Perioperative N-acetylcysteine: evidence and indications.

Nonopioid analgesics serve to improve analgesia and limit side effects and risks of perioperative opioids. N-acetylcysteine (NAC), the primary treatment of acetaminophen toxicity, may have perioperative indications, including analgesia. NAC impacts glutathione synthesis, oxidant scavenging, glutamate receptor modulation and neuroinflammation. Potential perioperative benefits include arrhythmia prevention after cardiac surgery, decreased contrast-induced nephropathy, improved post-transplant liver function and superior pulmonary outcomes with general anesthesia. NAC may improve perioperative analgesia, with some studies displaying a reduction in postoperative opioid use. NAC is generally well tolerated with an established safety profile. NAC administration may predispose to gastrointestinal effects, while parenteral administration may carry a risk of anaphylactoid reactions, including bronchospasm. Larger randomized trials may clarify the impact of NAC on perioperative analgesic outcomes.

Nonopioid mediations are important to help pain control after surgery and may decrease risks of opioids. N-acetylcysteine (NAC), the treatment of acetaminophen overdose, decreased inflammation and has other positive effects on the body that may help pain after surgery. Thus, NAC has been studied to prevent abnormal heart rhythms with heart surgery, help kidneys after surgery, improve the liver after liver transplant or other live surgeries and improve breathing after anesthesia. NAC may also decrease pain and the amount of pain medications needed after surgery. While NAC is generally well tolerated and considered safe, stomach upset can occur as can itching or asthma like reactions in certain patients. This review describes how NAC may improve pain, summarizes the other ways NAC may help a patient undergoing surgery, and describes potential side effects when NAC is given.

Evaluating a novel model of hepatitis B care, Hep B PAST, in the Northern Territory of Australia: results from a prospective, population-based study.

Background: The Northern Territory (NT) has the highest prevalence of chronic hepatitis B (CHB) in Australia. The Hep B PAST program aims to improve health outcomes for people living with CHB. Methods: This mixed methods study involves First Nations peoples living in the NT. We used participatory action research principles across three steps: 1. Foundation step: establishing hepatitis B virus (HBV) status and linkage to care; 2. Capacity building: training the health workforce; 3. Supported transition to primary healthcare: implementation of the "Hub and Spoke" model and in-language resources. Analysis occurred at three time points: 1. Pre-Hep B PAST (2018); 2. Foundation step (2020); and 3. Completion of Hep B PAST (2023). Evaluation focuses on four key indicators, the number of people: 1) with documented HBV status; 2) diagnosed with CHB; 3) receiving care; and 4) receiving treatment. Findings: Hep B PAST (2018-23) reached 40,555 people. HBV status was documented in 11% (1192/10,853), 79.2% (26,075/32,915) and 90.8% (28,675/31,588) of people at pre-Hep B PAST, foundation step, and completion respectively. An estimated 99.9% (821/822) of people were diagnosed, 86.3% (709/822) engaged in care, and 24.1% (198/822) on antiviral treatment at completion. CHB prevalence in the study population is 2.6%, decreasing from 6.1% to 0.4% in the pre- and post-vaccination cohorts. Interpretation: Hep B PAST is an effective model of care. Partner health services are exceeding elimination targets. This model could enable other countries to enhance the cascade of care and work towards eliminating HBV. Funding: National Health and Medical Research Council.

Rac1 and Nectin3 are essential for PCP-directed axon guidance in the peripheral auditory system.

