Venous thromboembolic prophylaxis after simultaneous bilateral total knee arthroplasty: aspirin versus warfarin.

AIMS: The aims of this study were to compare the efficacy of two agents, aspirin and warfarin, for the prevention of venous thromboembolism (VTE) after simultaneous bilateral total knee arthroplasty (SBTKA), and to elucidate the risk of VTE conferred by this procedure compared with unilateral TKA (UTKA). PATIENTS AND METHODS: A retrospective, multi-institutional study was conducted on 18 951 patients, 3685 who underwent SBTKA and 15 266 who underwent UTKA, using aspirin or warfarin as VTE prophylaxis. Each patient was assigned an individualised baseline VTE risk score based on a system using the Nationwide Inpatient Sample. Symptomatic VTE, including pulmonary embolism (PE) and deep vein thrombosis (DVT), were identified in the first 90 days post-operatively. Statistical analyses were performed with logistic regression accounting for baseline VTE risk. RESULTS: The adjusted incidence of PE following SBTKA was 1.0% (95% confidence interval (CI) 0.86 to 1.2) with aspirin and 2.2% (95% CI 2.0 to 2.4) with warfarin. Similarly, the adjusted incidence of VTE following SBTKA was 1.6% (95% CI 1.1 to 2.3) with aspirin and 2.5% (95% CI 1.9 to 3.3) with warfarin. The risk of PE and VTE were reduced by 66% (odds ratio (OR) 0.44, 95% CI 0.25 to 0.78) and 38% (OR 0.62, 95% CI 0.38 to 1.0), respectively, using aspirin. In addition, the risk of PE was 204% higher for patients undergoing SBTKA relative to those undergoing UTKA. For each ten-point increase in baseline VTE risk, the risk of PE increased by 25.5% for patients undergoing SBTKA compared with 10.5% for those undergoing UTKA. Patients with a history of myocardial infarction or peripheral vascular disease had the greatest increase in risk from undergoing SBTKA instead of UTKA. CONCLUSION: Aspirin is more effective than warfarin for the prevention of VTE following SBTKA, and serves as the more appropriate agent for VTE prophylaxis for patients in all risk categories. Furthermore, patients undergoing SBTKA are at a substantially increased risk of VTE, even more so for those with significant underlying risk factors. Patients should be informed about the risks associated with undergoing SBTKA. Cite this article: Bone Joint J 2018;100-B(1 Supple A):68-75.

Creating an integrated care model for childhood obesity: a randomized pilot study utilizing telehealth in a community primary care setting.

In an integrated care model, involving primary care providers (PCPs) and obesity specialists, telehealth may be useful for overcoming barriers to treating childhood obesity. We conducted a pilot study comparing body mass index (BMI) changes between two arms (i) PCP in-person clinic visits plus obesity specialist tele-visits ( PCP visits + specialist tele-visits) and (ii) PCP in-person clinic visits only ( PCP visits only), with ongoing tele-consultation between PCPs and obesity specialists for both arms. Patients (N = 40, 10-17 years, BMI ≥ 95th percentile) were randomized to Group 1 or 2. Both groups had PCP visits every 3 months for 12 months. Using a cross-over protocol, Group 1 had PCP visits + specialist tele-visits during the first 6 months and PCP visits only during the second 6 months, and Group 2 followed the opposite sequence. Each of 12 tele-visits was conducted by a dietitian or psychologist with a patient and parent. Retention rates were 90% at 6 months and 80% at 12 months. BMI (z-score) decreased more for Group 1 (started with PCP visits + specialist tele-visits) vs. Group 2 (started with PCP visits only) at 3 months (-0.11 vs. -0.05, P = 0.049) following frequent tele-visits. At 6 months (primary outcome), BMI was lower than baseline within Group 1 (-0.11, P = 0.0006) but not Group 2 (-0.06, P = 0.08); however, decrease in BMI at 6 months did not differ between groups. After crossover, BMI remained lower than baseline for Group 1 and dropped below baseline for Group 2. An integrated care model utilizing telehealth holds promise for treating children with obesity.

Schizophrenia and violent crime: a population-based study.

BACKGROUND: Previous studies have found that patients with schizophrenia are more likely to be violent than the general population. The aim of this study was to investigate the association between schizophrenia and violent crime in the Israeli population. METHOD: Using the Israeli Psychiatric Hospitalization Case Registry we identified 3187 patients with a discharge diagnosis of schizophrenia. For each proband we identified parents and siblings, and gender- and age-matched controls for patients, parents and siblings. Information on violent crimes was obtained from police records. RESULTS: Patients with schizophrenia were at increased risk for violent crimes compared with controls [odds ratio (OR) 4.3, 95% confidence interval (CI) 3.8-4.9], especially women (OR 9.9, 95% CI 6.2-15.7). Risk for violent crimes was higher among patients with co-morbid substance misuse than in patients without such co-morbidity (OR 5.1, 95% CI 4.2-6.3). CONCLUSIONS: The results of this study suggest that increased risk of violence is part of the clinical picture of schizophrenia and needs to be recognized as a legitimate, essential, aspect of clinical management.

