Challenges simulating the AMOC in climate models.

The latest assessment report from the Intergovernmental Panel on Climate Change concluded that the Atlantic Meridional Overturning Circulation (AMOC) was very likely to decline over the twenty-first century under all emissions scenarios; however, there was low confidence in the magnitude of the decline. Recent research has highlighted that model biases in the mean climate state can affect the AMOC in its mean state, variability and its response to climate change. Hence, understanding and reducing these model biases is critical for reducing uncertainty in the future changes of the AMOC and in its impacts on the wider climate. We discuss how model biases, in particular salinity biases, influence the AMOC and deep convection. We then focus on biases in the UK HadGEM3-GC3-1 climate model and how these biases change with resolution. We also discuss ongoing model development activities that affect these biases, and highlight priorities for improved representation of processes, such as the position of the North Atlantic Current, transports in narrow boundary current, resolution (or improved parameterization) of eddies and spurious numerical mixing in overflows. This article is part of a discussion meeting issue 'Atlantic overturning: new observations and challenges'.

What Are the Care Needs of Families Experiencing Sudden Cardiac Arrest? A Survivor- and Family-Performed Systematic Review, Qualitative Meta-Synthesis, and Clinical Practice Recommendations.

INTRODUCTION: Cardiac arrest care systems are being designed and implemented to address patients', family members', and survivors' care needs. We conducted a systematic review and a meta-synthesis to understand family experiences and care needs during cardiac arrest care to create treatment recommendations. METHODS: We searched eight electronic databases to identify articles. Study findings were extracted, coded and synthesized. Confidence in the quality, coherence, relevance, and adequacy of data underpinning the resulting findings was assessed using GRADE-CERQual methods. RESULTS: In total 4181 studies were screened, and 39 met our inclusion criteria; these studies enrolled 215 survivors and 418 family participants-which includes both co-survivors and bereaved family members. From these studies findings and participant data we identified 5 major analytical themes: (1) When the crisis begins we must respond; (2) Anguish from uncertainty, we need to understand; (3) Partnering in care, we have much to offer; (4) The crisis surrounding the victim, ignore us, the family, no longer; (5) Our family's emergency is not over, now is when we need help the most. Confidence in the evidence statements are provided along with our review findings. DISCUSSION: The family experience of cardiac arrest care is often chaotic, distressing, complex and the aftereffects are long-lasting. Patient and family experiences could be improved for many people. High certainty family care needs identified in this review include rapid recognition and response, improved information sharing, more effective communication, supported presence and participation, or supported absence, and psychological aftercare.

Shiga Toxin-Producing Escherichia coli Infection, Antibiotics, and Risk of Developing Hemolytic Uremic Syndrome: A Meta-analysis.

BACKGROUND: Antibiotic administration to individuals with Shiga toxin-producing Escherichia coli (STEC) infection remains controversial. We assessed if antibiotic administration to individuals with STEC infection is associated with development of hemolytic uremic syndrome (HUS). METHODS: The analysis included studies published up to 29 April 2015, that provided data from patients (1) with STEC infection, (2) who received antibiotics, (3) who developed HUS, and (4) for whom data reported timing of antibiotic administration in relation to HUS. Risk of bias was assessed; strength of evidence was adjudicated. HUS was the primary outcome. Secondary outcomes restricted the analysis to low-risk-of-bias studies employing commonly used HUS criteria. Pooled estimates of the odds ratio (OR) were obtained using random-effects models. RESULTS: Seventeen reports and 1896 patients met eligibility; 8 (47%) studies were retrospective, 5 (29%) were prospective cohort, 3 (18%) were case-control, and 1 was a trial. The pooled OR, including all studies, associating antibiotic administration and development of HUS was 1.33 (95% confidence interval [CI], .89-1.99; I(2) = 42%). The repeat analysis including only studies with a low risk of bias and those employing an appropriate definition of HUS yielded an OR of 2.24 (95% CI, 1.45-3.46; I(2) = 0%). CONCLUSIONS: Overall, use of antibiotics was not associated with an increased risk of developing HUS; however, after excluding studies at high risk of bias and those that did not employ an acceptable definition of HUS, there was a significant association. Consequently, the use of antibiotics in individuals with STEC infections is not recommended.

