Machine learning can accurately detect abnormal aortic valves in CMR

Background

Improving the efficiency of CMR by acquiring fewer, and more targeted sequences, would improve the diagnostic yield and reduce patient recalls. An AI-assisted clinical decision support system (CDSS) could deliver this efficiency using adaptive scanning protocols which replicate the expertise of highly trained clinicians. Normal aortic valve anatomy on the three-chamber (3CH) cine CMR is a guide to rationalising subsequent sequences, and therefore is a suitable base case for developing an AI-CDSS for CMR.

Purpose

We propose a machine learning approach to differentiate between normal and abnormal aortic valves from the 3CH cine.

Methods

We curated a unique expert-annotated dataset of 1221 frames from eighty CMR studies. For each frame, AV landmarks (two hinge points and two leaflets), and stenotic and regurgitant jets were labelled by three cardiologists.

We then tested two AI models (Figure 1) to detect these AV abnormalities: A) a convolutional neural network (CNN), and B) a random forest approach.

A) Using heat map regression, the AV was localised, and the jets (if present) were identified as pathological curves. We then tracked and quantified the curves in the estimated heatmaps based on their proximity, the length, orientation and angle with respect to the hinge points.

B) We used a random forest approach to classify cases as normal or abnormal by using the characteristics of estimated pathological curves obtained from the heat map regression output.

We trained and evaluated our models on an unseen dataset of 1017 CMR studies obtained from different scanner types across three NHS hospitals. Each CMR study report was manually assigned a binary ground truth label for a normal or abnormal AV. In total 496/1017 patients had an abnormal AV. Of those abnormal cases, 184 patients had aortic stenosis, 222 aortic regurgitation and 90 cases had mixed valve disease.

We assessed the classification performance of our method with accuracy and an F1 score – a composite of precision and recall, where 1 is perfect; and heatmap regression performance for curves with mean absolute error.

Results

This machine learning approach classified abnormal aortic valves with good agreement to the ground truth labels with mean accuracy of 0.93 (representing approximately 451/496 patients) and mean F1 score of 0.91. The AV hinge points were localised with a mean distance error of 3.5 pixels. This was despite the small size of expert labelled data.

Conclusion

This machine learning solution successfully differentiated between normal and abnormal aortic valves from routine 3CH cine CMR views. More labelled datasets will enable further classification of pathology and severity, and greater accuracy. Our results represent an important stepping stone towards an AI-assisted CDSS for CMR.

Funding Acknowledgement

Type of funding sources: Other. Main funding source(s): This work was supported by the UKRI CDT in AI for Healthcare http://ai4health.io

Automated left ventricular dimension assessment using artificial intelligence

Background and purpose

Artificial intelligence (AI) has the potential to greatly improve efficiency and reproducibility of quantification in echocardiography, but to gain widespread use it must both meet expert standards of excellence and have a transparent methodology. We developed an online platform to enable multiple collaborators to annotate medical images for training and validating neural networks.

Methods

Using our online collaborative platform 9 expert echocardiographers labelled 2056 images that comprised the training dataset. They labelled the four points from where the standard parasternal long axis (PLAX) measurements (interventricular septum, posterior wall, left ventricular dimension) would be made. Using these labelled images we trained a 2d convolutional neural network to replicate these labels. Separately, we curated an external validation dataset of the systolic and diastolic frames of 100 PLAX acquisitions. Each of these images were labelled twice by 13 different experts, and the average of the 26 measurements was taken as the consensus standard.

We then compared the individual experts and the AI measurements on the external validation dataset to the consensus standard, and calculated the precision standard deviation (SD) of the signed differences from the consensus standard.

Results

For diastolic septum thickness, the AI had a precision SD of 1.8 mm (ICC 0.81; 95% CI 0.73 to 0.97), compared with 2.0 mm for the individual experts (ICC 0.64; 95% CI 0.57 to 0.72). For diastolic posterior wall thickness, the AI had a precision SD 1.4 mm (ICC 0.54; 95% CI 0.38 to 0.66), and the individual experts 2.2 mm (ICC 0.37; 95% CI 0.29 to 0.46).

The AI's precision SD for left ventricular internal dimension was 3.5 mm (ICC 0.93, 95% CI 0.90 to 0.94), and for individual experts was 4.4mm (ICC 0.82, 95% CI 0.78 to 0.95). Both the experts and AI performed better in diastole than systole (precision SD AI 2.5mm vs 4.3mm, p<0.0001; experts 3.3mm vs 5.3mm, p<0.0001).

Conclusions

AI trained by a group of echocardiography experts was able to perform PLAX measurements which matched the reference standard more closely than any individual expert's own measurements.

This open, collaborative approach may be a model for the development of AI that is explainable to, and trusted by clinicians.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): NIHR Imperil BRC ITMATDr Howard was additionally funded by Wellcome. Online collaborative platformResults of AI and experts

Triage-HF plus: 12-month study of remote monitoring pathway for triage of heart failure risk initiated during the Covid-19 pandemic

Background

The Covid-19 pandemic necessitated rapid adoption of remote monitoring across cardiovascular patient cohorts. Most patients with cardiac implantable electronic devices (CIEDs) are now able to be remotely monitored using either scheduled, patient- or threshold-triggered transmissions. The validated “Triage Heart Failure Risk Score” (Triage-HFRS) is a medical algorithm within company-specific CIEDs that can risk-stratify patients as low-, medium- or high-risk of worsening heart failure (WHF) in the next 30 days based on integrated monitoring of physiological parameters. Building on a previous proof-of-concept of the Triage-HF Plus pathway, we integrated remote data with simple 5-question telephone triage within a clinical pathway to identify WHF during the first year of the Covid-19 pandemic.

Purpose

Prospective evaluation of clinical remote monitoring pathway integrating Triage-HFRS with protocolised telephone triage (Triage-HF Plus pathway).

Methods

Prospective, real-world evaluation of clinical pathway serving a large urban region over a 12-month period, using data from April 2020 to April 2021 (initiated during the first wave of Covid-19 pandemic in the UK). From a population of 435 patients with CIEDs, 87 “high” Triage-HFRS alerts were received and patients contacted for telephone triage assessment. Screening questions were designed to identify episodes of WHF and non-HF events. Intervention was at discretion of the clinical practitioner and in line with guideline-directed practice. A consecutive sample of 115 “medium” risk scores received the same triage.

Results

Successful contact was made with 72 (82.8%) high-risk patients. Classification for high scoring patients confirmed on triage included isolated heart failure (18.3%), heart failure concurrent to medical problem (5.7%), alternative medical problem (10.3%), and recent hospital admission (8.0%); triage reassured absence of acute cause of high score in 40.2%. The sensitivity and specificity for detection of WHF was 87.9% (0.77–0.99) and 59.4% (0.50–0.69) respectively. Positive and negative predictive values were 40.3% and 94.0%, respectively. Overall accuracy was 66.2%.

