2,853 research outputs found

    Patient-maintained sedation for oral surgery using a target-controlled infusion of propofol - a pilot study

    Get PDF
    OBJECTIVE: To assess the safety and efficacy of a new patient-maintained propofol system for conscious sedation in dentistry. DESIGN: Prospective clinical trial SETTING: Department of Sedation, Glasgow Dental Hospital and School, 2001 SUBJECTS AND METHODS: Patients scheduled for oral surgery with conscious sedation. Exclusions included ASA IV -V, inability to use the handset, opioid use and severe respiratory disease. INTERVENTIONS: Patients were given intravenous propofol to a level of 1.0 microg/ml (reducing from 1.5 microg/ml) using a target controlled infusion system, they then controlled their sedation level by double-clicking a handset which on each activation increased the propofol concentration by 0.2 microg/ml. MAIN OUTCOME MEASURES: Oxygen saturation, patient satisfaction, and surgeon satisfaction. RESULTS: Twenty patients were recruited, 16 female and four male. Nineteen patients completed sedation and treatment successfully. Mean lowest oxygen saturation was 94%. No patients were over-sedated. All patients successfully used the system to maintain a level of sedation adequate for their comfort. Patient and surgeon satisfaction were consistently high. CONCLUSIONS: Initial experience with this novel system has confirmed safety, patient satisfaction and surgeon satisfaction

    Acupuncture for chronic neck pain: a pilot for a randomised controlled trial

    Get PDF
    Background: Acupuncture is increasingly being used for many conditions including chronic neck pain. However the evidence remains inconclusive, indicating the need for further well-designed research. The aim of this study was to conduct a pilot randomised controlled parallel arm trial, to establish key features required for the design and implementation of a large-scale trial on acupuncture for chronic neck pain. Methods: Patients whose GPs had diagnosed neck pain were recruited from one general practice, and randomised to receive usual GP care only, or acupuncture ( up to 10 treatments over 3 months) as an adjunctive treatment to usual GP care. The primary outcome measure was the Northwick Park Neck Pain Questionnaire (NPQ) at 3 months. The primary analysis was to determine the sample size for the full scale study. Results: Of the 227 patients with neck pain identified from the GP database, 28 (12.3%) consenting patients were eligible to participate in the pilot and 24 (10.5%) were recruited to the trial. Ten patients were randomised to acupuncture, receiving an average of eight treatments from one of four acupuncturists, and 14 were randomised to usual GP care alone. The sample size for the full scale trial was calculated from a clinically meaningful difference of 5% on the NPQ and, from this pilot, an adjusted standard deviation of 15.3%. Assuming 90% power at the 5% significance level, a sample size of 229 would be required in each arm in a large-scale trial when allowing for a loss to follow-up rate of 14%. In order to achieve this sample, one would need to identify patients from databases of GP practices with a total population of 230,000 patients, or approximately 15 GP practices roughly equal in size to the one involved in this study (i.e. 15,694 patients). Conclusion: This pilot study has allowed a number of recommendations to be made to facilitate the design of a large-scale trial, which in turn will help to clarify the existing evidence base on acupuncture for neck pain

    Effects of seasonal and pandemic influenza on health-related quality of life, work and school absence in England: results from the Flu Watch cohort study

    Get PDF
    BACKGROUND: Estimates of health-related quality of life (HRQoL) and work/school absences for influenza are typically based on medically-attended cases or those meeting influenza-like-illness (ILI) case definitions, and thus biased towards severe disease. Although community influenza cases are more common, estimates of their effects on HRQoL and absences are limited. OBJECTIVES: To measure Quality-Adjusted Life Days and Years (QALDs and QALYs) lost and work/school absences among community cases of acute respiratory infections (ARI), ILI and influenza A and B and to estimate community burden of QALY loss and absences from influenza. PATIENTS/ METHODS: Flu Watch was a community cohort in England from 2006-2011. Participants were followed-up weekly. During respiratory illness they prospectively recorded daily symptoms, work/school absences and EQ-5D-3L data and submitted nasal swabs for RT-PCR influenza testing. RESULTS: Average QALD lost was 0.26, 0.93, 1.61 and 1.84 for ARI, ILI, H1N1pdm09 and influenza B cases respectively. 40% of influenza A cases and 24% of influenza B cases took time off work/school with an average duration of 3.6 days and 2.4 days respectively. In England, community influenza cases lost 24,300 QALYs in 2010/11 and had an estimated 2.9 million absences per season based on data from 2006/07 - 2009/10. CONCLUSIONS: Our QALDs and QALYs lost and work and school absence estimates are lower than previous estimates because we focus on community cases, most of which are mild, may not meet ILI definitions and do not result in healthcare consultations. Nevertheless, they contribute a substantial loss of HRQoL on a population level. This article is protected by copyright. All rights reserved