Our sense of hearing is critically dependent on the spiral ganglion neurons (SGNs) that connect the sound receptors in the organ of Corti (OC) to the cochlear nuclei of the hindbrain. Type I SGNs innervate inner hair cells (IHCs) to transmit sound signals, while type II SGNs (SGNIIs) innervate outer hair cells (OHCs) to detect moderate-to-intense sound. During development, SGNII afferents make a characteristic 90-degree turn toward the base of the cochlea and innervate multiple OHCs. It has been shown that the Planar Cell Polarity (PCP) pathway acts non-autonomously to mediate environmental cues in the cochlear epithelium for SGNII afferent turning towards the base. However, the underlying mechanisms are unknown. Here, we present evidence that PCP signaling regulates multiple downstream effectors to influence cell adhesion and the cytoskeleton in cochlear supporting cells (SCs), which serve as intermediate targets of SGNII afferents. We show that the core PCP gene Vangl2 regulates the localization of the small GTPase Rac1 and the cell adhesion molecule Nectin3 at SC-SC junctions through which SGNII afferents travel. Through in vivo genetic analysis, we also show that loss of Rac1 or Nectin3 partially phenocopied SGNII peripheral afferent turning defects in Vangl2 mutants, and that Rac1 plays a non-autonomous role in this process in part by regulating PCP protein localization at the SC-SC junctions. Additionally, epistasis analysis indicates that Nectin3 and Rac1 likely act in the same genetic pathway to control SGNII afferent turning. Together, these experiments identify Nectin3 and Rac1 as novel regulators of PCP-directed SGNII axon guidance in the cochlea.

Partial differential equation models for invasive species spread in the presence of spatial heterogeneity.

Models of invasive species spread often assume that landscapes are spatially homogeneous; thus simplifying analysis but potentially reducing accuracy. We extend a recently developed partial differential equation model for invasive conifer spread to account for spatial heterogeneity in parameter values and introduce a method to obtain key outputs (e.g. spread rates) from computational simulations. Simulations produce patterns of spatial spread which appear qualitatively similar to observed patterns in grassland ecosystems invaded by exotic conifers, validating our spatially explicit strategy. We find that incorporating spatial variation in different parameters does not significantly affect the evolution of invasions (which are characterised by a long quiescent period followed by rapid evolution towards to a constant rate of invasion) but that distributional assumptions can have a significant impact on the spread rate of invasions. Our work demonstrates that spatial variation in site-suitability or other parameters can have a significant impact on invasions and must be considered when designing models of invasive species spread.

"Putting the power back into community": A mixed methods evaluation of a chronic hepatitis B training course for the Aboriginal health workforce of Australia's Northern Territory.

BACKGROUND: Chronic hepatitis B (CHB) is endemic in the Aboriginal and Torres Strait Islander population of Australia's Northern Territory. Progression to liver disease can be prevented if holistic care is provided. Low health literacy amongst health professionals is a known barrier to caring for people living with CHB. We co-designed and delivered a culturally safe "Managing hepatitis B" training course for the Aboriginal health workforce. Here, we present an evaluation of the course. OBJECTIVES: 1. To improve course participants CHB-related knowledge, attitudes, and clinical practice. 2. To evaluate the "Managing hepatitis B" training course. 3. To enable participants to have the skills and confidence to be part of the care team. METHODS: We used participatory action research and culturally safe principles. We used purpose-built quantitative and qualitative evaluation tools to evaluate our "Managing hepatitis B" training course. We integrated the two forms of data, deductively analysing codes, grouped into categories, and assessed pedagogical outcomes against Kirkpatrick's training evaluation framework. RESULTS: Eight courses were delivered between 2019 and 2023, with 130 participants from 32 communities. Pre- and post-course questionnaires demonstrated statistically significant improvements in all domains, p<0.001 on 93 matched pairs. Thematic network analysis demonstrated high levels of course acceptability and significant knowledge acquisition. Other themes identified include cultural safety, shame, previous misinformation, and misconceptions about transmission. Observations demonstrate improvements in post-course engagement, a deep understanding of CHB as well as increased participation in clinical care teams. CONCLUSIONS: The "Managing hepatitis B" training course led to a sustained improvement in the knowledge and attitudes of the Aboriginal health workforce, resulting in improved care and treatment uptake for people living with CHB. Important non-clinical outcomes included strengthening teaching and leadership skills, and empowerment.

