Predictors of Respiratory Failure Development in a Multicenter Cohort of Inpatients With Cirrhosis.

INTRODUCTION: Hospitalized patients with cirrhosis can develop respiratory failure (RF), which is associated with a poor prognosis, but predisposing factors are unclear. METHODS: We prospectively enrolled a multicenter North American cirrhosis inpatient cohort and collected admission and in-hospital data (grading per European Association for the Study of Liver-Chronic Liver Failure scoring system, acute kidney injury [AKI], infections [admission/nosocomial], and albumin use) in an era when terlipressin was not available in North America. Multivariable regression to predict RF was performed using only admission day and in-hospital events occurring before RF. RESULTS: A total of 511 patients from 14 sites (median age 57 years, admission model for end-stage liver disease [MELD]-Na 23) were enrolled: RF developed in 15%; AKI occurred in 24%; and 11% developed nosocomial infections (NI). At admission, patients who developed RF had higher MELD-Na, gastrointestinal (GI) bleeding/AKI-related admission, and prior infections/ascites. During hospitalization, RF developers had higher NI (especially respiratory), albumin use, and other organ failures. RF was higher in patients receiving albumin (83% vs 59%, P < 0.0001) with increasing doses (269.5 ± 210.5 vs 208.6 ± 186.1 g, P = 0.01) regardless of indication. Admission for AKI, GI bleeding, and high MELD-Na predicted RF. Using all variables, NI (odds ratio [OR] = 4.02, P = 0.0004), GI bleeding (OR = 3.1, P = 0.002), albumin use (OR = 2.93, P = 0.01), AKI (OR = 3.26, P = 0.008), and circulatory failure (OR = 3.73, P = 0.002) were associated with RF risk. DISCUSSION: In a multicenter inpatient cirrhosis study of patients not exposed to terlipressin, 15% of patients developed RF. RF risk was highest in those admitted with AKI, those who had GI bleeding on admission, and those who developed NI and other organ failures or received albumin during their hospital course. Careful volume monitoring and preventing nosocomial respiratory infections and renal or circulatory failures could reduce this risk.

Comparison of different metrics of cerebral autoregulation in association with major morbidity and mortality after cardiac surgery.

BACKGROUND: Cardiac surgery studies have established the clinical relevance of personalised arterial blood pressure management based on cerebral autoregulation. However, variabilities exist in autoregulation evaluation. We compared the association of several cerebral autoregulation metrics, calculated using different methods, with outcomes after cardiac surgery. METHODS: Autoregulation was measured during cardiac surgery in 240 patients. Mean flow index and cerebral oximetry index were calculated as Pearson's correlations between mean arterial pressure (MAP) and transcranial Doppler blood flow velocity or near-infrared spectroscopy signals. The lower limit of autoregulation and optimal mean arterial pressure were identified using mean flow index and cerebral oximetry index. Regression models were used to examine associations of area under curve and duration of mean arterial pressure below thresholds with stroke, acute kidney injury (AKI), and major morbidity and mortality. RESULTS: Both mean flow index and cerebral oximetry index identified the cerebral lower limit of autoregulation below which MAP was associated with a higher incidence of AKI and major morbidity and mortality. Based on magnitude and significance of the estimates in adjusted models, the area under curve of MAP < lower limit of autoregulation had the strongest association with AKI and major morbidity and mortality. The odds ratio for area under the curve of MAP < lower limit of autoregulation was 1.05 (95% confidence interval, 1.01-1.09), meaning every 1 mm Hg h increase of area under the curve was associated with an average increase in the odds of AKI by 5%. CONCLUSIONS: For cardiac surgery patients, area under curve of MAP < lower limit of autoregulation using mean flow index or cerebral oximetry index had the strongest association with AKI and major morbidity and mortality. Trials are necessary to evaluate this target for MAP management.

Determining Thresholds for Three Indices of Autoregulation to Identify the Lower Limit of Autoregulation During Cardiac Surgery.