Conclusions

The Triage-HF Plus pathway served as a useful remote monitoring tool for identifying patients with WHF whose care had been otherwise disrupted by the Covid-19 pandemic, allowing timely intervention and cementing the longer-term role for such models of care delivery. Crucially, in this multimorbid, high-cost population, relevant non-HF issues were also identified. The high negative predictive value further highlights the potential of proactive surveillance over conventional, periodic follow up.

Funding Acknowledgement

Type of funding sources: Foundation. Main funding source(s): Imperial Health Charity

Fully automated global longitudinal strain assessment using artificial intelligence developed and validated by a UK-wide echocardiography expert collaborative

Background

Left ventricular longitudinal strain has been reported to deliver reproducibility, sensitivity and prognostic value over and above ejection fraction. However, it currently relies on uninspectable proprietary algorithms and suffers from a lack of widespread clinical use. Uptake may be improved by increasing user trust through greater transparency.

Purpose

We therefore developed a machine-learning based method, trained, and validated with accredited experts from our AI Echocardiography Collaborative. We make the dataset, code, and trained network freely available under an open-source license.

Methods

AI enables strain to be calculated without relying on speckle tracking by directly locating key points and borders across frames. Strain can then be calculated as the fractional shortening of the left ventricular perimeter. We first curated a dataset of 7523 images, including 2587 apical four chamber, each labelled by a single expert from our collaboration of 17 hospitals, using our online platform (Figure 1). Using both this dataset and a semi-supervised approach, we trained a 3d convolutional neural network to identify the annulus, apex, and the endocardial border throughout the cardiac cycle.

Separately, we constructed an external validation dataset of 100 apical 4 chamber video-loops. The systolic and diastolic frame were identified, and each image was separately labelled by 11 experts. From these labels we then derived the expert consensus strain for each of the 100 video loops. These experts also ordered all 100 echocardiograms by their visual grading of left ventricular longitudinal function. Finally, a single expert calculated strain using two different proprietary commercial packages (A and B).

Results

Consensus strain measurements (obtained by averaging individual assessments by the 11 experts) across the 100 cases ranged from −4% to −27%, with strong correlations with the individual experts and machine methods (Figure 2). Using each cases' consensus across experts as the gold standard, median error from consensus was 3.1% for individual experts, 3.4% for Propriety A, 2.6% for Proprietary B, 2.6% for our AI.

Using the visual grading of longitudinal strain as the reference, the 11 individual experts and 4 machine methods each showed significant correlation: coefficients ranged from 0.55 to 0.69 for experts, and for Proprietary A was 0.68, Proprietary B 0.69, and our AI 0.69.

Conclusions

Our open-source, vendor-independent AI-based strain measure automatically produces values that agree with expert consensus, as strongly as the individual experts do. It also agrees with the subjective visual ranking by longitudinal function. Our open-source AI strain performs at least as well as closed-source speckle-based approaches, and may enable increased clinical and research use of longitudinal strain.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): NIHR Imperial BRC ITMAT.Dr Howard was additionally funded by Wellcome. Figure 1. Collaborative online platformFigure 2. Correlations between strain methods

Framework for large-scale automatic curation of heterogeneous cardiac MRI (ACUR MRI)

Funding Acknowledgements

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): UKRI CDT in AI for Healthcare http://ai4health.io and British Heart Foundation

Background 

Data curation is an important process that structures and organises data, supporting research and the development of artificial intelligence models. However, manually curating a large volume of medical data is a time-consuming, repetitive and costly process that puts additional strain on clinical experts. The curation becomes more complex and demanding as more data sources are used. This leads to an introduction of disparity in the data structure and protocols. 

Purpose 

Here, we propose an automatic framework to curate large volumes of heterogenous cardiac MRI scans acquired across different sites and scanner vendors. Our framework requires minimal expert involvement throughout and works directly on DICOM images from the scanner or PACS.  The resulting structured standardised data allow for straightforward image analysis, hypothesis testing and the training and application of artificial intelligence models. 

Methods 

It is broken down into three main components

anonymisation, cataloguing and outlier detection (see Figure 1). Anonymisation automatically removes any identifiable patient information from the DICOM image attributes. These data are replaced with anonymised labels, whilst maintaining relevant longitudinal information from each patient. DICOM attributes are also used to automatically group the different images according to imaging sequence (e.g. CINE, Delayed-Enhancement, T1 maps), acquisition geometry (e.g. short-axis, 2-chamber, 4-chamber) and imaging attributes (e.g. slice thickness, TE, TR), for easier querying. The sorting characteristics are flexible and can easily be defined by the user. Finally, we detect and flag, for subsequent manual inspection, any outliers within those groups, based on the similarity levels of chosen DICOM attributes. This framework additionally offers interactive image visualisation to allow users to assess its performance in real time. 

Results 

We tested the performance of ACUR CMRI on 26,668 CMR image series (723,531 images) from 858 patient examinations, which took place across two sites in four different scanners. With an average execution time per patient of 100 seconds, ACUR was able to sort imaging data with 1191 different sequence names into 43 categories. The framework can be freely downloaded from https://bitbucket.org/cmr-ai-working-group/acur/. 

Conclusions 

We present ACUR, an automatic framework to curate large volumes of heterogeneous cardiac MRI data. We show how it can quickly and automatically curate data, grouping it according to desired imaging characteristics defined in DICOM attributes. The proposed framework is flexible and ideally suited as a pre-processing tool for large biomedical imaging data studies.

Laryngeal Injury and Upper Airway Symptoms After Endotracheal Intubation During Surgery: A Systematic Review and Meta-analysis