"The most culturally safe training I've ever had": the co-design of a culturally safe Managing hepatitis B training course with and for the Aboriginal health workforce of the Northern Territory of Australia.

BACKGROUND: The Aboriginal health workforce provide responsive, culturally safe health care. We aimed to co-design a culturally safe course with and for the Aboriginal health workforce. We describe the factors which led to the successful co-design, delivery, and evaluation of the "Managing hepatitis B" course for the Aboriginal health workforce. METHODS: A Participatory Action Research approach was used, involving ongoing consultation to iteratively co-design and then develop course content, materials, and evaluation tools. An Aboriginal and Torres Strait Islander research and teaching team received education in chronic hepatitis B and teaching methodologies. Pilot courses were held, in remote communities of the Northern Territory, using two-way learning and teach-back methods to further develop the course and assess acceptability and learnings. Data collection involved focus group discussions, in-class observations, reflective analysis, and use of co-designed and assessed evaluation tools. RESULTS: Twenty-six participants attended the pilot courses. Aboriginal and Torres Strait Islander facilitators delivered a high proportion of the course. Evaluations demonstrated high course acceptability, cultural safety, and learnings. Key elements contributing to success and acceptability were acknowledging, respecting, and integrating cultural differences into education, delivering messaging and key concepts through an Aboriginal and Torres Strait Islander lens, using culturally appropriate approaches to learning including storytelling and visual teaching methodologies. Evaluation of culturally safe frameworks and findings from the co-design process led to the creation of a conceptual framework, underpinned by meeting people's basic needs, and offering a safe and comfortable environment to enable productive learning with attention to the following: sustenance, financial security, cultural obligations, and gender and kinship relationships. CONCLUSIONS: Co-designed education for the Aboriginal health workforce must embed principles of cultural safety and meaningful community consultation to enable an increase in knowledge and empowerment. The findings of this research can be used to guide the design of future health education for First Nations health professionals and to other non-dominant cultures. The course model has been successfully transferred to other health issues in the Northern Territory.

Particulate Gastric Contents in Patients Prescribed Glucagon-Like Peptide 1 Receptor Agonists After Appropriate Perioperative Fasting: A Report of 2 Cases.

Glucagon-like peptide 1 (GLP-1) receptor agonists have surged in popularity for the treatment of both diabetes mellitus and obesity. While GLP-1 reduces proximal gastrointestinal motility and delays gastric emptying, the impact of these medications on adequate fasting before surgery is not clear. We present 2 cases of particulate gastric contents after following appropriate presurgical fasting in diabetic patients taking GLP-1 receptor agonists and review current literature regarding perioperative implications of these drugs.

A Trial of Adding Lung Protective Strategies to Existing Enhanced Recovery After Surgery Protocols and Its Effect on Improving Postoperative Lung Function.

Background: With this rising popularization of enhanced recovery after surgery (ERAS) protocols, it is important to ask if the current and developing pathways are fully comprehensive for the patient's perioperative experience. Many current pathways discuss aspects of care including fluid management, pain management, and anti-emetic medication regiments, but few delineate recommendations for lung protective strategies. The hypothesis was that intraoperative lung protective strategies would results in improved postoperative lung function. Methods: One hundred patients at the Medical University of South Carolina undergoing hepatobiliary and colorectal surgeries were randomized to receive intraoperative lung protective techniques or a standard intraoperative ventilation management. Three maximum vital capacity breaths were recorded preoperatively, and postoperatively 30 min, 1 h, and 2 h after anesthesia stop time. Average maximum capacity breaths from all four data collection interactions were analyzed between both study and control cohorts. Results: There was no significant difference in the preoperative inspiratory capacity between the control and the ERAS group (2,043.3 ± 628.4 mL vs. 2,012.2 ± 895.2 mL; P = 0.84). Additional data analysis showed no statistically significant difference between ERAS and control groups: total average of the inspiratory capacity volumes (1,253.5 ± 593.7 mL vs. 1,390.4 ± 964.9 mL; P = 0.47), preoperative oxygen saturation (97.76±2.3% vs. 98.04±1.7%; P = 0.50), the postoperative oxygen saturation (98.51±1.4% vs. 96.83±14.2%; P = 0.40), and change in inspiratory capacity (95% confidence interval (CI) (-211.2 - 366.6); P = 0.60). Conclusions: No statistically significant difference in postoperative inspiratory capacities were seen after the implementation of intraoperative lung protective strategies. The addition of other indicators of postoperative lung function like pneumonia incidence or length of inpatient stay while receiving oxygen treatment could provide a fuller picture in future studies, but a higher power will be needed.

