The effect of supervised exercise therapy for intermittent claudication on lower limb lean mass.

OBJECTIVE: Supervised exercise is currently recommended for the first-line treatment of intermittent claudication based on improvement in walking capacity. However, the promotion of skeletal muscle atrophy by repetitive ischemia-reperfusion caused by treadmill-based programs remains a concern. Because preservation of skeletal muscle mass (SMM) and lean mass (LM) is integral to functional capacity and longevity, this study measured the effect of standard treadmill-based supervised exercise on SMM and regional lower limb LM in patients with intermittent claudication. METHODS: Patients with calf claudication caused by infrainguinal peripheral artery disease underwent whole-body dual-energy X-ray absorptiometry scanning before and after completion of a 12-week supervised treadmill exercise program. Total body SMM and lower limb LM were measured according to anatomical regions of the lower limb (thigh vs calf) and side of symptoms. Walking performance was assessed using pain-free walking distance and 6-minute walking distance tests. RESULTS: Thirty-six patients with calf claudication completed exercise training and dual-energy X-ray absorptiometry scanning, allowing analysis of 55 symptomatic and 17 asymptomatic lower limbs. No difference in total body SMM (P = .41) or LM of symptomatic (P = .53) or asymptomatic calves (P = .59) was detected after the program. In contrast, a significant decrease in LM was observed in symptomatic (P = .04) and asymptomatic thighs (P = .005). Pain-free walking distance (P = .001) and the 6-minute walking distance both improved significantly (P = .004) but were not associated with changes in LM. CONCLUSIONS: Twelve weeks of standard treadmill-training for intermittent calf claudication did not result in loss of calf LM; however, a significant decrease in bilateral thigh LM was observed, even in patients with unilateral symptoms. Further research on optimum exercise modalities and end points are required to determine the pathophysiology and effects of these changes on function and survival.

Do Medications Commonly Prescribed to Patients with Peripheral Arterial Disease Have an Effect on Nutritional Status? A Review of the Literature.

BACKGROUND: Polypharmacy is common among patients with peripheral arterial disease (PAD) with a combination of medications used for risk-factor modification and medical management of the disease itself. Interaction between commonly prescribed medications and nutritional status has not previously been well described. This review aims to critically appraise evidence exploring associations between medications commonly prescribed to patients with PAD and nutritional status and provide recommendations for practice. METHODS: A comprehensive literature search was conducted to locate studies relating to nutrient interactions among lipid-lowering, antihypertensive, antiplatelet, and oral hypoglycemic drug classes. Quality of the evidence was rated on the basis of recommendations by the National Health and Medical Research Council. RESULTS: A total of 25 articles were identified as suitable and included in the review. No studies were specific to patients with PAD, and hence findings highlighting risk of ubiquinone (coenzyme Q10 [CoQ10]) depletion with lipid-lowering medications, zinc depletion with antihypertensive medications, and vitamin B12 depletion with oral hypoglycemic medications are extrapolated from heterogeneous groups of patients and healthy adults. The body of evidence ranged in quality from satisfactory to poor. CONCLUSIONS: High-quality research is required to confirm the interactions suggested by the included studies in patients with PAD specifically. It is, however, recommended that patients with PAD that are long-term consumers of the selected medications are monitored for CoQ10, zinc, and vitamin B12 to facilitate early identification of deficiencies and initiation of treatment. Treatment may involve dietary intervention and/or supplementation.

A randomised controlled trial of two supervised exercise regimens and their impact on inflammatory burden in patients with intermittent claudication.

OBJECTIVE: This study assesses the impact of treadmill-based SET alone or in combination with resistance training on systemic inflammatory response, in patients with intermittent claudication (IC). METHODS: Thirty-five patients with IC were randomised to 12 weeks of treadmill-only SET (Group 1) or a combination of treadmill and lower-limb resistance SET (Group 2). A panel of pro- and anti-inflammatory markers were assessed before, during and after the SET. RESULTS: Over the duration of SET, homocysteine increased within Group 1 (12.0-15.5 µmol/L, p = 0.003) but not Group 2, (13.7-14.7 µmol/) while neutrophil elastase (NE) increased within Group 2 (174.5-238.2 ng/mL, p = 0.007) but not Group 1 (300.8-312.0 ng/mL). In both groups NE increased following acute exercise at the start of the SET. Differences in cytokine expression was evident between the two groups (in Group 1, pro-inflammatory cytokines interleukin-12 and interferon-gamma decreased following an acute bout of exercise at the end of SET, where as in Group 2 pro-inflammatory cytokines interleukin-6 and 8 were seen to increase after an acute bout of exercise at the end of SET). CONCLUSION: SET in patients with IC influences the complex immune-modulatory state of atherosclerosis through inflammatory pathways that induce both pro-inflammatory and immunosuppressive responses.