OBJECTIVES: Monitoring cerebral autoregulation may help identify the lower limit of autoregulation in individual patients. Mean arterial blood pressure below lower limit of autoregulation appears to be a risk factor for postoperative acute kidney injury. Cerebral autoregulation can be monitored in real time using correlation approaches. However, the precise thresholds for different cerebral autoregulation indexes that identify the lower limit of autoregulation are unknown. We identified thresholds for intact autoregulation in patients during cardiopulmonary bypass surgery and examined the relevance of these thresholds to postoperative acute kidney injury. DESIGN: A single-center retrospective analysis. SETTING: Tertiary academic medical center. PATIENTS: Data from 59 patients was used to determine precise cerebral autoregulation thresholds for identification of the lower limit of autoregulation. These thresholds were validated in a larger cohort of 226 patients. METHODS AND MAIN RESULTS: Invasive mean arterial blood pressure, cerebral blood flow velocities, regional cortical oxygen saturation, and total hemoglobin were recorded simultaneously. Three cerebral autoregulation indices were calculated, including mean flow index, cerebral oximetry index, and hemoglobin volume index. Cerebral autoregulation curves for the three indices were plotted, and thresholds for each index were used to generate threshold- and index-specific lower limit of autoregulations. A reference lower limit of autoregulation could be identified in 59 patients by plotting cerebral blood flow velocity against mean arterial blood pressure to generate gold-standard Lassen curves. The lower limit of autoregulations defined at each threshold were compared with the gold-standard lower limit of autoregulation determined from Lassen curves. The results identified the following thresholds: mean flow index (0.45), cerebral oximetry index (0.35), and hemoglobin volume index (0.3). We then calculated the product of magnitude and duration of mean arterial blood pressure less than lower limit of autoregulation in a larger cohort of 226 patients. When using the lower limit of autoregulations identified by the optimal thresholds above, mean arterial blood pressure less than lower limit of autoregulation was greater in patients with acute kidney injury than in those without acute kidney injury. CONCLUSIONS: This study identified thresholds of intact and impaired cerebral autoregulation for three indices and showed that mean arterial blood pressure below lower limit of autoregulation is a risk factor for acute kidney injury after cardiac surgery.

Cerebral autoregulation in the operating room and intensive care unit after cardiac surgery.

BACKGROUND: Cerebral autoregulation monitoring is a proposed method to monitor perfusion during cardiac surgery. However, limited data exist from the ICU as prior studies have focused on intraoperative measurements. Our objective was to characterise cerebral autoregulation during surgery and early ICU care, and as a secondary analysis to explore associations with delirium. METHODS: In patients undergoing cardiac surgery (n=134), cerebral oximetry values and arterial BP were monitored and recorded until the morning after surgery. A moving Pearson's correlation coefficient between mean arterial proessure (MAP) and near-infrared spectroscopy signals generated the cerebral oximetry index (COx). Three metrics were derived: (1) globally impaired autoregulation, (2) MAP time and duration outside limits of autoregulation (MAP dose), and (3) average COx. Delirium was assessed using the 3-Minute Diagnostic Interview for CAM-defined Delirium (3D-CAM) and the Confusion Assessment Method for the ICU (CAM-ICU). Autoregulation metrics were compared using χ2 and rank-sum tests, and associations with delirium were estimated using regression models, adjusted for age, bypass time, and logEuroSCORE. RESULTS: The prevalence of globally impaired autoregulation was higher in the operating room vs ICU (40% vs 13%, P<0.001). The MAP dose outside limits of autoregulation was similar in the operating room and ICU (median 16.9 mm Hg×h; inter-quartile range [IQR] 10.1-38.8 vs 16.9 mm Hg×h; IQR 5.4-35.1, P=0.20). In exploratory adjusted analyses, globally impaired autoregulation in the ICU, but not the operating room, was associated with delirium. The MAP dose outside limits of autoregulation in the operating room and ICU was also associated with delirium. CONCLUSIONS: Metrics of cerebral autoregulation are altered in the ICU, and may be clinically relevant with respect to delirium. Further studies are needed to investigate these findings and determine possible benefits of autoregulation-based MAP targeting in the ICU.

Functional Outcomes of Frail Patients After Cardiac Surgery: An Observational Study.

