Reliability of a novel thermal imaging system for temperature assessment of healthy feet.

BACKGROUND: Thermal imaging is a useful modality for identifying preulcerative lesions ("hot spots") in diabetic foot patients. Despite its recognised potential, at present, there is no readily available instrument for routine podiatric assessment of patients at risk. To address this need, a novel thermal imaging system was recently developed. This paper reports the reliability of this device for temperature assessment of healthy feet. METHODS: Plantar skin foot temperatures were measured with the novel thermal imaging device (Diabetic Foot Ulcer Prevention System (DFUPS), constructed by Photometrix Imaging Ltd) and also with a hand-held infrared spot thermometer (Thermofocus® 01500A3, Tecnimed, Italy) after 20 min of barefoot resting with legs supported and extended in 105 subjects (52 males and 53 females; age range 18 to 69 years) as part of a multicentre clinical trial. The temperature differences between the right and left foot at five regions of interest (ROIs), including 1st and 4th toes, 1st, 3rd and 5th metatarsal heads were calculated. The intra-instrument agreement (three repeated measures) and the inter-instrument agreement (hand-held thermometer and thermal imaging device) were quantified using intra-class correlation coefficients (ICCs) and the 95% confidence intervals (CI). RESULTS: Both devices showed almost perfect agreement in replication by instrument. The intra-instrument ICCs for the thermal imaging device at all five ROIs ranged from 0.95 to 0.97 and the intra-instrument ICCs for the hand-held-thermometer ranged from 0.94 to 0.97. There was substantial to perfect inter-instrument agreement between the hand-held thermometer and the thermal imaging device and the ICCs at all five ROIs ranged between 0.94 and 0.97. CONCLUSIONS: This study reports the performance of a novel thermal imaging device in the assessment of foot temperatures in healthy volunteers in comparison with a hand-held infrared thermometer. The newly developed thermal imaging device showed very good agreement in repeated temperature assessments at defined ROIs as well as substantial to perfect agreement in temperature assessment with the hand-held infrared thermometer. In addition to the reported non-inferior performance in temperature assessment, the thermal imaging device holds the potential to provide an instantaneous thermal image of all sites of the feet (plantar, dorsal, lateral and medial views). TRIAL REGISTRATION: Diabetic Foot Ulcer Prevention System NCT02317835, registered December 10, 2014.

Home enteral tube feeding in children with inherited metabolic disorders: a review of long-term carer knowledge and technique.

BACKGROUND: Home enteral tube feeding (HETF) is commonly used in children with inherited metabolic disorders (IMD). It is unclear how caregiver knowledge and their safety in using tube feeding techniques changes over time. METHODS: Caregivers of children with IMD on HETF from one UK IMD centre had annual interviews over 3 years using a structured questionnaire and observation to assess HETF knowledge and safety techniques. RESULTS: Thirty-two caregivers of IMD children (median age 5.3 years; range 0.3-13.6 years) were studied. Seventy-eight percent (n = 25) of subjects had been on HETF for >5 years. Over 3 years, many caregivers' HETF techniques deteriorated: accurate feed ingredient measurement decreased from 36% to 11%; correct flushing of tubes decreased from 56% to 44%; checking tube position as recommended decreased from 72% to 56%; and correct hand washing decreased from 38% to 25%. Despite improvements, knowledge of some aspects remained poorly understood: dangers of incorrect tube placement increased from 41% to 56%; correct position for night feeding increased from 38% to 56%; and feed ingredient storage decreased from 87% to 38%. CONCLUSIONS: The HETF techniques of caregivers of children with IMD declined over time. Caregivers need to understand that HETF, particularly in IMD, is a serious procedure associated with life-threatening risks. Poor HETF practices may cause feed contamination, incorrect feed concentration, feed intolerance, aspiration, peritonitis and even metabolic decompensation. HETF skills should be reassessed annually, with compulsory retraining if basic 'core' HETF competencies are not demonstrated.

Diet in phenylketonuria: a snapshot of special dietary costs and reimbursement systems in 10 international centers.

