A neural network to predict the knee adduction moment in patients with osteoarthritis using anatomical landmarks obtainable from 2D video analysis

OBJECTIVE

The knee adduction moment (KAM) can inform treatment of medial knee osteoarthritis; however, measuring the KAM requires an expensive gait analysis laboratory. We evaluated the feasibility of predicting the peak KAM during natural and modified walking patterns using the positions of anatomical landmarks that could be identified from video analysis.

METHOD

Using inverse dynamics, we calculated the KAM for 86 individuals (64 with knee osteoarthritis, 22 without) walking naturally and with foot progression angle modifications. We trained a neural network to predict the peak KAM using the 3-dimensional positions of 13 anatomical landmarks measured with motion capture (3D neural network). We also trained models to predict the peak KAM using 2-dimensional subsets of the dataset to simulate 2-dimensional video analysis (frontal and sagittal plane neural networks). Model performance was evaluated on a held-out, 8-person test set that included steps from all trials.

RESULTS

The 3D neural network predicted the peak KAM for all test steps with r2( Murray et al., 2012) 2 = 0.78. This model predicted individuals' average peak KAM during natural walking with r2( Murray et al., 2012) 2 = 0.86 and classified which 15° foot progression angle modifications reduced the peak KAM with accuracy = 0.85. The frontal plane neural network predicted peak KAM with similar accuracy (r2( Murray et al., 2012) 2 = 0.85) to the 3D neural network, but the sagittal plane neural network did not (r2( Murray et al., 2012) 2 = 0.14).

CONCLUSION

Using the positions of anatomical landmarks from motion capture, a neural network accurately predicted the peak KAM during natural and modified walking. This study demonstrates the feasibility of measuring the peak KAM using positions obtainable from 2D video analysis.

Trends in Intensive Care for Patients with COVID-19 in England, Wales, and Northern Ireland

Rationale: By describing trends in intensive care for patients with coronavirus disease (COVID-19) we aim to support clinical learning, service planning, and hypothesis generation.Objectives: To describe variation in ICU admission rates over time and by geography during the first wave of the epidemic in England, Wales, and Northern Ireland; to describe trends in patient characteristics on admission to ICU, first-24-hours physiology in ICU, processes of care in ICU and patient outcomes; and to explore deviations in trends during the peak period.Methods: A cohort of 10,741 patients with COVID-19 in the Case Mix Program national clinical audit from February 1 to July 31, 2020, was used. Analyses were stratified by time period (prepeak, peak, and postpeak periods) and geographical region. Logistic regression was used to estimate adjusted differences in 28-day in-hospital mortality between periods.Measurements and Main Results: Admissions to ICUs peaked almost simultaneously across regions but varied 4.6-fold in magnitude. Compared with patients admitted in the prepeak period, patients admitted in the postpeak period were slightly younger but with higher degrees of dependency and comorbidity on admission to ICUs and more deranged first-24-hours physiology. Despite this, receipt of invasive ventilation and renal replacement therapy decreased, and adjusted 28-day in-hospital mortality was reduced by 11.8% (95% confidence interval, 8.7%-15.0%). Many variables exhibited u-shaped or n-shaped curves during the peak.Conclusions: The population of patients with COVID-19 admitted to ICUs, and the processes of care in ICUs, changed over the first wave of the epidemic. After adjustment for important risk factors, there was a substantial improvement in patient outcomes.

Reduced exposure to vasopressors through permissive hypotension to reduce mortality in critically ill people aged 65 and over: the 65 RCT

BACKGROUND

Vasopressors are administered to critical care patients to avoid hypotension, which is associated with myocardial injury, kidney injury and death. However, they work by causing vasoconstriction, which may reduce blood flow and cause other adverse effects. A mean arterial pressure target typically guides administration. An individual patient data meta-analysis (Lamontagne F, Day AG, Meade MO, Cook DJ, Guyatt GH, Hylands M, et al. Pooled analysis of higher versus lower blood pressure targets for vasopressor therapy septic and vasodilatory shock. Intensive Care Med 2018;44:12-21) suggested that greater exposure, through higher mean arterial pressure targets, may increase risk of death in older patients.

OBJECTIVE

To estimate the clinical effectiveness and cost-effectiveness of reduced vasopressor exposure through permissive hypotension (i.e. a lower mean arterial pressure target of 60-65 mmHg) in older critically ill patients.