BACKGROUND: Although frailty has been associated with major morbidity/mortality and increased length of stay after cardiac surgery, few studies have examined functional outcomes. We hypothesized that frailty would be independently associated with decreased functional status, increased discharge to a nonhome location, and longer duration of hospitalization after cardiac surgery, and that delirium would modify these associations. METHODS: This was an observational study nested in 2 trials, each of which was conducted by the same research team with identical measurement of exposures and outcomes. The Fried frailty scale was measured at baseline. The primary outcome (defined before data collection) was functional decline, defined as ≥2-point decline from baseline in Instrumental Activities of Daily Living (IADL) score at 1 month after surgery. Secondary outcomes were absolute decline in IADL score, discharge to a new nonhome location, and duration of hospitalization. Associations were analyzed using linear, logistic, and Poisson regression models with adjustments for variables considered before analysis (age, gender, race, and logistic European Score for Cardiac Operative Risk Evaluation [EuroSCORE]) and in a propensity score analysis. RESULTS: Data were available from 133 patients (83 from first trial and 50 from the second trial). The prevalence of frailty was 33% (44 of 133). In adjusted models, frail patients had increased odds of functional decline (primary outcome; odds ratio [OR], 2.41 [95% confidence interval {CI}, 1.03-5.63]; P = .04) and greater decline at 1 month in the secondary outcome of absolute IADL score (-1.48 [95% CI, -2.77 to -0.30]; P = .019), compared to nonfrail patients. Delirium significantly modified the association of frailty and change in absolute IADL score at 1 month. In adjusted hypothesis-generating models using secondary outcomes, frail patients had increased discharge to a new nonhome location (OR, 3.25 [95% CI, 1.37-7.69]; P = .007) and increased duration of hospitalization (1.35 days [95% CI, 1.19-1.52]; P < .0001) compared to nonfrail patients. The increased duration of hospitalization, but no change in functional status or discharge location, was partially mediated by increased complications in frail patients. CONCLUSIONS: Frailty may identify patients at risk of functional decline at 1 month after cardiac surgery. Perioperative strategies to optimize frail cardiac surgery patients are needed.

Observational Study Examining the Association of Baseline Frailty and Postcardiac Surgery Delirium and Cognitive Change.

BACKGROUND: Frailty is a geriatric syndrome thought to identify the most vulnerable older adults, and morbidity and mortality has been reported to be higher for frail patients after cardiac surgery compared to nonfrail patients. However, the cognitive consequences of frailty after cardiac surgery have not been well described. In this study, we examined the hypothesis that baseline frailty would be associated with postoperative delirium and cognitive change at 1 and 12 months after cardiac surgery. METHODS: This study was nested in 2 trials, each of which was conducted by the same research team with identical measurement of exposures and outcomes. Before surgery, patients were assessed with the validated "Fried" frailty scale, which evaluates 5 domains (shrinking, weakness, exhaustion, low physical activity, and slowed walking speed) and classifies patients as nonfrail, prefrail, and frail. The primary outcome was postoperative delirium during hospitalization, which was assessed using the Confusion Assessment Method, Confusion Assessment Method for the Intensive Care Unit, and validated chart review. Neuropsychological testing was a secondary outcome and was generally performed within 2 weeks of surgery and then 4-6 weeks and 1 year after surgery, and the outcome of interest was change in composite Z-score of the test battery. Associations were analyzed using logistic and linear regression models, with adjustment for variables considered a priori (age, gender, race, education, and logistic European System for Cardiac Operative Risk Evaluation). Multiple imputation was used to account for missing data at the 12-month follow-up. RESULTS: Data were available from 133 patients with baseline frailty assessments. Compared to nonfrail patients (13% delirium incidence), the incidence of delirium was higher in prefrail (48% delirium incidence; risk difference, 35%; 95% CI, 10%-51%) and frail patients (48% delirium incidence; risk difference, 35%; 95% CI, 7%-53%). In both univariable and multivariable models, the odds of delirium were significantly higher for prefrail (adjusted odds ratio, 6.43; 95% CI, 1.31-31.64; P = .02) and frail patients (adjusted odds ratio, 6.31; 95% CI, 1.18-33.74; P = .03) compared to nonfrail patients. The adjusted decline in composite cognitive Z-score was greater from baseline to 1 month only in frail patients compared to nonfrail patients. By 1 year after surgery, there were no differences in the association of baseline frailty with change in cognition. CONCLUSIONS: Compared to nonfrail patients, both prefrail and frail patients were at higher risk for the primary outcome of delirium after cardiac surgery. Frail patients were also at higher risk for the secondary outcome of greater decline in cognition from baseline to 1 month, but not baseline to 1 year, after surgery.

Selected Area Electron Beam Induced Deposition of Pt and W for EBSD Backgrounds.

Applying high-resolution electron backscatter diffraction (HR-EBSD) to materials without regions that are amenable to the acquisition of backgrounds for static flat fielding (background subtraction) can cause analysis problems. To address this difficulty, the efficacy of electron beam induced deposition (EBID) of material as a source for an amorphous background signal is assessed and found to be practical. Using EBID material for EBSD backgrounds allows single crystal and large-grained samples to be analyzed using HR-EBSD for strain and small angle rotation measurement.

Mechanical measurements of heterogeneity and length scale effects in PEG-based hydrogels.