Effects of exercise and lifestyle modification on fitness, insulin resistance, skeletal muscle oxidative phosphorylation and intramyocellular lipid content in obese children and adolescents.

BACKGROUND: Obesity is associated with poor fitness and adverse metabolic consequences in children. OBJECTIVE: To investigate how exercise and lifestyle modification may improve fitness and insulin sensitivity in this population. DESIGN AND SUBJECTS: Randomized controlled trial, 21 obese (body mass index ≥ 95% percentile) subjects, ages 10 to 17 years. METHODS: Subjects were given standardized healthful lifestyle advice for 8 weeks. In addition, they were randomized to an in-home supervised exercise intervention (n = 10) or control group (n = 11). MEASUREMENTS: Fasting laboratory studies (insulin, glucose, lipid profile) and assessments of fitness, body composition, skeletal muscle oxidative phosphorylation and intramyocellular lipid content (IMCL), were performed at baseline and study completion. RESULTS: Subjects were 13.0 ± 1.9 (standard deviation) years old, 72% female and 44% non-white. Exercise improved fitness (P = 0.03) and power (P = 0.01), and increased IMCL (P = 0.02). HOMA-IR decreased among all subjects in response to lifestyle modification advice (P = 0.01), regardless of exercise training assignment. In univariate analysis in all subjects, change in cardiovascular fitness was associated with change in HOMA-IR. In exploratory analyses, increased IMCL was associated with greater resting energy expenditure (r = 0.78, P = 0.005) and a decrease in fasting respiratory quotient (r = -0.70, P = 0.02) (n = 11). CONCLUSIONS: Change in fitness was found to be related to change in insulin resistance in response to lifestyle modification and exercise in obese children. IMCL increased with exercise in these obese children, which may reflect greater muscle lipid oxidative capacity.

Circulating branched-chain amino acid concentrations are associated with obesity and future insulin resistance in children and adolescents.

UNLABELLED: What is already known about this subject Circulating concentrations of branched-chain amino acids (BCAAs) can affect carbohydrate metabolism in skeletal muscle, and therefore may alter insulin sensitivity. BCAAs are elevated in adults with diet-induced obesity, and are associated with their future risk of type 2 diabetes even after accounting for baseline clinical risk factors. What this study adds Increased concentrations of BCAAs are already present in young obese children and their metabolomic profiles are consistent with increased BCAA catabolism. Elevations in BCAAs in children are positively associated with insulin resistance measured 18 months later, independent of their initial body mass index. BACKGROUND: Branched-chain amino acid (BCAA) concentrations are elevated in response to overnutrition, and can affect both insulin sensitivity and secretion. Alterations in their metabolism may therefore play a role in the early pathogenesis of type 2 diabetes in overweight children. OBJECTIVE: To determine whether paediatric obesity is associated with elevations in fasting circulating concentrations of BCAAs (isoleucine, leucine and valine), and whether these elevations predict future insulin resistance. METHODS: Sixty-nine healthy subjects, ages 8-18 years, were enrolled as a cross-sectional cohort. A subset of subjects who were pre- or early-pubertal, ages 8-13 years, were enrolled in a prospective longitudinal cohort for 18 months (n = 17 with complete data). RESULTS: Elevations in the concentrations of BCAAs were significantly associated with body mass index (BMI) Z-score (Spearman's Rho 0.27, P = 0.03) in the cross-sectional cohort. In the subset of subjects that followed longitudinally, baseline BCAA concentrations were positively associated with homeostasis model assessment for insulin resistance measured 18 months later after controlling for baseline clinical factors including BMI Z-score, sex and pubertal stage (P = 0.046). CONCLUSIONS: Elevations in the concentrations of circulating BCAAs are significantly associated with obesity in children and adolescents, and may independently predict future insulin resistance.

Monitoring the effect of mild ischemia with a built-in light-emitting diode contact lens electrode and a low-cost custom-made apparatus.