DESIGN

A pragmatic, randomised clinical trial with integrated economic evaluation.

SETTING

Sixty-five NHS adult general critical care units.

PARTICIPANTS

Critically ill patients aged ≥ 65 years receiving vasopressors for vasodilatory hypotension.

INTERVENTIONS

Intervention - permissive hypotension (i.e. a mean arterial pressure target of 60-65 mmHg). Control (usual care) - a mean arterial pressure target at the treating clinician's discretion.

MAIN OUTCOME MEASURES

The primary clinical outcome was 90-day all-cause mortality. The primary cost-effectiveness outcome was 90-day incremental net monetary benefit. Secondary outcomes included receipt and duration of advanced respiratory and renal support, mortality at critical care and acute hospital discharge, and questionnaire assessment of cognitive decline and health-related quality of life at 90 days and 1 year.

RESULTS

Of 2600 patients randomised, 2463 (permissive hypotension, n = 1221; usual care, n = 1242) were analysed for the primary clinical outcome. Permissive hypotension resulted in lower exposure to vasopressors than usual care [mean duration 46.0 vs. 55.9 hours, difference -9.9 hours (95% confidence interval -14.3 to -5.5 hours); total noradrenaline-equivalent dose 31.5 mg vs. 44.3 mg, difference -12.8 mg (95% CI -18.0 mg to -17.6 mg)]. By 90 days, 500 (41.0%) patients in the permissive hypotension group and 544 (43.8%) patients in the usual-care group had died (absolute risk difference -2.85%, 95% confidence interval -6.75% to 1.05%; p = 0.154). Adjustment for prespecified baseline variables resulted in an odds ratio for 90-day mortality of 0.82 (95% confidence interval 0.68 to 0.98) favouring permissive hypotension. There were no significant differences in prespecified secondary outcomes or subgroups; however, patients with chronic hypertension showed a mortality difference favourable to permissive hypotension. At 90 days, permissive hypotension showed similar costs to usual care. However, with higher incremental life-years and quality-adjusted life-years in the permissive hypotension group, the incremental net monetary benefit was positive, but with high statistical uncertainty (£378, 95% confidence interval -£1347 to £2103).

LIMITATIONS

The intervention was unblinded, with risk of bias minimised through central allocation concealment and a primary outcome not subject to observer bias. The control group event rate was higher than anticipated.

CONCLUSIONS

In critically ill patients aged ≥ 65 years receiving vasopressors for vasodilatory hypotension, permissive hypotension did not significantly reduce 90-day mortality compared with usual care. The absolute treatment effect on 90-day mortality, based on 95% confidence intervals, was between a 6.8-percentage reduction and a 1.1-percentage increase in mortality.

FUTURE WORK

Future work should (1) update the individual patient data meta-analysis, (2) explore approaches for evaluating heterogeneity of treatment effect and (3) explore 65 trial conduct, including use of deferred consent, to inform future trials.

TRIAL REGISTRATION

Current Controlled Trials ISRCTN10580502.

FUNDING

This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 25, No. 14. See the NIHR Journals Library website for further project information.

CT diagnosis of ilioinguinal lymph node metastases in melanoma using radiological characteristics beyond size and asymmetry

Background

Diagnosis of lymph node (LN) metastasis in melanoma with non-invasive methods is challenging. The aim of this study was to evaluate the diagnostic accuracy of six LN characteristics on CT in detecting melanoma-positive ilioinguinal LN metastases, and to determine whether inguinal LN characteristics can predict pelvic LN involvement.

Methods

This was a single-centre retrospective study of patients with melanoma LN metastases at a tertiary cancer centre between 2008 and 2016. Patients who had preoperative contrast-enhanced CT assessment and ilioinguinal LN dissection were included. CT scans containing significant artefacts obscuring the pelvis were excluded. CT scans were reanalysed for six LN characteristics (extracapsular spread (ECS), minimum axis (MA), absence of fatty hilum (FH), asymmetrical cortical nodule (CAN), abnormal contrast enhancement (ACE) and rounded morphology (RM)) and compared with postoperative histopathological findings.