Colloidal-probe spherical indentation load-relaxation experiments with a probe radius of 3 µm are conducted on poly(ethylene glycol) (PEG) hydrogel materials to quantify their steady-state mechanical properties and time-dependent transport properties via a single experiment. PEG-based hydrogels are shown to be heterogeneous in both morphology and mechanical stiffness at this scale; a linear-harmonic interpolation of hyperelastic Mooney-Rivlin and Boussinesq flat-punch indentation models was used to describe the steady-state response of the hydrogels and determine upper and lower bounds for indentation moduli. Analysis of the transient load-relaxation response during displacement-controlled hold periods provides a means of extracting two time constants τ1 and τ2, where τ1 and τ2 are assigned to the viscoelastic and poroelastic properties, respectively. Large τ2 values at small indentation depths provide evidence of a non-equilibrium state characterized by a phenomenon that restricts poroelastic fluid flow through the material; for larger indentations, the variability in τ2 values decreases and pore sizes estimated from τ2via indentation approach those measured via macroscopic swelling experiments. The contact probe methodology developed here provides a means of assessing hydrogel heterogeneity, including time-dependent mechanical and transport properties, and has potential implications in hydrogel biomedical and engineering applications.

Low-temperature plasma for compositional depth profiling of crosslinking organic multilayers: comparison with C60 and giant argon gas cluster sources.

RATIONALE: For organic electronics, device performance can be affected by interlayer diffusion across interfaces. Time-of-flight secondary ion mass spectrometry (TOF-SIMS) can resolve buried structures with nanometer resolution, but instrument artifacts make this difficult. Low-temperature plasma (LTP) is suggested as a way to prepare artifact-free surfaces for accurate determination of chemical diffusion. METHODS: A model organic layer system consisting of three 1 nm delta layers of 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP) separated by three 30 nm layers of tris(8-hydroxyquinolinato)aluminum (Alq3) was used to evaluate the effectiveness of LTP etching for the preparation of crater edge surfaces for subsequent compositional depth profile analysis. This was compared with depth profiles obtained using an instrument equipped with an argon cluster sputter source. RESULTS: The quality of the depth profiles was determined by comparing the depth resolutions of the BCP delta layers. The full width at half maximum gave depth resolutions of 6.9 nm and 6.0 nm using LTP, and 6.2 nm and 5.8 nm using argon clusters. In comparison, the 1/e decay length of the trailing edge gave depth resolutions of 2.0 nm and 1.8 nm using LTP, and 3.5 nm and 3.4 nm using argon clusters. CONCLUSIONS: The comparison of the 1/e decay lengths showed that LTP can determine the thickness and composition of the buried structures without instrument artifacts. Although it does suffer from contaminant deposition, LTP was shown to be a viable option for preparing crater edges for a more accurate determination of buried structures.

Whip it into shape: Revision of the Demansia psammophis (Schlegel, 1837) complex (Squamata: Elapidae), with a description of a new species from central Australia.

The genus Demansia Günther is the most diverse genus of Australian terrestrial elapids. A phylogenetic framework for the familiar but problematic taxa D. psammophis and D. reticulata (Gray) has been long overdue to ascertain interspecific relationships and resolve unclear taxonomic issues. Here we present an integrated molecular phylogenetic and morphological analyses to review species delineation, resulting in confirmation that both D. psammophis and D. reticulata are full species and that some populations referred to D. r. cupreiceps Storr are not distinguishable from more typical D. reticulata. We also find the widespread central Australian population (treated by most authors as part of cupreiceps) to be specifically distinct. We redescribe D. psammophis and D. reticulata to clarify morphological and geographical boundaries and describe D. cyanochasma sp. nov. based on a combination of molecular genetic markers, details of colour and pattern, adult total length and a few morphometric attributes. We also designate a lectotype for D. psammophis from the original syntype series and comment on the necessity for further taxonomic refinement of this distinctive group.

Prediction of lactate concentrations after cardiac surgery using machine learning and deep learning approaches.