Laryngeal injury from intubation can substantially impact airway, voice, and swallowing, thus necessitating multidisciplinary interventions. The goals of this systematic review were (1) to review the types of laryngeal injuries and their patient-reported symptoms and clinical signs resulting from endotracheal intubation in patients intubated for surgeries and (2) to better understand the overall the frequency at which these injuries occur. We conducted a search of 4 online bibliographic databases (ie, PubMed, Embase, Cumulative Index of Nursing and Allied Health Literature [CINAHL], and The Cochrane Library) and ProQuest and Open Access Thesis Dissertations (OPTD) from database inception to September 2019 without restrictions for language. Studies that completed postextubation laryngeal examinations with visualization in adult patients who were endotracheally intubated for surgeries were included. We excluded (1) retrospective studies, (2) case studies, (3) preexisting laryngeal injury/disease, (4) patients with histories of or surgical interventions that risk injury to the recurrent laryngeal nerve, (5) conference abstracts, and (6) patient populations with nonfocal, neurological impairments that may impact voice and swallowing function, thus making it difficult to identify isolated postextubation laryngeal injury. Independent, double-data extraction, and risk of bias assessment followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines and the Cochrane Collaboration's criteria. Twenty-one articles (1 cross-sectional, 3 cohort, 5 case series, 12 randomized controlled trials) representing 21 surgical studies containing 6140 patients met eligibility criteria. The mean patient age across studies reporting age was 49 (95% confidence interval [CI], 45-53) years with a mean intubation duration of 132 (95% CI, 106-159) minutes. Studies reported no injuries in 80% (95% CI, 69-88) of patients. All 21 studies presented on type of injury. Edema was the most frequently reported mild injury, with a prevalence of 9%-84%. Vocal fold hematomas were the most frequently reported moderate injury, with a prevalence of 4% (95% CI, 2-10). Severe injuries that include subluxation of the arytenoids and vocal fold paralysis are rare (<1%) outcomes. The most prevalent patient complaints postextubation were dysphagia (43%), pain (38%), coughing (32%), a sore throat (27%), and hoarseness (27%). Overall, laryngeal injury from short-duration surgical intubation is common and is most often mild. No uniform guidelines for laryngeal assessment postextubation from surgery are available and hoarseness is neither a good indicator of laryngeal injury or dysphagia. Protocolized screening for dysphonia and dysphagia postextubation may lead to improved identification of injury and, therefore, improved patient outcomes and reduced health care utilization.

The role of peer-led mental health training in undergraduate medical education - a way forward?

Introduction

Mental health is no doubt a topical conversation at medical school. We noted that whilst many students appreciated the power in talking openly about challenges faced, it was a topic many found hard to approach. In response, we have implemented a peer-led training programme at Bristol Medical School. The aim of the programme is to improve confidence and enable students to recognise and respond to their own, a peer or patient’s distress in a more proactive, supportive and overall effective way. It utilised peer-led, discussion based workshops during the first few months of medical school to achieve this.

Objectives

To evaluate the role of peer-led mental health training in undergraduate medical education.

Methods

The program was piloted in November 2019. T-tests compared 142 participating students’ baseline self-reported understanding and confidence and follow up, as measured on a likert scale (1-5). Qualitative feedback was also welcomed.

Results

Students showed a significant improvement in their self-reported understanding (24%, P<0.05), confidence when supporting a peer (18%, P<0.05) and confidence if faced with a more acute situation (21%, P<0.05). Students expressed particular admiration for the fact that the session was peer led ‘as it emphasised the importance of mental health in…society’.

Conclusions

This programme may be beneficial in creating a stronger community of doctors who are equipped with the confidence and ability to better care for themselves, their colleagues, and patients. Further evaluation is required to determine whether this reduces rate or severity of mental illness in participants or the broader student population.

From the lecture theatre to your digital device: Reflections on the production of educational podcasts within undergraduate psychiatry training

Introduction

The COVID-19 pandemic has highlighted a need for engaging online resources to enrich psychiatry training for undergraduate medical students. Podcasting is a well-established digital communication platform utilised daily in a myriad of capacities, including education. A group of medical students were tasked with creating their own educational podcasts covering specific aspects of psychiatry.

Objectives

Each pair was set a sub-topic of psychiatry and utilised software to produce educational resources. The objective of this project was to reflect upon production as well as explore the efficacy of podcasting as a tool within undergraduate training.

Methods

The medical students conducted research and contacted experts within the field to contribute to their podcasts. The majority of the students then conducted reviews of the literature surrounding podcasting within medical education, which informed the production of their own podcasts. From this, it was discussed how this project could impact future practice, and indicated that podcasts may become crucial asynchronous learning tools in medical education.

Results

Literature review and first-hand experience of podcast production enabled the students to appreciate the advantages of podcasting and the potential for its widespread future applications. Their wider reading revealed that podcast-using study participants outperformed or matched their peers in assessments, and overwhelmingly enjoyed using podcasts over traditional teaching methods.

Conclusions

The use of podcasting can complement traditional psychiatry training and appeal to a generation of digital natives that prefer this learning style. Podcast production is also an excellent revision method, highlighting the advantages of peer-to-peer education in both learning and increasing engagement with psychiatry.

Disclosure

No significant relationships.

Building interest in psychiatry: Could peer-to-peer learning be a way forward in improving engagement in psychiatric education amongst medical students?

Introduction

Stigma, stereotypes, and preconceptions have meant psychiatry has been subject to poor engagement from medical students when compared to other specialties. Whilst efforts have been made to understand reasons for this and formulate strategies to build interest, the problem still exists.

Objectives

This piece explores whether giving those with a passion for psychiatry a platform to share this could gradually but positively influence their peers and thus, be a potential way to drive engagement in psychiatry as a career.

Methods

Advanced literature searches explored items such as engagement in psychiatry and benefits of peer-to-peer education. CASP checklists facilitated selection and appraisal of literature for use in this discussion. Key themes were identified and used to formulate suggestions for the use of peer-to-peer teaching in building interest in psychiatry.

Results

Thematic analysis of the data found 4 main themes relating to engagement in psychiatry. Current strategies to improve this have varying impact and include clinical exposure, using patients with lived experience in learning and enrichment activities, whilst the main negative influence is a long-standing stigma and stereotype around psychiatry. Three themes regarding the relevant benefits of peer-to-peer teaching were found, being peer-to-peer connection, peer influence and means to overcome stigma.

Conclusions

Three key strategies for the use of peer to peer learning are suggested. These are ‘learning from students with lived experience’, ‘peer-teaching from passionate students prior to clinical exposure’ and ‘using peer learning to initially introduce topics in psychiatry in a relatable manor’.

95 Lack of Evidence for Reduced Efficacy of Medical Therapy for Heart Failure in Older Adults

Introduction

There are almost a million people with heart failure (HF) in the UK; the incidence increases sharply with age. Older adults receive less evidence-based therapy with few trials specifically examining therapeutic efficacy in older age groups representative of a contemporary UK HF population. Concern that efficacy is less in older adults may underlie under-prescription. With important recent advances in HF therapy, we reviewed the contemporary evidence base for any signal of different efficacy in older adults.

Methods

We reviewed recent RCTs of medical therapy for heart failure alongside meta-analyses updated with recent therapies including Angiotensin-Neprilysin inhibitors and SGLT2 inhibitors. For those trials in which effect size was presented for age subgroups we compared the effect size.