The impact of abdominal aortic aneurysm on muscle mass and energy expenditure: A novel preliminary investigation.

OBJECTIVE: Vascular surgical patients, including those with abdominal aortic aneurysm (AAA), are nutritionally vulnerable. The aim of this study was to compare resting energy expenditure (REE) of patients with AAA relative to age- and gender-matched controls and explore relationships between aneurysm size and muscle mass. METHODS: Twenty patients with AAA underwent assessment of REE using indirect calorimetry. Mid-arm circumference and triceps skinfold thickness were measured and corrected arm muscle area calculated. Twenty gender- and age-matched controls were assessed using the same procedures. RESULTS: Mean (SD) age of participants with AAA was 74.7 (7.7) years, size of AAA ranged from 45 to 70 mm. Median (IQR) REE was significantly higher than controls [5990 (5469, 7017) kJ/day versus 5086 (4536, 5886) kJ/day, p = .011; or 69 (64, 80) kJ/kg/day versus 66 (61, 69) kJ/kg/day, p = .046]. While weight-adjusted REE was independent of aneurysm size (r = .200; p = .397), as aneurysm size increased, weight-adjusted corrected arm muscle area decreased (r = -.576; p = .008). CONCLUSION: The raised REE and decline in muscle mass associated with larger AAA suggest that early detection and attention to nutritional requirements of patients with AAA may be warranted.

The impact of different supervised exercise regimens on endothelial function in patients with intermittent claudication.

BACKGROUND AND OBJECTIVES: The impact of supervised exercise training on endothelial function in patients with intermittent claudication is unclear. This study assesses the impact of treadmill-based supervised exercise training alone or in combination with resistance training on pain free walking distance, flow-mediated dilatation, reactive hyperaemia index, nitric oxide and asymmetric dimethylarginine. METHODS: Thirty-five patients with intermittent claudication were randomised to 12 weeks of treadmill-only supervised exercise training (Group 1) or a combination of treadmill and lower-limb resistance supervised exercise training (Group 2). Pain free walking distance was assessed by six-minute walk test. Endothelial function was assessed by brachial artery flow-mediated dilatation, reactive hyperaemia index and serum analysis of asymmetric dimethylarginine and nitric oxide. RESULTS: Pain free walking distance improved within Group 1 (160 m to 204 m, p = 0.03) but not Group 2 (181 m to 188 m, p = 0.82), no between group difference. No significant change in flow-mediated dilatation or reactive hyperaemia index in either group. Nitric oxide decreased in Group 1 (15.0 µmol/L to 8.3 µmol/L, p = 0.003) but not Group 2 (11.2 µmol/L to 9.1 µmol/L, p = 0.14), p = 0.07 between groups. Asymmetric dimethylarginine decreased in Group 2 (0.61 µmol/L to 0.56 µmol/L, p = 0.03) but not Group 1 (0.58 µmol/l to 0.58 µmol/L, p = 0.776), no between group difference. CONCLUSION: Supervised exercise training does not improve endothelial function as measured by flow-mediated dilatation, reactive hyperaemia index and nitric oxide bioavailability.

Neutrophil-lymphocyte ratio as a prognostic marker of outcome in infrapopliteal percutaneous interventions for critical limb ischemia.