    Measuring indirect transmission-reducing effects in tuberculosis vaccine efficacy trials: why and how?

    Get PDF
    Tuberculosis is the leading bacterial cause of death globally. In 2021, 10·6 million people developed symptomatic tuberculosis and 1·6 million died. Seven promising vaccine candidates that aim to prevent tuberculosis disease in adolescents and adults are currently in late-stage clinical trials. Conventional phase 3 trials provide information on the direct protection conferred against infection or disease in vaccinated individuals, but they tell us little about possible indirect (ie, transmission-reducing) effects that afford protection to unvaccinated individuals. As a result, proposed phase 3 trial designs will not provide key information about the overall effect of introducing a vaccine programme. Information on the potential for indirect effects can be crucial for policy makers deciding whether and how to introduce tuberculosis vaccines into immunisation programmes. We describe the rationale for measuring indirect effects, in addition to direct effects, of tuberculosis vaccine candidates in pivotal trials and lay out several options for incorporating their measurement into phase 3 trial designs

    Neural development features: Spatio-temporal development of the Caenorhabditis elegans neuronal network

    Full text link
    The nematode Caenorhabditis elegans, with information on neural connectivity, three-dimensional position and cell linage provides a unique system for understanding the development of neural networks. Although C. elegans has been widely studied in the past, we present the first statistical study from a developmental perspective, with findings that raise interesting suggestions on the establishment of long-distance connections and network hubs. Here, we analyze the neuro-development for temporal and spatial features, using birth times of neurons and their three-dimensional positions. Comparisons of growth in C. elegans with random spatial network growth highlight two findings relevant to neural network development. First, most neurons which are linked by long-distance connections are born around the same time and early on, suggesting the possibility of early contact or interaction between connected neurons during development. Second, early-born neurons are more highly connected (tendency to form hubs) than later born neurons. This indicates that the longer time frame available to them might underlie high connectivity. Both outcomes are not observed for random connection formation. The study finds that around one-third of electrically coupled long-range connections are late forming, raising the question of what mechanisms are involved in ensuring their accuracy, particularly in light of the extremely invariant connectivity observed in C. elegans. In conclusion, the sequence of neural network development highlights the possibility of early contact or interaction in securing long-distance and high-degree connectivity

    Quantum Acoustics with Surface Acoustic Waves

    Full text link
    It has recently been demonstrated that surface acoustic waves (SAWs) can interact with superconducting qubits at the quantum level. SAW resonators in the GHz frequency range have also been found to have low loss at temperatures compatible with superconducting quantum circuits. These advances open up new possibilities to use the phonon degree of freedom to carry quantum information. In this paper, we give a description of the basic SAW components needed to develop quantum circuits, where propagating or localized SAW-phonons are used both to study basic physics and to manipulate quantum information. Using phonons instead of photons offers new possibilities which make these quantum acoustic circuits very interesting. We discuss general considerations for SAW experiments at the quantum level and describe experiments both with SAW resonators and with interaction between SAWs and a qubit. We also discuss several potential future developments.Comment: 14 pages, 12 figure

    The Impact of Venous Thromboembolism on Risk of Death or Hemorrhage in Older Cancer Patients