Results

Of 68 randomised controlled trials, 10 presented effect sizes for different age groups. The median average cut-off between younger and older age groups was 66 years (IQR 65 to 72.5 years) and the highest cut-off used was 75 years. The median hazard ratio was 0.77 (IQR 0.67 to 0.80) for the younger age group and 0.76 (IQR 0.73 to 0.88) for the older age group. In 8 of the 10 trials, the effect size in the oldest age group was statistically significant on its own including Sacubitril-Valsartan and Dapagliflozin.

Conclusion

When considering the medical therapeutic armamentarium for heart failure as a totality, there is no evidence it is any less effective in older adults than younger adults. The recent Zannad et al cross-trial analysis supported this showing significant additional life years in the patients over 80 years on HF therapy. Whilst there may be practical and frailty-related reasons for not prescribing life-prolonging therapy, the proportional survival benefits of these medications is similar in older adults. This should be utilised where practically possible and discussed with patients when making an informed choice.

Ibrutinib in combination with nab-paclitaxel and gemcitabine for first-line treatment of patients with metastatic pancreatic adenocarcinoma: phase III RESOLVE study

BACKGROUND

First-line treatment of metastatic pancreatic ductal adenocarcinoma (PDAC) includes nab-paclitaxel/gemcitabine. Ibrutinib, a Bruton's tyrosine kinase inhibitor, exhibits antitumor activity through tumor microenvironment modulation. The safety and efficacy of first-line ibrutinib plus nab-paclitaxel/gemcitabine treatment in patients with PDAC were evaluated.

PATIENTS AND METHODS

RESOLVE (NCT02436668) was a phase III, randomized, double-blind, placebo-controlled study. Patients (histologically-confirmed PDAC; stage IV diagnosis ≥6 weeks of randomization; Karnofsky performance score ≥70) were randomized to once-daily oral ibrutinib (560 mg) or placebo plus nab-paclitaxel (125 mg/m²) and gemcitabine (1000 mg/m²). Primary endpoints were overall survival (OS) and investigator-assessed progression-free survival (PFS); overall response rate and safety were assessed.

RESULTS

In total, 424 patients were randomized (ibrutinib arm, n = 211; placebo arm, n = 213). Baseline characteristics were balanced across arms. After a median follow-up of 25 months, there was no significant difference in OS between ibrutinib plus nab-paclitaxel/gemcitabine versus placebo plus nab-paclitaxel/gemcitabine (median of 9.7 versus 10.8 months; P = 0.3225). PFS was shorter for ibrutinib plus nab-paclitaxel/gemcitabine compared with placebo plus nab-paclitaxel/gemcitabine (median 5.3 versus 6.0 months; P < 0.0001). Overall response rates were 29% and 42%, respectively (P = 0.0058). Patients in the ibrutinib arm had less time on treatment and received lower cumulative doses for all agents compared with the placebo arm. The most common grade ≥3 adverse events for ibrutinib versus placebo arms included neutropenia (24% versus 35%), peripheral sensory neuropathy (17% versus 8%), and anemia (16% versus 17%). Primary reasons for any treatment discontinuation were disease progression and adverse events.

CONCLUSIONS

Ibrutinib plus nab-paclitaxel/gemcitabine did not improve OS or PFS for patients with PDAC. Safety was consistent with known profiles for these agents.

AB1023 CARDIAC MRI IN HYPERFERRITINAEMIC DISEASE STATES REVEALS MYOCARDIAL INFLAMMATION NOT IDENTIFIED BY ECHOCARDIOGRAPHY

Background:

Acutely unwell adult patients with hyperinflammatory hyperferritinaemic states are typically challenging to diagnose. Case series suggest that cardiac involvement may be common (up to 20%) but the phenotype has not been well characterised1.

The elevation of cardiac biomarkers suggests cardiac involvement, but are non-specific in acute illness. Cardiac MRI (CMR) offers the ability to characterise the myocardium and identify inflammation, and modern motion-corrected sequences now allow the assessment of patients who may struggle to breath-hold in the recovery from acute illness.

Objectives:

We report 3 patients who underwent CMR in the acute phase of illness with raised cardiac biomarkers.

Methods:

Case records of acutely ill patients with hyperferritinaemia from two major London centres were reviewed and cases who had undergone CMR in the acute phase of illness were identified.

Results:

3 cases were identified from a cohort of 22, we report CMR findings from differing aetiologies of hyperferritinaemic states:

Case 1: A female in her 60s presented acutely unwell with fever, swollen joints and salmon pink rash. Ferritin was raised at 50574ug/L (20-300ug/L), troponin I 384ng/L (<34ng/L) and Brain Natriuretic Peptide (BNP) 324ng/L (<159ng/L). Echocardiography was normal. However CMR with T2 mapping revealed several small areas of raised signal consistent with myocardial inflammation. A diagnosis of systemic Adult Onset Stills Disease (AOSD) was made. She received IV methylprednisolone and anakinra with normalisation of cardiac biomarkers.

Case 2: A male in his 20s with known SLE with associated end stage renal failure requiring transplant. He had a previous prolonged admission secondary to HLH. He presented with chest pain and concave shaped ST elevation on ECG. Troponin peak 2168ng/L, BNP 1334ng/L. Peak ferritin 1300ug/l.

He was initiated on colchicine for likely pericarditis. Echocardiography showed a dilated left ventricle and mildly increased wall thickness, but overall systolic function within normal limits.

CMR reported nodular patchy late gadolinium enhancement in the mid inferoseptum and inferior wall associated with areas of raised T2 mapping values. NM cardiac rest gated PET reported abnormal FDG uptake to the myocardium with sites including the apical inferior wall, apical RV insertion point and basal septal/anterior right ventricular walls. Features were deemed in keeping with active myocarditis.

He responded to colchicine with improved troponin, and was discharged with close follow up.

Case 3: A male in his 20s presented with septic shock attributed to meningococcal septicaemia requiring ITU admission. Troponin was elevated at >9000ng/L. Bloods demonstrated raised ferritin and features consistent with HLH were identified.

CMR reported elevated native myocardial T1/T2 signal of the lateral and mid-anterior walls in keeping with myocardial oedema. Pericardium adjacent to the anterolateral wall had elevated T1/T2 signal with hyperenhancement on delayed enhancement imaging. Tissue characterisation was in keeping with an acute myopericarditis process.

In addition to broad spectrum antibiotics to treat his underlying infection, he received therapy for HLH including methylprednisolone, anakinra and IVIG. He subsequently made a good recovery to treatment.

Conclusion:

CMR in acute illness with hyperferritinaemia reveals abnormal tissue characterisation with myocardial inflammation, even when echocardiography is normal. We suggest CMR may be a useful test to expand our understanding of hyperferritinaemic disease states.

