Intraocular foreign bodies in children: A retrospective case series

INTRODUCTION

Open globe injuries are a major cause of visual impairment in children, related to the severity of the trauma or secondary to induced amblyopia. Intraocular foreign bodies (IOFB) have been reported in approximately one third of cases of open globe injuries. As clinical presentation and management may differ between adults and children, data is lacking about IOFBs in children under 18years of age. The purpose of this study was to assess the clinical characteristics and visual prognosis of ocular trauma associated with intraocular foreign bodies in children.

MATERIALS AND METHODS

This single-center retrospective study included patients under 18years of age treated for ocular trauma with IOFB. Demographic characteristics, complete initial and final ophthalmological examination, imaging data and details of medical and surgical management were collected.

RESULTS

Fourteen patients were included (78.6% boys), with a mean age of 10.3years (min 7months-max 17years). In 92.9% of cases, patients were found to have a single IOFB, mostly metallic (71.4%). Posterior segment IOFBs were found in 50% of cases, anterior segment IOFBs in 28.6% and orbital IOFBs in 21.4%. The clinical examination permitted detection of the IOFBs in 50% of cases, while they were visible on CT scan in all cases. The mean initial visual acuity was 20/320, and the mean final visual acuity was 20/125. Endophthalmitis occurred in 2 cases (14%).

DISCUSSION

Open globe injuries associated with IOFB are severe and sight-threatening. Localization of the IOFB in the posterior segment has a worse prognosis. CT scan is mandatory, especially in children, as the trauma history is often missing. Retinal detachment and endophthalmitis appear to be the main prognostic factors requiring urgent specialized pediatric ophthalmology management.

Enrichment, Characterization, and Proteomic Profiling of Small Extracellular Vesicles Derived from Human Limbal Mesenchymal Stromal Cells and Melanocytes

Limbal epithelial progenitor cells (LEPC) rely on their niche environment for proper functionality and self-renewal. While extracellular vesicles (EV), specifically small EVs (sEV), have been proposed to support LEPC homeostasis, data on sEV derived from limbal niche cells like limbal mesenchymal stromal cells (LMSC) remain limited, and there are no studies on sEVs from limbal melanocytes (LM). In this study, we isolated sEV from conditioned media of LMSC and LM using a combination of tangential flow filtration and size exclusion chromatography and characterized them by nanoparticle tracking analysis, transmission electron microscopy, Western blot, multiplex bead arrays, and quantitative mass spectrometry. The internalization of sEV by LEPC was studied using flow cytometry and confocal microscopy. The isolated sEVs exhibited typical EV characteristics, including cell-specific markers such as CD90 for LMSC-sEV and Melan-A for LM-sEV. Bioinformatics analysis of the proteomic data suggested a significant role of sEVs in extracellular matrix deposition, with LMSC-derived sEV containing proteins involved in collagen remodeling and cell matrix adhesion, whereas LM-sEV proteins were implicated in other cellular bioprocesses such as cellular pigmentation and development. Moreover, fluorescently labeled LMSC-sEV and LM-sEV were taken up by LEPC and localized to their perinuclear compartment. These findings provide valuable insights into the complex role of sEV from niche cells in regulating the human limbal stem cell niche.

HIF1α and HIF2α immunoreactivity in epithelial tissue of primary and recurrent pterygium by immunohistochemical analysis

PURPOSE

Hypoxia-inducible factors (HIFs) are considered to play a significant role in the pathogenesis of pterygium. The aim of this study was to investigate the relative expression or immunoreactivity of HIF1α and HIF2α in the epithelium of primary pterygium, recurrences and healthy conjunctiva.

METHODS

Immunohistochemical staining was performed with antibodies against HIF1α and HIF2α, respectively, on 55/84 primary pterygium specimens, 6/28 recurrences and 20/20 control tissues (healthy conjunctiva).

RESULTS

Immunohistochemical staining revealed lower epithelial immunoreactivity of HIF1α and HIF2α in both primary pterygium (11% and 38%) and recurrences (18% and 21%) when compared to healthy conjunctival tissue (46% and 66%). Differences between immunoreactivity of HIF1α and of HIF2α in primary pterygium and controls were each highly significant (p < .001). Within the group of primary pterygium, epithelial immunoreactivity of HIF2α (38%) was significantly higher than that of HIF1α (11%). In recurrent pterygium and healthy conjunctiva, immunoreactivity levels of HIF2α were higher than those of HIF1α as well; however, differences between both isoforms were not significant.

CONCLUSION

Our study shows evidence that the higher expressed epithelial HIF2α, rather than HIF1α, and the balance between both HIF isoforms might be relevant factors associated with pathogenesis of primary pterygium. Modulation of HIF2α levels and activity may thus offer a new therapeutic approach to the treatment of advancing pterygium where the initial stage with its HIF1-peak has already passed.

Influence of Organ Culture on the Characteristics of the Human Limbal Stem Cell Niche

Organ culture storage techniques for corneoscleral limbal (CSL) tissue have improved the quality of corneas for transplantation and allow for longer storage times. Cultured limbal tissue has been used for stem cell transplantation to treat limbal stem cell deficiency (LSCD) as well as for research purposes to assess homeostasis mechanisms in the limbal stem cell niche. However, the effects of organ culture storage conditions on the quality of limbal niche components are less well described. Therefore, in this study, the morphological and immunohistochemical characteristics of organ-cultured limbal tissue are investigated and compared to fresh limbal tissues by means of light and electron microscopy. Organ-cultured limbal tissues showed signs of deterioration, such as edema, less pronounced basement membranes, and loss of the most superficial layers of the epithelium. In comparison to the fresh limbal epithelium, organ-cultured limbal epithelium showed signs of ongoing proliferative activity (more Ki-67+ cells) and exhibited an altered limbal epithelial phenotype with a loss of N-cadherin and desmoglein expression as well as a lack of precise staining patterns for cytokeratin ((CK)14, CK17/19, CK15). The analyzed extracellular matrix composition was mainly intact (collagen IV, fibronectin, laminin chains) except for Tenascin-C, whose expression was increased in organ-cultured limbal tissue. Nonetheless, the expression patterns of cell-matrix adhesion proteins varied in organ-cultured limbal tissue compared to fresh limbal tissue. A decrease in the number of melanocytes (Melan-A+ cells) and Langerhans cells (HLA-DR+, CD1a+, CD18+) was observed in the organ-cultured limbal tissue. The organ culture-induced alterations of the limbal epithelial stem cell niche might hamper its use in the treatment of LSCD as well as in research studies. In contrast, reduced numbers of donor-derived Langerhans cells seem associated with better clinical outcomes. However, there is a need to consider the preferential use of fresh CSL for limbal transplants and to look at ways of improving the limbal stem cell properties of stored CSL tissue.