BACKGROUND: Endovascular intervention has become a frequently used treatment of critical limb ischemia (CLI) in recent times. The recent Bypass vs Angioplasty in Severe Ischaemia of the Leg (BASIL) trial consensus recommended endovascular treatment as a first-line treatment in patients who have a life expectancy that was limited to <2 years. Despite these recommendations, there still remains limited data available to clinicians when seeking to risk stratify patients who present with CLI. The neutrophil-lymphocyte ratio (NLR) has been suggested to be a marker for predicting mortality and patency. This study aimed to investigate the use of the NLR as a prognostic marker for primary patency and mortality after an infrapopliteal endovascular intervention in patients with CLI. METHODS: All patients who underwent tibial angioplasty for CLI were retrospectively analyzed. Demographics, degrees of stenosis, vessel patency rates, mortality, and comorbidities were recorded. NLRs were calculated from preoperative blood samples. Primary end points were all-cause mortality, primary patency, and amputation-free survival (AFS) within the follow-up period of 12 months. Multivariate Cox proportional hazard models were used to identify independent predictors. Overall survival, AFS, and the probability of a vessel remaining patent were evaluated by standard Kaplan-Meier survival curves and groups compared by the log-rank test. RESULTS: Eighty-three patients were monitored for 12 months. Ninety limbs were identified, with 104 procedural events and 127 vessels undergoing successful angioplasty. The technical success rate was 86%, and patency at 1 year was 19%. Survival at 1 year was 76% and AFS was 61%. Patients with a NLR ≥5.25 had an increased risk of death (hazard ratio, 1.97; 95% confidence interval, 1.08-3.62; P = .03) compared with those with a NLR of <5.25. Furthermore, those with lymphocytes counts of <1.5 × 10(9)/L had higher mortality (hazard ratio, 1.88; 95% confidence interval, 1.02-3.70; P = .045) than those with lymphocyte counts >1.5 × 10(9)/L. CONCLUSIONS: The NLR and absolute lymphocyte counts are potentially valuable prognostic indicators for risk stratification of patient's presenting with CLI undergoing infrapopliteal angioplasty.

A randomised controlled trial of supervised exercise regimens and their impact on walking performance, skeletal muscle mass and calpain activity in patients with intermittent claudication.

OBJECTIVES: Supervised exercise training (SET) is recommended for patients with intermittent claudication (IC). The optimal exercise programme has not been identified, and the potential adverse effects of exercise on these patients warrant consideration. Calpain proteases have been linked with tissue atrophy following ischaemia-reperfusion injury. High calpain activity may therefore cause muscle wasting in claudicants undergoing SET, and skeletal muscle mass (SMM) is integral to healthy ageing. This study assesses the impact of (1) treadmill-based SET alone; and (2) treadmill-based SET combined with resistance training on pain-free walking distance (PFWD), SMM, and calpain activity. METHODS: Thirty-five patients with IC were randomised to 12 weeks of treadmill only SET (group A), or combined treadmill and lower-limb resistance SET (group B). PFWD via a 6-minute walking test, SMM via dual energy X-ray absorptiometry, and calpain activity via biopsies of gastrocnemius muscles were analysed. RESULTS: Intention-to-treat analyses revealed PFWD improved within group A (160 m to 204 m, p = .03), but not group B (181 m to 188 m, p = .82). There was no between group difference (p = .42). Calpain activity increased within group A (1.62 × 10(5) fluorescent units [FU] to 2.21 × 10(5) FU, p = .05), but not group B. There was no between group difference (p = .09). SMM decreased within group A (-250 g, p = .11) and increased in group B (210 g, p = .38) (p = .10 between groups). Similar trends were evident for per protocol analyses, but, additionally, change in SMM was significantly different between groups (p = .04). CONCLUSIONS: Neither exercise regimen was superior in terms of walking performance. Further work is required to investigate the impact of the calpain system on SMM in claudicants undertaking SET.

Change in dietary intake of adults with intermittent claudication undergoing a supervised exercise program and compared to matched controls.