Alberta Provincial Pediatric EnTeric Infection TEam (APPETITE): epidemiology, emerging organisms, and economics.

BACKGROUND: Each year in Canada there are 5 million episodes of acute gastroenteritis (AGE) with up to 70% attributed to an unidentified pathogen. Moreover, 90% of individuals with AGE do not seek care when ill, thus, burden of disease estimates are limited by under-diagnosing and under-reporting. Further, little is known about the pathogens causing AGE as the majority of episodes are attributed to an "unidentified" etiology. Our team has two main objectives: 1) to improve health through enhanced enteric pathogen identification; 2) to develop economic models incorporating pathogen burden and societal preferences to inform enteric vaccine decision making. METHODS/DESIGN: This project involves multiple stages: 1) Molecular microbiology experts will participate in a modified Delphi process designed to define criteria to aid in interpreting positive molecular enteric pathogen test results. 2) Clinical data and specimens will be collected from children aged 0-18 years, with vomiting and/or diarrhea who seek medical care in emergency departments, primary care clinics and from those who contact a provincial medical advice line but who do not seek care. Samples to be collected will include stool, rectal swabs (N = 2), and an oral swab. Specimens will be tested employing 1) stool culture; 2) in-house multiplex (N = 5) viral polymerase chain reaction (PCR) panel; and 3) multi-target (N = 15) PCR commercially available array. All participants will have follow-up data collected 14 days later to enable calculation of a Modified Vesikari Scale score and a Burden of Disease Index. Specimens will also be collected from asymptomatic children during their well child vaccination visits to a provincial public health clinic. Following the completion of the initial phases, discrete choice experiments will be conducted to enable a better understanding of societal preferences for diagnostic testing and vaccine policy. All of the results obtained will be integrated into economic models. DISCUSSION: This study is collecting novel samples (e.g., oral swabs) from previously untested groups of children (e.g., those not seeking medical care) which are then undergoing extensive molecular testing to shed a new perspective on the epidemiology of AGE. The knowledge gained will provide the broadest understanding of the epidemiology of vomiting and diarrhea of children to date.

The Low-Resolution Version of HadGEM3 GC3.1: Development and Evaluation for Global Climate.

A new climate model, HadGEM3 N96ORCA1, is presented that is part of the GC3.1 configuration of HadGEM3. N96ORCA1 has a horizontal resolution of ~135 km in the atmosphere and 1° in the ocean and requires an order of magnitude less computing power than its medium-resolution counterpart, N216ORCA025, while retaining a high degree of performance traceability. Scientific performance is compared to both observations and the N216ORCA025 model. N96ORCA1 reproduces observed climate mean and variability almost as well as N216ORCA025. Patterns of biases are similar across the two models. In the northwest Atlantic, N96ORCA1 shows a cold surface bias of up to 6 K, typical of ocean models of this resolution. The strength of the Atlantic meridional overturning circulation (16 to 17 Sv) matches observations. In the Southern Ocean, a warm surface bias (up to 2 K) is smaller than in N216ORCA025 and linked to improved ocean circulation. Model El Niño/Southern Oscillation and Atlantic Multidecadal Variability are close to observations. Both the cold bias in the Northern Hemisphere (N96ORCA1) and the warm bias in the Southern Hemisphere (N216ORCA025) develop in the first few decades of the simulations. As in many comparable climate models, simulated interhemispheric gradients of top-of-atmosphere radiation are larger than observations suggest, with contributions from both hemispheres. HadGEM3 GC3.1 N96ORCA1 constitutes the physical core of the UK Earth System Model (UKESM1) and will be used extensively in the Coupled Model Intercomparison Project 6 (CMIP6), both as part of the UK Earth System Model and as a stand-alone coupled climate model.

Implementation of a novel portfolio of structured, curriculum-aligned, simulation-based, cardiothoracic surgery training courses: Evolving the delivery of surgical education.

