Serum anticholinergic activity and postoperative cognitive dysfunction in elderly patients

Background: Cerebral cholinergic transmission plays a key role in cognitive function and anticholinergic drugs are associated with impaired cognitive functions [1]. In the perioperative phase many substances with anticholinergic effects are administered and disturbed cholinergic transmission is a hypothetical cause of postoperative cognitive dysfunction (POCD). Serum anticholinergic activity (SAA; pmol/ml) may be measured as a summary marker of anticholinergic activity in an individual patient's blood. We hypothesised that an increase in SAA from preoperatively to one week postoperatively is associated with POCD in elderly patients. Methods: Thirty-two patients aged >65 yrs undergoing elective major surgery under standardized general anaesthesia (thiopental, sevoflurane, fentanyl) were investigated. Cognitive functions were measured preoperatively and 7 days postoperatively using the extended version of the Consortium to Establish a Registry for Alzheimer's Disease - Neuropsychological Assessment Battery. POCD was defined as a postoperative decline >1 z-score in at least 2 cognitive domains. SAA was measured preoperatively and 7 days postoperatively at the time of cognitive testing. Results: 50% of the investigated patients developed POCD. There were no statistically significant differences between patients with and without POCD regarding age, education, baseline cognitive function, duration of anaesthesia, SAA preoperatively (median (range) 1.0 (0.3 to 5.0) vs 1.5 (0.4 to 5.0), SAA 7 days postoperatively (median (range) 1.3 (0.1 to 7.0) vs 1.4 (0.6 to 5.5) or changes in SAA (median (range) 0.1 (-1.6 to 2.2) vs 0.2 (-1.4 to 2.8). The variability of SAA in individual patients was considerable and marked changes in SAA between the two examinations were observed in some patients. However, there was no significant relationship between changes in SAA and changes in cognitive function. Conclusion: In this preliminary analysis of a small group of patients, changes in SAA in the perioperative phase were highly variable. SAA was not associated with POCD suggesting that POCD is not simply caused by anticholinergic medications administered in the perioperative phase. A further analysis of a larger group of patients is in progress.

Resting metabolic rate and protein turnover in apparently healthy elderly Gambian men.

Body composition, resting energy expenditure (REE), and whole body protein metabolism were studied in 26 young and 28 elderly Gambian men matched for body mass index during the dry season in a rural village in The Gambia. REE was measured by indirect calorimetry (hood system) in the fasting state and after five successive meals. Rates of whole body nitrogen flux, protein synthesis, and protein breakdown were determined in the fed state from the level of isotopic enrichment of urinary ammonia over a period of 12 h after a single oral dose of [15N]glycine. Expressed in absolute value, REE was significantly lower in the elderly compared with the young group (3.21 +/- 0.07 vs. 4.04 +/- 0.07 kJ/min, P < 0.001) and when adjusted to body weight (3.29 +/- 0.05 vs. 3.96 +/- 0.05 kJ/min, P < 0.0001) and fat-free mass (FFM; 3.38 +/- 0.01 vs. 3.87 +/- 0.01 kJ/min, P < 0.0001). The rate of protein synthesis averaged 207 +/- 13 g protein/day in the elderly and 230 +/- 13 g protein/day in the young group, whereas protein breakdown averaged 184 +/- 13 g protein/day in the elderly and 203 +/- 13 g protein/day in the young group (nonsignificant). When values were adjusted for body weight or FFM, they did not reveal any difference between the two groups. It is concluded that the reduced REE adjusted for body composition observed in elderly Gambian men is not explained by a decrease in protein turnover.

Which screening strategy using BMD measurements would be most cost effective for hip fracture prevention in elderly women? A decision analysis based on a Markov model.