BACKGROUND AND AIMS: To gather exploratory data on the costs and reimbursement of special dietary foods used in the management of phenylketonuria (PKU) from ten international specialist PKU centers. METHODS: Experts from each center provided data on retail costs of the three most frequently used phenylalanine-free protein substitutes and low-protein foods at their center; reimbursement of protein substitutes and low-protein foods; and state monetary benefits provided to PKU patients. RESULTS: The mean annual cost of protein substitutes across 4 age groups (2 y, 8 y, 15 y and adults) ranged from €4273 to €21,590 per patient. The cost of low-protein products also differed; the mean cost of low-protein bread varied from €0.04 to €1.60 per 100 kcal. All protein substitutes were either fully reimbursed or covered by health insurance. However, reimbursement for low-protein products varied and state benefits differed between centers. CONCLUSIONS: The variation in the cost and reimbursement of diet therapy and the level of additional state benefits for PKU patients demonstrates the large difference in expenditure on and access to PKU dietary products. This highlights the inequality between healthcare systems and access to special dietary products for people with PKU, ultimately leading to patients in some countries receiving better care than others.

Cascade genetic testing for mismatch repair gene mutations.

Mismatch repair gene mutation carriers have a high risk of developing colorectal cancer, and can benefit from appropriate surveillance. A combined population based ascertainment cascade genetic testing approach provides a systematic and potentially effective strategy for identifying such carriers. We have developed a Markov Chain computer model system which simulates various factors influencing cascade genetic testing; including demographics, uptake, genetic epidemiology and family size. This was used to evaluate cascade genetic testing for mismatch repair gene mutations in theory and practice. Simulations focussed on the population of Scotland by way of illustration, and were based on a 20-year programme in which index cases were ascertained from colorectal cancer cases aged<55 years at onset. Results indicated that without practical barriers to cascade genetic testing, 545 (95% CI=522, 568) carriers could be identified; 42% of the population total. This comprised approximately 140 index cases, 302 asymptomatic relatives and 104 previously affected relatives. However, when realistic ascertainment and acceptance rates were used to inform simulations, only 257 (95% CI=246, 268) carriers, about 20% of the carrier population, were identifiable. Of these approximately 112 were index cases, 108 were asymptomatic relatives, and 37 were previously affected relatives. This contrast emphasises the importance of ascertainment and acceptance rates. Likewise the low number of index cases shows that case identification is a limiting factor. In the absence of robust data from epidemiological studies, these findings can inform decisions about the use of cascade genetic testing for mismatch repair gene mutations.

'They're all depressed, aren't they?' A qualitative study of social care workers and depression in older adults.

Statutory and voluntary social services provide care and support for vast numbers of vulnerable older adults, yet little is known about how social care practitioners respond to depression in this high risk population. This study elicited the perceptions and conceptualizations of this condition among social care staff, and views on how the response of social care and other agencies might be improved. Qualitative interviews were conducted with 20 social care practitioners working in generic services for older adults in south London. Depression was perceived to be remarkably common among clients, a phenomenon largely attributed to the adverse circumstances of old age, particularly social isolation. A key message from participants was that social causes indicate a need for social interventions. While primary care was criticised for not taking depression seriously in older people, mental health services were generally praised. Expansion of social, recreational and psychological interventions was advocated.

Home enteral feeding audit.

OBJECTIVE: To determine the main problems that families experience in the first month after their child is discharged from hospital on home enteral tube feeds (HETF) in terms of obtaining feed and equipment, managing tube feeding and accessing health professionals. METHODS: A multiple choice/short answer questionnaire was used to interview 81 parents/carers of children aged 0-16 years discharged from a supra regional children's hospital on HETF for the first time between December 2001 and August 2003. Questions addressed issues such as: contact with the home delivery company (HDC); delivery of feed and equipment; training; ability to access help; illnesses associated with tube feeding; and understanding of procedures post-discharge. RESULTS: The main problems identified were: delayed first deliveries (> or =7 days post-discharge; 47%); equipment missing from the first delivery (41%); difficulty obtaining a prescription from the general practitioner (GP) (17%); changing to different equipment post-discharge with minimal training on the new equipment (26%). CONCLUSIONS: There were many problems with delays in delivery of equipment, incorrect equipment and changing of equipment when patients were first discharged on HETF. Significant improvements are necessary in organization of home enteral feeding systems when patients are first discharged.