BACKGROUND: Presence of numerous diet responsive comorbidities and high atherosclerotic burden among adults with intermittent claudication demands attention is given to diet in an effort to delay progression of peripheral artery disease. The aim of this study was to compare diet of adults with intermittent claudication: (a) against dietary recommendations; (b) following 12 weeks of supervised exercise training; and (c) against non-peripheral artery disease controls. METHODS: Diet was assessed using a food frequency questionnaire pre and post supervised exercise training. Pre-exercise diet was compared against Suggested Dietary Targets and against non-peripheral artery disease controls matched for gender, age and body weight. Pre-exercise diet was also compared against post-exercise diet. RESULTS: Pre-exercise 25/31 participants, 5/31 participants, 16/31 participants and 4/31 participants achieved recommendations for protein, carbohydrate, total fat and saturated fat respectively. Few achieved recommended intakes for fibre (3/31 participants), cholesterol (8/31 participants), folate (11/31 participants), potassium (1/31 participants), sodium (4/31 participants), retinol equivalents (1/31 participants) and vitamin C (3/31 participants). There were no differences observed between participants compared to controls in achievement of recommendations. Post-exercise, marginally more participants were able to achieve targets for cholesterol, sodium and vitamin C but not for any other nutrients. CONCLUSIONS: Despite evidence to support benefits of dietary modification in risk reduction of peripheral artery disease, adults with intermittent claudication continue to consume poor diets. Research is required to determine whether dietary changes can be achieved with greater attention to nutrition counselling and the impact assessed in terms of delayed disease progression and long term health outcomes. TRIAL REGISTRATION: ClinicalTrials.gov: NCT01871779.

A comparison of flow-mediated dilatation and peripheral artery tonometry for measurement of endothelial function in healthy individuals and patients with peripheral arterial disease.

OBJECTIVE: Flow-mediated dilatation (FMD) and peripheral artery tonometry (PAT) are commonly used methods for assessing endothelial function in a research setting but it is unclear how well they correlate. This study aimed to compare and correlate these methods in patients with peripheral arterial disease (PAD) and in healthy individuals. MATERIALS AND METHODS: FMD and PAT measurements were obtained as samples of convenience from 26 patients with PAD and 25 healthy subjects. FMD was defined as the percentage increase in the brachial artery diameter after distal occlusion and PAT was measured using the reactive hyperaemia index (RHI). RESULTS: Patients with PAD had a significantly lower FMD than healthy subjects (2.43% vs. 5.80%, p < 0.001). No difference was found in RHI between the two groups. No correlation was found between the FMD and RHI in subjects with PAD (r = 0.284, p = 0.160), in healthy subjects (r = 0.153, p = 0.464) or when both groups were combined (r = 0.174, p = 0.22). CONCLUSION: The lack of change in RHI in PAD patients suggests that PAT is not a sensitive measure of endothelial function. The lack of correlation suggests that FMD and PAT are not interchangeable. PAT should not be used as a substitute for FMD as a measure of endothelial function.

The SPEAK study rationale and design: A linguistic corpus-based approach to understanding thought disorder.

AIM: Psychotic symptoms are typically measured using clinical ratings, but more objective and sensitive metrics are needed. Hence, we will assess thought disorder using the Research Domain Criteria (RDoC) heuristic for language production, and its recommended paradigm of "linguistic corpus-based analyses of language output". Positive thought disorder (e.g., tangentiality and derailment) can be assessed using word-embedding approaches that assess semantic coherence, whereas negative thought disorder (e.g., concreteness, poverty of speech) can be assessed using part-of-speech (POS) tagging to assess syntactic complexity. We aim to establish convergent validity of automated linguistic metrics with clinical ratings, assess normative demographic variance, determine cognitive and functional correlates, and replicate their predictive power for psychosis transition among at-risk youths. METHODS: This study will assess language production in 450 English-speaking individuals in Australia and Canada, who have recent onset psychosis, are at clinical high risk (CHR) for psychosis, or who are healthy volunteers, all well-characterized for cognition, function and symptoms. Speech will be elicited using open-ended interviews. Audio files will be transcribed and preprocessed for automated natural language processing (NLP) analyses of coherence and complexity. Data analyses include canonical correlation, multivariate linear regression with regularization, and machine-learning classification of group status and psychosis outcome. CONCLUSIONS: This prospective study aims to characterize language disturbance across stages of psychosis using computational approaches, including psychometric properties, normative variance and clinical correlates, important for biomarker development. SPEAK will create a large archive of language data available to other investigators, a rich resource for the field.

The Impact of Intravascular Ultrasound on Femoropopliteal Artery Endovascular Interventions: A Randomized Controlled Trial.