Background: Although conventional prediction models for surgical patients often ignore intraoperative time-series data, deep learning approaches are well-suited to incorporate time-varying and non-linear data with complex interactions. Blood lactate concentration is one important clinical marker that can reflect the adequacy of systemic perfusion during cardiac surgery. During cardiac surgery and cardiopulmonary bypass, minute-level data is available on key parameters that affect perfusion. The goal of this study was to use machine learning and deep learning approaches to predict maximum blood lactate concentrations after cardiac surgery. We hypothesized that models using minute-level intraoperative data as inputs would have the best predictive performance. Methods: Adults who underwent cardiac surgery with cardiopulmonary bypass were eligible. The primary outcome was maximum lactate concentration within 24 h postoperatively. We considered three classes of predictive models, using the performance metric of mean absolute error across testing folds: (1) static models using baseline preoperative variables, (2) augmentation of the static models with intraoperative statistics, and (3) a dynamic approach that integrates preoperative variables with intraoperative time series data. Results: 2,187 patients were included. For three models that only used baseline characteristics (linear regression, random forest, artificial neural network) to predict maximum postoperative lactate concentration, the prediction error ranged from a median of 2.52 mmol/L (IQR 2.46, 2.56) to 2.58 mmol/L (IQR 2.54, 2.60). The inclusion of intraoperative summary statistics (including intraoperative lactate concentration) improved model performance, with the prediction error ranging from a median of 2.09 mmol/L (IQR 2.04, 2.14) to 2.12 mmol/L (IQR 2.06, 2.16). For two modelling approaches (recurrent neural network, transformer) that can utilize intraoperative time-series data, the lowest prediction error was obtained with a range of median 1.96 mmol/L (IQR 1.87, 2.05) to 1.97 mmol/L (IQR 1.92, 2.05). Intraoperative lactate concentration was the most important predictive feature based on Shapley additive values. Anemia and weight were also important predictors, but there was heterogeneity in the importance of other features. Conclusion: Postoperative lactate concentrations can be predicted using baseline and intraoperative data with moderate accuracy. These results reflect the value of intraoperative data in the prediction of clinically relevant outcomes to guide perioperative management.

Exploring decarbonization pathways for USA passenger and freight mobility.

Passenger and freight travel account for 28% of U.S. greenhouse gas (GHG) emissions today. We explore pathways to reduce transportation emissions using NREL's TEMPO model under bounding assumptions on future travel behavior, technology advancement, and policies. Results show diverse routes to 80% or more well-to-wheel GHG reductions by 2050. Rapid adoption of zero-emission vehicles coupled with a clean electric grid is essential for deep decarbonization; in the median scenario, zero-emission vehicle sales reach 89% for passenger light-duty and 69% for freight trucks by 2030 and 100% sales for both by 2040. Up to 3,000 terawatt-hours of electricity could be needed in 2050 to power plug-in electric vehicles. Increased sustainable biofuel usage is also essential for decarbonizing aviation (10-42 billion gallons needed in 2050) and to support legacy vehicles during the transition. Managing travel demand growth can ease this transition by reducing the need for clean electricity and sustainable fuels.

Global disparities in mortality and liver transplantation in hospitalised patients with cirrhosis: a prospective cohort study for the CLEARED Consortium.