Electroretinography (ERG) is widely used in clinical work and research to assess the retinal function. We evaluated an easy to build ERG setup adapted for small animals comprising two contact lens electrodes with a built-in light-emitting diode and a custom-made amplification system. The system's sensitivity was tested by monitoring ERG in albino rat eyes subjected to mild ischemia. Flash ERG was recorded by two contact lens electrodes positioned on the rat's corneas and used alternately as test or reference. The a- and b-wave amplitudes, a-wave latency, b-wave implicit time and oscillatory potentials (OPs) were analyzed. Ischemia was achieved by elevating the intraocular pressure in the eye's anterior chamber. ERG was recorded on post-ischemia (PI) days -1, 1, 3 and 7. Morphological changes were analyzed on hematoxylin/eosin stained 5 µm sections of control 7d PI retinas. In control eyes, ERG exhibited a pattern similar to a standard recording. Retinas subjected to mild ischemia preserved ordered layered morphology, exhibiting approximately 30% loss of ganglion cells and no changes in gross morphology. By day 3 PI, ischemia caused an increase in the a-wave amplitude (from 34.9 ± 2.7 to 45.4 ± 4.3 µV), a decrease in the b-wave amplitude (from 248 ± 13 to 162 ± 8 µV), an increase in a-wave latency (from 11.1 ± 0.3 to 17.3 ± 1.4 ms) and b-wave implicit time (from 81.0 ± 1.6 to 90.0 ± 2.5 ms), and attenuation of OPs. The described setup proved sensitive and reliable for evaluating subtle changes in the retinal function in small animals.

Implanted renal replacement for end-stage renal disease.

The nearly 400000 American patients on dialysis suffer high cardiovascular and infectious mortality, but there is now evidence that this morbid phenotype can be rescued by intensive dialytic therapy. Self-care dialysis at home is limited by patient fears about skill and safety. An implanted artificial kidney would provide the benefits of intensive therapy while avoiding the focal points of patient concern. Hollow fiber polymer membranes and dialytic waste removal are lifesaving innovations but are difficult to adapt to implantable therapies. Biomimetic membranes and living cells can replicate the native kidney's strategy for waste removal. Three key technology developments are necessary for implementation of an implantable artificial kidney: high efficiency ultrafiltration membranes, control of blood-materials interactions such as thrombosis and fouling, and stable differentiated function of renal proximal tubule cells in an engineered construct. There has been significant progress in demonstrating proof-of-concept experiments in each key technology area.

Effects of biomedical sterilization processes on performance characteristics of MEMS pressure sensors.

The effects of steam and gamma sterilization on the performance of bulk-micromachined pressure sensors were investigated using a variable pressure setup. Commercially available piezoresistive MEMS (microelectromechanical systems) pressure sensor die were characterized prior and subsequent to sterilization over a 0-500 Torr pressure range. The effects of sterilization were examined as changes in sensor output voltage (DeltaV) at various applied pressures. For steam sterilization, DeltaV decreased with applied pressure ranging from +0.27 mV at 100 Torr to -0.14 mV at 500 Torr. In contrast, the corresponding values for gamma-sterilized sensors were lower, decreasing from +0.01 mV 100 Torr to -0.06 mV at 500 Torr. The increased variation in DeltaV for the steam-sterilized sensors was attributed to the formation of an oxide film, which was confirmed using energy dispersive X-ray (EDX) spectroscopy. Statistical analysis revealed that the effect of both sterilization procedures on sensor performance was insignificant.

Dialysis and nanotechnology: now, 10 years, or never?

Nanotechnology, defined as the science of material features between 10(-9) and 10(-7) of a meter, has received extensive attention in the popular press as proof-of-concept experiments in the laboratory are published. The inevitable delay between feature articles and clinical endpoints has led to unwarranted skepticism about the applicability of the technology to current medical therapy. The theoretic advantages of micro- and nanometer scale engineering to renal replacement include the manufacture of high-hydraulic permeability membranes with implanted sensing and control structures. Recent data in membrane design and testing is presented, with a review of the challenges remaining in implementation of this technology.

Silicon dermabrasion tools for skin resurfacing applications.

Miniature abrasion tools for potential skin resurfacing applications are created using microelectromechanical systems (MEMS) fabrication technology. The abrading microstructures are formed on silicon wafers by a bulk micromachining process based on isotropic xenon difluoride etching. The micromachined abraders (microdermabraders) are packaged and applied to human cadaveric skin to assess abrasion quality. Plastic (acrylic) microreplicated structures, non-coated and aluminum-coated versions, are also used in a similar fashion. Non-textured silicon and plastic samples are used as study controls. Dermabraded and intact skin regions are analyzed qualitatively and quantitatively by light microscopy, image processing techniques, and histology. The microdermabraders exhibit a cleaner, more uniform abrading pattern on the cadaveric skin compared to the plastic microreplicated structures. Furthermore, the microdermabraders provide a consistently uniform cut through the epidermal layer, leaving little debris and minimal pitting. In contrast, the plastic microreplicated structures exhibit non-uniform abrading patterns and leave behind more debris and eccentric pits. The results suggest micromachined dermabraders can successfully abrade fine dermatological flaws in human skin.

Crystal engineering of the composition of pharmaceutical phases.

The carboxylic acid-pyridine supramolecular heterosynthon can be exploited to predictably generate binary crystalline phases involving rac-ibuprofen, rac-flurbiprofen or aspirin.