Development of a 3D ultrafast laser written near-infrared spectro-interferometer

Direct ultrafast laser photoinscription of transparent materials is a powerful technique for the development of embedded 3D photonics. This is particularly adaptable for astrophotonic devices when a number of inputs are required. The process relies essentially on volume fabrication of waveguiding structures in flexible 3D designs and refractive index contrast parameters adjustable for specific spectral ranges. This enables 3D geometry and thus avoids in-plane crossings of waveguides that can induce losses and cross talk in multi-telescope beam combiners. The additional novel capability of the technique allows for the fabrication of high aspect ratio nanostructures nonperturbatively sampling the optical field. Combining ultrafast laser micro- and nanoprocessing with engineered beams, we present here results for the development of chip-sized silica glass integrated robust 3D three-telescope beam combiners in the near-IR range, as well as embedded diffraction gratings, for phase closure analysis and spectro-interferometry applications in astronomy.

Characterization of Porcine Ocular Surface Epithelial Microenvironment

The porcine ocular surface is used as a model of the human ocular surface; however, a detailed characterization of the porcine ocular surface has not been documented. This is due, in part, to the scarcity of antibodies produced specifically against the porcine ocular surface cell types or structures. We performed a histological and immunohistochemical investigation on frozen and formalin-fixed, paraffin-embedded ocular surface tissue from domestic pigs using a panel of 41 different antibodies related to epithelial progenitor/differentiation phenotypes, extracellular matrix and associated molecules, and various niche cell types. Our observations suggested that the Bowman's layer is not evident in the cornea; the deep invaginations of the limbal epithelium in the limbal zone are analogous to the limbal interpalisade crypts of human limbal tissue; and the presence of goblet cells in the bulbar conjunctiva. Immunohistochemistry analysis revealed that the epithelial progenitor markers cytokeratin (CK)15, CK14, p63α, and P-cadherin were expressed in both the limbal and conjunctival basal epithelium, whereas the basal cells of the limbal and conjunctival epithelium did not stain for CK3, CK12, E-cadherin, and CK13. Antibodies detecting marker proteins related to the extracellular matrix (collagen IV, Tenascin-C), cell-matrix adhesion (β-dystroglycan, integrin α3 and α6), mesenchymal cells (vimentin, CD90, CD44), neurons (neurofilament), immune cells (HLA-ABC; HLA-DR, CD1, CD4, CD14), vasculature (von Willebrand factor), and melanocytes (SRY-homeobox-10, human melanoma black-45, Tyrosinase) on the normal human ocular surface demonstrated similar immunoreactivity on the normal porcine ocular surface. Only a few antibodies (directed against N-cadherin, fibronectin, agrin, laminin α3 and α5, melan-A) appeared unreactive on porcine tissues. Our findings characterize the main immunohistochemical properties of the porcine ocular surface and provide a morphological and immunohistochemical basis useful to research using porcine models. Furthermore, the analyzed porcine ocular structures are similar to those of humans, confirming the potential usefulness of pig eyes to study ocular surface physiology and pathophysiology.

Undertaking risk and relational work to manage vulnerability: Acute medical patients' involvement in patient safety in the NHS

Over the last decade a wealth of studies have explored the way that patients are involved in patient safety internationally. Most begin from the premise that patients can and should take on the role of identifying and reporting safety concerns. Most give little attention, however, to the impact of the patient's health status and vulnerability on their ability to participate in their safety. Drawing on qualitative interviews with 28 acute medical patients, this article aims to show how patients' contributions to their safety in the acute medical context are less about involvement as a deliberate intervention, and more about how patients manage their own vulnerability in their interactions with staff. Our analysis is underpinned by theories of vulnerability and risk. This enables us to provide a deeper understanding of how vulnerability shapes patients' involvement in their safety. Acute medical patients engage in reassurance-seeking, relational and vigilance work to manage their vulnerability. Patients undertake reassurance seeking to obtain evidence that they can trust the organisation and the professionals who work in it and relational and vigilance work to manage the vulnerability associated with dependence on others and the unpredictability of their status as acute medical patients. Patients are made responsible for speaking up about their care but simultaneously, by virtue of the expectations of the sick role and their relational vulnerability, encouraged to remain passive, compliant or silent. We show how risk frames the extent to which patients can activate their role in creating patient safety at the point of care. Foregrounding the theory of vulnerability, the concept of the sick role and the relationship of both to risk offers new insights into the potentials and limits of patient involvement in patient safety in the acute care context.

High-sensitivity troponin is a biomarker of medium term mortality in 20,000 consecutive hospital patients undergoing a blood test for any reason

Introduction

High sensitivity troponin (hs-cTn) concentrations above the manufacturer recommended upper limit of normal (ULN) are frequently seen in patients without a clinical presentation consistent with type 1 myocardial infarction. There is increasing evidence that these concentrations may act as a marker of prognosis in a range of conditions. However, previous studies have been limited because they have only included patients in whom the clinician has requested the test. The aim of this study was to assess the relationship between medium term mortality and hs-cTn concentration in a large consecutive hospital population undergoing a blood test, regardless of whether there was a clinical indication for performing the hs-cTn.

Method

This single centre study included 20,000 consecutive patients undergoing a blood test for any reason, in whom hs-cTnI was added, regardless of the clinical indication (CHARIOT population). Mortality data up to 2.25 years was obtained via NHS Digital. The association between hs-cTnI concentration and one year mortality was evaluated using Kaplan-Meier plots (with log-rank test) and Cox proportional hazards analyses. After the cohort was considered as a whole, each of the clinical areas (inpatient (IPD), outpatient (OPD), emergency department (ED)) were considered separately. Furthermore, in the IPD and ED populations, a landmark analysis was performed excluding those patients who died within 30 days to assess whether any longer term relationship was driven by short term mortality.

Results

Overall, 2825 (14.1%) patients had died at 2.25 years. The mortality at 2.25 years was significantly higher if the hs-cTnI concentration was above the ULN (45.3% versus 12.3%, p&lt;0.001 (log rank) in the entire cohort (Figure 1). Multivariable Cox regression analysis demonstrated that the log10hs-cTnI concentration was independently associated with 2.25 year mortality (hazard ratio (HR) 1.69 (95% confidence interval (CI): 1.59–1.80)). This relationship was demonstrated for patients in each of the clinical areas (IPD HR 1.46 (95% CI: 1.33–1.60), OPD HR 2.19 (95% CI: 1.84–2.60), ED HR 1.87 (95% CI: 1.68–2.07)). Further analysis by excluding those patients that died within 30 days demonstrated that the relationship between hs-cTnI concentration and mortality persisted and it was not driven by short term mortality.

Conclusion

In a large, unselected hospital population of both in- and out-patients, the majority of whom there was no clinical indication for testing, hs-cTnI concentration was independently associated with medium term mortality. These data suggest that hs-cTnI may have a role as a biomarker of future risk.