OBJECTIVES: The aim of this study was to investigate whether the addition of intravascular ultrasound (IVUS) guidance during femoropopliteal artery interventions reduced the rate of binary restenosis within 12 months compared with angiographic guidance alone. BACKGROUND: IVUS is more accurate than angiography for assessment of vessel size and disease severity. Low-level studies suggest that the use of IVUS in femoropopliteal endovascular interventions improves outcomes, but currently, no level 1 evidence exists. METHODS: This was a prospective single-center trial of 150 patients undergoing femoropopliteal endovascular intervention, randomized (1:1) to guidance by angiography or angiography and IVUS. The primary outcome measure was freedom from binary restenosis, on duplex ultrasound, within 12 months. Secondary outcomes included clinically driven target lesion revascularization, disagreements in imaging findings between modalities, and changes in treatment caused by IVUS. RESULTS: Freedom from binary restenosis at 12 months was significantly higher in the IVUS group (72.4% vs 55.4%; P = 0.008). There was no significant difference between groups for clinically directed target lesion revascularization (84.2% and 82.4%; P = 0.776). Mean vessel diameter was significantly larger with IVUS (5.60 mm vs 5.10 mm; P < 0.001). A change in treatment occurred caused by IVUS in 79% of cases. Binary restenosis was lower in the IVUS group for cases treated with drug-coated balloons (9.1% vs 37.5%; P = 0.001). CONCLUSIONS: The use of IVUS resulted in a significant reduction in the rate of restenosis after endovascular intervention. This is the first randomized controlled trial to demonstrate that IVUS improves outcomes in femoropopliteal interventions. This benefit may primarily relate to cases treated with drug-coated balloons. (Does the use of intravascular ultrasound improve outcomes of endovascular interventional procedures for peripheral vascular disease of the superficial femoral artery or popliteal artery?; ACTRN12614000006640).

Stroke and transient ischaemic attack awareness.

OBJECTIVE: This study examined the knowledge of stroke warning signs and risk factors among the general public, including what they would do if they were to develop such symptoms. DESIGN, SETTING AND PARTICIPANTS: Population study of randomly selected members of the general public in Adelaide, South Australia. A simple survey assessed knowledge of stroke warning signs and gave four options for management. The survey was conducted on three separate occasions: before, immediately after and 3 months after the National Stroke Foundation's National Stroke Week in 2009. MAIN OUTCOME MEASURES: The outcome measures were the public perception of risk factors and warning signs of stroke and what the members of the public would do if presented with a range of warning signs. They were also asked about their knowledge of the Face, Arms, Speech, Time (FAST) test. RESULTS: The three surveys were completed by 251 members of the public. Hypertension and smoking were recognised as risk factors for stroke by 71% and 53% of respondents respectively. Before National Stroke Week, slurred speech was identified by 51% and both slurred speech and upper limb sensory loss was identified by 62% as warning signs to provoke presentation to an emergency department (ED). Amaurosis, upper limb sensory loss, upper limb numbness and upper limb weakness were correctly identified individually as warning signs to attend an ED by fewer than one-third of respondents. There was no significant difference in the survey results following National Stroke Week. CONCLUSIONS: Public awareness of the symptoms of stroke, and what to do about them, is limited. There was little improvement after the national week-long awareness campaign. The lack of public awareness about stroke warning signs must be addressed to reduce mortality and morbidity from stroke.

Anatomical suitability for endovascular AAA repair may affect outcomes following rupture.

OBJECTIVES: Single centre series have suggested that endovascular aneurysm repair (EVAR) for ruptured abdominal aortic aneurysms (rAAA) may reduce mortality versus open surgery. This has not been substantiated in the only randomized controlled trial, leading to suggestion that anatomical suitability for rEVAR may independently improve prognosis of rAAA. Our aim was to assess the outcome of open rAAA repair in patients dependant on their suitability for rEVAR on pre-operative computed tomography (CT) assessment. METHODS: A retrospective review of all ruptured aneurysms presenting to our unit since January 1998 was performed. Patients were grouped based on anatomical suitability for rEVAR by pre-operative CT. RESULTS: Of 118 patients presenting with rAAA, 48 underwent pre-operative CT. Of these 9 scans had been "culled" and were excluded. 16 patients were suitable for rEVAR and 23 unsuitable. The groups were well matched demographically with no difference in Glasgow Aneurysm Score between groups. There was a non-significant trend towards reduction in 30-day mortality for patients suitable for EVAR (suitable 6.9% versus unsuitable 30.4%; P = 0.066) with no difference in operative time, transfusion requirement, length of stay or in-hospital morbidity. CONCLUSIONS: Anatomical suitability for EVAR seems to beneficially affect outcome following open repair for ruptured AAA. Further study is required to confirm these findings.