Microelectromechanical systems and neurosurgery: a new era in a new millennium.

MICROMACHINES AND MICROELECTROMECHANICAL SYSTEMS (MEMS) are terms that are new to neurosurgeons but certain to become "household terms" in neurosurgery in the near future. These new terms serve as an introduction to a new world of sensors, actuators, and "smart systems" that will change the ways in which neurosurgeons interact with their environment. Through the use of microelectronics and micromachining technologies, MEMS will allow neurosurgeons to perform familiar tasks with greater precision, perform tasks that previously were not done at all, and monitor physiological and biochemical parameters more accurately and with greater safety. This review provides the information necessary to understand the fundamental concepts of MEMS and their application to the neurosurgical arena. It defines the relevant terms and describes the history behind the "micromachine revolution," the capabilities and limitations of MEMS technology, and how this revolution is germane to neurosurgery and to neurosurgeons.

Limits of viability: dilemmas, decisions, and decision makers.

Decision-making about treatments for neonates at the threshold of viability is a complex process that must involve physicians, other health-care professionals, and families. Parents and families bring personal, ideological, cultural, and religious beliefs into their relationship with health-care professionals that have the potential to conflict with professional perceptions of good medical care and the interests of the patient. Neonatologists often find themselves criticized for overtreatment of these extremely premature infants. Yet, from the perspective of the health-care provider, perceived obligations in the face of an uncertain outcome, parental wishes as well as perceptions about legal mandates are often cited as the reasons for the provision of such extraordinary care. Recent reductions in perinatal mortality for premature infants born at the cusp of viability, in conjunction with emerging data on the substantial short- and long-term morbidities experienced by infants born between 23-25 weeks' gestation, have engendered a serious debate about professional and parental obligations in the face of extreme uncertainty. The fundamental questions are who ought to be permitted, under the present circumstances of rapidly evolving technologies and innovative therapies, to decide the best interests of the child, and how to achieve consensus regarding treatment goals when the outcome is uncertain and there are divergent views with regard to the infant's best interests. As survival for these infants increases and morbidity remains a significant likelihood, physicians must be cognizant of the power of their technology to impose undesired burdens on these infants. A reasonable, and reasoned, approach for these vulnerable infants requires collaborative decision making incorporating professional recommendations, with an openness, trust and willingness to work with parents to ascertain the best interests of an individual infant. Understanding of and respect for the differing views of the moral obligations of perinatal specialists and families can aid neonatal professionals in resolving interdisciplinary and physician-family conflicts as well as facilitating resolution of neonatal ethical dilemmas.

Carbamazepine overdose recognized by a tricyclic antidepressant assay.

Altered mental status in an adolescent presents a diagnostic challenge, and the clinician depends on clinical evaluation and laboratory studies to determine therapy and prognosis. We report the case of an adolescent with altered consciousness caused by carbamazepine overdose with a positive tricyclic antidepressant level to alert clinicians to the cross-reactivity of carbamazepine with a toxicology screen for tricyclic antidepressants.

Development of a palliative education assessment tool for medical student education.

Studies assessing palliative care education in U.S. medical schools reveal that little attention is paid to this topic. Although core competencies have been defined, few schools have implemented effective means to incorporate formal palliative care education into undergraduate curricula. To promote reform, each school needs to conduct a thorough assessment to identify palliative care content throughout the four-year curriculum. The authors developed an innovative assessment instrument to facilitate curricular mapping of palliative care education. The Palliative Education Assessment Tool (PEAT) comprises seven palliative care domains: palliative medicine, pain, neuropsychologic symptoms, other symptoms, ethics and the law, patient/family/nonclinical caregiver perspectives on end-of-life care, and clinical communication skills. Each domain details specific curricular objectives of knowledge, skills, and attitudes. Designed as a flexible self-assessment tool, PEAT helps determine the existence of palliative care education, which usually is found in various formats throughout a medical school's curriculum and thus sometimes "hidden." PEAT enables educators to describe a specific, multidimensional aspect of the curriculum and use the information for strategic planning, educational reform, and evaluation. The curricular reform implications of such an instrument are broader than palliative care assessment. A modified version of PEAT can be used to assess systematically other topics that are taught in various formats in the curriculum and to develop collaborative approaches to fulfilling the educational objectives of those topics.

Physician participation in capital punishment: a question of professional integrity.

The death penalty is legal in 36 states, and physicians are expected to attend and participate in executions. Yet, every major medical and health-related organization opposes physician participation in capital punishment. This article argues that it is unethical for physicians within the role as medical professional to participate in capital punishment, and that such acts erode the foundation of trust at the heart of medical practice. We believe that it is important for professional groups and medical societies to impose sanctions on members who choose to participate in executions.