Results

A total of 90 patients were included. Median age was 58 (range 23–85) years. Eighty-eight patients (98 per cent) had pathology-positive inguinal disease and, of these, 45 (51 per cent) had concurrent pelvic disease. The most common CT characteristics found in pathology-positive inguinal LNs were MA greater than 10 mm (97 per cent), ACE (80 per cent), ECS (38 per cent) and absence of RM (38 per cent). In multivariable analysis, inguinal LN characteristics on CT indicative of pelvic disease were RM (odds ratio (OR) 3.3, 95 per cent c.i. 1.2 to 8.7) and ECS (OR 4.2, 1.6 to 11.3). Cloquet’s node is known to be a poor predictor of pelvic spread. Pelvic LN disease was present in 50 per cent patients, but only 7 per cent had a pathology-positive Cloquet’s node.

Conclusion

Additional CT radiological characteristics, especially ECS and RM, may improve diagnostic accuracy and aid clinical decisions regarding the need for inguinal or ilioinguinal dissection.

Genome-wide surveillance of transcription errors in response to genotoxic stress

Mutagenic compounds are a potent source of human disease. By inducing genetic instability, they can accelerate the evolution of human cancers or lead to the development of genetically inherited diseases. Here, we show that in addition to genetic mutations, mutagens are also a powerful source of transcription errors. These errors arise in dividing and nondividing cells alike, affect every class of transcripts inside cells, and, in certain cases, greatly exceed the number of mutations that arise in the genome. In addition, we reveal the kinetics of transcription errors in response to mutagen exposure and find that DNA repair is required to mitigate transcriptional mutagenesis after exposure. Together, these observations have far-reaching consequences for our understanding of mutagenesis in human aging and disease, and suggest that the impact of DNA damage on human physiology has been greatly underestimated.

Idiopathic systemic capillary leak syndrome (Clarkson's disease) presenting with recurrent hypovolemic shock

A 49-year old male with a past medical history of myocardial infarction and compartment syndromes requiring fasciotomies presented on five occasions with hypovolemic shock. We describe his admissions and presumptive diagnoses which required large volumes of intravenous fluids, admission to intensive care for vasopressors and renal replacement therapy. The presentations were always precipitated by a prodrome of fatigue and pre-syncopal episodes. On his last admission, a diagnosis of Idiopathic systemic capillary leak syndrome (ISCLS), also known as Clarkson's Disease, was reached. He is currently receiving high dose intravenous immunoglobulins on a monthly basis.

Prognostic Factors for 30-Day Mortality in Critically Ill Patients With Coronavirus Disease 2019: An Observational Cohort Study

OBJECTIVES

To identify characteristics that predict 30-day mortality among patients critically ill with coronavirus disease 2019 in England, Wales, and Northern Ireland.

DESIGN

Observational cohort study.

SETTING

A total of 258 adult critical care units.

PATIENTS

A total of 10,362 patients with confirmed coronavirus disease 2019 with a start of critical care between March 1, 2020, and June 22, 2020, of whom 9,990 were eligible (excluding patients with a duration of critical care less than 24 hr or missing core variables).

MEASUREMENTS AND MAIN RESULTS

The main outcome measure was time to death within 30 days of the start of critical care. Of 9,990 eligible patients (median age 60 yr, 70% male), 3,933 died within 30 days of the start of critical care. As of July 22, 2020, 189 patients were still receiving critical care and a further 446 were still in acute hospital. Data were missing for between 0.1% and 7.2% of patients across prognostic factors. We imputed missing data ten-fold, using fully conditional specification and continuous variables were modeled using restricted cubic splines. Associations between the candidate prognostic factors and time to death within 30 days of the start of critical care were determined after adjustment for multiple variables with Cox proportional hazards modeling. Significant associations were identified for age, ethnicity, deprivation, body mass index, prior dependency, immunocompromise, lowest systolic blood pressure, highest heart rate, highest respiratory rate, Pao2/Fio2 ratio (and interaction with mechanical ventilation), highest blood lactate concentration, highest serum urea, and lowest platelet count over the first 24 hours of critical care. Nonsignificant associations were found for sex, sedation, highest temperature, and lowest hemoglobin concentration.

CONCLUSIONS

We identified patient characteristics that predict an increased likelihood of death within 30 days of the start of critical care for patients with coronavirus disease 2019. These findings may support development of a prediction model for benchmarking critical care providers.

COVID-19 in critical care: epidemiology of the first epidemic wave across England, Wales and Northern Ireland

PURPOSE

To describe critical care patients with COVID-19 across England, Wales and Northern Ireland and compare them with a historic cohort of patients with other viral pneumonias (non-COVID-19) and with international cohorts of COVID-19.