BACKGROUND: Cirrhosis, the end result of liver injury, has high mortality globally. The effect of country-level income on mortality from cirrhosis is unclear. We aimed to assess predictors of death in inpatients with cirrhosis using a global consortium focusing on cirrhosis-related and access-related variables. METHODS: In this prospective observational cohort study, the CLEARED Consortium followed up inpatients with cirrhosis at 90 tertiary care hospitals in 25 countries across six continents. Consecutive patients older than 18 years who were admitted non-electively, without COVID-19 or advanced hepatocellular carcinoma, were enrolled. We ensured equitable participation by limiting enrolment to a maximum of 50 patients per site. Data were collected from patients and their medical records, and included demographic characteristics; country; disease severity (MELD-Na score); cirrhosis cause; medications used; reasons for admission; transplantation listing; cirrhosis-related history in the past 6 months; and clinical course and management while hospitalised and for 30 days post discharge. Primary outcomes were death and receipt of liver transplant during index hospitalisation or within 30 days post discharge. Sites were surveyed regarding availability of and access to diagnostic and treatment services. Outcomes were compared by country income level of participating sites, defined according to World Bank income classifications (high-income countries [HICs], upper-middle-income countries [UMICs], and low-income or lower-middle-income countries [LICs or LMICs]). Multivariable models controlling for demographic variables, disease cause, and disease severity were used to analyse the odds of each outcome associated with variables of interest. FINDINGS: Patients were recruited between Nov 5, 2021, and Aug 31, 2022. Complete inpatient data were obtained for 3884 patients (mean age 55·9 years [SD 13·3]; 2493 (64·2%) men and 1391 (35·8%) women; 1413 [36·4%] from HICs, 1757 [45·2%] from UMICs, and 714 [18·4%] from LICs or LMICs), with 410 lost to follow-up within 30 days after hospital discharge. The number of patients who died while hospitalised was 110 (7·8%) of 1413 in HICs, 182 (10·4%) of 1757 in UMICs, and 158 (22·1%) of 714 in LICs and LMICs (p<0·0001), and within 30 days post discharge these values were 179 (14·4%) of 1244 in HICs, 267 (17·2%) of 1556 in UMICs, and 204 (30·3%) of 674 in LICs and LMICs (p<0·0001). Compared with patients from HICs, increased risk of death during hospitalisation was found for patients from UMICs (adjusted odds ratio [aOR] 2·14 [95% CI 1·61-2·84]) and from LICs or LMICs (2·54 [1·82-3·54]), in addition to increased risk of death within 30 days post discharge (1·95 [1·44-2·65] in UMICs and 1·84 [1·24-2·72] in LICs or LMICs). Receipt of a liver transplant was recorded in 59 (4·2%) of 1413 patients from HICs, 28 (1·6%) of 1757 from UMICs (aOR 0·41 [95% CI 0·24-0·69] vs HICs), and 14 (2·0%) of 714 from LICs and LMICs (0·21 [0·10-0·41] vs HICs) during index hospitalisation (p<0·0001), and in 105 (9·2%) of 1137 patients from HICs, 55 (4·0%) of 1372 from UMICs (0·58 [0·39-0·85] vs HICs), and 16 (3·1%) of 509 from LICs or LMICs (0·21 [0·11-0·40] vs HICs) by 30 days post discharge (p<0·0001). Site survey results showed that access to important medications (rifaximin, albumin, and terlipressin) and interventions (emergency endoscopy, liver transplantation, intensive care, and palliative care) varied geographically. INTERPRETATION: Inpatients with cirrhosis in LICs, LMICs, or UMICs have significantly higher mortality than inpatients in HICs independent of medical risk factors, and this might be due to disparities in access to essential diagnostic and treatment services. These results should encourage researchers and policy makers to consider access to services and medications when evaluating cirrhosis-related outcomes. FUNDING: National Institutes of Health and US Department of Veterans Affairs.

PCBs in indoor air and human blood in Pittsfield, Massachusetts.

Concentrations of polychlorinated biphenyls (PCBs) and three chlorinated pesticides were determined in serum from 21 residents of Pittsfield, MA and in the basement, living room and outdoor air of the 10 homes in which they lived. Median serum PCB levels were 4.2 ng/g, which are at least four times the average level in the US population, and consisted primarily of more highly chlorinated, persistent congeners. This reflects contamination with PCBs coming from the local General Electric facility. Median basement air concentration was 20.3 ng/m3, while the median living room air was 11.4 ng/m3 and median outdoor air concentration was 3.0 ng/m3. The PCB congeners detected in air were primarily low chlorinated (four and fewer) congeners, reflecting the greater volatility of PCBs with fewer chlorines. The congener pattern between basement and living room air showed a 95% correlation, while correlation with outdoor air was much less. While the congener pattern in air is very different from that of the PCB products used in Pittsfield (Aroclors 1254 and 1260), low chlorinated PCBs are detected in the vapor phase after air is blown across the commercial mixtures. The human serum samples did not show detectible levels of many of the congeners seen in the basement air samples, reflecting rapid metabolism of lower chlorinated PCBs by the human body. However, with continuous inhalation of indoor air, especially in the living room, the exposure to these non-persistent congeners may still have adverse health effects. Cellular studies of some of these non-persistent, low chlorinated congeners indicate that they are neurotoxic, mutagenic and cytotoxic. These results demonstrate the importance of consideration of inhalation of PCBs as a route of exposure, especially in indoor sites, and suggest that monitoring serum PCB concentration may not always provide a good measurement of exposure, especially to congeners that are relatively rapidly metabolized but have significant toxicity.

Selected Transesophageal Echocardiographic Parameters of Left Ventricular Diastolic Function Predict Length of Stay Following Coronary Artery Bypass Graft-A Prospective Observational Study.