The use of ultrasound to assist deployment of the StarClose vascular closure device in arterial access sites.

Access site complication rates remain relatively high following interventional procedures and have not been shown to be reduced by the use of vascular closure devices. This report describes an ultrasound-assisted technique of deploying one type of vascular closure device, the StarClose (Abbott Vascular, Illinois, USA). This technique has significantly reduced failure rates and complication rates since its introduction. The technique is relatively simple but requires familiarity with the use of ultrasound and the StarClose device.

Particulate matter and carbon dioxide in classrooms - the impact of cleaning and ventilation.

UNLABELLED: The objective of the study was to measure the indoor air quality in classrooms with special emphasis on particulate matter (PM 10) and carbon dioxide (CO(2)) and the impact of cleaning and ventilation. MATERIAL AND METHOD: PM 10 was analysed via gravimetric method and by laser beam technology. CO(2) was analysed by infrared sensors. Measurements were collected for 3 weeks; first week: "normal" cleaning (twice a week) and ventilation; second week: intensified cleaning (five times a week); third week: intensified cleaning and intensified ventilation. RESULTS: Levels of PM 10 in the classrooms during the 3 weeks were 69+/-19microg/m(3) and they were dominated by occupancy and the persons' activity. Intensified cleaning showed a significant decrease in all classrooms (79+/-22 to 64+/-15microg/m(3)). The effect of ventilation on levels of PM10 was inconsistent - levels of CO(2) were very high in all schools and could be diminished by intensified ventilation (mean 1459 to 1051ppm). CONCLUSION: Although further investigation is needed to study detailed characteristics of the PM 10 (size distribution, chemical identity) the data are sufficient to improve the cleaning and the ventilation in schools.

Incomplete cellular depopulation may explain the high failure rate of bovine ureteric grafts.

BACKGROUND: The aim was to assess the results of a decellularized bovine ureter graft (SynerGraft) for complex venous access. METHODS: Bovine ureter conduits were implanted in patients with a failed fistula or access graft in whom native vessels were unsuitable as conduits. Graft histories were obtained from all patients who had undergone this procedure at one institution. Failed grafts were explanted and subjected to histological examination. A sample of fresh bovine ureter was immunostained for galactose (alpha1 --> 3) galactose (alpha-Gal). RESULTS: Nine patients with a median age of 46 (range 25-70) years underwent complex venous access surgery between August 2004 and November 2006 using a SynerGraft. Graft types included loop superficial femoral artery to stump of long saphenous vein (four patients), loop brachial artery to vein (two), brachial artery to axillary vein (two) and left axillary artery to innominate vein (one). Three grafts developed aneurysmal dilatation and two thrombosed. Histological assessment of the explanted bovine ureters revealed acute and chronic transmural inflammation. Immunostaining of fresh bovine ureter suggested residual cells and the xenoantigen alpha-Gal. CONCLUSION: Graft failure with aneurysmal dilatation and thrombosis in complex arteriovenous conduits using bovine ureter may be due to residual xenoantigens.

Stimulus timing by people with Parkinson's disease.

Previous literature suggests that Parkinson's disease is marked by deficits in timed behaviour. However, the majority of studies of central timing mechanisms in patients with Parkinson's disease have used timing tasks with a motor component. Since the motor abnormalities are a defining feature of the condition, the status of timing in Parkinson's disease remains uncertain. Data are reported from patients with mild to moderate Parkinson's disease (both on and off medication) and age- and IQ-matched controls on a range of stimulus timing tasks without counting. Tasks used were temporal generalization, bisection, threshold determination, verbal estimation, and a memory for duration task. Performance of patients was generally "normal" on all tasks, but significant differences from performance of controls were found on the memory for duration task. Among the "normal" effects noted were arithmetic mean bisection, asymmetric temporal generalization gradients, and subjective shortening on the memory for duration task. The results suggest (a) that some previous reports of timing "deficits" in Parkinson's patients were possibly due to the use of tasks requiring a timed manual response and (b) small differences between patients and controls may be found on tasks where two stimuli are presented on each trial, whether patients are on medication or off it.