Funding Acknowledgement

Type of funding sources: Private company. Main funding source(s): Beckman Coulter

Waveguide scattering antennas made by direct laser writing in bulk glass for spectrometry applications in the short-wave IR

A buried straight waveguide perturbed periodically by six antennas composed of submicronic cylinder voids is entirely fabricated using ultrafast laser photoinscription. The light scattered from each antenna is oriented vertically and is detected by a short-wave IR camera bonded to the surface of the glass with no relay optics. The response of each antenna is analyzed using a wavelength tunable laser source and compared to simulated responses verifying the behavior of the antenna. These results show the good potential of the direct laser writing technique to realize monolithic embedded detectors by combining complex optical functions within a 3D design. A wavelength meter application with a spectral resolution of 150 pm is proposed to demonstrate this combination.

Dramatic response to regorafenib in early glioblastoma progression: case report and review of the literature

BACKGROUND

Glioblastoma (GBM) is a highly lethal disease despite integrated treatment comprising radiotherapy plus concomitant and adjuvant temozolomide, with a median overall survival of less than 15 months. For recurrent glioblastoma, there is yet no standard therapy, considering that Bevacizumab have failed to improve overall survival (OS) while regorafenib had a little benefit over standard chemotherapy. In addition, the disease control rate is almost exclusively stability, with a poor objective response rate.

CASE REPORT

Here we present a case of rapid response to regorafenib in early glioblastoma progression at the end of adjuvant radiotherapy: after a single cycle of regorafenib the patient observed an impressive improvement in clinical condition, disappearance of headaches and a clear reduction of neoplastic tissue in MRI. A brief review about new radiological patterns in Magnetic Resonance Imaging (MRI) related to the introduction in clinical practice of antiangiogenic drugs and tyrosine kinase inhibitors has also been carried out.

CONCLUSIONS

Regorafenib was certainly a first turning point in the second-line treatment of GBM, showing longer response rates and mostly disease stability than bevacizumab. A switch-maintenance strategy with tyrosine kinase inhibitors may represent a valid second-line therapeutic option.

Methylglyoxal and high glucose inhibit VEGFR2 phosphorylation at specific tyrosine residues

Diabetes is characterized by hyperglycemia and a significant risk of vascular complications. Vascular endothelial growth factor (VEGF) and its main receptor VEGFR2 (KDR), which is highly expressed in vascular endothelial cells, are essential mediators of vascular maintenance and angiogenesis. During glycolysis after high calorie food intake, methylglyoxal (MGO) is formed and MGO blood levels are elevated in diabetes. MGO reacts with arginine residues to generate MG-H1 or with lysine residues to carboxyethyl lysine which are common components of advanced glycation end-products. Therefore, the question arises whether hyperglycemic conditions affect VEGF signaling via a ligand-independent direct modification of signaling components. As a first step, the effect of MGO on VEGFR2 activation was investigated in cultured endothelial cells from human umbilical vein by determination of VEGFR2 phosphorylation at selected tyrosine residues by ELISA and immunoblotting using phospho-specific antibodies. Phosphorylation of VEGFR2-Y996, VEGFR2-Y1054, or VEGFR2-Y1175 reached a maximum 5 min after stimulation of endothelial cells with VEGF. Phosphorylation was significantly inhibited by 100 µM MGO and to a lesser extent by high glucose treatment. 2,3-Pentanedione and glyoxal were investigated for comparison. In summary, VEGFR2 phosphorylation is sensitive to MGO or high glucose concentrations which may be relevant in the pathophysiology of microvascular disease in diabetes.

AB1435 CLINICAL PREDICTION MODELS FOR METHOTREXATE OUTCOMES IN PATIENTS WITH RHEUMATOID ARTHRITIS: SYSTEMATIC REVIEW AND CRITICAL APPRAISAL

Background

Methotrexate (MTX) is the preferred first line therapy for rheumatoid arthritis (RA). MTX has several advantages over other treatments including effectiveness and low cost; however, around 40% of patients are classed as non-responders after 6 months (1). Therefore, there is a clinical need to identify patients at high-risk of poor outcomes, such that patients could potentially be fast tracked onto alternative therapies to improve their clinical outcomes and quality of life. Such risk stratification is possible through prognostic prediction models, although models which have previously been developed appear to have had little impact on practice. This may be in part due to methodological features of their development and validation but, to date, no review has collated the evidence in this field.

Objectives

This systematic review aimed to (i) identify and summarise multivariable prediction models of MTX treatment outcomes in biologic-naïve adult RA patients, and (ii) critically appraise their methodological properties.

Methods

The electronic databases Medline and Embase were searched to identify studies developing or validating prediction models of MTX outcomes in the population of interest, including demographic, disease-specific or treatment-related covariates, published after 2005. Models were stratified by outcome definition, and information on participants, predictors, model performance, handling of missing data and model validation were extracted. A risk of bias (ROB) assessment using PROBAST (prediction model risk of bias assessment tool) was carried out. Two reviewers were independently involved in screening, data extraction, and ROB stages.

Results

The included studies used three main outcome definitions: a state of disease activity, such as low disease activity or remission; the EULAR response criteria; or discontinuation due to adverse events (AEs). Some studies incorporated AEs into a composite outcome with disease activity and few accounted for potential competing risks, which are events that preclude the occurrence of the primary outcome of interest. Not handling competing risks may result in under-prediction, leading to potentially compromised risk stratification. There was a lack of internal validation using cross sampling techniques, which is critical for reducing overfitting, as well as external validation in new data, a process necessary to ensure reproducibility and generalisability of a prediction model to the larger patient population. Missing data was mostly handled using complete case analysis, leading to potentially biased risk estimates. The ROB assessment showed overall high ROB of the included studies.

Conclusion

This systematic review summarises current prediction models of MTX treatment outcomes in RA. It highlights several methodological shortcomings, such as poor handling of missing data and competing risks to the primary outcome, and a lack of internal and external validation. These should be addressed in future model development and validation to improve accuracy of predictions. Without tackling these issues, prediction of MTX treatment outcomes will remain at high risk of bias and should not be recommended for informing risk stratification for RA treatment decisions.

References

[1]Sergeant JC, Hyrich KL, Anderson J, Kopec-Harding K, Hope HF, Symmons DPM, et al. Prediction of primary non-response to methotrexate therapy using demographic, clinical and psychosocial variables: Results from the UK Rheumatoid Arthritis Medication Study (RAMS). Arthritis Res Ther. 2018;20(1):1–11.

Disclosure of Interests

Celina Gehringer: None declared, Glen Martin: None declared, Kimme Hyrich Speakers bureau: Abbvie, Grant/research support from: BMS and Pfizer, Suzanne Verstappen: None declared, Jamie Sergeant: None declared

Single-Cell Protein and Transcriptional Characterization of Epiretinal Membranes From Patients With Proliferative Vitreoretinopathy

Purpose

Proliferative vitreoretinopathy (PVR) remains an unresolved clinical challenge and can lead to frequent revision surgery and blindness vision loss. The aim of this study was to characterize the microenvironment of epiretinal PVR tissue, in order to shed more light on the complex pathophysiology and to unravel new treatment options.

