Attenuating intrathoracic pressure swings decreases cardiac output at different intensities of exercise.

Intrathoracic pressure (ITP) swings that permit spontaneous ventilation have physiological implications for the heart. We sought to determine the effect of respiration on cardiac output ( Q ̇ $\dot Q$ ) during semi-supine cycle exercise using a proportional assist ventilator to minimize ITP changes and lower the work of breathing (Wb ). Twenty-four participants (12 females) completed three exercise trials at 30%, 60% and 80% peak power (Wmax ) with unloaded (using a proportional assist ventilator, PAV) and spontaneous breathing. Intrathoracic and intraabdominal pressures were measured with balloon catheters placed in the oesophagus and stomach. Left ventricular (LV) volumes and Q ̇ $\dot Q$ were determined via echocardiography. Heart rate (HR) was measured with electrocardiogram and a customized metabolic cart measured oxygen uptake ( V ̇ O 2 ${\dot V_{{{\mathrm{O}}_{\mathrm{2}}}}}$ ). Oesophageal pressure swings decreased from spontaneous to PAV breathing by -2.8 ± 3.1, -4.9 ± 5.7 and -8.1 ± 7.7 cmH2 O at 30%, 60% and 80% Wmax , respectively (P = 0.01). However, the decreases in Wb were similar across exercise intensities (27 ± 42 vs. 35 ± 24 vs. 41 ± 22%, respectively, P = 0.156). During PAV breathing compared to spontaneous breathing, Q ̇ $\dot Q$ decreased by -1.0 ± 1.3 vs. -1.4 ± 1.4 vs. -1.5 ± 1.9 l min-1 (all P < 0.05) and stroke volume decreased during PAV breathing by -11 ± 12 vs. -9 ± 10 vs. -7 ± 11 ml from spontaneous breathing at 30%, 60% and 80% Wmax , respectively (all P < 0.05). HR was lower during PAV breathing by -5 ± 4 beats min-1 at 80% Wmax (P < 0.0001). Oxygen uptake decreased by 100 ml min-1 during PAV breathing compared to spontaneous breathing at 80% Wmax (P < 0.0001). Overall, attenuating ITPs mitigated LV preload and ejection, thereby suggesting that the ITPs associated with spontaneous respiration impact cardiac function during exercise. KEY POINTS: Pulmonary ventilation is accomplished by alterations in intrathoracic pressure (ITP), which have physiological implications on the heart and dynamically influence the loading parameters of the heart. Proportional assist ventilation was used to attenuate ITP changes and decrease the work of breathing during exercise to examine its effects on left ventricular (LV) function. Proportional assist ventilation with progressive exercise intensities (30%, 60% and 80% Wmax ) led to reductions in cardiac output at all intensities, primarily through reductions in stroke volume. Decreases in LV end-diastolic volume (30% and 60% Wmax ) and increases in LV end-systolic volume (80% Wmax ) were responsible for the reduction in stroke volume. The relationship between cardiac output and oxygen uptake is disrupted during respiratory muscle unloading.

Prevalence of Diabetic Retinopathy in Indigenous and Non-Indigenous Australians: A Systematic Review and Meta-analysis.

