Proceedings of a conference on Cardiovascular Bioinstrumentation

The Ames Research Center (ARC) has a long history in the development of cardiovascular (CV) instrumentation for human and animal research. The ARC Cardiovascular Research Lab under the Space Physiology Branch, Space Research Directorate, supports both ground-based and space-based animal and human research goals. The Cardiovascular Research Laboratory was established at ARC in the mid 1960's to conduct ground-based animal research and support development of advanced cardiovascular instrumentation applicable to spaceflight. The ARC Biomedical Research Program also conducts human studies with a CV instrumentation focus

A retrospective analysis of geriatric trauma patients: venous lactate is a better predictor of mortality than traditional vital signs

BACKGROUND: Traditional vital signs (TVS), including systolic blood pressure (SBP), heart rate (HR) and their composite, the shock index, may be poor prognostic indicators in geriatric trauma patients. The purpose of this study is to determine whether lactate predicts mortality better than TVS. METHODS: We studied a large cohort of trauma patients age ≥ 65 years admitted to a level 1 trauma center from 2009-01-01 - 2011-12-31. We defined abnormal TVS as hypotension (SBP < 90 mm Hg) and/or tachycardia (HR > 120 beats/min), an elevated shock index as HR/SBP ≥ 1, an elevated venous lactate as ≥ 2.5 mM, and occult hypoperfusion as elevated lactate with normal TVS. The association between these variables and in-hospital mortality was compared using Chi-square tests and multivariate logistic regression. RESULTS: There were 1987 geriatric trauma patients included, with an overall mortality of 4.23% and an incidence of occult hypoperfusion of 20.03%. After adjustment for GCS, ISS, and advanced age, venous lactate significantly predicted mortality (OR: 2.62, p < 0.001), whereas abnormal TVS (OR: 1.71, p = 0.21) and SI ≥ 1 (OR: 1.18, p = 0.78) did not. Mortality was significantly greater in patients with occult hypoperfusion compared to patients with no sign of circulatory hemodynamic instability (10.67% versus 3.67%, p < 0.001), which continued after adjustment (OR: 2.12, p = 0.01). CONCLUSIONS: Our findings demonstrate that occult hypoperfusion was exceedingly common in geriatric trauma patients, and was associated with a two-fold increased odds of mortality. Venous lactate should be measured for all geriatric trauma patients to improve the identification of hemodynamic instability and optimize resuscitative efforts

The impact of changing work schedules on American firefighters’ sleep patterns and well-being

Across the nation, fire departments are adopting the 48/96 work schedule, in which firefighters work 48 consecutive hours with the following 96 hours off. Our study objective was to explain and quantify the impact of switching from the Kelly schedule to the 48/96 schedule by measuring changes in sleep, feelings of daytime function, as well as perceptions of professional and personal well-being for American firefighters. Sleep diaries and self-reported surveys were administered to firefighters at an urban fire department. Sleep diaries measuring the number of hours slept and feelings of refreshment were compared one month before and four months after implementation of the 48/96 schedule. The self-reported surveys measured sleepiness levels via the Epworth Sleepiness Scale. Secondary study objectives included changes in professional and personal well-being time for personal schedules, satisfaction, and health habits before and after the 48/96 schedule was implemented. The 59 firefighters included in the study reported an increase in sleep on-shift after the new schedule implementation (5.8 to 6.6 hours/night, p < 0.001). Participants also reported increased feelings of refreshment on days off (p < 0.001) and decreased daytime sleepiness (p < 0.001). We also found a general trend of improved perceptions of satisfaction, less shift interference with personal schedules and decreased feelings of burnout. American firefighters appeared to benefit from a 48/96 schedule, with short-term improvements in sleep patterns, feelings of burnout, and time for personal schedules

Injury severity and serum amyloid A correlate with plasma oxidation-reduction potential in multi-trauma patients: a retrospective analysis

<p>Abstract</p> <p>Background</p> <p>In critical injury, the occurrence of increased oxidative stress or a reduced antioxidant status has been observed. The purpose of this study was to correlate the degree of oxidative stress, by measuring the oxidation-reduction potential (ORP) of plasma in the critically injured, with injury severity and serum amyloid A (SAA) levels.</p> <p>Methods</p> <p>A total of 140 subjects were included in this retrospective study comprising 3 groups: healthy volunteers (N = 21), mild to moderate trauma (ISS < 16, N = 41), and severe trauma (ISS ≥ 16, N = 78). For the trauma groups, plasma was collected on an almost daily basis during the course of hospitalization. ORP analysis was performed using a microelectrode, and ORP maxima were recorded for the trauma groups. SAA, a sensitive marker of inflammation in critical injury, was measured by liquid chromatography/mass spectrometry.</p> <p>Results</p> <p>ORP maxima were reached on day 3 (± 0.4 SEM) and day 5 (± 0.5 SEM) for the ISS < 16 and ISS ≥ 16 groups, respectively. ORP maxima were significantly higher in the ISS < 16 (-14.5 mV ± 2.5 SEM) and ISS ≥ 16 groups (-1.1 mV ± 2.3 SEM) compared to controls (-34.2 mV ± 2.6 SEM). Also, ORP maxima were significantly different between the trauma groups. SAA was significantly elevated in the ISS ≥ 16 group on the ORP maxima day compared to controls and the ISS < 16 group.</p> <p>Conclusion</p> <p>The results suggest the presence of an oxidative environment in the plasma of the critically injured as measured by ORP. More importantly, ORP can differentiate the degree of oxidative stress based on the severity of the trauma and degree of inflammation.</p