Methods

A total of 44 tissue samples were analyzed in this study, including 19 epiretinal PVRs, 13 epiretinal membranes (ERMs) from patients with macular pucker, as well as 12 internal limiting membranes (ILMs). The cellular and molecular microenvironment was assessed by cell type deconvolution analysis (xCell), RNA sequencing data and single-cell imaging mass cytometry. Candidate drugs for PVR treatment were identified in silico via a transcriptome-based drug-repurposing approach.

Results

RNA sequencing of tissue samples demonstrated distinct transcriptional profiles of PVR, ERM, and ILM samples. Differential gene expression analysis revealed 3194 upregulated genes in PVR compared with ILM, including FN1 and SPARC, which contribute to biological processes, such as extracellular matrix (ECM) organization. The xCell and IMC analyses showed that PVR membranes were composed of macrophages, retinal pigment epithelium, and α-SMA-positive myofibroblasts, the latter predominantly characterized by the co-expression of immune cell signature markers. Finally, 13 drugs were identified as potential therapeutics for PVR, including aminocaproic acid and various topoisomerase-2A inhibitors.

Conclusions

Epiretinal PVR membranes exhibit a unique and complex transcriptional and cellular profile dominated by immune cells and myofibroblasts, as well as a variety of ECM components. Our findings provide new insights into the pathophysiology of PVR and suggest potential targeted therapeutic options.

1152 “A Hypoxic Dilemma”- Compliance with Oxygen Prescriptions on The Acute Surgical Take

Aim

British Thoracic Society Guidelines state that all patients admitted to hospital should have oxygen targets prescribed to promptly start oxygen therapy should clinical deterioration occur. We aimed to assess oxygen prescribing compliance for new surgical patients.

Method

We assessed prescription of oxygen in patients admitted on the surgical take, once weekly for 8 weeks looking at target values, route of administration, frequency and appropriate signing and dating. A re-audit was performed after presenting the initial results at a department meeting.

Results

61 patients were included. Out of 61, 8 patients had COPD. Only 9 patients had adequate oxygen prescriptions with all the criteria completed. After re-audit, 50 surgical take patients’ drug charts were reviewed. 42 out of 50 patients had correctly completed oxygen prescriptions.

Conclusions

Correct oxygen administration in high-risk patients is vital in their management, particularly during clinical deterioration. A discernible improvement in prescriptions was noted in this study.

Viral S protein histochemistry reveals few potential SARS-CoV-2 entry sites in human ocular tissues

Despite the reported low expression of the primary SARS-CoV-2 receptor ACE2 in distinct ocular tissues, some clinical evidence suggests that SARS-CoV-2 can infect the eye. In this study, we explored potential entry sites for SARS-CoV-2 by viral S protein histochemistry on various ocular tissues and compared the staining patterns with RNA and protein expression of TMPRSS2 and ACE2. Potential viral entry sites were investigated by histochemistry using tagged recombinant viral S protein on 52 ocular tissue samples including specimens of the cornea, conjunctiva, lid margin, lacrimal gland tissue, retina, choroid, and RPE. In addition, ACE2 and TMPRSS2 immunohistochemistry were performed on the same ocular tissue, each with distinct antibodies binding to different epitopes. Lung tissue samples were used as positive controls. Finally, bulk RNA sequencing (RNA-Seq) was used to determine the expression of ACE2 and its auxiliary factors in the tissues mentioned above. S protein histochemistry revealed a positive staining in lung tissue but absent staining in the cornea, the conjunctiva, eye lid samples, the lacrimal glands, the retina and the optic nerve which was supported by hardly any immunoreactivity for ACE2 and TMPRSS2 and scarce ACE2 and TMPRSS2 RNA expression. Negligible staining with antibodies targeting ACE2 or TMPRSS2 was seen in the main and accessory lacrimal glands. In contrast, ocular staining (S protein, ACE2, TMPRSS2) was distinctly present in pigmented cells of the RPE and choroid, as well as in the ciliary body and the iris stroma. S protein histochemistry revealed hardly any SARS-CoV-2 entry sites in all ocular tissues examined. Similarly, no significant ACE2 or TMPRSS2 expression was found in extra- and intraocular tissue. While this study suggest a rather low risk of ocular infection with SARS-CoV-2, it should be noted, that potential viral entry sites may increase in response to inflammation or in certain disease states.

Developing Healthcare Team Observations for Patient Safety (HTOPS): senior medical students capture everyday clinical moments

BACKGROUND

Aviation has used a real-time observation method to advance anonymised feedback to the front-line and improve safe practice. Using an experiential learning method, this pilot study aimed to develop an observation-based real-time learning tool for final-year medical students with potential wider use in clinical practice.

METHODS

Using participatory action research, we collected data on medical students' observations of real-time clinical practice. The observation data was analysed thematically and shared with a steering group of experts to agree a framework for recording observations. A sample of students (observers) and front-line clinical staff (observed) completed one-to-one interviews on their experiences. The interviews were analysed using thematic analysis.

RESULTS

Thirty-seven medical students identified 917 issues in wards, theatres and clinics in an acute hospital trust. These issues were grouped into the themes of human influences, work environment and systems. Aviation approaches were adapted to develop an app capable of recording real-time positive and negative clinical incidents. Five students and eleven clinical staff were interviewed and shared their views on the value of a process that helped them learn and has the potential to advance the quality of practice. Concerns were shared about how the observational process is managed.

CONCLUSION

The study developed an app (Healthcare Team Observations for Patient Safety-HTOPS), for recording good and poor clinical individual and team behaviour in acute-care practice. The process advanced medical student learning about patient safety. The tool can identify the totality of patient safety practice and illuminate strength and weakness. HTOPS offers the opportunity for collective ownership of safety concerns without blame and has been positively received by all stakeholders. The next steps will further refine the app for use in all clinical areas for capturing light noise.

What is the significance of the conjunctiva as a potential transmission route for SARS-CoV-2 infections?

Recent studies have described conjunctivitis in approximately 1% of COVID-19 patients and speculated that SARS-CoV‑2 can be transmitted via the conjunctiva. In this article we recapitulate the molecular mechanisms of host cell entry of SARS-CoV‑2 and discuss the current evidence for a potential conjunctival transmission of SARS-CoV‑2. The current body of evidence indicates that SARS-CoV‑2 requires the membrane-bound angiotensin-converting enzyme 2 (ACE2) and the membrane-bound serine protease TMPRSS2 to enter cells. Recent studies suggest that COVID-19 patients rarely exhibit viral RNA in tear film and conjunctival smears and that, ACE2 and TMPRSS2 are only expressed in small amounts in the conjunctiva, making conjunctival infection with SARS-CoV‑2 via these mediators unlikely. Nevertheless, we consider the current evidence to be still too limited to provide a conclusive statement and recommend appropriate protective measures for healthcare personnel who are in close contact with suspected and confirmed COVID-19 patients.

Secondary bleeding following proctological surgery: Rare but potentially severe

PURPOSE

Haemorrhage following proctological surgery is one of the complications with the greatest potential for severity. The aim of this work was to assess the frequency and risk factors of haemorrhage requiring hospitalization during 30-days postoperatively.