METHODS

Extracted data on patient characteristics, acute illness severity, organ support and outcomes from the Case Mix Programme, the national clinical audit for adult critical care, for a prospective cohort of patients with COVID-19 (February to August 2020) are compared with a recent retrospective cohort of patients with other viral pneumonias (non-COVID-19) (2017-2019) and with other international cohorts of critical care patients with COVID-19, the latter identified from published reports.

RESULTS

10,834 patients with COVID-19 (70.1% male, median age 60 years, 32.6% non-white ethnicity, 39.4% obese, 8.2% at least one serious comorbidity) were admitted across 289 critical care units. Of these, 36.9% had a PaO₂/FiO₂ ratio of ≤ 13.3 kPa (≤ 100 mmHg) consistent with severe ARDS and 72% received invasive ventilation. Acute hospital mortality was 42%, higher than for 5782 critical care patients with other viral pneumonias (non-COVID-19) (24.7%), and most COVID-19 deaths (88.7%) occurred before 30 days. Meaningful international comparisons were limited due to lack of standardised reporting.

CONCLUSION

Critical care patients with COVID-19 were disproportionately non-white, from more deprived areas and more likely to be male and obese. Conventional severity scoring appeared not to adequately reflect their acute severity, with the distribution across PaO₂/FiO₂ ratio categories indicating acutely severe respiratory disease. Critical care patients with COVID-19 experience high mortality and place a great burden on critical care services.

Critical care outcomes, for the first 200 patients with confirmed COVID-19, in England, Wales and Northern Ireland: A report from the ICNARC Case Mix Programme

Background

Early in a pandemic, outcomes are biased towards patients with shorter durations of critical illness. We describe 60-day outcomes for patients critically ill with confirmed COVID-19 and explore the potential bias in the weekly reported data by ICNARC.

Methods

First 200 consecutive patients with confirmed COVID-19, admitted for critical care in England, Wales and Northern Ireland, followed-up for a minimum of 60 days from admission. Outcomes included survival and duration of critical care, receipt/duration of organ support in critical care and hospital survival.

Results

Mean age was 62.6 years, 70.5% were male, 52.0% were white, 39.2% obese and 9.0% had serious comorbidities. Median APACHE II score was 16 (IQR 12, 19). After 60 days, 83 (41.5%) patients had been discharged from hospital, 15 (7.5%) had been discharged from critical care but remained in hospital, 1 (0.5%) was still receiving critical care, 90 (45.0%) had died while receiving critical care and 11 (5.5%) had died in hospital after discharge from critical care. Median duration of critical care was 14.0 days (IQR 6.1, 23.0) for survivors and 10.0 days (IQR 5.0, 16.0) for non-survivors of critical care. Overall, 158 (79.0%) patients received advanced respiratory support for a median of 13 (IQR 8, 20) calendar days. Compared with weekly reports during the pandemic, critical care mortality started higher than but then decreased below that of the first 200 consecutive patients. Duration of critical care, for both survivors and non-survivors increased over time; however, both were still lower than those for the first 200 consecutive patients. Receipt and duration of organ support increased to values similar to those for the first 200 consecutive patients.

Conclusion

COVID-19 in critical care has high mortality and places a large burden on resources. Analysis of preliminary data with limited follow-up should be interpreted with caution, particularly for future planning in a pandemic.

Induction of Sustained Clinical Remission in Early Axial Spondyloarthritis Following Certolizumab Pegol Treatment: 48-Week Outcomes from C-OPTIMISE

INTRODUCTION

Achievement of remission is a key treatment goal for patients with axial spondyloarthritis (axSpA). C-OPTIMISE assessed achievement of sustained clinical remission in patients with axSpA, including radiographic (r) and non-radiographic (nr) axSpA, during certolizumab pegol (CZP) treatment, and subsequent maintenance of remission following CZP dose continuation, dose reduction or withdrawal. Here, we report outcomes from the first 48 weeks (induction period) of C-OPTIMISE, during which patients received open-label CZP.

METHODS

C-OPTIMISE (NCT02505542) was a two-part, multicenter, phase 3b study in adult patients with early axSpA (r-/nr-axSpA), including a 48-week open-label induction period followed by a 48-week maintenance period. Patients with active adult-onset axSpA, < 5 years' symptom duration, and fulfilling Assessment of SpondyloArthritis international Society classification criteria, were included. During the induction period, patients received a loading dose of CZP 400 mg at weeks 0, 2, and 4, followed by CZP 200 mg every 2 weeks (Q2W) up to week 48. The main outcome of the 48-week induction period was the achievement of sustained clinical remission (defined as an Ankylosing Spondylitis Disease Activity Score [ASDAS] < 1.3 at week 32 and < 2.1 at week 36 [or vice versa], and < 1.3 at week 48).

RESULTS

In total, 736 patients (407 with r-axSpA, 329 with nr-axSpA) were enrolled into the study. At week 48, 43.9% (323/736) of patients achieved sustained remission, including 42.8% (174/407) of patients with r-axSpA and 45.3% (149/329) with nr-axSpA. Patients also demonstrated substantial improvements in axSpA symptoms, MRI outcomes and quality of life measures. Adverse events occurred in 67.9% (500/736) of patients, of which 6.0% (44/736) were serious.

CONCLUSIONS

Over 40% of patients with early axSpA achieved sustained remission during 48 weeks of open-label CZP treatment. Additionally, patients across the axSpA spectrum demonstrated substantial improvements in imaging outcomes and quality of life following treatment. No new safety signals were identified.

TRIAL REGISTRATION

NCT02505542.

Blood Pressure Measurement Error in Children: Lessons in Measurement Reliability

BACKGROUND AND PURPOSE

Blood pressure measurement represents the pressure exerted during heart ejection and filling. There are several ways to measure blood pressure and a valid measure is essential. The purpose of this study was to evaluate the approach to noninvasive blood pressure measurement in children.

METHODS

Blood pressure measurements were taken using the automatic Phillips MP30 monitor and compared against Welch Allyn blood pressure cuffs with Medline manual sphygmomanometers.

RESULTS

A total of 492 measurements were taken on 82 subjects, and they demonstrated comparability between automatic and manual devices.

CONCLUSIONS

Although our study indicated acceptable agreement between automatic and manual blood pressure measurement, it also revealed measurement error remains a concern, with sample size, study protocol, training, and environment all playing a role.

The landscape of paediatric in-hospital cardiac arrest in the United Kingdom National Cardiac Arrest Audit

AIM

To report the patient characteristics and clinical outcome of paediatric in-hospital cardiac arrest in the United Kingdom (UK) National Cardiac Arrest Audit (NCAA) database.

METHODS

Analysis of all recorded paediatric cardiac arrests in the NCAA dataset over a seven-year period ending on 31 December 2018, within acute children's hospitals (including standalone paediatric hospitals and hospitals with tertiary paediatric services) and acute general hospitals participating in NCAA. In this period 1456 patients (with 1580 events), 1 month to 16 years of age, received chest compressions and/or defibrillation and were attended by a hospital-based resuscitation team in response to an emergency call. The main outcome measure was survival to discharge.

RESULTS

For this cohort of paediatric in-hospital cardiac arrest patients the overall rates of sustained return of spontaneous circulation (ROSC) were 69.1% with unadjusted survival to hospital discharge of 54.2%. The presenting rhythm was shockable in 4.3% of events and non-shockable in 82.1% (remainder undetermined); rates of survival to hospital discharge associated with these rhythms were 63.9% and 51.7%. A difference in outcomes was observed between Children's hospitals and acute general hospitals with ROSC rates of 79.1% and 55.5% respectively and survival to hospital discharge rates of 57.7% and 49.3% respectively.

CONCLUSIONS

These first results from the NCAA database describing the outcome of paediatric in-hospital cardiac arrest in UK hospitals will serve as a benchmark from which to assess the future impact of changes in service delivery, organisation and treatment for in-hospital cardiac arrest in young people. Outcomes for specialist paediatric centres should be studied further as higher rates of ROSC and survival to hospital discharge were observed.