TOPIC: This systematic review and meta-analysis summarizes evidence relating to the prevalence of diabetic retinopathy (DR) among Indigenous and non-Indigenous Australians. CLINICAL RELEVANCE: Indigenous Australians suffer disproportionately from diabetes-related complications. Exploring ethnic variation in disease is important for equitable distribution of resources and may lead to identification of ethnic-specific modifiable risk factors. Existing DR prevalence studies comparing Indigenous and non-Indigenous Australians have shown conflicting results. METHODS: This study was conducted following Joanna Briggs Institute guidance on systematic reviews of prevalence studies (PROSPERO ID: CRD42022259048). We performed searches of Medline (Ovid), EMBASE, and Web of Science until October 2021, using a strategy designed by an information specialist. We included studies reporting DR prevalence among diabetic patients in Indigenous and non-Indigenous Australian populations. Two independent reviewers performed quality assessments using a 9-item appraisal tool. Meta-analysis and meta-regression were performed using double arcsine transformation and a random-effects model comparing Indigenous and non-Indigenous subgroups. RESULTS: Fifteen studies with 8219 participants met criteria for inclusion. The Indigenous subgroup scored lower on the appraisal tool than the non-Indigenous subgroup (mean score 50% vs. 72%, P = 0.04). In the unadjusted meta-analysis, DR prevalence in the Indigenous subgroup (30.2%; 95% confidence interval [CI], 24.9-35.7) did not differ significantly (P = 0.17) from the non-Indigenous subgroup (23.7%; 95% CI, 16.8-31.4). After adjusting for age and quality, DR prevalence was higher in the Indigenous subgroup (P < 0.01), with prevalence ratio point estimates ranging from 1.72 to 2.58, depending on the meta-regression model. For the secondary outcomes, prevalence estimates were higher in the Indigenous subgroup for diabetic macular edema (DME) (8.7% vs. 2.7%, P = 0.02) and vision-threatening DR (VTDR) (8.6% vs. 3.0%, P = 0.03) but not for proliferative DR (2.5% vs. 0.8%, P = 0.07). CONCLUSIONS: Indigenous studies scored lower for methodological quality, raising the possibility that systematic differences in research practices may be leading to underestimation of disease burden. After adjusting for age and quality, we found a higher DR prevalence in the Indigenous subgroup. This contrasts with a previous review that reported the opposite finding of lower DR prevalence using unadjusted pooled estimates. Future epidemiological work exploring DR burden in Indigenous communities should aim to address methodological weaknesses identified by this review.

The impact of housing on birth outcomes in breeding macaque groups across multiple research centers.

Demand for nonhuman primates in research has increased over the past several years, while nonhuman primate supply remains a challenge in the United States. Global nonhuman primate supply issues make it increasingly important to maximize domestic colony production. To explore how housing conditions across primate breeding colonies impact infant survival and animal production more broadly, we collected medical records from 7959 rhesus macaques (Macaca mulatta) and 492 pigtail macaques (Macaca nemestrina) across seven breeding facilities and used generalized mixed-effect modeling to determine prenatal and infant survival odds by housing type and group size. Infant survival odds for each housing type and group size varied for prenatal, neonatal, early infant, and late infant age groups. Odds of prenatal survival were lowest in paired indoor housing and small and medium outdoor groups. No housing type performed better than large outdoor groups for neonatal survival. Odds of early infant survival was greatest in indoor and mixed indoor/outdoor housing compared to large outdoor enclosures. Large outdoor housing was associated with higher survival odds for late infant survival compared to small and medium outdoor housing. These results may influence housing choices at macaque breeding facilities hoping to maximize infant success, although there are relative care costs, the promotion of species-typical behaviors, and infrastructure factors to also consider. Our study used an interinstitutional collaboration that allowed for the analysis of more infant macaque medical records than ever before and used the broad variations across the seven national primate research centers to make the results applicable to many other facilities housing macaques.

Analyzing the quality and educational value of Achilles tendinopathy-related videos on TikTok.