    Get PDF
    BACKGROUND: Among older cancer patients, there is uncertainty about the degree to which venous thromboembolism (VTE) and its treatment increase the risk of death or major hemorrhage. OBJECTIVE: To determine the prevalence of VTE in a cohort of older cancer patients, as well as the degree to which VTE increased the risk of death or major hemorrhage. METHODS: We conducted a retrospective cohort study of linked Surveillance, Epidemiology, and End Results cancer registry and Medicare administrative claims data. Patients with any of ten invasive cancers diagnosed during 1995 through 1999 were included; the independent variable was VTE diagnosed concomitantly with cancer diagnosis. Outcomes included major hemorrhage during the first year after cancer diagnosis and all-cause mortality; RESULTS: Overall, about 1% of patients who were diagnosed with cancer also had a VTE diagnosed concomitantly. After adjusting for sociodemographic factors and cancer stage and grade, concomitant VTE was associated with a relative increase in the risk of death for 8 of the 10 cancer types; the increase in risk tended to range 20–40% across most cancer types. Approximately 16.8% (95% confidence interval [CI] 14.9–18.8%) of patients with a concomitant VTE and 7.9% (95% CI 7.7–8.0%) of patients without a VTE experienced a major hemorrhage during the year after cancer diagnosis (P value <.001). The excess risk of hemorrhage associated with VTE varied substantially across cancer types, ranging from no significant excess (kidney and uterine cancer) to 11.5% (lymphoma). CONCLUSION: Concomitant VTE is not only a marker and potential mediator of increased risk of death among older cancer patients, but patients with a VTE have a marked increased risk of major hemorrhage

    Simulations of extensional flow in microrheometric devices

    Get PDF
    We present a detailed numerical study of the flow of a Newtonian fluid through microrheometric devices featuring a sudden contraction–expansion. This flow configuration is typically used to generate extensional deformations and high strain rates. The excess pressure drop resulting from the converging and diverging flow is an important dynamic measure to quantify if the device is intended to be used as a microfluidic extensional rheometer. To explore this idea, we examine the effect of the contraction length, aspect ratio and Reynolds number on the flow kinematics and resulting pressure field. Analysis of the computed velocity and pressure fields show that, for typical experimental conditions used in microfluidic devices, the steady flow is highly three-dimensional with open spiraling vortical structures in the stagnant corner regions. The numerical simulations of the local kinematics and global pressure drop are in good agreement with experimental results. The device aspect ratio is shown to have a strong impact on the flow and consequently on the excess pressure drop, which is quantified in terms of the dimensionless Couette and Bagley correction factors. We suggest an approach for calculating the Bagley correction which may be especially appropriate for planar microchannels

    Ethanol reversal of tolerance to the respiratory depressant effects of morphine

    Get PDF
    Opioids are the most common drugs associated with unintentional drug overdose. Death results from respiratory depression. Prolonged use of opioids results in the development of tolerance but the degree of tolerance is thought to vary between different effects of the drugs. Many opioid addicts regularly consume alcohol (ethanol), and post-mortem analyses of opioid overdose deaths have revealed an inverse correlation between blood morphine and ethanol levels. In the present study, we determined whether ethanol reduced tolerance to the respiratory depressant effects of opioids. Mice were treated with opioids (morphine, methadone, or buprenorphine) for up to 6 days. Respiration was measured in freely moving animals breathing 5% CO(2) in air in plethysmograph chambers. Antinociception (analgesia) was measured as the latency to remove the tail from a thermal stimulus. Opioid tolerance was assessed by measuring the response to a challenge dose of morphine (10 mg/kg i.p.). Tolerance developed to the respiratory depressant effect of morphine but at a slower rate than tolerance to its antinociceptive effect. A low dose of ethanol (0.3 mg/kg) alone did not depress respiration but in prolonged morphine-treated animals respiratory depression was observed when ethanol was co-administered with the morphine challenge. Ethanol did not alter the brain levels of morphine. In contrast, in methadone- or buprenorphine-treated animals no respiratory depression was observed when ethanol was co-administered along with the morphine challenge. As heroin is converted to morphine in man, selective reversal of morphine tolerance by ethanol may be a contributory factor in heroin overdose deaths
    corecore