METHODS

A retrospective cohort review of all surgeries performed in a Parisian department of medico-surgical proctology between January 2016 and June 2018 was performed. Demographic and surgical data were collected for patients who were hospitalized for postoperative haemorrhage. Their analysis was conducted as a single analysis followed by multivariate analysis.

RESULTS

A total of 7533 surgeries were performed on 6727 patients. The mean patient age was 42.6 (±14.3) years and 67.2% were males. Postoperative haemorrhage occurred in 111 patients (1.5%) with a total of 123 haemorrhagic episodes (12 relapses) within a mean of 6 (±5.5) days. In therapeutic terms, 28.5% of haemorrhages required transfusion, 37.4% required haemostasis in the operating theatre and 14.6% required haemostasis under local anaesthesia. Using multivariate analysis, haemorrhage was more frequent after haemorrhoid surgery and in the case of anticoagulant treatment, particularly direct oral anticoagulants, and if the ASA score was equal to 3. Active smoking was associated with a decreased risk of haemorrhage.

CONCLUSION

Haemorrhage requiring hospitalization occurred in 1.5% of cases following proctological surgery, 52.8% were severe and recurred in 10.8% of cases. The study also specified certain risk factors for haemorrhage and demonstrated the protective effect of active smoking.

Arteriovenous crossing in retinal vessels of mice, rats, and pigs

Purpose

Retinal vein occlusions (RVOs) are a common disease, but there are no animal models for spontaneous RVO formation. The critical sites of predilection, especially for branch RVO (BRVO), are the arteriovenous crossing sites in the inner retina. To gain more insight into possible animal models, the anatomic structure of retinal arteriovenous crossings was investigated in mice, rats, and pigs and compared to the human situation.

Methods

Retinal flat mounts and paraffin sections of eyes from mice, rats, pigs, and humans were stained with GS lectin, Masson's trichrome, or immunohistochemistry for ACTA2 and GFAP. Serial sections of arteriovenous crossing sites were investigated.

Results

Mice usually do not show retinal arteriovenous crossings. Rats have a mean of 2.8±1.4 crossings per eye at a mean distance from the optic nerve head of 2.79±0.53 mm, though the diameters of the crossing vessels are small. The situation in pigs is similar to that in humans, with many arteriovenous crossings of vessels and with similar diameters as found in humans. A mean of 28.4±3.5 crossings per retina was found, and 23% of these were arterial overcrossings. Serial paraffin sections showed that the tunica media of the artery touched that of the vein, but they did not fuse.

Conclusions

While the retinal arteriovenous crossings of mice and rats are absent or comprised of rather thin vessels, those in the porcine retina are similar to adult humans. Therefore, the porcine retinal vascular bed may serve as a model to assess early steps in the formation of RVOs.

Robustesse du guidage surfacique en comparaison avec le spiromètre dans la mise en place du blocage respiratoire pour le traitement du cancer du sein

Introduction et but de l’étude

Le blocage respiratoire est désormais un standard de traitement pour les cancers du sein gauche dont la mise en œuvre implique typiquement l’utilisation d’un spiromètre. L’étude a consisté à valider la robustesse du guidage surfacique (SGRT) par le système AlignRT® (Vision RT Ltd., Royaume-Uni) comme une alternative au spiromètre Dyn’R® (Dyn’R Medical Systems, France).

Matériel et méthodes

Une étude sur bénévole a d’abord été conduite pour mesurer la concordance entre le volume inhalé et les déformations surfaciques quand le guidage visuel est réalisé par spirométrie ou guidage surfacique. Ensuite, plusieurs apnées guidées par Dyn’R® ont été réalisée avec la simulation d’une respiration abdominale pour valider, à volume inhalé constant, la sensibilité d’AlignRT® aux modifications de la respiration thoracique/abdominale. En outre, les systèmes Dyn’R® et AlignRT® ont été conjointement utilisés pour sept patientes prises en charge entre octobre 2019 et février 2020. La reproductibilité du volume inhalé et du positionnement surfacique a été étudiée lors de l’imagerie (par rayons X internes et externes) et des faisceaux d’irradiation. Enfin, une alternance entre le positionnement sur les points de tatouage aux séances impaires et le guidage surfacique pour les séances paires a été réalisée et les décalages après l’imagerie ont été comparés.

Résultats et analyse statistique

Pour cinq apnées consécutive guidées par Dyn’R®, le volume d’air moyen inhalé par le volontaire était de 2,31 ± 0,1 l. Pour ces mêmes apnées, la surface du patient a reproduit la position attendue avec un écart moyen de 1,5 ± 1,4 mm et −0,1° ± 0,2° sur les translations et les rotations. De même, pour les cinq apnées guidées par AlignRT®, le volume moyen inhalé était de 2,3 ± 0,05 l et l’écart moyen sur les translations et les rotations était de −0,1 ± 0,9 mm et 0,02° ± 0,2° validant la reproductibilité du blocage avec guidage surfacique. Enfin, pour les cinq apnées guidées par Dyn’R® avec une respiration abdominale, le volume moyen d’air inhalé était de 2,31 ± 0,1 l mais la déformation de la surface a mis en évidence une mauvaise reproductibilité du blocage respiratoire (écart moyen de −3,2 ± 6,4 mm et −0,8° ± 0,4°). Par ailleurs, les sept patientes prises en charge avec le guidage par Dyn’R® ont réalisé en moyenne de 5 ± 1 apnées par séance (dont deux apnées d’imagerie) avec une durée moyenne d’apnée de 17 ± 12 s et un volume médian inspiré de 2 l (extrêmes : 1,7–2,4 l). Bien que le volume inhalé soit sensiblement identique, les déformations surfaciques ont montré une grande disparité (jusqu’à 1 cm) entre les apnées sous rayons X et les apnées de traitement chez trois patientes de l’étude. Par opposition, les quatre autres patientes étaient bien plus stables avec un écart au niveau de la surface toujours de moins de 5 mm et 3°. Il a également été observé chez certaines patientes une tendance à réaliser quelques rotations et à se cambrer lors de la prise d’apnée. Enfin, le centrage du patient sur les points de tatouage entraîne de plus grands décalages après l’imagerie (magnitude de 4,9 ± 6,1 mm) par rapport aux séances où l’installation est guidée par AlignRT® (2,9 ± 4,5 mm).

Conclusion

Le guidage surfacique est une alternative robuste et fiable au spiromètre pour la mise en place du blocage respiratoire qui devient une nécessité dans le contexte de l’épidémie de coronavirus disease 2019 (COVID-19).