BACKGROUND: Social media platforms, like TikTok, have become popular options for the consumption and distribution of healthcare information. Due to the lack of scientific oversight, the consistency of healthcare-related videos has become a focus of the current literature. However, orthopaedic surgery has lagged behind other specialties in acknowledging the widespread utilization of TikTok videos for medical information. This study aims to assess the quality and educational benefits of Achilles tendinopathy-related TikTok videos. METHODS: TikTok was queried using the hashtags "#achillestendonexercises", "achillestendonitisexercises", "achillestendinosisexercises", and "achillestendinopathyexercises". 100 videos (25 for each term) were included after applying the exclusion criteria. The number of views, likes, shares, comments, and favorites was recorded. The content was graded using DISCERN (a well-validated informational analysis tool) and ATEES (a self-designed tool for exercise evaluation). RESULTS: The total number of views of the 100 videos was 1647,148, with a median of 7562.5 (IQR = 2,281- 19,575). The videos collectively received 73,765 likes, 1125 comments, 14,491 favorites and 6897 shares with a median of 283 (IQR= 73.8-957.8), 7 (IQR= 1.8-16.0), 61.5 (IQR= 8.8-184.3), and 18.5 (IQR= 2.0-49.8), respectively. General users uploaded slightly less (48%) when compared to healthcare professionals (52%). Healthcare professionals had more videos graded as "very poor" (43.4%) in comparison to the general users (36.2%). General users had more videos graded as "poor" (63.8%) in comparison to healthcare professionals (54.7%). However, there were no significant differences between the groups on either of the video grading scales. CONCLUSION: Although TikTok is a powerful tool for information distribution, the educational value of the videos related to Achilles tendinopathy exercises was poor. With only 1% of videos receiving a grade of 'fair,' and no videos reaching a score of 'good' or 'excellent', healthcare professionals should be aware of the high viewership of low-quality content easily accessible on TikTok.

Antibodies in action: the role of humoral immunity in the fight against atherosclerosis.

The sequestering of oxidation-modified low-density lipoprotein by macrophages results in the accumulation of fatty deposits within the walls of arteries. Necrosis of these cells causes a release of intercellular epitopes and the activation of the adaptive immune system, which we predict leads to robust autoantibody production. T cells produce cytokines that act in the plaque environment and further stimulate B cell antibody production. B cells in atherosclerosis meanwhile have a mixed role based on subclass. The current model is that B-1 cells produce protective IgM antibodies in response to oxidation-specific epitopes that work to control plaque formation, while follicular B-2 cells produce class-switched antibodies (IgG, IgA, and IgE) which exacerbate the disease. Over the course of this review, we discuss further the validation of these protective antibodies while evaluating the current dogma regarding class-switched antibodies in atherosclerosis. There are several contradictory findings regarding the involvement of class-switched antibodies in the disease. We hypothesize that this is due to antigen-specificity, and not simply isotype, being important, and that a closer evaluation of these antibodies' targets should be conducted. We propose that specific antibodies may have therapeutical potential in preventing and controlling plaque development within a clinical setting.

The impact of competitive integrated employment on economic, psychological, and physical health outcomes for individuals with intellectual and developmental disabilities.

BACKGROUND: Although competitive integrated employment (CIE) has been established as a goal of employment research, policy, and practice for individuals with intellectual and developmental disabilities, the secondary benefits of CIE are rarely discussed. AIMS: The purpose of this systematic review was to analyze and synthesise research related to the association between CIE and improved economic, psychological health, and physical health outcomes for individuals with intellectual and developmental disabilities. MATERIALS & METHODS: Our review searched peer-reviewed literature from seven electronic databases and screened 1110 peer-reviewed articles based on inclusion criteria established following PRISMA guidelines. RESULTS: Our search procedures produced a final sample of 17 studies. DISCUSSION: Implications of these findings for future research, policy, and practice are provided. CONCLUSION: Our findings showed strong evidence associated with economic outcomes of CIE, moderate associated with psychological health outcomes, and limited evidence related to physical health outcomes.

Strength training restores force-generating capacity in patients with schizophrenia.

Patients with schizophrenia spectrum disorders have impaired skeletal muscle force-generating capacity (FGC) of the lower extremities, that is, one repetition maximum (1RM) and rapid force development, and poor functional performance. We therefore investigated whether 12 weeks of maximal strength training (MST) could (a) restore FGC and functional performance to the level of healthy references, (b) increase patient activation and quality of life, and (c) explore associations between symptom severity, defined daily dose of medication, illness duration, level of patient activation, and improvements in FGC and functional performance. Forty-eight outpatients were randomized to a training group (TG) or control group (CG). TG performed leg press MST 2 day/week at ~ 90% 1RM. The CG received two introductory training sessions and encouragement to train independently. Leg press 1RM, rapid force development, a battery of functional performance tests, Patient Activation Measure-13, and 36-Item Short Form Health Survey were tested. Healthy references performed baseline tests of FGC and functional performance. Thirty-six patients completed the study (TG: 17, CG: 19). TG improved 1RM (28%) and rapid force development (20%, both P < .01) to a level similar to healthy references, while no change was apparent in the CG. TG's improvement in rapid force development was negatively associated with defined daily dose of medication (r = -0.5, P = .05). Both TG and CG improved 30-second sit-to-stand test performance (P < .05) which was associated with improved rapid force development (r = 0.6, P < .05). In conclusion, 12 weeks of MST restored patients' lower extremity FGC to a level similar to healthy references and improved 30-second sit-to-stand test performance.

Evaluating the Effect of Work Incentives Benefits Counseling on Employment Outcomes of Transition-Age and Young Adult Supplemental Security Income Recipients with Intellectual Disabilities: A Case Control Study.

Purpose Work incentives benefits counseling (WIBC) can be a strong facilitator contributing to improved employment outcomes for individuals with intellectual disabilities (ID) by providing information about how income may affect disability benefits eligibility. The purpose of this study is to evaluate the effect of WIBC as a VR intervention to improve on employment outcomes and earnings of transition-age youth and young adults with ID who are Supplemental Security Income benefits recipients using a propensity score matching analysis approach. Propensity score matching using logistic regression analysis and the nearest neighbour method was conducted to equalize the treatment (received WIBC) and control groups (not received WIBC) on the six prominent demographic covariates. The treatment group had higher rates of employment, higher hourly wages than the control group, while the treatment group worked less hours per week than the control group. Methods Propensity score matching using logistic regression analysis and the nearest neighbour method was conducted to equalize the treatment (received WIBC) and control groups (not received WIBC) on the six prominent demographic covariates. Results The treatment group had higher rates of employment, higher hourly wages than the control group, while the treatment group worked less hours per week than the control group. Conclusions Findings of the present study can be used by policy makers, transition specialists, rehabilitation counselors, and other disability service providers to increase employment outcomes and earnings for individuals with ID through WIBC services. Future research and practice implications are provided.

The hyperpnoea of exercise in health: Respiratory influences on neurovascular control.

NEW FINDINGS: What is the topic of this review? Elevated demand is placed on the respiratory muscles during whole-body exercise-induced hyperpnoea. What is the role of elevated demand in neural modulation of cardiovascular control in respiratory and locomotor skeletal muscle, and what are the mechanisms involved? What advances does it highlight? There is a sympathetic restraint of blood flow to locomotor muscles during near-maximal exercise, which might function to maintain blood pressure. During submaximal exercise, respiratory muscle blood flow might be also be reduced if ventilatory load is sufficiently high. Methodological advances (near-infrared spectroscopy with indocyanine green) confirm that blood flow is diverted away from respiratory muscles when the work of breathing is alleviated. ABSTRACT: It is known that the respiratory muscles have a significant increasing oxygen demand in line with hyperpnoea during whole-body endurance exercise and are susceptible to fatigue, in much the same way as locomotor muscles. The act of ventilation can itself be considered a form of exercise. The manipulation of respiratory load at near-maximal exercise alters leg blood flow significantly, demonstrating a competitive relationship between different skeletal muscle vascular beds to perfuse both sets of muscles adequately with a finite cardiac output. In recent years, the question has moved towards whether this effect exists during submaximal exercise, and the use of more direct measurements of respiratory muscle blood flow itself to confirm assumptions that uphold the concept. Evidence thus far has shown that there is a reciprocal effect on blood flow redistribution during ventilatory load manipulation observed at the respiratory muscles themselves and that the effect is observable during submaximal exercise, where active limb blood flow was reduced in conditions that simulated a high work of breathing. This has clinical applications for populations with respiratory disease and heart failure, where the work of breathing is remarkably high, even during submaximal efforts.

Home-field advantage: native gecko exhibits improved exertion capacity and locomotor ability in structurally complex environments relative to its invasive counterpart.