(1) Importance: Abnormal left ventricular (LV) diastolic function, with or without a diagnosis of heart failure, is a common finding that can be easily diagnosed by intra-operative transesophageal echocardiography (TEE). The association of diastolic function with duration of hospital stay after coronary artery bypass (CAB) is unknown. (2) Objective: To determine if selected TEE parameters of diastolic dysfunction are associated with length of hospital stay after coronary artery bypass surgery (CAB). (3) Design: Prospective observational study. (4) Setting: A single tertiary academic medical center. (5) Participants: Patients with normal systolic function undergoing isolated CAB from September 2017 through June 2018. (6) Exposures: LV function during diastole, as assessed by intra-operative TEE prior to coronary revascularization. (7) Main Outcomes and Measures: The primary outcome was duration of postoperative hospital stay. Secondary intermediate outcomes included common postoperative cardiac, respiratory, and renal complications. (8) Results: The study included 176 participants (mean age 65.2 ± 9.2 years, 73% male); 105 (60.2%) had LV diastolic dysfunction based on selected TEE parameters. Median time to hospital discharge was significantly longer for subjects with selected parameters of diastolic dysfunction (9.1/IQR 6.6−13.5 days) than those with normal LV diastolic function (6.5/IAR 5.3−9.7 days) (p < 0.001). The probability of hospital discharge was 34% lower (HR 0.66/95% CI 0.47−0.93) for subjects with diastolic dysfunction based on selected TEE parameters, independent of potential confounders, including a baseline diagnosis of heart failure. There was a dose−response relation between severity of diastolic dysfunction and probability of discharge. LV diastolic dysfunction based on those selected TEE parameters was also associated with postoperative cardio-respiratory complications; however, these complications did not fully account for the relation between LV diastolic dysfunction and prolonged length of hospital stay. (9) Conclusions and Relevance: In patients with normal systolic function undergoing CAB, diastolic dysfunction based on selected TEE parameters is associated with prolonged duration of postoperative hospital stay. This association cannot be explained by baseline comorbidities or common post-operative complications. The diagnosis of diastolic dysfunction can be made by TEE.

Synergies between centralized and federated approaches to data quality: a report from the national COVID cohort collaborative.

OBJECTIVE: In response to COVID-19, the informatics community united to aggregate as much clinical data as possible to characterize this new disease and reduce its impact through collaborative analytics. The National COVID Cohort Collaborative (N3C) is now the largest publicly available HIPAA limited dataset in US history with over 6.4 million patients and is a testament to a partnership of over 100 organizations. MATERIALS AND METHODS: We developed a pipeline for ingesting, harmonizing, and centralizing data from 56 contributing data partners using 4 federated Common Data Models. N3C data quality (DQ) review involves both automated and manual procedures. In the process, several DQ heuristics were discovered in our centralized context, both within the pipeline and during downstream project-based analysis. Feedback to the sites led to many local and centralized DQ improvements. RESULTS: Beyond well-recognized DQ findings, we discovered 15 heuristics relating to source Common Data Model conformance, demographics, COVID tests, conditions, encounters, measurements, observations, coding completeness, and fitness for use. Of 56 sites, 37 sites (66%) demonstrated issues through these heuristics. These 37 sites demonstrated improvement after receiving feedback. DISCUSSION: We encountered site-to-site differences in DQ which would have been challenging to discover using federated checks alone. We have demonstrated that centralized DQ benchmarking reveals unique opportunities for DQ improvement that will support improved research analytics locally and in aggregate. CONCLUSION: By combining rapid, continual assessment of DQ with a large volume of multisite data, it is possible to support more nuanced scientific questions with the scale and rigor that they require.

Identifying the Gaps: Needs Assessment to Guide Development of a Dedicated Toxicology Curriculum for Emergency Medicine Residents.

INTRODUCTION: The American Board of Emergency Medicine identifies medical toxicology as an essential curricular element for emergency medicine (EM) residencies; however, access to medical toxicology education varies widely by institution. We hypothesized that EM residents are uncomfortable with core toxicology content and would be interested in  a dedicated toxicology curriculum. METHODS: An electronic needs assessment survey developed by experts in EM and medical toxicology was sent to residents and program leadership at nine EM programs participating in the Emergency Medicine Education Research Alliance (EMERA), a geographically diverse sampling of academic EM residency programs. We queried the presence of a current toxicology curriculum, interest in a dedicated toxicology curriculum, and comfort with core toxicology concepts for board examinations and in clinical practice.  RESULTS: A total of 148 residents and 8 faculty leadership completed the survey.  Only 29% of resident respondents felt comfortable with toxicology concepts, and only 66% of respondents reported access to a toxicology curriculum. Of those without a known toxicology curriculum, most were interested in a formal curriculum. Faculty respondents reported 6/8 programs offered a toxicology curriculum. Faculty at the two programs without a formal curriculum expressed interest in a dedicated curriculum. CONCLUSIONS: Emergency medicine residents remain uncomfortable with the core toxicology content in clinical practice. The majority of residents without a known toxicology curriculum would be interested in a dedicated toxicology curriculum.