The Association of α Angle on Disease Severity in Adolescent Femoroacetabular Impingement.

BACKGROUND: Femoroacetabular Impingement (FAI) is a common cause of hip pain in adolescent patients. Clinical exam and radiographic markers, such as α angle and lateral center edge angle (LCEA), are commonly used to aid in the diagnosis of this condition. The purpose of this study was to correlate preoperative α angle and LCEA with preoperative symptoms, intraoperative findings, and preoperative and postoperative patient reported outcomes (PROs) in the adolescent patient. METHODS: A retrospective analysis of prospectively collected data was conducted for all patients who underwent operative intervention for FAI at an academic institution over an 11-year period. Preoperative imaging was obtained and measured for LCEA and α angle. PROs (modified Harris Hip Score, Hip Disability and Osteoarthritis Outcome Score, and UCLA score) were collected preoperatively, as well as 1, 2, and 5 years postoperatively. Operative intervention was either open surgical hip dislocation or arthroscopic, and intraoperative disease was graded using the Beck Classification system. Patients with minimum 1-year follow-up were included in statistical analysis. RESULTS: There were 86 hips (64 female hips) included with an average age of 16.3 years (range, 10.4 to 20.5 y), with an average of 37 months of follow-up. There was no correlation between severity of preoperative symptoms or difference between pre and postoperative PROs for both α angle and LCEA. Overall, significant improvement was noted in modified Harris Hip Score, Hip Disability and Osteoarthritis Outcome Score, and UCLA Score (P<0.001 for each). Independent of preoperative symptoms, increased α angle correlated with more severe intraoperative labral disease (P<0.001), and longer length of labral tear (Corr 0.295, P<0.01). Femoral head and acetabular articular cartilage damage did not correlate with α angle or LCEA, nor did overall severity of disease. CONCLUSIONS: In adolescent patients with FAI, increased α angle was found to significantly correlate with labral pathology, including increased length of tear and severity of disease, irrespective of preoperative symptoms or postoperative patient reported outcomes. LEVEL OF EVIDENCE: Level III-retrospective.

To Infinity and Beyond: The Past, Present, and Future of Tele-Anesthesia.

Because the scope of anesthesia practice continues to expand, especially within the perioperative domain, our specialty must continually examine technological services that allow us to provide care in innovative ways. Telemedicine has facilitated the remote provision of medical services across many different specialties, but it remains somewhat unclear whether the use of telemedicine would fit within the practice of anesthesiology on a consistent basis. There have been several reports on the successful use of telemedicine within the preoperative and intraoperative realm. However, patient selection, patient and provider satisfaction, case cancellation rates, equipment reliability, and security of protected health information are just some of the issues that require further examination. This article seeks to review comprehensively the available literature related to the use of telemedicine within the preoperative, intraoperative, and postoperative phases of anesthetic care as well as analyze the major hurdles often encountered when implementing a teleconsultation service. Security of connection, data storage and encryption, federal and state medical licensure compliance, as well as overall cost/savings analysis are a few of the issues that warrant further exploration and research. As telemedicine programs develop within the perioperative arena, it is imperative for institutions to share knowledge, successes, and pitfalls to improve the delivery of care in today's technology-driven medical landscape.

Acute air pollution exposure and risk of suicide completion.