BACKGROUND: Invasive species are of substantial concern because they may threaten ecosystem stability and biodiversity worldwide. Not surprisingly, studies examining the drivers of biological invasion have increased in number over the past few decades in an effort to curtail invasive species success by way of informing management decisions. The common house gecko, Hemidactylus frenatus, has successfully invaded the Pacific islands where it appears to thrive in and dominate non-natural habitats offering high food availability (i.e., well-lit human dwellings) compared to native geckos. Previous work demonstrated that H. frenatus can outperform the native gecko, Lepidodactylus lugubris, in terms of maximal sprint speed on relatively simple planar surfaces (e.g., building walls). Lepidodactylus lugubris and other native geckos, however, may have superior locomotor performance in three-dimensional, structurally complex habitats. RESULTS: Here we compared the locomotor behaviour and exertion capacity of the native gecko, Gehyra oceanica, and the invasive gecko, Hemidactylus frenatus, on the island of Mo'orea, French Polynesia, on fabricated structures simulating structurally complex substrates. We found that the native gecko exhibits improved locomotor performance compared to the invasive gecko on structurally complex substrates. We also completed encounter surveys to document free-ranging habitat use and behaviour of these two species. We discovered that H. frenatus were more common in natural habitats than previously observed and used similar substrates as G. oceanica, although G. oceanica appeared to use substrates with greater perch heights (i.e., trees). CONCLUSIONS: Our findings revealed that locomotor performance in complex environments may contribute to the previously observed habitat segregation between native and invasive Pacific island geckos. Furthermore, our locomotor and habitat use data are consistent with the hypothesis that G. oceanica may be resistant to invasion of H. frenatus in natural environments. Our study calls for more detailed ecophysiological and ecomorphological studies of both native and invasive Pacific gecko species.

Medical Practitioners Who Deny Young Women Sterilisation Surgery "Because They Will Regret It Later": Patient-centred Practice or Discrimination?

Women in Australia routinely access medical services which, by design or consequence, sterilise them. There is evidence which suggests that some medical practitioners are not offering procedures to young women where the surgery will make them infertile. These decisions are often defended on the basis that women who lose their fertility will go on to regret the medical procedure in the future. This article will consider the legal and ethical implications of this practice. It will first critically analyse the ethics of this decision according to the Beauchamp and Childress principles of justice, applying them through the lens of a patient-centred practice framework. It will then examine whether such practice may constitute discrimination under the Federal and Victorian discrimination frameworks, focusing on whether such decisions constitute age discrimination, gender discrimination, or discrimination on the basis of parental status. This article will draw the conclusion that such decisions are generally unethical and may constitute discrimination under Australian laws.

Exclusion criteria and adverse events in perioperative trials of tranexamic acid: a systematic review and meta-analysis.

BACKGROUND: Tranexamic acid (TXA) is an inexpensive therapy effective at minimizing perioperative blood loss and transfusion. However, it remains underutilized due to safety concerns. To date, no evidence-based guidelines exist identifying which patients should not receive TXA therapy. This study determined patient groups for whom safety information regarding TXA is lacking due to common exclusion from perioperative TXA trials. STUDY DESIGN AND METHODS: A systematic review searching the databases Medline, EMBASE, CENTRAL, and Clinicaltrials.gov was performed. Randomized controlled trials (RCTs) administering systemic TXA perioperatively to elective or emergent surgery patients were eligible. Our primary outcome was to describe exclusion criteria of RCTs, and the secondary outcome was TXA safety. A descriptive synthesis of exclusion criteria was performed, and TXA safety was assessed by meta-analysis. RESULTS: A total of 268 eligible RCTs were included. Meta-analysis showed that systemic TXA did not increase risk of adverse events compared to placebo or no intervention (relative risk, 1.05; 95% confidence interval, 0.99-1.12). Patient groups commonly excluded from perioperative TXA trials, and thus potentially lacking TXA safety data, were those with major comorbidities, a history of thromboembolism, medication use affecting coagulation, TXA allergy, and coagulopathy. Exclusion of patients with major comorbidities may not be necessary; we showed that the risk of adverse events was similar in studies that excluded patients with major comorbidities and those that did not. CONCLUSION: Sufficient evidence exists to develop perioperative guidelines for TXA use in many populations. Further studies evaluating perioperative TXA use in patients with a history of thromboembolism are warranted.