References:

[1]M Gerfaud-Valentin et al. Myocarditis in Adult-Onset Still Disease. Medicine (Baltimore) 2014 Oct; 93(17): 280-289

Disclosure of Interests:

None declared

Improvement of AOAC Official Method 984.27 for the Determination of Nine Nutritional Elements in Food Products by Inductively Coupled Plasma-Atomic Emission Spectroscopy After Microwave Digestion: Single-Laboratory Validation and Ring Trial

A single-laboratory validation (SLV) and a ring trial (RT) were undertaken to determine nine nutritional elements in food products by inductively coupled plasma-atomic emission spectroscopy in order to improve and update AOAC Official Method 984.27. The improvements involved optimized microwave digestion, selected analytical lines, internal standardization, and ion buffering. Simultaneous determination of nine elements (calcium, copper, iron, potassium, magnesium, manganese, sodium, phosphorus, and zinc) was made in food products. Sample digestion was performed through wet digestion of food samples by microwave technology with either closed or open vessel systems. Validation was performed to characterize the method for selectivity, sensitivity, linearity, accuracy, precision, recovery, ruggedness, and uncertainty. The robustness and efficiency of this method was proved through a successful internal RT using experienced food industry laboratories. Performance characteristics are reported for 13 certified and in-house reference materials, populating the AOAC triangle food sectors, which fulfilled AOAC criteria and recommendations for accuracy (trueness, recovery, and z-scores) and precision (repeatability and reproducibility RSD and HorRat values) regarding SLV and RT. This multielemental method is cost-efficient, time-saving, accurate, and fit-for-purpose according to ISO 17025 Norm and AOAC acceptability criteria, and is proposed as an improved version of AOAC Official Method 984.27 for fortified food products, including infant formula.

Use of Telemedicine to Screen Patients in the Emergency Department: Matched Cohort Study Evaluating Efficiency and Patient Safety of Telemedicine

BACKGROUND

Early efforts to incorporate telemedicine into Emergency Medicine focused on connecting remote treatment clinics to larger emergency departments (EDs) and providing remote consultation services to EDs with limited resources. Owing to continued ED overcrowding, some EDs have used telemedicine to increase the number of providers during surges of patient visits and offer scheduled "home" face-to-face, on-screen encounters. In this study, we used remote on-screen telemedicine providers in the "screening-in-triage" role.

OBJECTIVE

This study aimed to compare the efficiency and patient safety of in-person screening and telescreening.

METHODS

This cohort study, matched for days and proximate hours, compared the performance of real-time remote telescreening and in-person screening at a single urban academic ED over 22 weeks in the spring and summer of 2016. The study involved 337 standard screening hours and 315 telescreening hours. The primary outcome measure was patients screened per hour. Additional outcomes were rates of patients who left without being seen, rates of analgesia ordered by the screener, and proportion of patients with chest pain receiving or prescribed a standard set of tests and medications.

RESULTS

In-person screeners evaluated 1933 patients over 337 hours (5.7 patients per hour), whereas telescreeners evaluated 1497 patients over 315 hours (4.9 patients per hour; difference=0.8; 95% CI 0.5-1.2). Split analysis revealed that for the final 3 weeks of the evaluation, the patient-per-hour rate differential was neither clinically relevant nor statistically discernable (difference=0.2; 95% CI -0.7 to 1.2). There were fewer patients who left without being seen during in-person screening than during telescreening (2.6% vs 3.8%; difference=-1.2; 95% CI -2.4 to 0.0). However, compared to prior year-, date-, and time-matched data on weekdays from 1 am to 3 am, a period previously void of provider screening, telescreening decreased the rate of patients LWBS from 25.1% to 4.5% (difference=20.7%; 95% CI 10.1-31.2). Analgesia was ordered more frequently by telescreeners than by in-person screeners (51.2% vs 31.6%; difference=19.6%; 95% CI 12.1-27.1). There was no difference in standard care received by patients with chest pain between telescreening and in-person screening (29.4% vs 22.4%; difference=7.0%; 95% CI -3.4 to 17.4).

CONCLUSIONS

Although the efficiency of telescreening, as measured by the rate of patients seen per hour, was lower early in the study period, telescreening achieved the same level of efficiency as in-person screening by the end of the pilot study. Adding telescreening during 1-3 am on weekdays dramatically decreased the number of patients who left without being seen compared to historic data. Telescreening was an effective and safe way for this ED to expand the hours in which patients were screened by a health care provider in triage.

Laryngeal Injury and Upper Airway Symptoms After Oral Endotracheal Intubation With Mechanical Ventilation During Critical Care: A Systematic Review

OBJECTIVES

To systematically review the symptoms and types of laryngeal injuries resulting from endotracheal intubation in mechanically ventilated patients in the ICU.

DATA SOURCES

PubMed, Embase, CINAHL, and Cochrane Library from database inception to September 2017.

STUDY SELECTION

Studies of adult patients who were endotracheally intubated with mechanical ventilation in the ICU and completed postextubation laryngeal examinations with either direct or indirect visualization.

DATA EXTRACTION

Independent, double-data extraction and risk of bias assessment followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Risk of bias assessment followed the Cochrane Collaboration's criteria.

DATA SYNTHESIS

Nine studies (seven cohorts, two cross-sectional) representing 775 patients met eligibility criteria. The mean (SD; 95% CI) duration of intubation was 8.2 days (6.0 d; 7.7-8.7 d). A high prevalence (83%) of laryngeal injury was found. Many of these were mild injuries, although moderate to severe injuries occurred in 13-31% of patients across studies. The most frequently occurring clinical symptoms reported post extubation were dysphonia (76%), pain (76%), hoarseness (63%), and dysphagia (49%) across studies.

CONCLUSIONS

Laryngeal injury from intubation is common in the ICU setting. Guidelines for laryngeal assessment and postextubation surveillance do not exist. A systematic approach to more robust investigations could increase knowledge of the association between particular injuries and corresponding functional impairments, improving understanding of both time course and prognosis for resolution of injury. Our findings identify targets for future research and highlight the long-known, but understudied, clinical outcomes from endotracheal intubation with mechanical ventilation in ICU.

The Effect of Medicaid Expansion on Utilization in Maryland Emergency Departments

STUDY OBJECTIVE

A proposed benefit of expanding Medicaid eligibility under the Patient Protection and Affordable Care Act (ACA) was a reduction in emergency department (ED) utilization for primary care needs. Pre-ACA studies found that new Medicaid enrollees increased their ED utilization rates, but the effect on system-level ED visits was less clear. Our objective was to estimate the effect of Medicaid expansion on aggregate and individual-based ED utilization patterns within Maryland.

METHODS

We performed a retrospective cross-sectional study of ED utilization patterns across Maryland, using data from Maryland's Health Services Cost Review Commission. We also analyzed utilization differences between pre-ACA (July 2012 to December 2013) uninsured patients who returned post-ACA (July 2014 to December 2015).