Research into environmental factors associated with suicide has historically focused on meteorological variables. Recently, a heightened risk of suicide related to short-term exposure to airborne particulate matter was reported. Here, we examined the associations between short-term exposure to nitrogen dioxide, particulate matter, and sulfur dioxide and completed suicide in Salt Lake County, Utah (n = 1,546) from 2000 to 2010. We used a time-stratified case-crossover design to estimate adjusted odds ratios for the relationship between suicide and exposure to air pollutants on the day of the suicide and during the days preceding the suicide. We observed maximum heightened odds of suicide associated with interquartile-range increases in nitrogen dioxide during cumulative lag 3 (average of the 3 days preceding suicide; odds ratio (OR) = 1.20, 95% confidence interval (CI): 1.04, 1.39) and fine particulate matter (diameter ≤2.5 µm) on lag day 2 (day 2 before suicide; OR = 1.05, 95% CI: 1.01, 1.10). Following stratification by season, an increased suicide risk was associated with exposure to nitrogen dioxide during the spring/fall transition period (OR = 1.35, 95% CI: 1.09, 1.66) and fine particulate matter in the spring (OR = 1.28, 95% CI: 1.01, 1.61) during cumulative lag 3. Findings of positive associations between air pollution and suicide appear to be consistent across study locations with vastly different meteorological, geographical, and cultural characteristics.

A mathematical model of the metabolic and perfusion effects on cortical spreading depression.

Cortical spreading depression (CSD) is a slow-moving ionic and metabolic disturbance that propagates in cortical brain tissue. In addition to massive cellular depolarizations, CSD also involves significant changes in perfusion and metabolism-aspects of CSD that had not been modeled and are important to traumatic brain injury, subarachnoid hemorrhage, stroke, and migraine. In this study, we develop a mathematical model for CSD where we focus on modeling the features essential to understanding the implications of neurovascular coupling during CSD. In our model, the sodium-potassium-ATPase, mainly responsible for ionic homeostasis and active during CSD, operates at a rate that is dependent on the supply of oxygen. The supply of oxygen is determined by modeling blood flow through a lumped vascular tree with an effective local vessel radius that is controlled by the extracellular potassium concentration. We show that during CSD, the metabolic demands of the cortex exceed the physiological limits placed on oxygen delivery, regardless of vascular constriction or dilation. However, vasoconstriction and vasodilation play important roles in the propagation of CSD and its recovery. Our model replicates the qualitative and quantitative behavior of CSD--vasoconstriction, oxygen depletion, extracellular potassium elevation, prolonged depolarization--found in experimental studies. We predict faster, longer duration CSD in vivo than in vitro due to the contribution of the vasculature. Our results also help explain some of the variability of CSD between species and even within the same animal. These results have clinical and translational implications, as they allow for more precise in vitro, in vivo, and in silico exploration of a phenomenon broadly relevant to neurological disease.

Fluid-body interactions: clashing, skimming, bouncing.

Solid-solid and solid-fluid impacts and bouncing are the concern here. A theoretical study is presented on fluid-body interaction in which the motion of the body and the fluid influence each other nonlinearly. There could also be many bodies involved. The clashing refers to solid-solid impacts arising from fluid-body interaction in a channel, while the skimming refers to another area where a thin body impacts obliquely upon a fluid surface. Bouncing usually then follows in both areas. The main new contribution concerns the influences of thickness and camber which lead to a different and more general form of clashing and hence bouncing.

Flavodoxin hydroquinone reduces Azotobacter vinelandii Fe protein to the all-ferrous redox state with a S = 0 spin state.