Expression of the COVID-19 receptor ACE2 in the human conjunctiva

SARS‐CoV‐2 is assumed to use angiotensin‐converting enzyme 2 (ACE2) and other auxiliary proteins for cell entry. Recent studies have described conjunctival congestion in 0.8% of patients with laboratory‐confirmed severe acute respiratory syndrome coronavirus‐2 (SARS‐CoV‐2), and there has been speculation that SARS‐CoV‐2 can be transmitted through the conjunctiva. However, it is currently unclear whether conjunctival epithelial cells express ACE2 and its cofactors. In this study, a total of 38 conjunctival samples from 38 patients, including 12 healthy conjunctivas, 12 melanomas, seven squamous cell carcinomas, and seven papilloma samples, were analyzed using high‐throughput RNA sequencing to assess messenger RNA (mRNA) expression of the SARS‐CoV‐2 receptor ACE2 and its cofactors including TMPRSS2, ANPEP, DPP4, and ENPEP. ACE2 protein expression was assessed in eight healthy conjunctival samples using immunohistochemistry. Our results show that the SARS‐CoV‐2 receptor ACE2 is not substantially expressed in conjunctival samples on the mRNA (median: 0.0 transcripts per million [TPM], min: 0.0 TPM, max: 1.7 TPM) and protein levels. Similar results were obtained for the transcription of other auxiliary molecules. In conclusion, this study finds no evidence for a significant expression of ACE2 and its auxiliary mediators for cell entry in conjunctival samples, making conjunctival infection with SARS‐CoV‐2 via these mediators unlikely.

Natural History of Perianal Fistulising Lesions in Patients With Elderly-onset Crohn's Disease: A Population-based Study

INTRODUCTION

Most studies of elderly-onset Crohn's disease [CD; diagnosed in patients aged 60 or over] have described a mild course. However, data on the natural history of perianal fistulising CD [pfCD] in this population are scarce. In a population-based cohort study, we described the prevalence, natural history, and treatment of pfCD in patients with elderly-onset CD vs patients with paediatric-onset CD.

METHOD

All patients diagnosed with CD at or after the age of 60 between 1988 and 2006, were included [n = 372]. Logistic regression, Cox models, and a nested case-control method were used to identify factors associated with pfCD.

RESULTS

A total of 34 elderly patients [9% of the 372] had pfCD at diagnosis. After a median follow-up of 6 years (interquartile range [IQR]: 3; 10), 59 patients [16%] had pfCD; the same prevalence [16%] was observed in paediatric-onset patients. At last follow-up, anal incontinence was more frequent in elderly patients with pfCD than in elderly patients without pfCD [22% vs 4%, respectively; p < 10-4]. Rectal CD at diagnosis was associated with pfCD: hazard ratio (95% confidence interval [CI] = 2.8 [1.6-5.0]). Although 37% of the patients received immunosuppressants and 17% received anti-tumour necrosis factor agents, 24% [14 out of 59] had a definitive stoma at last follow-up.

CONCLUSION

During the first 6 years of disease, the prevalence of pfCD was similar in elderly and paediatric patients. Rectal involvement was associated with the appearance of pfCD in elderly-onset patients. Around a quarter of patients with elderly-onset CD will have a stoma. Our results suggest that treatment with biologics should be evaluated in these patients.

Aortocaval fistula, a potentially favourable complication of abdominal aortic aneurysm rupture in endovascular repair

Endovascular aneurysm repair is an established treatment for ruptured abdominal aortic aneurysm. Primary aortocaval fistula is an exceedingly rare finding in ruptured abdominal aortic aneurysm, with a reported incidence of less than 1%. The presence of an aortocaval fistula used to be an unexpected finding in open surgical repair which often resulted in massive haemorrhage and caval injury. We present a case of ruptured abdominal aortic aneurysm with an aortocaval fistula that was successfully treated with percutaneous endovascular aneurysm repair under local anaesthesia. Despite a persistent type 2 endoleak the aneurysm sack shrank from 8.4cm to 4.8cm in 12 months. The presence of an aortocaval fistula may have depressurised the aneurysm, resulting in less bleeding retroperitoneally and may have promoted rapid shrinkage of the sac despite the presence of a persistent type 2 endoleak.

Investigating the role of hallucinatory experiences in the transition from suicidal thoughts to attempts

OBJECTIVE

Psychotic experiences, including auditory hallucinatory experiences (HEs), are strongly associated with both suicidal thoughts and behaviour. This study examined their role in the ideation-to-attempt transition in adolescents, including their direct and indirect effect via potential mediators.

METHOD

Participants were from an Australian prospective longitudinal cohort of 1669 adolescents (12-17 years); of which a subsample endorsing baseline suicidal ideation (n = 216) was the focus of most analyses. Suicidal thoughts and behaviours were measured using the Self-Harm Behaviour Questionnaire. The Diagnostic Interview Schedule for Children was used to assess auditory HEs. Potential mediators of interest were psychological distress and Interpersonal Theory of Suicide (IPTS) constructs.

RESULTS

Among adolescents reporting suicidal ideation at baseline (n = 216), 6.5% had attempted suicide during follow-up. The size of auditory HEs' univariate effect suggests a possible strong relationship with increased risk of incident suicide attempts (OR = 2.40; 95%CI = 0.76-7.56); however, there was inadequate statistical power to produce a precise estimate. When HEs were accompanied by distress there was a nine-fold increased risk of acting on suicidal thoughts. Distress was independently associated with risk of attempt transition (OR = 4.09), whereas IPTS constructs were poor explanatory variables in most models.

CONCLUSION

Adolescents with psychological distress and auditory HEs are at high risk of incident suicide attempts. Further investigations on the role of negative/distressing content of hallucinations in the ideation-to-attempt transition are warranted.

Determination of Patulin in Apple Juice by Liquid Chromatography: Collaborative Study

An AOAC International-International Union of Pure and Applied Chemistry-International Fruit Juice Union (AOAC-IUPAC-IFJU) collaborative study was conducted to evaluate a liquid chromatographic (LC) procedure for determination of patulin in apple juice. Patulin is a mold metabolite found naturally in rotting apples. Patulin is extracted with ethyl acetate, treated with sodium carbonate solution, and determined by reversed-phase LC with UV detection at 254 or 276 nm. Water, water-tetrahydrofuran, or water-acetonitrile was used as mobile phase. Levels determined in spiked test samples were 20, 50,100, and 200 μg/L. A test sample naturally contaminated at 31 μg/L was also included. Twenty-two collaborators in 10 countries analyzed 12 test samples of apple juice. Recoveries averaged 96%, with a range of 91-108%. Repeatability relative standard deviations (RSDr) ranged from 10.9 to 53.8%. The reproducibility relative standard deviation (RSDR) ranged from 15.1 to 68.8%. The LC method for determination of patulin in apple juice has been adopted first action by AOAC INTERNATIONAL.

Squamous cell carcinoma related with dental implants. A clinical cases report

One third of all cases of head and neck carcinoma (CA) concern the oral mucosa. The use of dental implants (DI) for dental rehabilitation is widely extended. However, a few studies have reported some cases with neoplasic alterations, among the tissue surrounding implants. Our aim was to analyze possible alterations at the bone-implant interface in patients with oral squamous cell carcinoma (SCC), providing new evidence that could relate or discard a possible link between these factors. We used, for the first time, different techniques, including electron microscopy and histology, to analyze the implant ´s surface and the surrounding tissue from four clinical cases with neoplasic alterations surrounding DI. Histologically, ample inflammatory tissue was found in direct contact with the implant surface. Surface analysis of this tissue, revealed titanium percentages. According to our study, no oncological relation with deterioration of the implant surface was found, although DI were constantly related with peri-implantitis, a chronic trauma of the oral mucosa that could involve a neoplastic factor.