Phthalate esters used as plasticizers in packed red blood cell storage bags may lead to progressive toxin exposure and the release of pro-inflammatory cytokines

Phthalate esters (PE's) are plasticizers used to soften PVC-based medical devices. PE's are the most abundant man-made pollutants and increase the risk of developing an allergic respiratory disease or a malignancy. The leaching of PE's in donated packed red blood cells (PRBC) during storage was assessed. PRBC transfusion bags containing CPD/AS-1 (ADSOL) buffer were analyzed. Samples were collected on storage day 1 and day 42. Two PE's, di-(2-ethylhexyl) phthalate (DEHP) and mono-(2-ethylhexyl) phthalate (MEHP), were measured by liquid chromatography coupled to mass spectrometry (LCMS). Interleukin-8 (IL-8) was measured by standard ELISA techniques. DEHP significantly increased from 34.3 µM (±20.0 SD) on day 1 to 433.2 µM (±131.2 SD) on day 42, a 12.6-fold increase. Similarly, MEHP significantly increased from 3.7 µM (±2.8 SD) on day 1 to 74.0 µM (±19.1 SD) on day 42, a 20.2-fold increase. Also, DEHP and MEHP increased the release of IL-8 from human umbilical vein endothelial cells (HUVEC). The transfusion of older units of PRBC could lead to an accumulation of PE's possibly resulting in inflammation and other effects. This accumulation could be exacerbated due to the decreased metabolism of PE's since trauma patients have a lower esterase activity, the enzymes responsible for metabolizing PE's. The effect of oxidative stress caused by PE's is discussed as a potential mechanism for increases in inflammation caused by older units of PRBC

Stress Hyperglycemia in Critically Ill Patients: Insight Into Possible Molecular Pathways

Severe sepsis, systemic inflammatory response syndrome (SIRS), and traumatic brain injury are frequently associated with hyperglycemia in non-diabetic patients. In patients suffering from any of these conditions, hyperglycemia at admission to an intensive care unit (ICU) is directly correlated with increased mortality or morbidity. Although there was initial enthusiasm for insulin treatment to blood glucose levels below 110 mg/dL in these patients, recent understanding suggests that the potential for hypoglycemic complications make this approach potentially dangerous. More moderate glucose control seems to be more beneficial than the aggressive glucose lowering initially suggested. An important publication has shown that hyperlactatemia accompanying hyperglycemia could be the real culprit in bad outcomes. This suggests that coupling moderate glucose lowering with therapeutic agents which might treat the underlying metabolic disturbances in these conditions may be a better strategy. The key metabolic disturbance in these three conditions seems to be persistent glycolysis as an energy source even in the presence of adequate tissue oxygenation (the Warburg Effect). We look at recent advances in understanding aerobic glycolysis and possibly the action of DPP4 on incretins resulting in insulin dysregulation and suggest key metabolic pathways involved in hyperglycemia regulation

The Uses of Stance in Media Production: Embodied Sociolinguistics and Beyond

While many conversation analysts, and scholars in related fields, have used video-recordings to study interaction, this study is one of a small but growing number that investigates video-recordings of the joint activities of media professionals working with, and on, video. It examines practices of media production that are, in their involvement with the visual and verbal qualities of video, both beyond talk and deeply shaped by talk. The article draws upon video recordings of the making of a feature-length documentary. In particular, it analyses a complex course of action where an editing team are reviewing their interview of the subject of the documentary, their footage is being intercut with existing reality TV footage of that same interviewee. The central contributions that the article makes are, firstly, to the sociolinguistics of mediatisation, through the identification of the workplace concerns of the members of the editing team, secondly showing how editing is accomplished, moment-by-moment, through the use of particular forms of embodied action and, finally, how the media themselves feature in the ordering of action. While this is professional work it sheds light on the video-mediated practices in contemporary culture, especially those found in social media where video makers carefully consider their editing of the perspective toward themselves and others

New insights into the genetic etiology of Alzheimer's disease and related dementias

Characterization of the genetic landscape of Alzheimer's disease (AD) and related dementias (ADD) provides a unique opportunity for a better understanding of the associated pathophysiological processes. We performed a two-stage genome-wide association study totaling 111,326 clinically diagnosed/'proxy' AD cases and 677,663 controls. We found 75 risk loci, of which 42 were new at the time of analysis. Pathway enrichment analyses confirmed the involvement of amyloid/tau pathways and highlighted microglia implication. Gene prioritization in the new loci identified 31 genes that were suggestive of new genetically associated processes, including the tumor necrosis factor alpha pathway through the linear ubiquitin chain assembly complex. We also built a new genetic risk score associated with the risk of future AD/dementia or progression from mild cognitive impairment to AD/dementia. The improvement in prediction led to a 1.6- to 1.9-fold increase in AD risk from the lowest to the highest decile, in addition to effects of age and the APOE ε4 allele

Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries

Abstract Background Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres. Methods This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries. Results In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia. Conclusion This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries