Wearable sensors in patient acuity assessment in critical care

Acuity assessments are vital for timely interventions and fair resource allocation in critical care settings. Conventional acuity scoring systems heavily depend on subjective patient assessments, leaving room for implicit bias and errors. These assessments are often manual, time-consuming, intermittent, and challenging to interpret accurately, especially for healthcare providers. This risk of bias and error is likely most pronounced in time-constrained and high-stakes environments, such as critical care settings. Furthermore, such scores do not incorporate other information, such as patients' mobility level, which can indicate recovery or deterioration in the intensive care unit (ICU), especially at a granular level. We hypothesized that wearable sensor data could assist in assessing patient acuity granularly, especially in conjunction with clinical data from electronic health records (EHR). In this prospective study, we evaluated the impact of integrating mobility data collected from wrist-worn accelerometers with clinical data obtained from EHR for estimating acuity. Accelerometry data were collected from 87 patients wearing accelerometers on their wrists in an academic hospital setting. The data was evaluated using five deep neural network models: VGG, ResNet, MobileNet, SqueezeNet, and a custom Transformer network. These models outperformed a rule-based clinical score (Sequential Organ Failure Assessment, SOFA) used as a baseline when predicting acuity state (for ground truth we labeled as unstable patients if they needed life-supporting therapies, and as stable otherwise), particularly regarding the precision, sensitivity, and F1 score. The results demonstrate that integrating accelerometer data with demographics and clinical variables improves predictive performance compared to traditional scoring systems in healthcare. Deep learning models consistently outperformed the SOFA score baseline across various scenarios, showing notable enhancements in metrics such as the area under the receiver operating characteristic (ROC) Curve (AUC), precision, sensitivity, specificity, and F1 score. The most comprehensive scenario, leveraging accelerometer, demographics, and clinical data, achieved the highest AUC of 0.73, compared to 0.53 when using SOFA score as the baseline, with significant improvements in precision (0.80 vs. 0.23), specificity (0.79 vs. 0.73), and F1 score (0.77 vs. 0.66). This study demonstrates a novel approach beyond the simplistic differentiation between stable and unstable conditions. By incorporating mobility and comprehensive patient information, we distinguish between these states in critically ill patients and capture essential nuances in physiology and functional status. Unlike rudimentary definitions, such as equating low blood pressure with instability, our methodology delves deeper, offering a more holistic understanding and potentially valuable insights for acuity assessment.

Development and validation of a race-agnostic computable phenotype for kidney health in adult hospitalized patients

Standard race adjustments for estimating glomerular filtration rate (GFR) and reference creatinine can yield a lower acute kidney injury (AKI) and chronic kidney disease (CKD) prevalence among African American patients than non-race adjusted estimates. We developed two race-agnostic computable phenotypes that assess kidney health among 139,152 subjects admitted to the University of Florida Health between 1/2012-8/2019 by removing the race modifier from the estimated GFR and estimated creatinine formula used by the race-adjusted algorithm (race-agnostic algorithm 1) and by utilizing 2021 CKD-EPI refit without race formula (race-agnostic algorithm 2) for calculations of the estimated GFR and estimated creatinine. We compared results using these algorithms to the race-adjusted algorithm in African American patients. Using clinical adjudication, we validated race-agnostic computable phenotypes developed for preadmission CKD and AKI presence on 300 cases. Race adjustment reclassified 2,113 (8%) to no CKD and 7,901 (29%) to a less severe CKD stage compared to race-agnostic algorithm 1 and reclassified 1,208 (5%) to no CKD and 4,606 (18%) to a less severe CKD stage compared to race-agnostic algorithm 2. Of 12,451 AKI encounters based on race-agnostic algorithm 1, race adjustment reclassified 591 to No AKI and 305 to a less severe AKI stage. Of 12,251 AKI encounters based on race-agnostic algorithm 2, race adjustment reclassified 382 to No AKI and 196 (1.6%) to a less severe AKI stage. The phenotyping algorithm based on refit without race formula performed well in identifying patients with CKD and AKI with a sensitivity of 100% (95% confidence interval [CI] 97%-100%) and 99% (95% CI 97%-100%) and a specificity of 88% (95% CI 82%-93%) and 98% (95% CI 93%-100%), respectively. Race-agnostic algorithms identified substantial proportions of additional patients with CKD and AKI compared to race-adjusted algorithm in African American patients. The phenotyping algorithm is promising in identifying patients with kidney disease and improving clinical decision-making.

Machine learning-based prediction models for home discharge in patients with COVID-19: Development and evaluation using electronic health records

OBJECTIVE

This study aimed to develop and validate predictive models using electronic health records (EHR) data to determine whether hospitalized COVID-19-positive patients would be admitted to alternative medical care or discharged home.

METHODS

We conducted a retrospective cohort study using deidentified data from the University of Florida Health Integrated Data Repository. The study included 1,578 adult patients (≥18 years) who tested positive for COVID-19 while hospitalized, comprising 960 (60.8%) female patients with a mean (SD) age of 51.86 (18.49) years and 618 (39.2%) male patients with a mean (SD) age of 54.35 (18.48) years. Machine learning (ML) model training involved cross-validation to assess their performance in predicting patient disposition.

RESULTS

We developed and validated six supervised ML-based prediction models (logistic regression, Gaussian Naïve Bayes, k-nearest neighbors, decision trees, random forest, and support vector machine classifier) to predict patient discharge status. The models were evaluated based on the area under the receiver operating characteristic curve (ROC-AUC), precision, accuracy, F1 score, and Brier score. The random forest classifier exhibited the highest performance, achieving an accuracy of 0.84 and an AUC of 0.72. Logistic regression (accuracy: 0.85, AUC: 0.71), k-nearest neighbor (accuracy: 0.84, AUC: 0.63), decision tree (accuracy: 0.84, AUC: 0.61), Gaussian Naïve Bayes (accuracy: 0.84, AUC: 0.66), and support vector machine classifier (accuracy: 0.84, AUC: 0.67) also demonstrated valuable predictive capabilities.

SIGNIFICANCE

This study's findings are crucial for efficiently allocating healthcare resources during pandemics like COVID-19. By harnessing ML techniques and EHR data, we can create predictive tools to identify patients at greater risk of severe symptoms based on their medical histories. The models developed here serve as a foundation for expanding the toolkit available to healthcare professionals and organizations. Additionally, explainable ML methods, such as Shapley Additive Explanations, aid in uncovering underlying data features that inform healthcare decision-making processes.

Adverse Long-Term Outcomes and an Immune Suppressed Endotype in Sepsis Patients with Reduced Interferon-γELISpot: A Multicenter, Prospective Observational Study

BACKGROUND

Sepsis remains a major clinical challenge for which successful treatment requires greater precision in identifying patients at increased risk of adverse outcomes requiring different therapeutic approaches. Predicting clinical outcomes and immunological endotyping of septic patients has generally relied on using blood protein or mRNA biomarkers, or static cell phenotyping. Here, we sought to determine whether functional immune responsiveness would yield improved precision.

METHODS

An ex vivo whole blood enzyme-linked immunosorbent (ELISpot) assay for cellular production of interferon-γ (IFN-γ) was evaluated in 107 septic and 68 non-septic patients from five academic health centers using blood samples collected on days 1, 4 and 7 following ICU admission.

RESULTS

Compared with 46 healthy subjects, unstimulated and stimulated whole blood IFNγ expression were either increased or unchanged, respectively, in septic and nonseptic ICU patients. However, in septic patients who did not survive 180 days, stimulated whole blood IFNγ expression was significantly reduced on ICU days 1, 4 and 7 (all p<0.05), due to both significant reductions in total number of IFNγ producing cells and amount of IFNγ produced per cell (all p<0.05). Importantly, IFNγ total expression on day 1 and 4 after admission could discriminate 180-day mortality better than absolute lymphocyte count (ALC), IL-6 and procalcitonin. Septic patients with low IFNγ expression were older and had lower ALC and higher sPD-L1 and IL-10 concentrations, consistent with an immune suppressed endotype.

CONCLUSIONS

A whole blood IFNγ ELISpot assay can both identify septic patients at increased risk of late mortality, and identify immune-suppressed, sepsis patients.

Re-Aiming Equity Evaluation in Clinical Decision Support: A Scoping Review of Equity Assessments in Surgical Decision Support Systems

OBJECTIVE

We critically evaluated the surgical literature to explore the prevalence and describe how equity assessments occur when using clinical decision support systems.

BACKGROUND

Clinical decision support (CDS) systems are increasingly used to facilitate surgical care delivery. Despite formal recommendations to do so, equity evaluations are not routinely performed on CDS systems and underrepresented populations are at risk of harm and further health disparities. We explored surgical literature to determine frequency and rigor of CDS equity assessments and offer recommendations to improve CDS equity by appending existing frameworks.

METHODS

We performed a scoping review up to Augus 25, 2021 using PubMed and Google Scholar for the following search terms: clinical decision support, implementation, RE-AIM, Proctor, Proctor's framework, equity, trauma, surgery, surgical. We identified 1415 citations and 229 abstracts met criteria for review. A total of 84 underwent full review after 145 were excluded if they did not assess outcomes of an electronic CDS tool or have a surgical use case.

RESULTS

Only 6% (5/84) of surgical CDS systems reported equity analyses, suggesting that current methods for optimizing equity in surgical CDS are inadequate. We propose revising the RE-AIM framework to include an Equity element (RE 2 -AIM) specifying that CDS foundational analyses and algorithms are performed or trained on balanced datasets with sociodemographic characteristics that accurately represent the CDS target population and are assessed by sensitivity analyses focused on vulnerable subpopulations.

CONCLUSION

Current surgical CDS literature reports little with respect to equity. Revising the RE-AIM framework to include an Equity element (RE 2 -AIM) promotes the development and implementation of CDS systems that, at minimum, do not worsen healthcare disparities and possibly improve their generalizability.

Evaluation of federated learning variations for COVID-19 diagnosis using chest radiographs from 42 US and European hospitals

OBJECTIVE

Federated learning (FL) allows multiple distributed data holders to collaboratively learn a shared model without data sharing. However, individual health system data are heterogeneous. "Personalized" FL variations have been developed to counter data heterogeneity, but few have been evaluated using real-world healthcare data. The purpose of this study is to investigate the performance of a single-site versus a 3-client federated model using a previously described Coronavirus Disease 19 (COVID-19) diagnostic model. Additionally, to investigate the effect of system heterogeneity, we evaluate the performance of 4 FL variations.

MATERIALS AND METHODS

We leverage a FL healthcare collaborative including data from 5 international healthcare systems (US and Europe) encompassing 42 hospitals. We implemented a COVID-19 computer vision diagnosis system using the Federated Averaging (FedAvg) algorithm implemented on Clara Train SDK 4.0. To study the effect of data heterogeneity, training data was pooled from 3 systems locally and federation was simulated. We compared a centralized/pooled model, versus FedAvg, and 3 personalized FL variations (FedProx, FedBN, and FedAMP).

RESULTS

We observed comparable model performance with respect to internal validation (local model: AUROC 0.94 vs FedAvg: 0.95, P = .5) and improved model generalizability with the FedAvg model (P < .05). When investigating the effects of model heterogeneity, we observed poor performance with FedAvg on internal validation as compared to personalized FL algorithms. FedAvg did have improved generalizability compared to personalized FL algorithms. On average, FedBN had the best rank performance on internal and external validation.

CONCLUSION

FedAvg can significantly improve the generalization of the model compared to other personalization FL algorithms; however, at the cost of poor internal validity. Personalized FL may offer an opportunity to develop both internal and externally validated algorithms.

Early Biomarker Signatures in Surgical Sepsis

INTRODUCTION

Sepsis has complex, time-sensitive pathophysiology and important phenotypic subgroups. The objective of this study was to use machine learning analyses of blood and urine biomarker profiles to elucidate the pathophysiologic signatures of subgroups of surgical sepsis patients.

METHODS

This prospective cohort study included 243 surgical sepsis patients admitted to a quaternary care center between January 2015 and June 2017. We applied hierarchical clustering to clinical variables and 42 blood and urine biomarkers to identify phenotypic subgroups in a development cohort. Clinical characteristics and short-term and long-term outcomes were compared between clusters. A naïve Bayes classifier predicted cluster labels in a validation cohort.

RESULTS

The development cohort contained one cluster characterized by early organ dysfunction (cluster I, n = 18) and one cluster characterized by recovery (cluster II, n = 139). Cluster I was associated with higher Acute Physiologic Assessment and Chronic Health Evaluation II (30 versus 16, P < 0.001) and SOFA scores (13 versus 5, P < 0.001), greater prevalence of chronic cardiovascular and renal disease (P < 0.001) and septic shock (78% versus 17%, P < 0.001). Cluster I had higher mortality within 14 d of sepsis onset (11% versus 1.5%, P = 0.001) and within 1 y (44% versus 20%, P = 0.032), and higher incidence of chronic critical illness (61% versus 30%, P = 0.001). The Bayes classifier achieved 95% accuracy and identified two clusters that were similar to development cohort clusters.

CONCLUSIONS

Machine learning analyses of clinical and biomarker variables identified an early organ dysfunction sepsis phenotype characterized by inflammation, renal dysfunction, endotheliopathy, and immunosuppression, as well as poor short-term and long-term clinical outcomes.

Evaluation of a Multivalent Transcriptomic Metric for Diagnosing Surgical Sepsis and Estimating Mortality Among Critically Ill Patients

Importance

Rapid and accurate discrimination of sepsis and its potential severity currently require multiple assays with slow processing times that are often inconclusive in discerning sepsis from sterile inflammation.

Objective

To analyze a whole-blood, multivalent, host-messenger RNA expression metric for estimating the likelihood of bacterial infection and 30-day mortality and compare performance of the metric with that of other diagnostic and prognostic biomarkers and clinical parameters.

Design, Setting, and Participants

This prospective diagnostic and prognostic study was performed in the surgical intensive care unit (ICU) of a single, academic health science center. The analysis included 200 critically ill adult patients admitted with suspected sepsis (cohort A) or those at high risk for developing sepsis (cohort B) between July 1, 2020, and July 30, 2021.

Exposures

Whole-blood sample measurements of a custom 29-messenger RNA transcriptomic metric classifier for likelihood of bacterial infection (IMX-BVN-3) or 30-day mortality (severity) (IMX-SEV-3) in a clinical-diagnostic laboratory setting using an analysis platform (510[k]-cleared nCounter FLEX; NanoString, Inc), compared with measurement of procalcitonin and interleukin 6 (IL-6) plasma levels, and maximum 24-hour sequential organ failure assessment (SOFA) scores.

Main Outcomes and Measures

Estimated sepsis and 30-day mortality performance.

Results

Among the 200 patients included (124 men [62.0%] and 76 women [38.0%]; median age, 62.5 [IQR, 47.0-72.0] years), the IMX-BVN-3 bacterial infection classifier had an area under the receiver operating characteristics curve (AUROC) of 0.84 (95% CI, 0.77-0.90) for discriminating bacterial infection at ICU admission, similar to procalcitonin (0.85 [95% CI, 0.79-0.90]; P = .79) and significantly better than IL-6 (0.67 [95% CI, 0.58-0.75]; P < .001). For estimating 30-day mortality, the IMX-SEV-3 metric had an AUROC of 0.81 (95% CI, 0.66-0.95), which was significantly better than IL-6 levels (0.57 [95% CI, 0.37-0.77]; P = .006), marginally better than procalcitonin levels (0.65 [95% CI, 0.50-0.79]; P = .06), and similar to the SOFA score (0.76 [95% CI, 0.62-0.91]; P = .48). Combining IMX-BVN-3 and IMX-SEV-3 with procalcitonin or IL-6 levels or SOFA scores did not significantly improve performance. Among patients with sepsis, IMX-BVN-3 scores decreased over time, reflecting the resolution of sepsis. In 11 individuals at high risk (cohort B) who subsequently developed sepsis during their hospital course, IMX-BVN-3 bacterial infection scores did not decline over time and peaked on the day of documented infection.

Conclusions and Relevance

In this diagnostic and prognostic study, a novel, multivalent, transcriptomic metric accurately estimated the presence of bacterial infection and risk for 30-day mortality in patients admitted to a surgical ICU. The performance of this single transcriptomic metric was equivalent to or better than multiple alternative diagnostic and prognostic metrics when measured at admission and provided additional information when measured over time.

Nutritional impact of omega 3 fatty acids and metabolites in acute and chronic critical illness

PURPOSE OF REVIEW

Lipids have been utilized historically as a calorie dense means to ensure delivery of essential fatty acids (FA). Since the development of mixed lipid emulsion and investigation of immunomodulatory formulas, there has been an awakening that not all lipids are created equal. This narrative review focuses on contemporary evidence in the utilization of lipids (namely omega 3 fatty acids) in both acute and chronic critical illness.

RECENT FINDINGS

Though randomized control trials and meta-analyses provide little guidance regarding clinical practice for patients suffering from chronic critical illness, available literature suggests the potential to use lipid formulas to decrease the inflammatory cycle that drives catabolism. Additionally, this review will address the expanding evidence that specialized pro-resolving mediators (SPMs) may be the future of immunomodulating inflammation in acute and chronic critical illness and the persistent inflammation, immunosuppression, and catabolic syndrome (PICS).

SUMMARY

Although societal guidelines, expert consensus, and literature support the use of omega 3 fatty acids in the acute critically ill population, more research is needed regarding omega 3 fatty acids for chronic critical illness and PICS.

A core outcome set for damage control laparotomy via modified Delphi method

OBJECTIVES

Damage control laparotomy (DCL) remains an important tool in the trauma surgeon's armamentarium. Inconsistency in reporting standards have hindered careful scrutiny of DCL outcomes. We sought to develop a core outcome set (COS) for DCL clinical studies to facilitate future pooling of data via meta-analysis and Bayesian statistics while minimizing reporting bias.

METHODS

A modified Delphi study was performed using DCL content experts identified through Eastern Association for the Surgery of Trauma (EAST) 'landmark' DCL papers and EAST ad hoc COS task force consensus.

RESULTS

Of 28 content experts identified, 20 (71%) participated in round 1, 20/20 (100%) in round 2, and 19/20 (95%) in round 3. Round 1 identified 36 potential COS. Round 2 achieved consensus on 10 core outcomes: mortality, 30-day mortality, fascial closure, days to fascial closure, abdominal complications, major complications requiring reoperation or unplanned re-exploration following closure, gastrointestinal anastomotic leak, secondary intra-abdominal sepsis (including anastomotic leak), enterocutaneous fistula, and 12-month functional outcome. Despite feedback provided between rounds, round 3 achieved no further consensus.

CONCLUSIONS

Through an electronic survey-based consensus method, content experts agreed on a core outcome set for damage control laparotomy, which is recommended for future trials in DCL clinical research. Further work is necessary to delineate specific tools and methods for measuring specific outcomes.

LEVEL OF EVIDENCE

V, criteria.

A Novel Single Cell RNA-seq Analysis of Non-Myeloid Circulating Cells in Late Sepsis

Background

With the successful implementation of the Surviving Sepsis Campaign guidelines, post-sepsis in-hospital mortality to sepsis continues to decrease. Those who acutely survive surgical sepsis will either rapidly recover or develop a chronic critical illness (CCI). CCI is associated with adverse long-term outcomes and 1-year mortality. Although the pathobiology of CCI remains undefined, emerging evidence suggests a post-sepsis state of pathologic myeloid activation, inducing suboptimal lymphopoiesis and erythropoiesis, as well as downstream leukocyte dysfunction. Our goal was to use single-cell RNA sequencing (scRNA-seq) to perform a detailed transcriptomic analysis of lymphoid-derived leukocytes to better understand the pathology of late sepsis.

Methods

A mixture of whole blood myeloid-enriched and Ficoll-enriched peripheral blood mononuclear cells from four late septic patients (post-sepsis day 14-21) and five healthy subjects underwent Cellular Indexing of Transcriptomes and Epitopes by Sequencing (CITE-seq).

Results

We identified unique transcriptomic patterns for multiple circulating immune cell subtypes, including B- and CD4⁺, CD8⁺, activated CD4⁺ and activated CD8⁺ T-lymphocytes, as well as natural killer (NK), NKT, and plasmacytoid dendritic cells in late sepsis patients. Analysis demonstrated that the circulating lymphoid cells maintained a transcriptome reflecting immunosuppression and low-grade inflammation. We also identified transcriptomic differences between patients with bacterial versus fungal sepsis, such as greater expression of cytotoxic genes among CD8⁺ T-lymphocytes in late bacterial sepsis.

Conclusion

Circulating non-myeloid cells display a unique transcriptomic pattern late after sepsis. Non-myeloid leukocytes in particular reveal a host endotype of inflammation, immunosuppression, and dysfunction, suggesting a role for precision medicine-guided immunomodulatory therapy.

Is provision of contraception at discharge following delivery associated with postpartum visit attendance?

OBJECTIVES

We examined whether provision of contraception at discharge following delivery was associated with lower rates of postpartum visit (PPV) attendance.

METHODS

We conducted a retrospective cohort study of women who received pregnancy care at a Midwestern medical center in 2013. Attendance at the postpartum visit was compared for women with sterilization, contraception initiated prior to discharge (depot medroxyprogesterone acetate or etonogestrel implant), hormonal contraception prescription, or no contraception provided at postpartum discharge. Poisson regression models with robust standard errors were used to estimate the relative risk of postpartum visit attendance controlling for age, race, and parity, insurance status, and histories of both depression and drug abuse.

RESULTS

Of the 1015 women who met inclusion criteria, 55% had been prescribed contraception, had initiated contraception prior to discharge, or were sterilized at the time of discharge following delivery. After adjustment for confounders, there was no association between receiving contraception and PPV attendance (relative risk for prescribed contraception = 1.09 [95% CI 0.85, 1.39], for contraception initiated prior to discharge = 0.83 [95% CI 0.67, 1.03], for sterilization = 0.86 [95% CI 0.63, 1.17] compared to no contraception).

CONCLUSIONS

We found no evidence that prescribing or administering contraception post-delivery was associated with lower rates of return for postpartum follow up.

IMPLICATIONS

This single site study suggests that providing effective contraception at discharge following delivery does not appear to impact PPV attendance.

Chronic Critically Ill Septic Patients Exhibit Persistent Expression of Pro-Inflammatory Lipidomics

Objectives

In order to evaluate the therapeutic potential of resolvins to reduce inflammation in CCI-PICS, we recapitulated Glue Grant leukotriene and resolvin lipidomic scores above to quantify lipidomics in severe sepsis/septic shock survivors.

Methods

Ongoing University of Florida (UF) Sepsis Critical Illness Research Center (SCIRC) research studies indicate that Persistent Inflammation, Immunosuppression, and Catabolism Syndrome (PICS) occurs as a result of a self-perpetuating cycle of low-grade inflammation. However, specialized pro-resolving mediators (SPMs) – metabolically active lipid byproducts of omega-3 fatty acids – can promote inflammatory deceleration and resolution.,1 Post hoc analysis of the Glue Grant Data developed a mathematical lipidomic expression to better understand genes responsible for production and degradation of resolvins and leukotrienes.,2

Leukotriene Score = (ALOX5 * ALX5AP * LTA4H * LTB4R)/(HPGD + PTGR1 + CYP4F3)

Resolvin Score = [(ALOX5 * ALOX15) * (FPR2 + GPR32 + CMKLR1)]/(HPGD + PTGR1)

When the targeted genes were scored using a weighted scheme accounting for enzyme and receptor activity, patients with uncomplicated recoveries had higher resolvin scores (P &lt; 0.001) and lower leukotriene scores (P &lt; 0.001).

Utilizing our PICS patient data, we recapitulated the aforementioned lipidomic scores above to quantify expression in severe sepsis/septic shock survivors.

Results

Leukotriene and resolvin scores are depicted in Figure 1 at specific time points 0 (healthy controls), 3 hours, 1 and 14 days. The leukotriene score remains elevated consistent with ongoing inflammatory genotypic expression. Interestingly, the resolvin score also remains elevated in the CCI (Glue Grant complicated cohort) patient population when compared to our Rapid Recovery (RAP or uncomplicated) patients

*Accompanied by two graphs depicting correlating numerical values for the aforementioned Leukotriene and Resolvin scores.

Conclusions

In our patient population of sepsis survivors, the leukotriene score is similarly elevated to the complicated Glue Grant patients of polytrauma. The resolvin score, however, remains elevated in the CCI-PICS population compared to RAP; this is contrary to expected scores if resolution of inflammation is predicted.

Funding Sources

University of Florida.

Chronic Critical Illness Patients Fail to Respond to Current Evidence-Based Intensive Care Nutrition Secondarily to Persistent Inflammation, Immunosuppression, and Catabolic Syndrome

BACKGROUND

Sepsis-induced multiple-organ failure (MOF) has plagued surgical intensive care units (ICUs) for decades. Early nutrition (principally enteral) improves hospital outcomes of high-risk ICU patients. The purpose of this study is to document how the growing epidemic of chronic critical illness (CCI) patients responds to adequate evidence-based ICU nutrition.

METHODS

This retrospective post hoc subgroup analysis of an ongoing sepsis database identified 56 CCI patients who received early, adequate nutrition per an established surgical ICU protocol compared with 112 matched rapid-recovery (RAP) patients.

RESULTS

The matched CCI and RAP groups had similar baseline characteristics. Serial biomarkers showed that CCI patients remained persistently inflamed with ongoing stress metabolism and that despite receiving evidence-based protocol nutrition, they had persistent catabolism and immunosuppression with more secondary infections. More CCI patients were discharged to poor nonhome destinations (ie, skilled nursing facilities, long-term acute care, hospice) (81% vs 29%, P < 0.05). At 12-month follow-up, CCI patients had worse functional status by Zubrod score (3.17 vs 1.62, P < 0.001) and Short Physical Battery Testing (4.78 vs 8.59, P < 0.02), worse health-related quality of life by EQ-5D-3L descriptive measures (9.07 vs 7.45, P < 0.003), and lower survival (67% vs 92%, P < 0.05).

CONCLUSIONS

Despite early, adequate, evidence-based ICU nutrition, septic surgical ICU patients who develop CCI exhibit persistent inflammation, immunosuppression, and catabolism with unacceptable long-term morbidity and mortality. Although current evidence-based ICU nutrition may improve short-term ICU outcomes, novel adjuncts are needed to improve long-term outcomes for CCI patients.

Brain biopsies requiring Creutzfeldt-Jakob disease precautions in the Republic of Ireland 2005-2016

AIMS

Creutzfeldt-Jakob disease (CJD) risk precautions are required when performing brain biopsies on patients with a dementing illness and in 'risk' groups. The impact on a diagnostic neuropathology service is considerable. We sought to determine if better case selection might reduce the necessity for application of CJD risk precautions.

METHODS

We reviewed the clinical information, contributory investigations and final neuropathologic diagnosis in a cohort of patients (n = 21), referred to the National CJD Surveillance Centre between January 1, 2005, and December 31, 2016.

RESULTS

Of this 21-patient cohort, five were positive for CJD, four belonged to the 'at risk of CJD' category requiring brain surgery, while the remaining 12 were referred to the National CJD Surveillance Unit with CJD as part of their differential diagnosis. CJD was confirmed in 5/21 (three sporadic [s]CJD, one variant [v]CJD and one iatrogenic [i] CJD). CJD was clinically probable in 4/5 proven CJD patients (80%). The patients (n = 4) in the 'at risk of CJD' group were diagnosed with tumour (n = 2), inflammation (n = 1) and non-specific changes (n = 1). Of the remaining 12 patients (in whom CJD was included in the differential diagnosis), the final neuropathologic diagnoses included tumour (n = 2), neurodegenerative (n = 2), inflammatory (n = 1), metabolic (n = 2), vascular (n = 2) and non-specific gliosis (n = 3).

CONCLUSIONS

More often than not, the clinical suspicion of CJD was not borne out by the final neuropathological diagnosis. Failure by clinicians to adhere to the recommended CJD investigation algorithm impacts adversely on the neuropathology workload and causes unnecessary concern among operating theatre, laboratory and nursing personnel.

Intravascular large B-cell lymphoma presenting clinically as rapidly progressive dementia

BACKGROUND

In patients presenting with rapidly progressive dementia, prion disease may enter the differential diagnosis. The commonest malignancies masquerading as prion disease are primary CNS lymphoma and intravascular large B-cell lymphoma, both rare and difficult to diagnose without brain biopsy.

CASE PRESENTATION

This 82-year-old lady with a past history of hypertension, presented with rapidly progressive cognitive impairment and ataxia. The possibility of sCJD was raised. Brain biopsy was carried out. Western blot for prion protein was negative. Brain biopsy showed intravascular large B-cell lymphoma. She died shortly afterwards.

CONCLUSION

The clinical presentation of intravascular large B-cell lymphoma is diverse. Patients may present as in this case with dementia, seizures, and myoclonus leading to a clinical diagnosis of sCJD. The diagnosis here was made at biopsy but is made at autopsy in over 50% of cases.

Resonant control of elastic collisions in an optically trapped fermi gas of atoms

We have loaded an ultracold gas of fermionic atoms into a far-off resonance optical dipole trap and precisely controlled the spin composition of the trapped gas. We have measured a magnetic-field Feshbach resonance between atoms in the two lowest energy spin states, /9/2,-9/2> and /9/2,-7/2>. The resonance peaks at a magnetic field of 201.5+/-1.4 G and has a width of 8.0+/-1.1 G. Using this resonance, we have changed the elastic collision cross section in the gas by nearly 3 orders of magnitude.

Instability and pulse area quantization in accelerated superradiant atom-cavity systems

We study the interaction of pulsed excitation fields with optically thin atomic ensembles subject to strong cavity-accelerated superradiance. In homogeneously broadened atom-field systems the excitation of superradiant instabilities is seen to lead to a quantization of the total pulse area accrued during excitation and subsequent superradiant decay. In inhomogeneously broadened systems, quasidiscretized area values and pulse area gaps (i.e., forbidden area values) are found. Predicted area discontinuities are demonstrated in cryogenically coherence-stabilized Tm(3+) ions.

Land-use dynamics in a southern Illinois (USA) watershed

The Cache River of southernmost Illinois is used as a case study for developing and demonstrating an approach to quantitatively link (1) national agricultural policy and global agricultural markets, (2) landowner's decisions on land use, (3) spatial patterns of land use at a watershed scale, and (4) hydrologic impacts, thus providing a basis to predict, under a certain set of circumstances, the environmental consequences of economic and political decisions made at larger spatial scales. The heart of the analysis is an estimation, using logistic regression, of the affect of crop prices and Conservation Reserve Program (CRP) rental rates on farmland owner's decisions whether to reenroll in the CRP or return to crop production. This analysis shows that reasonable ranges for crop prices (80%-150% of 1985-1995 values) and CRP rental rates (0-125% of 1985-1995 rates) result in a range of 3%-92% of CRP lands being returned to crop production, with crop prices having a slightly greater effect than CRP rental rates. Four crop price/CRP rental rate scenarios are used to display resulting land-use patterns, and their effect on sediment loads, a critical environmental quality parameter in this case, using the agricultural non point source (AGNPS) model. These scenarios demonstrate the importance of spatial pattern of land uses on hydrological and ecological processes within watersheds. The approach developed can be adapted for use by local governments and watershed associations whose goals are to improve watershed resources and environmental quality.

Induction of apoptosis by conjugated linoleic acid in cultured mammary tumor cells and premalignant lesions of the rat mammary gland

Conjugated linoleic acid (CLA) is an effective agent in preventing mammary cancer in rats treated with a carcinogen. The appearance of a tumor mass is the net result of cell proliferation minus cell death. Thus, apoptosis could be an important mechanism in controlling clonal expansion of the early premalignant lesions. The overall objective of this report was to determine whether CLA stimulated apoptosis. In the first part of the study, CLA was found to increase chromatin condensation (visualized through fluorescent 4',6-diamidino-2-phenylindole staining to DNA) and to induce DNA laddering, both evidence of apoptosis, in a rat mammary tumor cell line. The second part was to investigate the effect of CLA feeding on the development of histologically identifiable premalignant lesions in the rat mammary gland, as well as on the quantification of apoptosis (by terminal uridyltransferase nick end labeling assay) and the expression by immunohistochemistry of apoptosis regulatory proteins (bcl-2, bak, and bax) in normal versus premalignant mammary structures. CLA inhibited the formation of premalignant lesions by approximately 50%. It also significantly increased apoptosis and reduced the expression of bcl-2 in these lesions, but it did not modulate the levels of bak or bax. In contrast, neither apoptosis nor any of the apoptosis regulatory proteins was affected by CLA in normal mammary gland alveoli or terminal end buds. The data suggest that early pathological lesions may be particularly sensitive to CLA. In addition to providing a molecular basis for elucidating the mechanism of action of CLA in cancer prevention, the research on CLA-responsive biomarkers also has a practical side because these assays can be applied to biopsied human tissue samples in future CLA intervention trials.

Gastrointestinal zygomycotic infection caused by Basidiobolus ranarum: case report and review

Basidiobolus species are filamentous fungi belonging to the order Entomophthorales. Unlike other zygomycetes, Basidiobolus species have been mainly associated with a tropical form of subcutaneous zygomycosis in otherwise healthy individuals. Visceral disease caused by this pathogen is rare, but cases of gastrointestinal infection with Basidiobolus ranarum have been reported worldwide. In many of these reports, the inflammatory disease of the colon has been confused with Crohn's disease. We report the third case of B. ranarum gastrointestinal infection in the United States, which was initially treated as inflammatory bowel disease.

Morphological and biochemical status of the mammary gland as influenced by conjugated linoleic acid: implication for a reduction in mammary cancer risk

Previous research showed that treatment with conjugated linoleic acid (CLA) during the period of active mammary gland morphogenesis was sufficient to confer a lasting protection against subsequent mammary tumorigenesis induced by methylnitrosourea. The present study was designed to characterize certain morphological and biochemical changes of the mammary gland that might potentially render it less susceptible to cancer induction. Female Sprague Dawley rats were fed a 1% CLA diet from weaning until about 50 days of age. The mammary gland parameters under investigation included (a) the deposition of neutral lipid, (b) the identification and quantification of CLA and its metabolites, (c) the density of the epithelium, and (d) the proliferative activity of various structural components. Our results showed that CLA treatment did not affect total fat deposition in the mammary tissue nor the extent of epithelial invasion into the surrounding fat pad but was able to cause a 20% reduction in the density of the ductal-lobular tree as determined by digitized image analysis of the whole mounts. This was accompanied by a suppression of bromodeoxyuridine labeling in the terminal end buds and lobuloalveolar buds. The recovery of desaturation and elongation products of CLA in the mammary gland confirmed our prior suggestion that the metabolism of CLA might be critical to risk modulation. The significance of the above findings was investigated in a mammary carcinogenesis bioassay with the use of the dimethylbenz[a]anthracene model. When CLA was started at weaning and continued for 6 months until the end of the experiment, this schedule of supplementation produced essentially the same magnitude of mammary tumor inhibition in the dimethylbenz[a]anthracene model as that produced by 1 month of CLA feeding from weaning. The observation is consistent with the hypothesis that exposure to CLA during the time of mammary gland maturation may modify the developmental potential of a subset of target cells that are normally susceptible to carcinogen-induced transformation.

Characterization of complexes of oligonucleotides with polyamidoamine starburst dendrimers and effects on intracellular delivery

This study evaluates polyamidoamine PAMAM "starburst" dendrimers (generation 3, Mr 6909) as a potential delivery vehicle for oligonucleotides. Complexes between dendrimer and phosphorothioate oligonucleotides were observed by agarose gel electrophoresis and were positive, negative, or neutral in charge depending on stoichiometry. Complexes were stable in 50% serum to variations in pH (3, 5, and 10) and ionic strength (0-500 mM). Ultrafiltration and gel filtration characterization indicated that the dendrimer:oligonucleotide complexes were primarily < 100 kD, although some larger complexes were formed at oligonucleotide excess. Use of dendrimers resulted in a 50-fold enhancement in cell uptake of oligonucleotide as determined by flow cytometry, and enhanced cytosolic and nuclear availability, as shown by confocal microscopy. These data support the further evaluation of dendrimers for oligonucleotide delivery in cell culture and in vivo.

Prevention of metastasis from mouse mammary carcinomas with liposomes carrying doxorubicin

Weekly treatments with doxorubicin encapsulated in long circulating, sterically stabilised liposomes (DOX-SL) reduced the incidence of metastases from primary mammary carcinoma from 24 of 47 untreated mice to 3 of 23 treated mice. Toxic side-effects were limited to minor, transient weight losses.