Performance feedback of hand hygiene, using alcohol gel as the skin decontaminant, reduces the number of inpatients newly affected by MRSA and antibiotic costs.

In March 2000 the Plastic Surgery Unit of our 600-bedded district general hospital agreed to be the pilot ward for the introduction of a new standard of hand hygiene, emphasizing the use of alcohol gel on socially clean hands between clinical contact with patients. Hand hygiene practice of healthcare workers (HCWs) was observed using Formic forms. The data from completed forms were scanned into an Excel database, and results fed back to HCWs in graphical form. The case notes of patients newly affected by methicillin-resistant Staphylococcus aureus (MRSA), likely to have been acquired as inpatients, were reviewed for one year before and after this performance feedback of hand hygiene. The cost of teicoplanin use (for MRSA infections) was also determined for the two periods. There was a significant reduction in the number of patients newly affected by MRSA (P<0.05), and in the use of teicoplanin, suggesting that performance feedback of hand hygiene reduces nosocomial MRSA infection rates and antibiotic use.

Pilot study: quality of life assessment of postnatal fatigue and other physical morbidity.

Postnatal morbidity is increasingly recognized, but standard assessments may not capture what is most important to the woman with such morbidity in terms of her quality of life. The Mother-Generated Index (MGI) is a proposed postnatal quality-of-life instrument which allows the mother to determine both content and scoring. In this pilot study we found that although a degree of psychological and physical morbidity (including tiredness) is common, and may be very significant, for most women these factors are low-grade, and other aspects of their lives are more important. A quality-of-life approach allows the mother to determine her own postnatal assessment, and encourages practitioners to view her more holistically.

An assessment of surgeons' abilites to site colostomies accurately.

AIMS: The ability of surgeons to site a colostomy is assessed in a clinical model. In addition, the tuition received by surgical trainees in stoma siting is also reviewed. MATERIALS AND METHODS: Eleven surgeons (trainees--six, colorectal subspeciality interest--two) were asked to site an end colostomy on nine patients using an adhesive disc (diameter--1cm). The position of the stoma was then measured on the 'x' and 'y' axis of a 2cm box grid, (maximum error--1cm) which was placed on the abdomen and centred on the umbilicus. The positions were then compared with that chosen by the stoma nurse who was taken as the gold standard. Results were compared using ANOVA and the Mann Whitney--U test. A telephone questionnaire was then undertaken to review the training of junior surgeons. RESULTS: There was variance present within the group of surgeons studied (p<0.01). Trainees and consultants had a similar accuracy in stoma-siting (p<0.2). Consultants with a colorectal subspeciality interest were better at placing stomas than those with a general interest (p<0.002). Badly placed stomas were three times more likely to be too low than too high (p<0.002). Thirty of 37 trainees reported receiving no undergraduate training from a specialist stoma nurse. Ninety per cent received postgraduate training from another surgeon while a specialist nurse trained only 35%. CONCLUSION: There was no difference between trainees and consultants in their ability to site a colostomy. However, surgeons with a subspeciality interest chose stoma sites that were more consistent with the specialist nurse than general surgeons. Training is haphazard and ability is frequently assumed rather than proven.

Analysis of solvent central nervous system toxicity and ethanol interactions using a human population physiologically based kinetic and dynamic model.