INTRODUCTION: Hip fractures are responsible for excessive mortality, decreasing the 5-year survival rate by about 20%. From an economic perspective, they represent a major source of expense, with direct costs in hospitalization, rehabilitation, and institutionalization. The incidence rate sharply increases after the age of 70, but it can be reduced in women aged 70-80 years by therapeutic interventions. Recent analyses suggest that the most efficient strategy is to implement such interventions in women at the age of 70 years. As several guidelines recommend bone mineral density (BMD) screening of postmenopausal women with clinical risk factors, our objective was to assess the cost-effectiveness of two screening strategies applied to elderly women aged 70 years and older. METHODS: A cost-effectiveness analysis was performed using decision-tree analysis and a Markov model. Two alternative strategies, one measuring BMD of all women, and one measuring BMD only of those having at least one risk factor, were compared with the reference strategy "no screening". Cost-effectiveness ratios were measured as cost per year gained without hip fracture. Most probabilities were based on data observed in EPIDOS, SEMOF and OFELY cohorts. RESULTS: In this model, which is mostly based on observed data, the strategy "screen all" was more cost effective than "screen women at risk." For one woman screened at the age of 70 and followed for 10 years, the incremental (additional) cost-effectiveness ratio of these two strategies compared with the reference was 4,235 euros and 8,290 euros, respectively. CONCLUSION: The results of this model, under the assumptions described in the paper, suggest that in women aged 70-80 years, screening all women with dual-energy X-ray absorptiometry (DXA) would be more effective than no screening or screening only women with at least one risk factor. Cost-effectiveness studies based on decision-analysis trees maybe useful tools for helping decision makers, and further models based on different assumptions should be performed to improve the level of evidence on cost-effectiveness ratios of the usual screening strategies for osteoporosis.

Santé et besoins en soins des personnes âgées: différences liées au genre [Health status and care giving needs in the elderly: gender related differences].

The health status and need for care differ depending on the gender. The most notable differences are life expectancy, life expectancy in good health and the prevalence of geriatric syndromes or chronic illnesses. Some social health determinants (social isolation or financial precariousness) seem to act as risk factors for vulnerability, mostly amongst old or very old women. Through some examples of differences between men and women in terms of health and caregiving needs, this article tries to heighten the awareness of health professionals to a gender based approach of the elderly patient in order to promote the best possible equity in healthcare.

Why is it so Hard to Value Intangibles? Evidence from Investments in High-Technology Start-Ups

The paper uses a range of primary-source empirical evidence to address the question: ‘why is it to hard to value intangible assets?’ The setting is venture capital investment in high technology companies. While the investors are risk specialists and financial experts, the entrepreneurs are more knowledgeable about product innovation. Thus the context lends itself to analysis within a principal-agent framework, in which information asymmetry may give rise to adverse selection, pre-contract, and moral hazard, post-contract. We examine how the investor might attenuate such problems and attach a value to such high-tech investments in what are often merely intangible assets, through expert due diligence, monitoring and control. Qualitative evidence is used to qualify the more clear cut picture provided by a principal-agent approach to a more mixed picture in which the ‘art and science’ of investment appraisal are utilised by both parties alike

Firms in Scottish High Technology Clusters: software, life sciences, microelectronics, optoelectronics and digital media – preliminary evidence and analysis on firm size, growth and optimality

This paper reports on: (a) new primary source evidence on; and (b) statistical and econometric analysis of high technology clusters in Scotland. It focuses on the following sectors: software, life sciences, microelectronics, optoelectronics, and digital media. Evidence on a postal and e-mailed questionnaire is presented and discussed under the headings of: performance, resources, collaboration & cooperation, embeddedness, and innovation. The sampled firms are characterised as being small (viz. micro-firms and SMEs), knowledge intensive (largely graduate staff), research intensive (mean spend on R&D GBP 842k), and internationalised (mainly selling to markets beyond Europe). Preliminary statistical evidence is presented on Gibrat’s Law (independence of growth and size) and the Schumpeterian Hypothesis (scale economies in R&D). Estimates suggest a short-run equilibrium size of just 100 employees, but a long-run equilibrium size of 1000 employees. Further, to achieve the Schumpeterian effect (of marked scale economies in R&D), estimates suggest that firms have to grow to very much larger sizes of beyond 3,000 employees. We argue that the principal way of achieving the latter scale may need to be by takeovers and mergers, rather than by internally driven growth.

Technology shocks and aggregate fluctuations in an estimated hybrid RBC model

This paper contributes to the on-going empirical debate regarding the role of the RBC model and in particular of technology shocks in explaining aggregate fluctuations. To this end we estimate the model’s posterior density using Markov-Chain Monte-Carlo (MCMC) methods. Within this framework we extend Ireland’s (2001, 2004) hybrid estimation approach to allow for a vector autoregressive moving average (VARMA) process to describe the movements and co-movements of the model’s errors not explained by the basic RBC model. The results of marginal likelihood ratio tests reveal that the more general model of the errors significantly improves the model’s fit relative to the VAR and AR alternatives. Moreover, despite setting the RBC model a more difficult task under the VARMA specification, our analysis, based on forecast error and spectral decompositions, suggests that the RBC model is still capable of explaining a significant fraction of the observed variation in macroeconomic aggregates in the post-war U.S. economy.

