simulated to identify the most effective PCM configuration (horizontal or vertical) and phase change temperature. A test rig was designed and constructed to validate experimentally the theoretical models which predicted the performance of the refrigerator with a horizontal PCM. The experimental results obtained for a prototype refrigerator will be presented and discussed

REalist Synthesis Of non-pharmacologicaL interVEntions for antipsychotic-induced weight gain (RESOLVE) in people living with severe mental illness (SMI)

Background People with severe mental illnesses (SMI) such as schizophrenia die on average 15 to 20 years earlier than everyone else. Two thirds of these deaths are from preventable physical illnesses such as hypertension, cardiovascular disease, and diabetes, which are worsened by weight gain. Antipsychotics are associated with significant weight gain. In REalist Synthesis Of non-pharmacologicaL interVEntions (RESOLVE), a realist synthesis, combining primary and secondary data, will be used to understand and explain how, why, for whom, and in what contexts non-pharmacological interventions can help service users to manage antipsychotic-induced weight gain. Methods A five-step approach will be used to develop guidance: 1. Developing the initial programme theory An initial (candidate) programme theory, which sets out how and why outcomes occur within an intervention, will be developed. 2. Developing the search The initial programme theory will be refined using academic and grey literature. The proposed initial sampling frame are as follows: Context: people living with SMI, taking antipsychotics, different types of SMI. Intervention: non-pharmacological interventions. Mechanisms: triggered by the intervention. Outcomes e.g. weight, metabolic adverse events, quality of life, adherence, burden, economic. Searching for relevant documents will continue until sufficient data is found to conclude that the refined programme theory is coherent and plausible. Lived experience (service users) and stakeholder (practitioners) groups will provide feedback. 3. Selection, appraisal and data extraction Documents will be screened against inclusion and exclusion criteria. The text extracted from these documents will be coded as contexts, mechanisms and their relationships to outcomes. 4. Primary data collection Realist interviews with up to 30 service users and informal carers, and 20 practitioners will gather data to support, refute or refine the programme theory. 5. Data analysis A realist logic of analysis will be used to develop and refine the programme theory from secondary and primary data. The analysis will aim to identify practical intervention strategies to change contexts so that key mechanisms are triggered to produce desired outcomes. Guidance will be produced based on these strategies. Discussion This realist synthesis aims to develop guidance for service users and practitioners on the most appropriate interventional strategies to manage and limit antipsychotic weight gain. Systematic review registration PROSPERO: CRD4202126869

Medication reconciliation by a pharmacy technician in a mental health assessment unit

Background Medication discrepancies are common when patients cross organisational boundaries. However, little is known about the frequency of discrepancies within mental health and the efficacy of interventions to reduce discrepancies. Objective To evaluate the impact of a pharmacy-led reconciliation service on medication discrepancies on admissions to a secondary care mental health trust. Setting In-patient mental health services. Methods Prospective evaluation of pharmacy technician led medication reconciliation for admissions to a UK Mental Health NHS Trust. From March to June 2012 information on any unintentional discrepancies (dose, frequency and name of medication); patient demographics; and type and cause of the discrepancy was collected. The potential for harm was assessed based on two scenarios; the discrepancy was continued into primary care, and the discrepancy was corrected during admission. Logistic regression identified factors associated with discrepancies. Main outcome measure Mean number of discrepancies per admission corrected by the pharmacy technician. Results Unintentional medication discrepancies occurred in 212 of 377 admissions (56.2 %). Discrepancies involving 569 medicines (mean 1.5 medicines per admission) were corrected. The most common discrepancy was omission (n = 464). Severity was assessed for 114 discrepancies. If the discrepancy was corrected within 16 days the potential harm was minor in 71 (62.3 %) cases and moderate in 43 (37.7 %) cases whereas if the discrepancy was not corrected the potential harm was minor in 27 (23.7 %) cases and moderate in 87 (76.3 %) cases. Discrepancies were associated with both age and number of medications; the stronger association was age. Conclusions Medication discrepancies are common within mental health services with potentially significant consequences for patients. Trained pharmacy technicians are able to reduce the frequency of discrepancies, improving safety