Patients with schizophrenia have impaired muscle force-generating capacity and functional performance.

Patients with schizophrenia have impaired physical health. However, evidence of how skeletal muscle force-generating capacity (FGC), a key component of functional performance, may contribute to the impairment is scarce. Thus, the aim of this study was to investigate the patient groups' skeletal muscle FGC and its association with functional performance. Leg-press FGC was assessed along with a battery of functional performance tests in 48 outpatients (28 men, 34 ± 10 years; 20 women, 36 ± 12 years) with schizophrenia spectrum disorder (ICD-10, F20-29), and compared with 48 healthy age- and gender-matched references. Results revealed reduced one-repetition maximum (1RM) in men (-19%, P < .01) and a trend toward reduction in women (-13%, P = .067). The ability to develop force rapidly was also impaired (men: -30%; women: -25%, both P < .01). Patients scored worse than healthy references on all physical performance tests (stair climbing: -63%; 30-second sit-to-stand (30sSTS): -48%; six-minute walk test (6MWT): -22%; walking efficiency: -14%; and unipedal stance eyes open: -20% and closed: -73%, all P < .01). 1RM correlated with 6MWT (r = .45), stair climbing (r = -.44), 30sSTS (r = .43), walking efficiency (r = .26), and stance eyes open (r = .33) and closed (r = .45), all P < .01. Rapid force development correlated with 6MWT (r = .54), stair climbing (r = -.49), 30sSTS (r = .45), walking efficiency (r = .26), and stance eyes open (r = .44) and closed (r = .51), all P < .01. In conclusion, skeletal muscle FGC and functional performance are reduced in patients with schizophrenia and should be recognized as important aspects of the patient groups' impaired health. Resistance training aiming to improve these components should be considered an important part of clinical treatment.

A comprehensive cardiovascular disease risk profile in patients with schizophrenia.

Patients with schizophrenia are physically inactive and have high prevalence of cardiovascular disease (CVD). Peak oxygen uptake (V̇O2peak ) is one of the strongest predictors for CVD, yet is rarely investigated in this patient population, and how V̇O2peak relates to other conventional CVD risk measures in this population is unclear. We measured treadmill V̇O2peak along with daily physical activity assessed by triaxial accelerometry, body mass index (BMI), waist circumference, blood pressure, lipid profiles, and glucose in 48 outpatients (28 men, 35 ± 10 (SD) years; 20 women, 35 ± 12 years), diagnosed with schizophrenia, schizotypal, or delusional disorders (ICD-10; F20-29). The patients were compared with 48 age- and sex-matched healthy references (±2 years) and normative data from the population. V̇O2peak was 34.5 ± 8.7 mL/kg/min (men) and 26.4 ± 7.0 mL/kg/min (women), which was 27% and 30% lower than healthy references, respectively (both P < 0.01). V̇O2peak was not associated with daily physical activity in men while a weak association was seen in women (steps per day: r2  = 0.26; counts per minute: r2  = 0.25; P < 0.05). BMI (26.0 ± 6.1 kg/m2 ) revealed that patients were moderately overweight with a waist circumference of 103 ± 17 cm. Lipid- and glucose levels, and blood pressure were all within normative range. Our data advocate the utilization of V̇O2peak assessment for CVD risk profile determination in patients with schizophrenia. Daily physical activity was poorly and inconsistently related to V̇O2peak, suggesting increased daily physical activity might not translate into improved V̇O2peak and CVD risk reduction.

Exclusion criteria and adverse events in perioperative trials of tranexamic acid in cardiac surgery: a systematic review and meta-analysis.