Key words:Dental implants, carcinoma, peri-implantitis.

P882 Heart murmur in a 74-year-old patient with a Dacron aortic graft admitted for sepsis after a laparoscopic left colectomy

Introduction

Aortic graft infections (AGI) can have catastrophic consequences with an operative mortality of nearly 50%. The majority of AGI are a result of bacterial exposure at the time of operation (surgical-site related), nearly three quarters a caused by the Staphylococcus organisms. Late onset infections are less common. The mechanism can be through hematogenous spread and bacterial invasion of the graft. Diagnosis is challenging, done by a combination of clinical, radiological and laboratory findings in which echocardiography plays an important role. Fundamental tenets of AGI management are removal of the infected device and adjunctive antimicrobial therapy.

Case

A 74-year-old man, who had undergone supracoronary ascending aortic replacement in 2015 for an aneurism, visited our hospital with fever of 39°, general malaise and abdominal pain for the last 3 days. He had been discharged one week ago after laparoscopic left colectomy due to descending colon neoplasia. Physical examination showed a systolic heart murmur loudest over the left-upper sternal border. Hematological findings included C-reactive protein (CRP) of 82 mg/l and white blood cell count of 16 700/μl. Blood culture was positive por Pseudomonas aeruginosa. Transthoracic echocardiography revealed a supravalvular pulmonary stenosis (figure 1, A) Transesophageal examination showed an extensive peritubular collection (figure 1, B) that extended into the main pulmonary artery, conditioning extrinsic compression and severe stenosis. No blood flow was observed inside the collection. A 6 mm long and filiform image was detected on the right coronary leaflet, causing a moderate aortic regurgitation. Chest CT revealed a low density area around the vascular graft (figure 1, C) and the positron emission tomography (PET)-CT (figure 1, D) showed increased glucidic metabolism in the aneurysmal sac, periaortic fat and the proximal and distal portion of the prosthesis. With the diagnosis of prosthetic vascular graft infection, the patient was referred to cardiac surgery. The surgical sample cultures (graft and mediastinal pus) were all positive for P. aeruginosa. The patient completed antibiotic therapy with ceftazidime and gentamicine.

Discussion

AGI is an extremely complex clinical challenge. Mortality is high, and diagnostic and treatment approaches are controversial. Cardiovascular imaging is one of the most important diagnostic tools in the diagnosis. An echocardiogram should be done in every patient to look for findings of endocarditis. CT is the most informative radiologic study and can be also very helpful in identifying characteristics and extension of AGI. A concurrent PET-CT study has significant potential in improving diagnosis of AGI and monitoring response to treatment.Nevertheless there is an unavoidable degree of subjective judgment in the interpretation of imaging findings making clinical suspicion and laboratory findings crucial in determining whether an AGI exists.

Abstract P882 Figure.

Avoidable 30-day readmissions in patients undergoing vascular surgery

BACKGROUND

Vascular surgery has one of the highest unplanned 30-day readmission rates of all surgical specialties. The degree to which these may be avoidable and the optimal strategies to reduce their occurrence are unknown. The aim of this study was to identify and classify avoidable 30-day readmissions in patients undergoing vascular surgery in order to plan targeted interventions to reduce their occurrence, improve outcomes and reduce cost.

METHODS

A retrospective analysis of discharges over a 12-month period from a single tertiary vascular unit was performed. A multidisciplinary panel conducted a manual case-note review to identify and classify those 30-day unplanned emergency readmissions deemed avoidable.

RESULTS

An unplanned 30-day readmission occurred in 72 of 885 admissions (8·1 per cent). These unplanned readmissions were deemed avoidable in 36 (50 per cent) of these 72 patients, and were most frequently due to unresolved medical issues (19 of 36, 53 per cent) and inappropriate admission with the potential for outpatient management (7 of 36, 19 per cent). A smaller number were due to inadequate social care provision (4 of 36, 11 per cent) and the occurrence of other avoidable adverse events (4 of 36, 11 per cent).

CONCLUSION

Half of all 30-day readmissions following vascular surgery are potentially avoidable. Multidisciplinary coordination of inpatient care and the transition from hospital to community care after discharge need to be improved.

Evaluation of a Chemiluminescence Method for Measuring Alkaline Phosphatase Activity in WholeMilk of Multiple Species and Bovine Dairy Drinks: Interlaboratory Study

Alkaline phosphatase (ALP) is a ubiquitous enzyme in milk with timetemperature destruction similar to that of certain pathogens destroyed in pasteurization. Measurement of ALP to indicate proper pasteurization is a common practice. Recently the public health level for ALP was decreased to 350 mU/L, a level below the sensitivity of older colorimetric ALP methods. This study was conducted within the structure of the International Dairy Federation and the International Organization for Standardization to evaluate the reproducibility of the chemiluminescence method (Charm PasLite) for ALP at 50, 100, 350, and 500 mU/L in whole milk of multiple species to meet new regulations in the United States and proposed regulations in the European Union (EU). Fifteen laboratories from 8 countries evaluated bovine, goat, sheep, and buffalo milk, bovine skim milk, 20% fat cream, and 2% fat chocolate milk. At ALP levels of 350 and 500 mU/L, the average relative standard deviation for repeatability (RSDr) was 7.5%, and the average relative standard deviation of reproducibility was (RSDR) 15%. For ALP at 100 and 50 mU/L, the average RSDr values were 10.5 and 12.6%, respectively, and the average RSDR values were 18 and 25%, respectively. The limit of detection was 20 mU/L. Results are comparable to those obtained with other enzymatic photo-activated system methods such as the fluorometric method. Results indicate that the method is suitable for measuring ALP in the milk of multiple species and in dairy drinks at U.S. and proposed EU levels.

Determination of Total Vitamin C in Fruit Juices and Related Products by Liquid Chromatography: Interlaboratory Study

A interlaboratory study was conducted to evaluate a liquid chromatographic (LC) procedure for the determination of total vitamin C in foods at levels of 5–60 mg/100 g. Emphasis was placed on fruit juices, although selected foods were also included in the study. Following dissolution of sample in water, endogenous dehydroascorbic acid was converted to ascorbic acid by precolumn reduction with dithiothreitol at neutral pH. Total ascorbate was determined by C18 reversed-phase LC with a phosphate eluent at pH 2.5, incorporating dithiothreitol to maintain vitamin C in the reduced form, and UV detection at 254 nm. Seven types of fruit juices and foods were tested by 19 collaborators in 7 countries. Three duplicate juices and foods met the criteria for Youden pairs and yielded repeatability relative standard deviation of 5.80–14.66%. Reproducibility relative standard deviation ranged from 6.36 to 35.54% (n = 10) with HORRAT values of 0.82–4.04. The LC method is suitable for routine use in fruit products and foods containing &gt;5 mg/100 g vitamin C and is recommended for further validation by AOAC INTERNATIONAL and International Fruit Juice Union.

