Images in Anesthesia: Transesophageal echocardiography enhances endovascular stent placement in traumatic trans-section of the thoracic aorta

Canadian Journal of Anesthesia/Journal canadien d'anesthésie -     

Challenges and directions for the pathogen hypothesis of Alzheimer's disease

This paper critically reviews the possibility that infiltration of the brain by pathogens (e.g. Herpes simplex virus type 1 (HSV1) or Chlamydophila pneumoniae (Cp)) acts as a trigger or co-factor for Alzheimer's disease (AD). The evidence currently available is limited and in some cases inconsistent, but it does justify the need for more vigorous investigation of this hypothesis. An issue of particular concern is the paucity of experimental evidence showing that pathogens can elicit the neuropathological changes and cognitive deficits that characterise AD. Other weaknesses include a failure to obtain independent confirmation of Cp in AD brains, and a lack of evidence for HSV1 proteins or intact virions in AD brain tissue. Future avenues of investigation that might prove fruitful include epidemiological investigations of the incidence of AD in individuals who are either immunosuppressed or have received chronic antiviral or antibiotic therapy. There is also a need to consider systemic infections as potential contributors to the pathogenesis of AD.     

Multiple imputation for body mass index: lessons from the Australian Longitudinal Study on Women's Health

In large epidemiological studies missing data can be a problem, especially if information is sought on a sensitive topic or when a composite measure is calculated from several variables each affected by missing values. Multiple imputation is the method of choice for 'filling in' missing data based on associations among variables. Using an example about body mass index from the Australian Longitudinal Study on Women's Health, we identify a subset of variables that are particularly useful for imputing values for the target variables. Then we illustrate two uses of multiple imputation. The first is to examine and correct for bias when data are not missing completely at random. The second is to impute missing values for an important covariate; in this case omission from the imputation process of variables to be used in the analysis may introduce bias. We conclude with several recommendations for handling issues of missing data.     

Managing Obstetric Emergencies and Trauma (MOET) structured skills training in Armenia, utilising models and reality based scenarios

Background

Mortality rates in Western Europe have fallen significantly over the last 50 years. Maternal mortality now averages 10 maternal deaths per 100,000 live births but in some of the Newly Independent States of the former Soviet Union, the ratio is nearly 4 times higher. The availability of skilled attendants to prevent, detect and manage major obstetric complications may be the single most important factor in preventing maternal deaths. A modern, multidisciplinary, scenario and model based training programme has been established in the UK (Managing Obstetric Emergencies and Trauma (MOET)) and allows specialist obstetricians to learn or revise the undertaking of procedures using models, and to have their skills tested in scenarios.

Methods

Given the success of the MOET course in the UK, the organisers were keen to evaluate it in another setting (Armenia). Pre-course knowledge and practice questionnaires were administered. In an exploratory analysis, post-course results were compared to pre-course answers obtained by the same interviewer.

Results

All candidates showed an improvement in post-course scores. The range was far narrower afterwards (167–188) than before (85–129.5). In the individual score analysis only two scenarios showed a non-significant change (cord prolapse and breech delivery).

Conclusion

This paper demonstrates the reliability of the model based scenarios, with a highly significant improvement in obstetric emergency management. However, clinical audit will be required to measure the full impact of training by longer term follow up. Audit of delays, specific obstetric complications, referrals and near misses may all be amenable to review.     

Cognitive therapy of depression: pretreatment patient predictors of outcome

This review examines the role of patient predictors of outcome in cognitive therapy of depression. Studies that meet eligibility criteria are reviewed for demonstrated linkage between various predictors (i.e., pretreatment severity, historical features, demographic predictors, dysfunctional attitudes and other cognitive features, and treatment acceptability) and outcome, and several effects are found. Notably, high pretreatment severity scores are associated with poorer response to cognitive therapy, as are high chronicity, younger age at onset, an increased number of previous episodes, and marital status. High pretreatment levels of dysfunctional attitudes and certain beliefs about the nature of depression were also found to predict differential response to cognitive therapy of depression. Limitations of the research and directions for further investigations of patient predictors of outcome in cognitive therapy of depression are provided.     

Development of vaccines to help treat drug dependence

The social and economic consequences of drug addiction are immense. Although many methods are adopted to treat addiction, including therapeutic intervention and counseling, the long-term success rate has been limited and there continues to be a need for more effective treatments. A novel approach that has sparked a significant degree of interest recently is the use of vaccines designed to raise specific antibodies against drugs of abuse. Antibodies that prevent addictive substances crossing the blood-brain barrier may prove to be an effective mechanism that will help prevent relapse during efforts to abstain from the drug. Proof-of-principle for this approach has been established in numerous animal models. Currently a cocaine vaccine is in phase II clinical trials and, more recently, two vaccines to nicotine have entered phase I trials. Key efficacy trials are required to establish the true potential of these therapeutic vaccines.