PURPOSE: Tranexamic acid (TXA) reduces perioperative blood loss and transfusion requirement following cardiac surgery. Nevertheless, TXA remains underutilized because of concerns regarding development of adverse events. We conducted a systematic review to determine which patients are commonly excluded from TXA cardiac surgery clinical trials to determine if there are patient groups lacking safety data on TXA. METHODS: The databases Medline, EMBASE, and the Cochrane Central Register of Controlled Trials were searched until September 2017. Eligible studies were randomized-controlled trials (RCTs) administering systemic TXA perioperatively to patients undergoing any cardiac surgery. Our primary outcome was the exclusion criteria for each RCT, and the secondary endpoint was TXA safety. A descriptive synthesis was performed to analyze the exclusion criteria. TXA safety was assessed with meta-analysis. PRINCIPAL FINDINGS: Seventy eligible RCTs were included. The most common reasons for excluding patients from TXA cardiac surgery trials were major hepatic, renal, or cardiac comorbidities (76% of studies). Meta-analysis showed that TXA did not increase the risk of adverse events compared with placebo or no intervention (risk ratio, 0.97; 95% confidence interval, 0.88 to 1.07), including thrombosis and seizure. CONCLUSION: We found that systemic TXA is safe to use in cardiac surgery. Certain patient groups are frequently excluded from TXA cardiac surgery trials, and may consequently have limited efficacy and safety data on TXA. Further research in these patient groups may be needed; nevertheless, for many patient populations there are sufficient data to inform evidence-based guidelines for TXA use in cardiac surgery. TRIAL REGISTRATION: PROSPERO (CRD42017060971); registered 4 April, 2017.

RéSUMé: OBJECTIF: L'acide tranexamique (ATX) réduit les pertes sanguines périopératoires et les besoins transfusionnels après une chirurgie cardiaque. L'ATX demeure toutefois sous-utilisé en raison de craintes quant à la survenue d'événements indésirables. Nous avons réalisé une revue systématique afin d'identifier les patients le plus fréquemment exclus des études cliniques sur l'utilisation d'ATX en chirurgie cardiaque pour déterminer si les données d'innocuité de l'ATX sont insuffisantes pour certains groupes de patients. MéTHODE: Des recherches ont été effectuées dans les bases de données Medline, EMBASE et dans le Cochrane Central Register of Controlled Trials pour en tirer les études publiées jusqu'en septembre 2017. Pour être éligibles, les études devaient être des études randomisées contrôlées (ERC) examinant l'administration systémique d'ATX en période périopératoire à des patients subissant une chirurgie cardiaque, quelle qu'elle soit. Le critère d'évaluation principal de notre étude s'intéressait aux critères d'exclusion de chaque ERC, et le critère d'évaluation secondaire à l'innocuité de l'ATX. Une synthèse descriptive a été réalisée afin d'analyser les critères d'exclusion. L'innocuité de l'ATX a été évaluée par une méta-analyse. CONSTATATIONS PRINCIPALES: Soixante-dix ERC éligibles ont été incluses dans notre revue. Les raisons les plus fréquentes d'exclusion de patients des études d'ATX en chirurgie cardiaque étaient des comorbidités hépatiques, rénales ou cardiaques majeures (76 % des études). La méta-analyse a démontré que l'ATX n'augmentait pas le risque d'événements indésirables par rapport au placebo ou à toute autre intervention (risque relatif, 0,97; intervalle de confiance 95 %, 0,88 à 1,07), y compris le risque de thrombose ou de convulsion. CONCLUSION: Nous avons observé que l'ATX par voie systémique peut être utilisé en toute sécurité en chirurgie cardiaque. Certains groupes de patients sont fréquemment exclus des études portant sur l'ATX en chirurgie cardiaque, et les données sur l'efficacité et l'innocuité de l'ATX dans ces populations pourraient par conséquent être limitées. Des recherches supplémentaires dans ces groupes pourraient être nécessaires; toutefois, les données pour plusieurs populations de patients sont suffisantes pour établir des directives fondées sur les données probantes concernant l'utilisation d'ATX en chirurgie cardiaque. ENREGISTREMENT DE L'éTUDE: PROSPERO (CRD42017060971); enregistrée le 4 avril 2017.

Guilt after placement questionnaire: a new instrument to assess caregiver emotional functioning following nursing home placement.