Acute Cardiac Failure Due to Takotsubo Cardiomyopathy Secondary to a Phone Call for Lung Transplantation: A Case Report

Lung transplantation is a therapeutic option for certain end-stage lung diseases. The phone call for lung transplantation is a major event in the life of these patients; as a result, it can generate significant stress. We herein present the case of a 58-year-old female patient with end-stage chronic obstructive pulmonary disease (COPD) who, while on the lung transplantation waiting list, received such a call. Complete transplant work-up, including cardiac tests undertaken shortly before, had revealed no contraindication to lung transplantation. She was admitted with severe acute respiratory failure, and her extensive work-up was compatible with pulmonary edema due to takotsubo cardiomyopathy. The lung transplantation was thus cancelled, owing to the patient's health condition and the poor quality of the graft as well. The patient stayed in the intensive care unit for several days, requiring noninvasive ventilation. The left ventricular function recovered completely within 10 days postdiagnosis, and the patient was discharged 13 days after her admission. The patient was transplanted 1 month thereafter, without any particular problems; she is currently, 8 months post-transplantation, in good condition. In the given case, the call for lung transplantation could have generated emotional stress severe enough to lead to takotsubo cardiomyopathy.

P6510Frailty and in-hospital outcomes in percutaneous coronary interventions

Background

Frailty may be an important marker for poor outcomes in percutaneous coronary intervention (PCI) and there is limited literature on outcomes based on frailty from national cohorts.

Purpose

This study evaluates the prevalence of frailty, changes in frailty over time and outcomes associated with frailty in a national American cohort of patients who underwent PCI.

Methods

The study included adults who underwent PCI in the National Inpatients Sample between 2004 and 2014. Frailty risk was determined using a validated Hospital Frailty Risk Score (HFRS) using the cutoffs <5, 5–15 and >15 corresponding to low, intermediate and high HFRS.

Results

There were 7,306,007 PCI admissions in this cohort. A total of 94.58%, 5.39% and 0.03% of admissions were for low HFRS, intermediate HFRS and high HFRS, respectively. The proportion of intermediate or high frailty risk patients increased over time from 1.9% in 2004 to 11.7% in 2014. In-hospital death increased from 1.0% with low HFRS to 13.9% with high HFRS and average length of stay increased from 2.9±3.3 days to 17.1±15.5 days from low to high HFRS. Greater frailty risk was associated with greater average inpatient cost which was $17,743±11,059, $38,824±34,809 and $56,119±49,772 for low, intermediate and high HFRS, respectively. There were increased adverse outcomes with high frailty including greater in-hospital death (OR 9.91 95% CI 7.17–13.71), in-hospital bleeding complications (OR 4.99 95% CI 3.82–6.51), in-hospital vascular complications (OR 3.96 95% CI 3.00–5.23) and in-hospital stroke (OR 10.49 95% CI 8.28–13.29) comparing high to low HFRS.

Conclusions

More than 1 in 20 patients who undergo PCI have intermediate or high risk of frailty which has significantly increased over time. There are poor outcomes and increased inpatient costs associated with greater frailty. Improvements in education of healthcare workers and increased awareness of frailty could facilitate frailty-tailored care to minimise risk of adverse outcomes and its associated costs.

Acknowledgement/Funding

Research and Development Department at the Royal Stoke Hospital, Keele University and Biosensors International

Rheology and Extrusion Foaming of Partially Crosslinked Thermoplastic Vulcanizates Silicone

This work focuses on the foaming behavior of thermoplastic vulcanized silicones (TPVs) in which partially crosslinked silicone nodules are dispersed. In these TPVs, silicone nodules dispersed in a low density polyethylene (LDPE) phase have an average size of about 1 μm. The crosslinking densities of the elastomer phase were selected according to their viscoelastic behavior. Surprisingly, linear and non-linear shear rheology appeared more sensitive to formulations than extensional rheology. Indeed, each formulation has an extensional rheological behavior similar to that of pure LDPE and meets the requirements for foaming applications in terms of elongation at break and melt strength. In accordance with non-linear shear rheology, the foaming behavior of these formulations has been correlated to extrusion foaming parameters that are known to control nucleation, i. e. pre-die pressure and die exit depressurization rate. With an appropriate crosslinking density of silicone nodules, the TPV foamability tends to the foamability of pure LDPE to reach a foam density of 0.54 g/cm3 with an average cell size of 140 ± 50 μm and a cell density of 3 × 105 cells/cm3. Since partially crosslinked silicone nodules cannot foam, it is assumed that they improve nucleation while allowing sufficient expansion of the LDPE phase.

Improving care at scale: process evaluation of a multi-component quality improvement intervention to reduce mortality after emergency abdominal surgery (EPOCH trial)

BACKGROUND

Improving the quality and safety of perioperative care is a global priority. The Enhanced Peri-Operative Care for High-risk patients (EPOCH) trial was a stepped-wedge cluster randomised trial of a quality improvement (QI) programme to improve 90-day survival for patients undergoing emergency abdominal surgery in 93 hospitals in the UK National Health Service.

METHODS

The aim of this process evaluation is to describe how the EPOCH intervention was planned, delivered and received, at both cluster and local hospital levels. The QI programme comprised of two interventions: a care pathway and a QI intervention to aid pathway implementation, focussed on stakeholder engagement, QI teamwork, data analysis and feedback and applying the model for improvement. Face-to-face training and online resources were provided to support senior clinicians in each hospital (QI leads) to lead improvement. For this evaluation, we collated programme activity data, administered an exit questionnaire to QI leads and collected ethnographic data in six hospitals. Qualitative data were analysed with thematic or comparative analysis; quantitative data were analysed using descriptive statistics.

RESULTS

The EPOCH trial did not demonstrate any improvement in survival or length of hospital stay. Whilst the QI programme was delivered as planned at the cluster level, self-assessed intervention fidelity at the hospital level was variable. Seventy-seven of 93 hospitals responded to the exit questionnaire (60 from a single QI lead response on behalf of the team); 33 respondents described following the QI intervention closely (35%) and there were only 11 of 37 care pathway processes that > 50% of respondents reported attempting to improve. Analysis of qualitative data suggests QI leads were often attempting to deliver the intervention in challenging contexts: the social aspects of change such as engaging colleagues were identified as important but often difficult and clinicians frequently attempted to lead change with limited time or organisational resources.

CONCLUSIONS

Significant organisational challenges faced by QI leads shaped their choice of pathway components to focus on and implementation approaches taken. Adaptation causing loss of intervention fidelity was therefore due to rational choices made by those implementing change within constrained contexts. Future large-scale QI programmes will need to focus on dedicating local time and resources to improvement as well as on training to develop QI capabilities.

EPOCH TRIAL REGISTRATION

ISRCTN80682973 https://doi.org/10.1186/ISRCTN80682973 Registered 27 February 2014 and Lancet protocol 13PRT/7655.