OBJECTIVE: The provision of high-quality cardiothoracic surgical training faces many challenges. This has generated an increased interest in simulation-based learning, which can provide a less stressful environment for deliberate practice. We developed a comprehensive, structured program of knowledge and simulation-based learning aligned to the official cardiothoracic surgery curriculum. METHODS: A portfolio of 10 curriculum-aligned training courses was designed for cardiothoracic surgical trainees during their 6-year training program. The courses were delivered through a multitude of education methods, including live porcine operating simulation models, and were evaluated through a series of quantitative (5-point Likert-scale) and qualitative assessments. The trainees (n = 15-21 per course) also completed pre- and postsession self-confidence and competency levels for each training episode of knowledge and skill, respectively. In addition, board examination pass rates were assessed in the 3-year periods before and after implementation of the courses. RESULTS: Quantitative analysis of the trainees' feedback demonstrated an extremely positive view of the portfolio of the simulation-based training courses with excellent satisfaction scores (out of 5) for teaching sessions (4.44 ± 0.07), faculty (4.64 ± 0.07), content and materials (4.63 ± 0.07), and facilities (4.73 ± 0.05). The courses have shown a significant improvement in the post-self-confidence (7.98 ± 0.13 vs 5.62 ± 0.20, P < .01) and perceived self-competency (8.10 ± 0.10 vs 5.67 ± 0.11, P < .01) scores for all courses. Examination pass rates significantly improved in the 3-year period after attendance at the courses (94.82% ± 2.34% vs 76.26% ± 3.23%, P < .005). CONCLUSIONS: This study has described the implementation of the only extensive program of structured simulation-based courses that has been developed to complement clinical training in cardiothoracic surgery.

Evaluating Surgical Residents Quickly and Easily Against the Milestones Using Electronic Formative Feedback.

OBJECTIVE: This study was conducted to assess the effectiveness of a newly implemented electronic web-based review system created at our institution for evaluating resident performance relative to established milestones. DESIGN: Retrospective review of data collected from a survey of general surgery faculty and residents. SETTING: Tertiary care teaching hospital system and independent academic medical center. PARTICIPANTS: A total of 12 general surgery faculty and 17 general surgery residents participated in this study. The survey queried the level of satisfaction before and after the adoption of QuickNotes using several statements scored on a 5-point scale, with 1 being the lowest rating as "not satisfied," and 5 being the highest rating as "completely satisfied." RESULTS: The weighted average improvements from pre- to post-QuickNotes implementation for the faculty responding to the survey ranged from 10% to 40%; weighted average improvements for the residents responding to the survey ranged from 5% to 73%. For the survey of faculty, both sets of weighted averages tended to be higher than the weighted average for the resident's survey responses. The highest rated topic was the faculty's level of satisfaction with the "frequency to provide feedback" with a post-QuickNotes implementation weighted average of 4.25, closely followed by the residents' level of satisfaction with the "evaluation includes positive feedback" with a post-QuickNotes implementation weighted average of 4.24. The most notable increases in weighted averages from preimplementation to postimplementation were noted for "overall satisfaction" (20% increase for faculty, 37% for residents), "reflects actual criteria that matter" (36% increase for faculty, 73% for residents), faculty "opportunity for follow-up" (increase of 40%), resident "reflects overall trends" (increase of 37%), and resident "provides new information about my performance" (increase of 37%). CONCLUSIONS: Our institutional adoption of QuickNotes into the resident evaluation process has been associated with an overall increased level of satisfaction in the evaluation process by both faculty and residents. The design of QuickNotes facilitates its integration into the resident training environment, as it is web based, easy to use, and has no additional cost over the standard New Innovations subscription. Although it is designed to capture snapshots of trainee behavior and performance, monthly reports through QuickNotes can be used effectively in conjunction with the more traditional end-of-rotation evaluations to show trends, identify areas of strength that should be reinforced, demonstrate areas needing improvement, allow for a more tailored individual education plan to be developed, and permit a more accurate determination of milestone progression.

A comparison of the efficacy of 70% v/v isopropyl alcohol with either 0.5% w/v or 2% w/v chlorhexidine gluconate for skin preparation before harvest of the long saphenous vein used in coronary artery bypass grafting.

