Does anaesthesia cause postoperative cognitive dysfunction? A randomised study of regional versus general anaesthesia in 438 elderly patients

Keywords:anesthesia;cognitive function;complications;postoperative period;regional anesthesia;surgery Background: Postoperative cognitive dysfunction (POCD) is a common complication after cardiac and major non-cardiac surgery with general anaesthesia in the elderly. We hypothesized that the incidence of POCD would be less with regional anaesthesia rather than general. Methods: We included patients aged over 60 years undergoing major non-cardiac surgery. After giving written informed consent, patients were randomly allocated to general or regional anaesthesia. Cognitive function was assessed using four neuropsychological tests undertaken preoperatively and at 7 days and 3 months postoperatively. POCD was defined as a combined Z score >1.96 or a Z score >1.96 in two or more test parameters. Results: At 7 days, POCD was found in 37/188 patients (19.7%, [14.3–26.1%]) after general anaesthesia and in 22/176 (12.5%, [8.0–18.3%]) after regional anaesthesia, P = 0.06. After 3 months, POCD was present in 25/175 patients (14.3%, [9.5–20.4%]) after general anaesthesia vs. 23/165 (13.9%, [9.0–20.2%]) after regional anaesthesia, P = 0.93. The incidence of POCD after 1 week was significantly greater after general anaesthesia when we excluded patients who did not receive the allocated anaesthetic: 33/156 (21.2%[15.0–28.4%]) vs. 20/158 (12.7%[7.9–18.9%]) (P = 0.04). Mortality was significantly greater after general anaesthesia (4/217 vs. 0/211 (P <0.05)). Conclusion: No significant difference was found in the incidence of cognitive dysfunction 3 months after either general or regional anaesthesia in elderly patients. Thus, there seems to be no causative relationship between general anaesthesia and long-term POCD. Regional anaesthesia may decrease mortality and the incidence of POCD early after surgery

The Visibility of (In)security: The Aesthetics of Planning Urban Defences Against Terrorism

Urban defences against terrorism have traditionally been based on territorial interventions that sought to seal off and surveil certain public and private spaces considered targets. Lately, though, a much wider range of crowded and public spaces have been viewed as potential targets and thus have been identified as requiring additional security. This has immense implications for the experience of the ‘everyday’ urban landscape. Drawing on contemporary notions that incorporate the study of aesthetics and emotions within critical security and terrorism studies, this article discusses the visual impact of counter-terrorism security measures. It analyses the ‘transmission’ of symbolic messages, as well as the variety of ways in which security might be ‘received’ by various stakeholders. The analysis takes place against the backdrop of concern that obtrusive security measures have the capacity to radically alter public experiences of space and in some cases lead to (intended and unintended) exclusionary practices or a range of negative emotional responses. The article concludes by outlining a ‘spectrum of visible security’ ranging between traditional obtrusive fortified approaches and approaches that embed security features seamlessly or even ‘invisibly’ into the urban fabric

Biofilm structure and influence on biofouling under laminar and turbulent flows

A flow system was designed so that biofilms could be grown simultaneously in parallel flow cells under laminar and turbulent flows using shared nutrients and inocula. The flow cells were made from rectangular glass tubing chosen to simulate flow in industrial pipes. The hydrodynamics in the flow cells were characterized using dye tracers and the relationship between the Fanning friction factor (f) and Reynolds number (Re). Flow was laminar at Re 100 and turbulent at Re 3000. Transition between flows occurred at approximately Re 1000. Biofilms from environmental inocula were grown on tap water or a minimal salts medium with 40 ppm glucose. Biofilms grown under laminar flow were patchy and consisted of cell clusters separated by interstitial voids. Biofilms grown under turbulent flow were filamentous. The filaments had a complex structure and were formed by the colonization of filamentous sheathed bacteria with microcolonies of non-filamentous bacteria. The filamentous bacteria were often tangled together and subsequent colonization by microcolonies resulted in the formation of cohesive structures that we termed “biofilm streamers”. The frictional loss coefficient (kf) across the flow cell colonized with biofilm grown under turbulent flow was almost twice the kf across the flow cell colonized with biofilm grown under laminar flow. There was little difference in kf across the flow cell colonized with biofilm grown under laminar flow and the kf across a clean flow cell

Computer automated prediction of potential therapeutic and toxicity protein targets of bioactive compounds from Chinese medicinal plants

10.1142/S0192415X02000156American Journal of Chinese Medicine301139-154AJCM

Cognitive dysfunction after minor surgery in the elderly

Background: Major surgery is frequently associated with postoperative cognitive dysfunction (POCD) in elderly patients. Type of surgery and hospitalization may be important prognostic factors. The aims of the study were to find the incidence and risk factors for POCD in elderly patients undergoing minor surgery. Methods: We enrolled 372 patients aged greater than 60 years scheduled for minor surgery under general anesthesia. According to local practice, patients were allocated to either in- (199) or out-patient (173) care. Cognitive function was assessed using neuropsychological testing preoperatively and 7 days and 3 months postoperatively. Postoperative cognitive dysfunction was defined using Z-score analysis. Results: At 7 days, the incidence (confidence interval) of POCD in patients undergoing minor surgery was 6.8% (4.3-10.1). At 3 months the incidence of POCD was 6.6% (4.1-10.0). Logistic regression analysis identified the following significant risk factors: age greater than 70 years (odds ratio [OR]: 3.8 [1.7-8.7], P=0.01) and in- vs. out-patient surgery (OR: 2.8 [1.2-6.3], P=0.04). Conclusions: Our finding of less cognitive dysfunction in the first postoperative week in elderly patients undergoing minor surgery on an out-patient basis supports a strategy of avoiding hospitalization of older patients when possible