The effect of acute ethanol-mediated inhibition of m-xylene metabolism on central nervous system (CNS) depression in the human worker population was investigated using physiologically based pharmacokinetic (PBPK) models and probabilistic random (Monte Carlo) sampling. PBPK models of inhaled m-xylene and orally ingested ethanol were developed and combined by a competitive enzyme (CYP2E1) inhibition model. Human interindividual variability was modeled by combining estimated statistical distributions of model parameters with the deterministic PBPK models and multiple random or Monte Carlo simulations. A simple threshold pharmacodynamic model was obtained by simulating m-xylene kinetics in human studies where CNS effects were observed and assigning the peak venous blood m-xylene concentration (C(V,max)) as the dose surrogate of toxicity. Probabilistic estimates of an individual experiencing CNS disturbances given exposure to the current UK occupational exposure standard (100 ppm time-weighted average over 8 h), with and without ethanol ingestion, were obtained. The probability of experiencing CNS effects given this scenario increases markedly and nonlinearly with ethanol dose. As CYP2E1-mediated metabolism of other occupationally relevant organic compounds may be inhibited by ethanol, simulation studies of this type should have an increasingly significant role in the chemical toxicity risk assessment.

The utility of PBPK in the safety assessment of chloroform and carbon tetrachloride.

Occupational exposure limits (OELs) for individual substances are established on the basis of the available toxicological information at the time of their promulgation, expert interpretation of these data in light of industrial use, and the framework in which they sit. In the United Kingdom, the establishment of specific OELs includes the application of uncertainty factors to a defined starting point, usually the NOAEL from a suitable animal study. The magnitude of the uncertainty factors is generally determined through expert judgment including a knowledge of workplace conditions and management of exposure. PBPK modeling may help in this process by informing on issues relating to extrapolation between and within species. This study was therefore designed to consider how PBPK modeling could contribute to the establishment of OELs. PBPK models were developed for chloroform (mouse and human) and carbon tetrachloride (rat and human). These substances were chosen for examination because of the extent of their toxicological databases and availability of existing PBPK models. The models were exercised to predict the rate (chloroform) or extent (carbon tetrachloride) of metabolism of these substances, in both rodents and humans. Monte Carlo analysis was used to investigate the influence of variability within the human and animal model populations. The ratio of the rates/extent of metabolism predicted for humans compared to animals was compared to the uncertainty factors involved in setting the OES. Predictions obtained from the PBPK models indicated that average rat and mouse metabolism of carbon tetrachloride and chloroform, respectively, are much greater than that of the average human. Application of Monte Carlo analysis indicated that even those people who have the fastest rates or most extensive amounts of metabolism in the population are unlikely to generate the levels of metabolite of these substances necessary to produce overt toxicity in rodents. This study highlights the value that the use of PBPK modeling may add to help inform and improve toxicological aspects of a regulatory process.

Hepatitis B immunization in a low-incidence province of Canada: comparing alternative strategies.

This study provides a comparative cost-effectiveness analysis of three universal immunization programs for hepatitis B virus (HBV). Using three theoretical cohorts of infants, 10-year-olds, and 12-year-olds, a universal immunization program was compared with a prenatal screening/newborn immunization program involving testing of prepartum women and immunization of newborns of HBsAg-positive mothers. A Markov long-term outcome model used Manitoba data to estimate costs and health outcomes across the lifespan. The model was based on an HBV incidence rate of 19/100,000 and a discount rate of 5% and incorporated the most recent treatment advances (interferon therapy). Cost-effectiveness was calculated as the ratio of dollars spent per year of life saved, with costs determined from the perspective of a third-party payer. The universal infant-immunization program, although not cost-saving, was associated with a low, economically attractive cost-effectiveness ratio of $15,900 (Canadian) per year of life saved, a figure substantially lower than the ratios of $97,600 and $184,800 (Canadian) associated with the universal programs for 10- and 12-year-olds, respectively. Cost-effectiveness ratios were found to be sensitive to changes in immunization costs, HBV incidence rates, and the rate at which protective antibody levels are lost over time: If these variables move in the directions suggested by current trends, the authors anticipate an increasing economic appeal of universal programs well into the future. A universal program of HBV immunization for infants appears to be economically practical in regions where HBV infection rates are low and stable.