Azotobacter vinelandii flavodoxin hydroquinone (FldHQ) is a physiological reductant to nitrogenase supporting catalysis that is twice as energy efficient (ATP/2e- = 2) as dithionite (ATP/2e- = 4). This catalytic efficiency results from reduction of Fe protein from A. vinelandii (Av2) to the all-ferrous oxidation state ([Fe4S4]0), in contrast to dithionite, which only reduces Av2 to the [Fe4S4]1+ state. Like FldHQ, Ti(III) citrate yields ATP/2e- = 2, and Ti(III)-reduced [Fe4S4]0 Av2 has a S = 4 spin state and characteristic Mossbauer spectrum, a parallel mode g = 16.4 EPR signal, and a shoulder at 520 nm in its UV-vis spectrum, each of which distinguish the S = 4 [Fe4S4]0 Av2 from other states. In this study, we demonstrate that FldHQ makes [Fe4S4]0 Av2, which is sufficiently characterized to demonstrate unique physical properties that distinguish it from the previously characterized Ti(III)-reduced [Fe4S4]0 Av2. In particular, Evans NMR magnetic susceptibility and EPR measurements indicate that FldHQ-reduced [Fe4S4]0 Av2 has an S = 0 spin state (like [Fe4S4]2+ Av2). There is no g = 16.4 EPR signal and no shoulder at 520 nm in its absorbance spectrum, which resembles that of [Fe4S4]1+ Av2. That the physiological reductant to Av2 is capable of forming [Fe4S4]0 Av2 has important implications for in vivo nitrogenase activity.

Ferritin-catalyzed consumption of hydrogen peroxide by amine buffers causes the variable Fe2+ to O2 stoichiometry of iron deposition in horse spleen ferritin.

Ferritin catalyzes the oxidation of Fe2+ by O2 to form a reconstituted Fe3+ oxy-hydroxide mineral core, but extensive studies have shown that the Fe2+ to O2 stoichiometry changes with experimental conditions. At Fe2+ to horse spleen ferritin (HoSF) ratios greater than 200, an upper limit of Fe2+ to O2 of 4 is typically measured, indicating O2 is reduced to 2H2O. In contrast, a lower limit of Fe2+ to O2 of approximately 2 is measured at low Fe2+ to HoSF ratios, implicating H2O2 as a product of Fe2+ deposition. Stoichiometric amounts of H2O2 have not been measured, and H2O2 is proposed to react with an unknown system component. Evidence is presented that identifies this component as amine buffers, including 3-N-morpholinopropanesulfonic acid (MOPS), which is widely used in ferritin studies. In the presence of non-amine buffers, the Fe2+ to O2 stoichiometry was approximately 4.0, but at high concentrations of amine buffers (0.10 M) the Fe2+ to O2 stoichiometry is approximately 2.5 for iron loadings of eight to 30 Fe2+ per HoSF. Decreasing the concentration of amine buffer to zero resulted in an Fe2+ to O2 stoichiometry of approximately 4. Direct evidence for amine buffer modification during Fe2+ deposition was obtained by comparing authentic and modified buffers using mass spectrometry, NMR, and thin layer chromatography. Tris(hydroxymethyl)aminomethane, MOPS, and N-methylmorpholine (a MOPS analog) were all rapidly chemically modified during Fe2+ deposition to form N-oxides. Under identical conditions no modification was detected when amine buffer, H2O2, and O2 were combined with Fe2+ or ferritin separately. Thus, a short-lived ferritin intermediate is required for buffer modification by H2O2. Variation of the Fe2+ to O2 stoichiometry versus the Fe2+ to HoSF ratio and the amine buffer concentration are consistent with buffer modification.

Evidence for a synergistic salt-protein interaction -- complex patterns of activation vs. inhibition of nitrogenase by salt.