BACKGROUND: Chlorhexidine gluconate (CHG) is often recommended for skin antisepsis; however, the most efficacious concentration is currently unclear. Our objective was to compare the efficacy of 70% isopropyl alcohol (IPA) containing either 0.5% or 2% CHG for antiseptic skin preparation in patients undergoing coronary artery bypass grafting. METHODS: One hundred patients were randomized to 1 of the 2 CHG concentrations. The designated antiseptic was applied to the skin of the operative site of patients before long saphenous vein harvest. Bacterial counts on the skin incision site were determined at various time points to assess any immediate and persistent antimicrobial activity. The number of patients developing surgical site infection was also determined. RESULTS: The total numbers of microorganisms on the skin 2 minutes after skin antisepsis and after wound closure was lower with 2% CHG/70% IPA compared with 0.5% CHG/70% IPA (P = .033 and P = .016, respectively). Six of 41 patients in the 0.5% CHG/70%IPA group developed a superficial surgical site infection compared with 2 of 44 patients in the 2% CHG/70% IPA group (relative risk, 3.22; 95% confidence interval, 0.63-22.75; P = .147). CONCLUSIONS: Isopropyl alcohol (70%) containing 2% CHG compared with 0.5% CHG reduces the number of microorganisms detectable on a surgical patient's skin perioperatively.

Clinical outcomes of Carbomedics Top Hat valve with a robust follow-up system.

AIM: Late failure of bioprosthetic valves may limit their use in patients < 60 years. The superior hemodynamic performance offered by the Carbomedics Top Hat supraannular valve enables greater effective orifice areas to be achieved. The aim of this study was to assess the clinical outcomes of this valve, using a robust follow-up system. METHODS: Patients who underwent aortic valve replacement with or without coronary artery bypass grafting between July 1997 and January 2010 with Carbomedics supraannular Top Hat valves were identified. Details of readmissions and late deaths were obtained from the National Hospital Episodes Statistics data and the Office of National Statistics, tracked by the Quality and Outcomes Research Unit. Late complications associated with this prosthesis were evaluated. RESULTS: Of 253 patients identified, 181 underwent isolated aortic valve replacement and 72 had aortic valve replacement with coronary artery bypass grafting. The 30-day mortality was 1.6%, and 5- and 10-year survival rates were 91.4% and 80.5%, respectively. Detailed readmission data were available after 2001 (n = 170). Two (1.2%) patients required reoperation for endocarditis and pannus formation. Of the 17 late deaths in this subset, 4 were attributable to cardiac causes. One patient was treated for heart failure, and 2 developed bleeding complications. CONCLUSIONS: Implantation of the Carbomedics Top Hat supraannular valve in our unit resulted in satisfactory in-hospital and midterm survival with low incidences of endocarditis and late heart failure.

Standards for heart valve surgery in a 'Heart Valve Centre of Excellence'.

Surgical centres of excellence should include multidisciplinary teams with specialist expertise in imaging, clinical assessment and surgery for patients with heart valve disease. There should be structured training programmes for the staff involved in the periprocedural care of the patient and these should be overseen by national or international professional societies. Good results are usually associated with high individual and centre volumes, but this relationship is complex. Results of surgery should be published by centre and should include rates of residual regurgitation for mitral repairs and reoperation rates matched to the preoperative pathology and risk.

UK specialist cardiothoracic management of thoracic injuries in military casualties sustained in the wars in Iraq and Afghanistan.