Prophylaxis and therapy of mouse mammary carcinomas with doxorubicin and vincristine encapsulated in sterically stabilised liposomes

This study tested the prophylactic efficacies of doxorubicin hydrochloride and vincristine sulphate, encapsulated in sterically stabilised long circulating liposomes, against the spontaneous development of mammary carcinomas in C3H/He mice. Monthly prophylactic intravenous (i.v.) injections of 6 mg/kg doses of liposome-encapsulated doxorubicin (DOX-SL) or 1 mg/kg doses of liposome-encapsulated vincristine (VIN-SL) were begun when retired breeding mice were 26 weeks old. Mice that developed a mammary carcinoma while on the monthly prophylactic protocols were then given weekly i.v. injections of 6 mg/kg DOX-SL or 1 mg/kg VIN-SL to test the therapeutic efficacies of the drugs, and to determine whether the tumours were susceptible or resistant to therapy. The monthly prophylactic injections reduced the incidence of first mammary carcinomas from 87/88 (99%) in untreated mice to 24/42 (57%) in DOX-SL-treated mice and to 26/32 (81%) in VIN-SL-treated mice. Of the mice that developed a mammary tumour while on the prophylactic protocols, 12 of 30 mice were cured by the weekly therapeutic use of DOX-SL, and the growth of 18 tumours was inhibited. The weekly therapeutic use of VIN-SL cured 3 of 8 mice, and inhibited the growth of five tumours. Weekly DOX-SL therapy cured 7 of 22 previously untreated mice. The mean survival of tumour-bearing mice was extended from 24 days in untreated mice to 87 days in DOX-SL-treated mice, which had not received prophylactic treatment. Metastases were found in 29 of 54 untreated mice, and in 3 of 72 mice treated with DOX-SL and VIN-SL. Toxic side effects were limited to a transient weight loss during the weekly treatments. Drug resistance as a result of treatments was not observed.

Chemoprevention and therapy of mouse mammary carcinomas with doxorubicin encapsulated in sterically stabilized liposomes

BACKGROUND

The objective of this study was to determine the ability of doxorubicin, encapsulated in sterically stabilized liposomes (Doxil [Liposome Technology, Inc., Menlo Park, CA]), to inhibit the spontaneous development of mammary carcinomas in mice.

METHODS

Monthly prophylactic intravenous injections of 6 mg/kg doses of Doxil were started when retired breeding C3H/He mice were 26 weeks old. Mice that developed a mammary carcinoma were then given weekly intravenous injections of 6 mg/kg doses to determine whether the tumors were susceptible or resistant to Doxil therapy.

RESULTS

The monthly injections reduced the incidence of first mammary carcinomas in up to 88-week-old retired breeding C3H/He mice from 65 of 66 (98%) in untreated mice to 22 of 47 (47%) in treated mice. The first 15 mice that developed a mammary tumor while on the prophylactic protocol were then placed on a weekly therapeutic protocol. The therapeutic use of Doxil cured 3 of 15 mice and inhibited the growth of 12 tumors. Drug resistance as a result of treatments was not observed. The mean survival of tumor-bearing mice was extended from 24 days in untreated mice to 87 days in treated mice. Toxic side effects were limited to transient weight loss during the weekly Doxil treatments and to epidermal necrosis and dermal fibrosis due to drug extravasation at the sites of intravenous injections.

CONCLUSIONS

The authors concluded that doxorubicin in sterically stabilized liposomes deserves to be explored further in comparative studies with free doxorubicin for the prophylaxis and therapy of mammary cancer.

Normal inhibition of mammary tumor metastasis in C3H/He mice

The blood of normal C3H mice contains molecular factors that can rapidly lyse mammary carcinoma cells that enter the circulation. The cytotoxic effect of blood on tumor cells during incubation was most clearly demonstrated if fibrin formation was prevented. The conversion of the mammary carcinoma cells to ascites growth increased both the resistance to lysis in plasma and the ability to form lung colonies after intravenous injection. Mice that were surgically cured of numerous 9 mm tumors and survived for an average 10 months had a lower incidence (36%) of spontaneous metastases than mice that experienced one 30 mm tumor and survived for an average 8 weeks (65%). This is interpreted to mean that mice that retained their vitality by early surgical cures, could suppress the development of metastases by the action of normal serum factors that can destroy neoplastic cells that enter the circulation.

Adenosinergic modulation of homocysteine-induced seizures in mice

Homocysteine thiolactone (HTL) elicits seizures in mice at a dose of 850 mg/kg (95-100% of animals) with an average latency time of 19.5 min. These seizures are reversed by both 5' N-ethylcarboximide adenosine (NECA) and flunitrazepam, with respective ED50 doses of 0.025 and 0.20 mg/kg. NECA was approximately four-fold more potent as an inhibitor of HTL-induced seizures than of seizures induced by pentylenetetrazol (PTZ, 75 mg/kg). Flunitrazepam was equipotent in both seizure paradigms. The purine precursor 5-amino-4-imidazole carboxamide riboside, (AICAr), although virtually ineffective against PTZ-induced seizures at doses greater than 1 g/kg, was able to inhibit HTL-induced seizures with an ED50 of approximately 350 mg/kg. The anticonvulsant effect of AICAr was dose and time dependent. The anticonvulsant potency of AICAr was increased by simultaneous administration of the adenosine uptake blocker Mioflazine, whereas the central nervous system (CNS)-impermeable adenosine uptake blocker dipyridamole had no effect. The ability of AICAr to permeate the blood-brain barrier (BBB) is limited (less than 1%) and may explain its low potency as an anticonvulsant. AICAr also has very low potency at brain adenosine A1 and A2 receptors as well as adenosine uptake sites (IC50 greater than 10(-3) M), suggesting that its anticonvulsant properties are not mediated by direct action at these sites. The results indicate that AICAr does have frank anticonvulsant effects and further suggest that HTL-induced seizures may represent a useful paradigm for evaluation of adenosinergic agents. AICAr or more potent derivatives thereof may represent a new class of anticonvulsants with the ability to target seizure foci selectively.