The molybdenum nitrogenase enzyme system, comprised of the MoFe protein and the Fe protein, catalyzes the reduction of atmospheric N(2) to NH(3). Interactions between these two proteins and between Fe protein and nucleotides (MgADP and MgATP) are crucial to catalysis. It is well established that salts are inhibitors of nitrogenase catalysis that target these interactions. However, the implications of salt effects are often overlooked. We have reexamined salt effects in light of a comprehensive framework for nitrogenase interactions to offer an in-depth analysis of the sources of salt inhibition and underlying apparent cooperativity. More importantly, we have identified patterns of salt activation of nitrogenase that correspond to at least two mechanisms. One of these mechanisms is that charge screening of MoFe protein-Fe protein interactions in the nitrogenase complex accelerates the rate of nitrogenase complex dissociation, which is the rate-limiting step of catalysis. This kind of salt activation operates under conditions of high catalytic activity and low salt concentrations that may resemble those found in vivo. While simple kinetic arguments are strong evidence for this kind of salt activation, further confirmation was sought by demonstrating that tight complexes that have previously displayed little or no activity due to the inability of Fe protein to dissociate from the complex are activated by the presence of salt. This occurs for the combination Azotobacter vinelandii MoFe protein with: (a) the L127Delta Fe protein; and (b) Clostridium pasteurianum Fe protein. The curvature of activation vs. salt implies a synergistic salt-protein interaction.

Advanced heart failure: feasibility study of long-term continuous axial flow pump support.

AIMS: A lack of donor hearts has stimulated interest in using blood pumps to treat severe heart failure. We tested the hypothesis that a new continuous flow circulatory assist device could be employed safely to relieve symptoms of heart failure and evaluated the potential to prolong life. METHODS AND RESULTS: An intracardiac axial flow pump was implanted in 17 heart failure patients [idiopathic dilated (12), ischaemic (4), or amyloid cardiomyopathy (1)]. All were deemed ineligible for transplantation. Implantation of the device was by left thoracotomy (15) or median sternotomy (2). Power delivery was by a skull-mounted titanium pedestal. All patients survived surgery. None needed right ventricular support. There were three hospital deaths, two early from subdural haematoma and aortic thrombosis, one late after switching to transplantation. A total of 14 patients left hospital with a cumulative support-time of 15.9 years (median: 293 days, interquartile range: 286 days, 1-44 months). Actuarial 1-, 2-, and 3-year survivals were 56, 47, and 24%, respectively. There was no pump failure. Quality of life scores improved. Two superficial pedestal infections were successfully treated. Four patients had cerebral thrombo-embolism: two early events attributed to inadequate anticoagulation and two late with near-complete resolution. An improved anticoagulant regime addressed this problem. Late death occurred in five patients from battery disconnection, subdural haematoma, bowel ischaemia, respiratory failure, and after cardiac transplantation. CONCLUSION: Continuous flow blood pumps provided symptomatic relief of severe heart failure with high quality of life. Event-free survival reached 4 years. Analysis of adverse events led to improved management strategies. There is potential for widespread use of blood pumps in the community. A controlled trial is required.

The influence of self-efficacy and outcome expectations on the relationship between perceived environment and physical activity in the workplace.

BACKGROUND: Recent research and commentary contends that ecological approaches may be particularly useful for understanding and promoting physical activity participation in various settings including the workplace. Yet within the physical activity domain there is a lack of understanding of how ecological environment factors influence behaviour. Thus, the purpose of this study was to examine the relationships between perceived environment, social-cognitive variables, and physical activity behaviour. METHODS: Participants (N = 897) were employees from three large worksites who completed self-report inventories containing measures of self-efficacy, outcome expectations, perceptions of the workplace environment (PWES), and physical activity behaviour during both leisure-time and incorporated throughout the workday. RESULTS: Results of both bivariate and multiple regression analyses indicated the global PWES scores had a limited association with leisure-time physical activity (R2adj =.01). Sequential regression analyses supported a weak association between physical activity incorporated in the workplace and PWES (R2adj =.04) and the partial mediation of self-efficacy on the relationship between PWES and workplace physical activity (variance accounted for reduced to R2adj =.02 when self-efficacy was controlled). CONCLUSION: Overall, the results of the present investigation indicate that self-efficacy acted as a partial mediator of the relationship between perceived environment and workplace physical activity participation. Implications of the findings for physical activity promotion using ecological-based approaches, and future directions for research from this perspective in worksite settings are discussed.