The association of bispectral index values and metrics of cerebral perfusion during cardiopulmonary bypass.

STUDY OBJECTIVE: Low bispectral index (BIS) values have been associated with adverse postoperative outcomes. However, trials of optimizing BIS by titrating anesthetic administration have reported conflicting results. One potential explanation is that cerebral perfusion may also affect BIS, but the extent of this relationship is not clear. Therefore, we examined whether BIS would be associated with cerebral perfusion during cardiopulmonary bypass, when anesthetic concentration was constant. DESIGN: Observational cohort study. SETTING: Cardiac operating room. PATIENTS: Seventy-nine patients with cardiopulmonary bypass surgery were included. MEASUREMENTS: Continuous BIS, mean arterial blood pressure (MAP), cerebral blood flow velocity (CBFV), and regional cerebral oxygen saturation (rSO2) were monitored, with analysis during a period of constant anesthetic. Mean flow index (Mx) was calculated as Pearson correlation between MAP and CBFV. The lower limit of autoregulation (LLA) was identified as the MAP value at which Mx increased >0.4 with decreasing blood pressure. Postoperative delirium was assessed using the 3D-Confusion Assessment Method. RESULTS: Mean BIS was lower during periods of MAP < LLA compared with BIS when MAP>LLA (mean 49.35 ± 10.40 vs. 50.72 ± 10.04, p = 0.002, mean difference = 1.38 [standard error: 0.42]). There was a dose response effect, with the BIS proportionately decreasing as MAP decreased below LLA (ß = 0.15, 95% CI for the average slope across all patients 0.07 to 0.23, p < 0.001). In contrast, BIS was relatively unchanged when MAP was above LLA (ß = 0.03, 95% CI for the average slope across all patients -0.02 to 0.09, p = 0.22). Additionally, increasing CBFV and rSO2 were associated with increasing BIS. Patients with postoperative delirium had lower mean BIS and higher percentage of time duration with BIS <45 compared to patients without delirium. CONCLUSIONS: There was an association of BIS and metrics of cerebral perfusion during a period of constant anesthetic administration, but the absolute magnitude of change in BIS as MAP decreased below the LLA was small.

Outcomes of lumbar to sacral nerve rerouting for spina bifida.

PURPOSE: Restoring bladder and bowel function in spina bifida by creation of a skin-central nervous system-bladder reflex arc via lumbar to sacral nerve rerouting has a reported success rate of 87% in China. We report 1-year results of the first North American trial on nerve rerouting. MATERIALS AND METHODS: Nine subjects were enrolled in the study. Intradural lumbar to sacral nerve rerouting was performed. Subjects underwent urodynamic testing with stimulation of the cutaneous dermatome and careful neurological followup. Adverse events were closely monitored along with changes in bowel and bladder function. RESULTS: At 1 year 7 patients (78%) had a reproducible increase in bladder pressure with stimulation of the dermatome. Two patients were able to stop catheterization and all safely stopped antimuscarinics. No patient achieved complete urinary continence. The majority of subjects reported improved bowel function. One patient was continent of stool at baseline and 4 were continent at 1 year. Of the patients 89% had variable weakness of lower extremity muscle groups at 1 month. One child had persistent foot drop and the remainder returned to baseline by 12 months. CONCLUSIONS: At 1 year a novel reflex arc with stimulation of the appropriate dermatome was seen in the majority of subjects. Improvements in voiding and bowel function were noted. Lower extremity weakness was mostly self-limited, except in 1 subject with a persistent foot drop. More patients and longer followup are needed to assess the risk/benefit ratio of this novel procedure.

An inventory of online reptile images.

No central online repository exists for the collection of animal images; hence it remains unclear how extensively species have been illustrated in the published literature or online. Here we compiled a list of more than 8000 reptile species (out of 11,341) that have photos in one of six popular online repositories, namely iNaturalist (6,349 species), the Reptile Database (5,144), Flickr (4,386), CalPhotos (3,071), Wikimedia (2,952), and Herpmapper (2,571). These sites have compiled over one million reptile photos, with some species represented by tens of thousands of images. Despite the number of images, many species have only one or a few images. This suggests that a considerable fraction of morphological and geographic variation is under documented or difficult to access. We highlight prominent gaps in amphisbaenians, lizards, and snakes, with geographic hotspots for species without images in Central Africa, Pacific Islands, and the Andes Mountains. We present a list of ~3,000 species without photos in any of the six databases and ask the community to fill the gaps by depositing images on one of these sites (preferably with minimal copyright restrictions).