OBJECTIVES: Outcomes of casualties with thoracic wounding at the deployed UK military field hospital (Role 3(R3)) have been previously described. The level of cardiothoracic specialist input required on repatriation to the UK is less clear. This study aimed to assess the outcomes of casualties with thoracic injuries repatriated to the UK (Role 4 (R4)) and evaluate the impact of specialist cardiothoracic care. METHODS: Casualties were identified through the UK Joint Theatre Trauma Registry. Casualties coded for pulmonary contusions and/or thoracotomy between March 2006 and March 2011 were identified and case-notes reviewed. Subgroup analysis was performed for patients with a documented thoracic abbreviated injury score ≥3. RESULTS: One hundred and eighty-two UK patients were admitted to UK R4 coded to have a thoracic injury; overall mortality 4.9%. Ninety-three were classified as a thoracic AIS of ≥3; mortality 6.5%. Sixty-four were coded for pulmonary contusions and/or thoracotomy; mortality 1.6, and 66% had thoracic AIS ≥3. Improvised explosive devices injured 54 and 62% had a penetrating injury. Pulmonary contusions were present in 70%; 43% developed a chest infection. Thoracotomy/sternotomy was performed in 13 casualties in R3; 3 re-explored in R4. Oscillatory ventilation and extracorporeal membrane oxygenation was required in 1 case. Cardiothoracic surgery was involved in managing 39% (n = 24) of cases; 11 (45%) required surgical intervention and 19 (79%) had cardiothoracic outpatient follow-up. CONCLUSION: Morbidity and mortality associated with significant thoracic injury is low at UK R4. Follow-up is required to assess long-term outcomes. Specialist cardiothoracic support and intervention was required in the management of complex thoracic trauma. Early specialist support at R4 may improve morbidity and outcomes associated with life-threatening thoracic injury.

Stab to the chest causing severe great vessel injury.

Penetrating trauma has increased in developed and urban environments. Pulmonary artery injury is rare, but can be associated with significant morbidity. We report a case of delayed cardiac arrest following a stab injury to the chest. The patient had active great vessel bleeding and required extensive surgical intervention. Clinicians should have a high index of suspicion for life-threatening thoracic injuries following a stab injury to the chest, despite initial clinical stability or negative baseline radiological findings.

Patient-prosthesis mismatch in patients with aortic stenosis undergoing isolated aortic valve replacement does not affect survival.

BACKGROUND: Data suggest that patient-prosthesis mismatch (PPM) adversely effects late survival after aortic valve replacement (AVR). This study examined the incidence and implications of PPM in patients undergoing isolated AVR. METHODS: Prospectively collected data on patients undergoing isolated AVR for aortic stenosis between January 1, 1997 and December 31, 2007 were analyzed. The projected effective valve orifice area from in vivo data was indexed to body surface area (EOAi). PPM was defined as moderate for EOAi of < or = 0.85 cm(2)/m(2) and severe if < or = 0.6 cm(2)/m(2). The reference group comprised patients with EOAi > 0.85 cm(2)/m(2). The effect of PPM on postoperative survival was assessed by multivariate analysis. RESULTS: Of 801 patients, PPM was severe in 48 (6.0%), moderate in 462 (57.8%), and nonexistent in 291 (36.4%). Mismatch was associated with increasing age and female gender, thus resulting in an increase in the EuroSCORE (reference group, 4.9 +/- 2.6; moderate PPM, 5.8 +/- 2.4; and severe PPM, 6.1+/-2.1; p < 0.001). PPM did not significantly increase hospital mortality. Four deaths occurred in the reference group (1.4%), 12 in the moderate PPM (2.6%), and none in the severe PPM group (p = 0.311). The 5-year survival estimates were 83% in reference, 86% in moderate PPM, and 89% in severe PPM (p = 0.25). By multivariate analysis, PPM was not an independent risk factor for reduced in-hospital or late survival. CONCLUSIONS: Moderate PPM is common in patients undergoing AVR for aortic stenosis, but severe mismatch is rare. Patients with PPM have similar early and late postoperative survival rate.

Informatics and knowledge translation.

To ensure that the benefits of knowledge translation synthesis are accessible to care providers at the point of decision-making, fast, efficient, usable clinical information systems are required. Medical informatics appears to hold the greatest promise to be able to create systems with the necessary capacity and functionality. Emergency medicine needs to be actively engaged at all levels of the process. This includes driving the development and filtering of emergency-specific synopses and summaries. It requires advocating for hardware and software that suit the needs of the emergency department environment. It is increasingly important to educate and participate on committees with funders and policy-makers to ensure they support this growing evolution. To determine the outcome of these initiatives, careful evaluation is required to inform the discussion. End-users need to be actively involved in the development and usability testing of clinical information retrieval technology and clinical decision-support systems and make certain relevant best evidence is readily accessible and formatted to meet the needs of the working emergency physician. The integration of knowledge translation into clinical practice, and the impact of delivering electronic clinical decision-support, requires methodologically sound studies to confirm or refute its benefits and guide future development of medical informatics.