OBJECTIVE: Guilt is a core feature of dementia caregivers' experiences following placement. This study describes and validates a new assessment tool for monitoring caregiver adjustment after placement. METHODS: Forty-six items addressing ambivalence and guilt about placement were tested with 170 dementia caregivers (M age = 56.79, SD = 13.19; 69.4% female; 54.7% adult child). RESULTS: Using principal axis factor analysis, 10 items were retained that showed acceptable internal consistency (Cronbach's alpha of 0.92). Construct validity was established in a subset of the sample (n = 53) with measures of depression (r = 0.53), burden (r = 0.48), conflict with staff (r = 0.47), and well-being (r = -0.30). CONCLUSIONS: This scale may be used to identify caregivers at risk for adjustment problems following placement and to monitor adjustment over time.

Weak interspecific interactions in a sagebrush steppe? Conflicting evidence from observations and experiments.

Stable coexistence requires intraspecific limitations to be stronger than interspecific limitations. The greater the difference between intra- and interspecific limitations, the more stable the coexistence, and the weaker the competitive release any species should experience following removal of competitors. We conducted a removal experiment to test whether a previously estimated model, showing surprisingly weak interspecific competition for four dominant species in a sagebrush steppe, accurately predicts competitive release. Our treatments were (1) removal of all perennial grasses and (2) removal of the dominant shrub, Artemisia tripartita. We regressed survival, growth, and recruitment on the locations, sizes, and species identities of neighboring plants, along with an indicator variable for removal treatment. If our "baseline" regression model, which accounts for local plant-plant interactions, accurately explains the observed responses to removals, then the removal coefficient should be non-significant. For survival, the removal coefficients were never significantly different from zero, and only A. tripartita showed a (negative) response to removals at the recruitment stage. For growth, the removal treatment effect was significant and positive for two species, Poa secunda and Pseudoroegneria spicata, indicating that the baseline model underestimated interspecific competition. For all three grass species, population models based on the vital rate regressions that included removal effects projected 1.4- to 3-fold increases in equilibrium population size relative to the baseline model (no removal effects). However, we found no evidence of higher response to removal in quadrats with higher pretreatment cover of A. tripartita, or by plants experiencing higher pre-treatment crowding by A. tripartita, raising questions about the mechanisms driving the positive response to removal. While our results show the value of combining observations with a simple removal experiment, more tightly controlled experiments focused on underlying mechanisms may be required to conclusively validate or reject predictions from phenomenological models.

Red blood cell transfusion in adult palliative care: a systematic review.

BACKGROUND: The risks and benefits of red blood cell (RBC) transfusion in palliative care patients remain poorly understood. We reviewed the literature to summarize available information on RBC transfusion in this population. STUDY DESIGN AND METHODS: We searched electronic databases (MEDLINE, Embase, PsycINFO, CINAHL) from inception through September 2016 to identify studies reporting data on palliative patients receiving RBC transfusion. Original studies that assessed RBC transfusion as an intervention and reported at least one clinical outcome were included. Study characteristics, results on transfusion-related outcomes, and authors' conclusions on the value of transfusion in palliative patients were abstracted and reported. RESULTS: We identified 1839 studies, of which 137 were selected for data extraction and 13 were included (11 case series, one prospective cohort, and one retrospective cohort). Nine studies addressed symptom relief following transfusion using subjective symptom scales, of which eight (89%) indicated some degree of short-term benefit and one study (11%) showed no benefit. Posttransfusion survival was reported in four studies-one demonstrated prolonged survival in patients receiving RBC transfusion; three had no comparison group. Other outcomes reported included hemoglobin values posttransfusion in four studies and adverse events following transfusion in three studies. CONCLUSIONS: In palliative care, RBC transfusion may provide symptom relief and improve subjective well-being, though the duration and magnitude of this effect, and transfusion-associated risks specific to this population remain unclear. Currently, no high quality evidence exists to support or guide the use of RBC transfusion in this population. Moreover, the clinical heterogeneity within the palliative population limits the interpretation of most studies.