RESULTS

The total number of ED visits in Maryland decreased by 36,531 (-1.2%) between the 6 quarters pre-ACA and the 6 quarters post-ACA. Medicaid-covered ED visits increased from 23.3% to 28.9% (159,004 additional visits), whereas uninsured patient visits decreased from 16.3% to 10.4% (181,607 fewer visits). Coverage by other insurance types remained largely stable between periods. We found no significant relationship between Medicaid expansion and changes in ED volume by hospital. For patients uninsured pre-ACA who returned post-ACA, the adjusted visits per person during 6 quarters was 2.38 (95% confidence interval 2.35 to 2.40) for those newly enrolled in Medicaid post-ACA compared with 1.66 (95% confidence interval 1.64 to 1.68) for those remaining uninsured.

CONCLUSION

There was a substantial increase in patients covered by Medicaid in the post-ACA period, but this did not significantly affect total ED volume. Returning patients newly enrolled in Medicaid visited the ED more than their uninsured counterparts; however, this cohort accounted for only a small percentage of total ED visits in Maryland.

Effect of Reverse Triage on Creation of Surge Capacity in a Pediatric Hospital

IMPORTANCE

The capacity of pediatric hospitals to provide treatment to large numbers of patients during a large-scale disaster remains a concern. Hospitals are expected to function independently for as long as 96 hours. Reverse triage (early discharge), a strategy that creates surge bed capacity while conserving resources, has been modeled for adults but not pediatric patients.

OBJECTIVE

To estimate the potential of reverse triage for surge capacity in an academic pediatric hospital.

DESIGN, SETTING, AND PARTICIPANTS

In this retrospective cohort study, a blocked, randomized sampling scheme was used including inpatients from 7 units during 196 mock disaster days distributed across the 1-year period from December 21, 2012, through December 20, 2013. Patients not requiring any critical interventions for 4 successive days were considered to be suitable for low-risk immediate reverse triage. Data were analyzed from November 1, 2014, through November 21, 2016.

MAIN OUTCOMES AND MEASURES

Proportionate contribution of reverse triage to the creation of surge capacity measured as a percentage of beds newly available in each unit and in aggregate.

RESULTS

Of 3996 inpatients, 501 were sampled (268 boys [53.5%] and 233 girls [46.5%]; mean [SD] age, 7.8 [6.6] years), with 10.8% eligible for immediate low-risk reverse triage and 13.2% for discharge by 96 hours. The psychiatry unit had the most patients eligible for immediate reverse triage (72.7%; 95% CI, 59.6%-85.9%), accounting for more than half of the reverse triage effect. The oncology (1.3%; 95% CI, 0.0%-3.9%) and pediatric intensive care (0%) units had the least effect. Gross surge capacity using all strategies (routine patient discharges, full use of staffed and unstaffed licensed beds, and cancellation of elective and transfer admissions) was estimated at 57.7% (95% CI, 38.2%-80.2%) within 24 hours and 84.1% (95% CI, 63.9%-100%) by day 4. Net surge capacity, estimated by adjusting for routine emergency department admissions, was about 50% (range, 49.1%-52.6%) throughout the 96-hour period. By accepting higher-risk patients only (considering only major critical interventions as limiting), reverse triage would increase surge capacity by nearly 50%.

CONCLUSIONS AND RELEVANCE

Our estimates indicate considerable potential pediatric surge capacity by using combined strategic initiatives. Reverse triage adds a meaningful but modest contribution and may depend on psychiatric space. Large volumes of pediatric patients discharged early to the community during disasters could challenge pediatricians owing to the close follow-up likely to be required.

An Analysis of the Relationship Between the Heat Index and Arrivals in the Emergency Department

BACKGROUND

Heatwaves are one of the most deadly weather-related events in the United States and account for more deaths annually than hurricanes, tornadoes, floods, and earthquakes combined. However, there are few statistically rigorous studies of the effect of heatwaves on emergency department (ED) arrivals. A better understanding of this relationship can help hospitals plan better and provide better care for patients during these types of events.

METHODS

 A retrospective review of all ED patient arrivals that occurred from April 15 through August 15 for the years 2008 through 2013 was performed. Daily patient arrival data were combined with weather data (temperature and humidity) to examine the potential relationships between the heat index and ED arrivals as well as the length of time patients spend in the ED using generalized additive models. In particular the effect the 2012 heat wave that swept across the United States, and which was hypothesized to increase arrivals was examined.

RESULTS

 While there was no relationship found between the heat index and arrivals on a single day, a non-linear relationship was found between the mean three-day heat index and the number of daily arrivals. As the mean three-day heat index initially increased, the number of arrivals significantly declined. However, as the heat index continued to increase, the number of arrivals increased. It was estimated that there was approximately a 2% increase in arrivals when the mean heat index for three days approached 100°F. This relationship was strongest for adults aged 18-64, as well as for patients arriving with lower acuity. Additionally, a positive relationship was noted between the mean three-day heat index and the length of stay (LOS) for patients in the ED, but no relationship was found for the time from which a patient was first seen to when a disposition decision was made. No significant relationship was found for the effect of the 2012 heat wave on ED arrivals, though it did have an effect on patient LOS.

CONCLUSION

 A single hot day has only a limited effect on ED arrivals, but continued hot weather has a cumulative effect. When the heat index is high (~90°F) for a number of days in a row, this curtails peoples activities, but if the heat index is very hot (~100°F) this likely results in an exacerbation of underlying conditions as well as heat-related events that drives an increase in ED arrivals. Periods of high heat also affects the length of stay of patients either by complicating care or by making it more difficult to discharge patients.

Multiple pathological fractures and delayed union associated with lead exposure in a German Shepherd Dog

CASE REPORT

An 8-year-old 40.8-kg intact male German Shepherd Dog was evaluated for bilateral antebrachial fractures. Radiographs revealed osteopenia and comminuted proximal diaphyseal fractures of the left radius and ulna, and proximal articular fracture of the right ulna. A dual energy X-ray absorptiometry scan confirmed decreased bone mineral density. Bone mineral analysis collected at the time of definitive surgical repair demonstrated high lead concentration. Analysis further demonstrated normal bone calcium and phosphorus concentrations. Serum lead concentration was normal. The left radial and ulnar fractures were surgically stabilised with an external fixator. The right ulnar fracture was splinted. The left antebrachial fractures were palpably unstable at 12 weeks after surgery. Moderate callus formation and incomplete bone union were present at 17 weeks postoperatively. The dog was re-presented 15 months later for right metacarpal and left metatarsal fractures, which were managed conservatively. Complete bone union of the right radial and ulnar fractures was not present at that time.