Treatment of Coronavirus Disease 2019 (COVID-19) Patients with Convalescent Plasma

Coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2, has spread globally, and no proven treatments are available. Convalescent plasma therapy has been used with varying degrees of success to treat severe microbial infections for >100 years. Patients (n = 25) with severe and/or life-threatening COVID-19 disease were enrolled at the Houston Methodist hospitals from March 28, 2020, to April 14, 2020. Patients were transfused with convalescent plasma, obtained from donors with confirmed severe acute respiratory syndrome coronavirus 2 infection who had recovered. The primary study outcome was safety, and the secondary outcome was clinical status at day 14 after transfusion. Clinical improvement was assessed on the basis of a modified World Health Organization six-point ordinal scale and laboratory parameters. Viral genome sequencing was performed on donor and recipient strains. At day 7 after transfusion with convalescent plasma, nine patients had at least a one-point improvement in clinical scale, and seven of those were discharged. By day 14 after transfusion, 19 (76%) patients had at least a one-point improvement in clinical status, and 11 were discharged. No adverse events as a result of plasma transfusion were observed. Whole genome sequencing data did not identify a strain genotype-disease severity correlation. The data indicate that administration of convalescent plasma is a safe treatment option for those with severe COVID-19 disease.

A Service Development Evaluation of Retrospective Data Exploring Prophylactic Risk-Reducing Advice for Patients with Gynecological Cancers

Objective: Patients at risk of lymphedema following pelvic lymph-node dissection for gynecologic cancers (PLND) often receive prophylactic risk-reducing advice and compression stockings to wear for 6 months, without clear supportive evidence or evaluation of the impact. This study explored if these measures affected lymphedema development 1 year after PLND. Materials and Methods: Relevant data of patients who had undergone PLND over a 10-year period were allocated into 2 groups: Group A had data on patients who received prophylactic lymphedema risk-reduction advice and compression stockings for to wear for 6 months. Group B had data on patients who did not receive prophylactic lymphedema risk-reduction advice or prophylactic compression stockings. Exclusion criteria were preexisting swelling, medication that increased edema, symptom management during end-of-life care. Data were analyzed for statistical significance between the groups. Results: Of 108 patients, 19/60 patients (35%) in Group A and 6/48 (12.5%) patients in Group B developed lymphedema. There was no statistical difference between the groups for the presence of lymphedema. Conclusions: This study did not show that prophylactic compression stockings reduced the development of lymphedema but suggested an increased awareness of the signs and symptoms of lymphedema among patients who received risk-reducing education and the compression garments. These results should be tested in a prospective, controlled trial, and suggest that a change in current clinical practice is appropriate. (J GYNECOL SURG 36:198).

Evaluating the clinical and cost-effectiveness of permissive hypotension in critically ill patients aged 65 years or over with vasodilatory hypotension: Statistical and health economic analysis plan for the 65 trial in article

The 65 trial is a pragmatic, multicentre, parallel-group, open-label, randomised clinical trial of permissive hypotension (targeting a mean arterial pressure target of 60-65 mmHg during vasopressor therapy) versus usual care in critically ill patients aged 65 years or over with vasodilatory hypotension. The trial will recruit 2600 patients from 65 United Kingdom adult general critical care units. The primary outcome is all-cause mortality at 90 days. An economic evaluation is embedded. This paper describes the proposed statistical and health economic analysis for the 65 trial.

Exploring How Pediatric Residents Develop Adaptive Expertise in Communication: The Importance of "Shifts" in Understanding Patient and Family Perspectives

PURPOSE

Communication with patients and families can be complex, especially in challenging discussions. To communicate effectively, expert physicians must often use flexible approaches. This innovative use of knowledge to handle complexity is an essential capability of adaptive expertise. Despite its importance for effective communication and implications for medical education, little is known about how adaptive expertise develops in trainees. The purpose of this study was to explore how pediatric residents developed adaptive expertise in communication.

METHOD

A constructivist grounded theory study, using observations of physician-patient communication and semistructured interviews as data sources and purposeful sampling of 10 pediatric subspecialty residents at the University of Toronto, was conducted in 2016-2017. Data collection and analysis occurred iteratively, and themes were identified through the research team's constant comparative analysis.

RESULTS

Residents navigated challenging discussions with patients and families by enabling them to express their own narratives and integrating these with their medical knowledge to provide care. At times, a "shift" in the residents' understanding of the families' perspectives was needed to effectively navigate the discussion. Residents used this shift purposefully to create new communication strategies, resulting in an opportunity for learning.

CONCLUSIONS

"Shifts" are defined as adjustments in the resident's understanding of a family's perspective that affect clinical care. Analysis suggests that these "shifts" can be understood to support development of adaptive expertise. The workplace learning environment promoted this development by providing opportunities that prepared residents for future learning through active experimentation, offering multiple perspectives and enhancing deeper conceptual learning.