Using Effluent Charges in Promoting Investment in Water Pollution Control Technology: A Model of Coordination Failure among Firms

Untreated wastewater being directly discharged into rivers is a very harmful environmental hazard that needs to be tackled urgently in many countries. In order to safeguard the river ecosystem and reduce water pollution, it is important to have an effluent charge policy that promotes the investment of wastewater treatment technology by domestic firms. This paper considers the strategic interaction between the government and the domestic firms regarding the investment in the wastewater treatment technology and the design of optimal e­ffluent charge policy that should be implemented. In this model, the higher is the proportion of non-investing firms, the higher would be the probability of having to incur an e­ffluent charge and the higher would be that charge. On one hand the government needs to impose a sufficiently strict policy to ensure that firms have strong incentive to invest. On the other hand, it cannot be too strict that it drives out firms which cannot afford to invest in such expensive technology. The paper analyses the factors that affect the probability of investment in this technology. It also explains the difficulty of imposing a strict environment policy in countries that have too many small firms which cannot afford to invest unless subsidised.

Assessing Spiritual Distress in Elderly Patients Undergoing Rehabilitation

Spiritual distress has been associated with worse health outcomes. Assessing patient's spirituality seems especially relevant in older patients undergoing post-acute rehabilitation. However, few instruments are designed to assess spiritual distress. The objectives of this research were 1) to conceptualize the spiritual dimension and to develop an instrument to assess spiritual distress in hospitalized older patients; 2) to determine spiritual distress prevalence and to investigate its relationship with rehab outcomes. A qualitative approach was used to develop the Spiritual Distress Assessment Tool (SDAT). The SDAT is a semi-structured interview that assess unmet spiritual needs, and quantifies spiritual distress. In a pilot study among rehab patients (N=69, 82.58.3 years), 61% reported spiritual distress. Compared to the others, these patients had more functional impairment and tended to have longer stay. Further studies are needed to determine whether spiritual intervention would be effective to address spiritual distress and improve health outcomes.

Extending contingency: the impact of strategy, technology, size and business environment on the organisational form of small Chinese firms

This paper is inspired by articles in the last decade or so that have argued for more attention to theory, and to empirical analysis, within the well-known, and long-lasting, contingency framework for explaining the organisational form of the firm. Its contribution is to extend contingency analysis in three ways: (a) by empirically testing it, using explicit econometric modelling (rather than case study evidence) involving estimation by ordered probit analysis; (b) by extending its scope from large firms to SMEs; (c) by extending its applications from Western economic contexts, to an emerging economy context, using field work evidence from China. It calibrates organizational form in a new way, as an ordinal dependent variable, and also utilises new measures of familiar contingency factors from the literature (i.e. Environment, Strategy, Size and Technology) as the independent variables. An ordered probit model of contingency was constructed, and estimated by maximum likelihood, using a cross section of 83 private Chinese firms. The probit was found to be a good fit to the data, and displayed significant coefficients with plausible interpretations for key variables under all the four categories of contingency analysis, namely Environment, Strategy, Size and Technology. Thus we have generalised the contingency model, in terms of specification, interpretation and applications area.

Prevention and treatment options for postoperative delirium in the elderly.

PURPOSE OF REVIEW: To review recent findings and developments in strategies for prevention and treatment of postoperative delirium. RECENT FINDINGS: Current advances in the field include improved knowledge about predisposing and precipitating factors, evidence for efficacy of multicomponent prevention programmes, refinement of perioperative procedures, and promising pharmacological approaches for prophylaxis and management of postoperative delirium. SUMMARY: Postoperative delirium is a common and serious complication in elderly patients. Preoperative assessment of risk profiles and tailored multimodal prevention approaches proved effective and should be integrated into clinical practice. Despite promising recent findings, at present, the routine use of pharmacological prophylaxis cannot be recommended. Validated and easy-to-use bedside diagnostic tools are available and should be regularly applied for delirium screening in the first days after surgery. In patients developing delirium, causal conditions and contributing factors need to be identified and addressed. Whereas administration of antipsychotics may represent an option for symptomatic treatment, further studies are needed to evaluate the effects of pharmacological approaches on long-term outcomes in elderly patients with delirium.