Supporting medical planning by mitigating cognitive load.

OBJECTIVES: Developing a care plan for a patient is a complex task, requiring an understanding of interactions and dependencies between procedures and of their possible outcomes for an individual patient. Decision support for planning has broader requirements than are typically considered in medical informatics applications. We consider the appropriate design of software to assist medical planning. METHODS: The likely cognitive loads imposed by planning tasks were assessed with a view to directly supporting these via software. RESULTS: Five types of cognitive load are likely to be important. A planning support system, REACT, was designed to ameliorate these cognitive loads by providing targeted dynamic feedback during planning. An initial evaluation study in genetic counselling indicates that the approach is successful in that role. CONCLUSIONS: The approach provides the basis of a general aid for visualizing, customizing and evaluating care plans.

A Comparison of Measures of Endothelial Function in Patients with Peripheral Arterial Disease and Age and Gender Matched Controls.

This study compared flow-mediated dilatation (FMD), peripheral artery tonometry (PAT), and serum nitric oxide (NO) measures of endothelial function in patients with peripheral artery disease (PAD) against age/gender matched controls. 25 patients (mean age: 72.4 years, M : F 18 : 7) with established PAD and an age/gender matched group of 25 healthy controls (mean age: 72.4 years, M : F 18 : 7) were studied. Endothelial function was measured using the % FMD, reactive hyperemia index (RHI) using PAT and serum NO (µmol). Difference for each method between PAD and control patients and correlation between the methods were investigated. FMD and RHI were lower in patients with PAD (median FMD for PAD = 2.16% versus control = 3.77%, p = 0.034 and median RHI in PAD = 1.64 versus control = 1.92, p = 0.005). NO levels were not significantly different between the groups (PAD median = 7.70 µmol, control median = 13.05 µmol, p = 0.662). These results were obtained in elderly patients and cannot be extrapolated to younger individuals. FMD and PAT both demonstrated a lower hyperaemic response in patients with PAD; however, FMD results in PAD patients were unequivocally reduced whereas half the PAD patients had RHI values above the established threshold for endothelial dysfunction. This suggests that FMD is a more appropriate method for the measurement of NO-mediated endothelial function.

Estimating energy expenditure in vascular surgery patients: Are predictive equations accurate enough?

BACKGROUND & AIMS: Malnutrition is prevalent in vascular surgical patients who commonly seek tertiary care at advanced stages of disease. Adjunct nutrition support is therefore pertinent to optimise patient outcomes. To negate consequences related to excessive or suboptimal dietary energy intake, it is essential to accurately determine energy expenditure and subsequent requirements. This study aims to compare resting energy expenditure (REE) measured by indirect calorimetry, a commonly used comparator, to REE estimated by predictive equations (Schofield, Harris-Benedict equations and Miller equation) to determine the most suitable equation for vascular surgery patients. METHODS: Data were collected from four studies that measured REE in 77 vascular surgery patients. Bland-Altman analyses were conducted to explore agreement. Presence of fixed or proportional bias was assessed by linear regression analyses. RESULTS: In comparison to measured REE, on average REE was overestimated when Schofield (+857 kJ/day), Harris-Benedict (+801 kJ/day) and Miller (+71 kJ/day) equations were used. Wide limits of agreement led to an over or underestimation from 1552 to 1755 kJ. Proportional bias was absent in Schofield (R2 = 0.005, p = 0.54) and Harris-Benedict equations (R2 = 0.045, p = 0.06) but was present in the Miller equation (R2 = 0.210, p < 0.01) even after logarithmic transformation (R2 = 0.213, p < 0.01). CONCLUSIONS: Whilst the Miller equation tended to overestimate resting energy expenditure and was affected by proportional bias, the limits of agreement and mean bias were smaller compared to Schofield and Harris-Benedict equations. This suggested that it is the preferred predictive equation for vascular surgery patients. Future research to refine the Miller equation to improve its overall accuracy will better inform the provision of nutritional support for vascular surgery patients and subsequently improve outcomes. Alternatively, an equation might be developed specifically for use with vascular surgery patients.