CONCLUSION

Excessive lead accumulation in bone should be considered as a differential diagnosis for increased susceptibility to pathologic fracture and delayed fracture healing in dogs.

The impact of interruptions on the duration of nursing interventions: a direct observation study in an academic emergency department

BACKGROUND

Interruptions to nursing workload may contribute to procedural failures and clinical errors impacting quality/safety of care, but the impact of interruptions on the duration of these activities has not been closely scrutinised. This study analyses the effect of interruptions to care provided by nurses and clinical technicians on the length of clinical procedures and interventions (excluding the length of the interruption).

METHODS

An observational time study of the effect of interruptions on common nursing interventions in the emergency department (ED) of a large academic medical centre was conducted. This study used direct observations of nurses and clinical technicians while delivering care to patients.

RESULTS

The average time spent on an uninterrupted intervention was 296.47 s (median:185.15, SD:319.05), while interrupted interventions took 682.02 s (median:589.63, SD:504.59). Controlling for intervention type and other potential confounding factors using multiple linear regression found that interrupted interventions were 121.36 s (95% CI 79.57 to 163.15) longer, a 19 percentage point increase (95% CI 11.31 to 26.89), than an intervention without (excluding the length of the interruption). Family/patient interruptions effected duration the most while staff interruptions affected the intervention time the least.

DISCUSSION

Our findings are consistent with outcomes of studies in non-healthcare domains, but are contrary to a study of ED physicians, suggesting differential responses to interruptions by physicians and nurses. Future studies on interruptions in healthcare should thus be discipline specific. Though the effect of interruptions on intervention length is only about 2 min, in an ED setting, this can increase patient risks and costs. To better focus efforts to reduce interruptions future research should focus on further separation of interruption type (eg, urgent vs routine or unnecessary).

Critical resources for hospital surge capacity: an expert consensus panel

Background: Hospital surge capacity (HSC) is dependent on the ability to increase or conserve resources. The hospital surge model put forth by the Agency for Healthcare Research and Quality (AHRQ) estimates the resources needed by hospitals to treat casualties resulting from 13 national planning scenarios. However, emergency planners need to know which hospital resource are most critical in order to develop a more accurate plan for HSC in the event of a disaster. Objective: To identify critical hospital resources required in four specific catastrophic scenarios; namely, pandemic influenza, radiation, explosive, and nerve gas. Methods: We convened an expert consensus panel comprised of 23 participants representing health providers (i.e., nurses and physicians), administrators, emergency planners, and specialists. Four disaster scenarios were examined by the panel. Participants were divided into 4 groups of five or six members, each of which were assigned two of four scenarios. They were asked to consider 132 hospital patient care resources- extracted from the AHRQ's hospital surge model- in order to identify the ones that would be critical in their opinion to patient care. The definition for a critical hospital resource was the following: absence of the resource is likely to have a major impact on patient outcomes, i.e., high likelihood of untoward event, possibly death. For items with any disagreement in ranking, we conducted a facilitated discussion (modified Delphi technique) until consensus was reached, which was defined as more than 50% agreement. Intraclass Correlation Coefficients (ICC) were calculated for each scenario, and across all scenarios as a measure of participant agreement on critical resources. For the critical resources common to all scenarios, Kruskal-Wallis test was performed to measure the distribution of scores across all scenarios. Results: Of the 132 hospital resources, 25 were considered critical for all four scenarios by more than 50% of the participants. The number of hospital resources considered to be critical by consensus varied from one scenario to another; 58 for the pandemic influenza scenario, 51 for radiation exposure, 41 for explosives, and 35 for nerve gas scenario. Intravenous crystalloid solution was the only resource ranked by all participants as critical across all scenarios. The agreement in ranking was strong in nerve agent and pandemic influenza (ICC= 0.7 in both), and moderate in explosives (ICC= 0.6) and radiation (ICC= 0.5). Conclusion: In four disaster scenarios, namely, radiation, pandemic influenza, explosives, and nerve gas scenarios; supply of as few as 25 common resources may be considered critical to hospital surge capacity. The absence of any these resources may compromise patient care. More studies are needed to identify critical hospital resources in other disaster scenarios.

54. Assessing cardiac physical examination competence using simulation technology and real patientss

Assessment of residents’ physical examination skills often involves the use of standardized patients lacking physical abnormalities. Simulation technology offers the potential benefit of mimicking physical abnormalities. The current study was undertaken to examine the relationship between physicians’ competence in cardiac physical examination as assessed using simulation technology compared to real patients. An OSCE was created using 3 modalities of cardiac patients: real patients (RP) with cardiac abnormalities, standardized patients (SP) combined with a computer-based audio-video simulation of auscultatory abnormalities and a cardiopulmonary patient simulator (CPS). The same four cardiac diagnoses were tested with each modality. Participants were 28 internists, within 3 years of passing the Royal College of Physicians and Surgeons of Canada’s (RCPSC) Comprehensive Examination in Internal Medicine. At each station, two RCPSC examiners independently rated a participant’s physical examination technique and provided a global rating of clinical competence. The accuracy of a participant’s cardiac diagnosis for each patient was scored separately by two investigators. The inter-rater reliability between examiners, for the global rating outcome, was 0.76 for RP stations, 0.78 for SP stations and 0.75 for CPS stations. The correlations between participants’ global ratings on each modality were: RP vs. SP, r=0.19; RP vs. CPS, r=0.22; SP vs. CPS, r=0.57 (p < 0.01). A number of methodological limitations were highlighted during the study, including difficulties in truly matching patients within and between modalities, differential weighting of components into the examiners’ global ratings based on modality and limitations of case specificity. No modality provided a clear “gold standard” to assess residents’ cardiac physical examination competence. In the context of assessment, until these limitations are addressed, simulation modalities may not be directly interchangeable with real patients. Boulet JR, Swanson DB. Psychometric challenges of using simulations for high-stakes assessment. In: Dunn WF (ed). Simulators in critical care education and beyond. Des Plaines, IL: Society of Critical Care Medicine 2004; 119-30. Hatala R, Kassen BO, Nishikawa J, Cole G, Issenberg SB. Incorporating simulation technology in a Canadian national specialty examination: a descriptive report. Academic Medicine. 2005; 80(6):554-6. Issenberg SB, McGaghie WC, Petrusa ER, Gordon DL, Scalese RJ. Features and uses of high-fidelity medical simulations that lead to effective learning: a BEME systematic review. Med Teach. 2005; 27(1):10-28.

Quantitative assessment of a new preparatory tool for board certification in urology

OBJECTIVE

To analyse the performance of candidates in a Canadian national mock-examination for final-year urology residents with respect to North American speciality examinations in urology.

METHODS

In 1997 the Queen's Urology Examination Skills Training Program (QUEST) was established as an annual national mock examination for final-year Canadian urology residents. It consists of a short answer question component and an objective structured clinical examination. During the 5-year period (1997-2001), 91 final-year residents from all 11 Canadian urology residency-training programmes participated in QUEST and the Royal College of Physicians and Surgeons of Canada certifying examinations (RCPSCE); 43 (47%) of candidates also attempted the American Board of Urology part 1 qualifying examinations (ABU 1). Performance on QUEST was correlated with the RCPSCE and ABU 1 in a blinded fashion after submitting QUEST scores to governing bodies. Thresholds were determined to help to predict a candidate's performance on the RCPSCE and ABU 1, based on QUEST scores.

RESULTS

There was a moderately close correlation between overall QUEST and RCPSCE performance (r = 0.68, P < 0.001) and a moderate correlation between overall QUEST and ABU 1 performance (r = 0.42, P = 0.005). For the following QUEST scores, the probability of success on the RCPSCE was: < 65%, 67% pass; 66-75%, 80% pass; > 75%, 100% pass (P = 0.002). For ABU 1, QUEST overall score of 80% gave a 69% probability of scoring > or = 70% on ABU 1 (P = 0.003).

CONCLUSIONS

QUEST is a moderate predictor of performance on speciality examinations in urology. We consider that the time, effort and expense to maintain QUEST are justified.

HCV and HIV binding lectin, DC-SIGNR, is expressed at all stages of HCV induced liver disease

The process by which hepatitis C virus (HCV) enters cells and the reason for its hepatotropism remain obscure. Recently, the human immunodeficiency virus (HIV) binding lectins, DC-SIGN and DC-SIGNR, were shown to bind HCV. This article reports the expression of DC-SIGN and DC-SIGNR in HCV related liver disease and discusses whether these lectins, in particular DC-SIGNR, are responsible for HCV hepatotropism.

The American Urological Association In-Service Examination: performance correlates with Canadian and American specialty examinations

PURPOSE

To our knowledge literature that correlates American Urological Association In-Service Examination (AUA ISE) scores with performance on final specialty examinations is lacking. We report an analysis of Canadian resident performance on the AUA ISE in relation to the Royal College of Physicians and Surgeons of Canada Certifying Examinations in Urology (RCPSCE) and the American Board of Urology Qualifying Examination Part 1 (ABU 1).

MATERIALS AND METHODS

During the 5-year period 1997 to 2001 AUA ISE scores were analyzed from 91 final year residents attempting the RCPSCE and a subset of 43 of the 91 (47%) attempting ABU 1. Blinded correlation of scores on the AUA ISE with RCPSCE and ABU 1 was performed.

RESULTS

Final year postgraduate year (PGY 5) AUA ISE results correlated strongly with the RCPSCE (r = 0.68, p <0.001) and ABU 1 (r = 0.600, p <0.001). PGY 4 and PGY 3 scores showed a statistically significant correlation, while PGY 2 performance did not meet statistical significance. For the RCPSCE a cutoff point could be determined for pass/failure, namely an AUA ISE raw score of 43% to 55% equaled a 75% pass, a score of 55% to 70% equaled a 88% pass and greater than 70% resulted in a 100% pass. The probability of scoring 70% or greater on ABU 1 as a best guess estimate of successful certification could also be predicted based on AUA ISE raw scores.

CONCLUSIONS

The AUA ISE is a good predictor of performance on Canadian and American specialty examinations with the strongest correlation in the final year of residency.

The effect of material characteristics of shoe soles on muscle activation and energy aspects during running

The purposes of this study were (a) to determine group and individual differences in oxygen consumption during heel-toe running and (b) to quantify the differences in EMG activity for selected muscle groups of the lower extremities when running in shoes with different mechanical heel characteristics. Twenty male runners performed heel-toe running using two shoe conditions, one with a mainly elastic and a visco-elastic heel. Oxygen consumption was quantified during steady state runs of 6 min duration, running slightly above the aerobic threshold providing four pairs of oxygen consumption results for comparison. Muscle activity was quantified using bipolar surface EMG measurements from the tibialis anterior, medial gastrocnemius, vastus medialis and the hamstrings muscle groups. EMG data were sampled for 5 s every minute for the 6 min providing 30 trials. EMG data were compared for the different conditions using an ANOVA (alpha=0.05). The findings of this study showed that changes in the heel material characteristics of running shoes were associated with (a) subject specific changes in oxygen consumption and (b) subject and muscle specific changes in the intensities of muscle activation before heel strike in the lower extremities. It is suggested that further study of these phenomena will help understand many aspects of human locomotion, including work, performance, fatigue and possible injuries.

Effect of object onset on the distribution of visual attention

There now exists considerable evidence to suggest that the appearance of a new object in the visual field captures visual attention. One of the consequences of this attentional capture is that the object initiates a redistribution of attentional resources across visual space. This is classically observed in the precuing paradigm in which the onset of an abrupt cue influences the processing of a subsequently presented target. The present research describes a new phenomenon that occurs as a result of a new object appearing in the visual field. A stimulus presented in a region of space adjacent to a corner of an onsetting object receives an enhancement of processing relative to a stimulus presented adjacent to one of the object's straight edges. With the use of 2 converging methods, evidence is presented that suggests that the effect is a higher order attentional phenomenon whereby greater resources become directed to the corners of objects.

Predicting performance on the Royal College of Physicians and Surgeons of Canada internal medicine written examination

BACKGROUND

Although the written component of the Royal College of Physicians and Surgeons of Canada (RCPSC)internal medicine examination is important for obtaining licensure and certification as a specialist, no methods exist to predict a candidate's performance on the examination.

METHOD

We obtained data from 5 Canadian universities from 1988 to 1998 in order to compare raw scores from the American Internal Medicine In-Training Examination (AIMI-TE) with raw scores and outcomes (pass or fail) of the written component of the RCPSC internal medicine examination.

RESULTS

Mean scores on the AIMI-TE correlated well with scores on the RCPSC internal medicine written examination for all postgraduate years (r = 0.62, r = 0.55 and r = 0.65 for postgraduate years 1, 2 and 3 respectively). Scores above the 50th percentile on the AIMI-TE w/ere predictive of a low failure rate (< 1.5%) on the RCPSC internal medicine written examination, whereas scores at or below the 10th percentile were associated with a high failure rate (about 24%).

INTERPRETATION

Candidates who are eligible to take the written component of the RCPSC certification examination in internal medicine can use the AIMI-TE to predict their performance on the Canadian examination. The AIMI-TE is a useful test for residents in all levels of training, because the examination scores have a strong relation to expected performance on the Canadian examination for each year of postgraduate training.