PRECISION-TBI: a study protocol for a vanguard prospective cohort study to enhance understanding and management of moderate to severe traumatic brain injury in Australia

INTRODUCTION

Traumatic brain injury (TBI) is a heterogeneous condition in terms of pathophysiology and clinical course. Outcomes from moderate to severe TBI (msTBI) remain poor despite concerted research efforts. The heterogeneity of clinical management represents a barrier to progress in this area. PRECISION-TBI is a prospective, observational, cohort study that will establish a clinical research network across major neurotrauma centres in Australia. This network will enable the ongoing collection of injury and clinical management data from patients with msTBI, to quantify variations in processes of care between sites. It will also pilot high-frequency data collection and analysis techniques, novel clinical interventions, and comparative effectiveness methodology.

METHODS AND ANALYSIS

PRECISION-TBI will initially enrol 300 patients with msTBI with Glasgow Coma Scale (GCS) <13 requiring intensive care unit (ICU) admission for invasive neuromonitoring from 10 Australian neurotrauma centres. Demographic data and process of care data (eg, prehospital, emergency and surgical intervention variables) will be collected. Clinical data will include prehospital and emergency department vital signs, and ICU physiological variables in the form of high frequency neuromonitoring data. ICU treatment data will also be collected for specific aspects of msTBI care. Six-month extended Glasgow Outcome Scores (GOSE) will be collected as the key outcome. Statistical analysis will focus on measures of between and within-site variation. Reports documenting performance on selected key quality indicators will be provided to participating sites.

ETHICS AND DISSEMINATION

Ethics approval has been obtained from The Alfred Human Research Ethics Committee (Alfred Health, Melbourne, Australia). All eligible participants will be included in the study under a waiver of consent (hospital data collection) and opt-out (6 months follow-up). Brochures explaining the rationale of the study will be provided to all participants and/or an appropriate medical treatment decision-maker, who can act on the patient's behalf if they lack capacity. Study findings will be disseminated by peer-review publications.

TRIAL REGISTRATION NUMBER

NCT05855252.

The pressure reactivity index as a measure of cerebral autoregulation and its application in traumatic brain injury management

Severe traumatic brain injury (TBI) is a major cause of morbidity and mortality globally. The Brain Trauma Foundation guidelines advocate for the maintenance of a cerebral perfusion pressure (CPP) between 60 and 70 mmHg following severe TBI. However, such a uniform goal does not account for changes in cerebral autoregulation (CA). CA refers to the complex homeostatic mechanisms by which cerebral blood flow is maintained, despite variations in mean arterial pressure and intracranial pressure. Disruption to CA has become increasingly recognised as a key mediator of secondary brain injury following severe TBI. The pressure reactivity index is calculated as the degree of statistical correlation between the slow wave components of mean arterial pressure and intracranial pressure signals and is a validated dynamic marker of CA status following brain injury. The widespread acceptance of pressure reactivity index has precipitated the consideration of individualised CPP targets or an optimal cerebral perfusion pressure (CPPopt). CPPopt represents an alternative target for cerebral haemodynamic optimisation following severe TBI, and early observational data suggest improved neurological outcomes in patients whose CPP is more proximate to CPPopt. The recent publication of a prospective randomised feasibility study of CPPopt guided therapy in TBI, suggests clinicians caring for such patients should be increasingly familiar with these concepts. In this paper, we present a narrative review of the key landmarks in the development of CPPopt and offer a summary of the evidence for CPPopt-based therapy in comparison to current standards of care.

Intra-Aortic Balloon Pump Exacerbates Left Ventricular Outflow Tract Obstruction in a Patient With Takotsubo and Hypertrophic Cardiomyopathy

•Obstructive HCM with superimposed takotsubo syndrome led to shock. •The use of an IABP worsened outflow obstruction. •Putting the IABP on standby improved outflow tract gradients dramatically. •An IABP should not be used in shock with LVOT obstruction.

Noninferiority Clinical Trial of Adapted START NOW Psychotherapy for Outpatient Opioid Treatment

Background

Medications for opioid use disorder (MOUD) such as buprenorphine is effective for treating opioid use disorder (OUD). START NOW (SN) is a manualized, skills-based group psychotherapy originally developed and validated for the correctional population and has been shown to result in reduced risk of disciplinary infractions and future psychiatric inpatient days with a dose response effect. We investigate whether adapted START NOW is effective for treating OUD in a MOUD office-based opioid treatment (OBOT) setting in this non-inferiority clinical trial.

Methods

Patients enrolled in once weekly buprenorphine/suboxone MOUD OBOT were eligible for enrollment in this study. Participants were cluster-randomized, individually-randomized, or not randomized into either START NOW psychotherapy or treatment-as-usual (TAU) for 32 weeks of therapy. Treatment effectiveness was measured as the number of groups attended, treatment duration, intensity of attendance, and overall drug use as determined by drug screens.

Results

137 participants were quasi-randomized to participate in SN (n = 79) or TAU (n = 58). Participants receiving START NOW psychotherapy, when compared to TAU, had comparable number of groups attended (16.5 vs. 16.7, p = 0.80), treatment duration in weeks (24.1 vs. 23.8, p = 0.62), and intensity defined by number of groups attended divided by the number of weeks to last group (0.71 vs. 0.71, p = 0.90). SN compared to TAU also had similar rates of any positive drug screen result (81.0% vs. 91.4%, p = 0.16). This suggests that adapted START NOW is noninferior to TAU, or the standard of care at our institution, for treating opioid use disorder.

Conclusion

Adapted START NOW is an effective psychotherapy for treating OUD when paired with buprenorphine/naloxone in the outpatient group therapy setting. Always free and publicly available, START NOW psychotherapy, along with its clinician manual and training materials, are easily accessible and distributable and may be especially useful for low-resource settings in need of evidence-based psychotherapy.

Development of Traumatic Brain Injury Associated Intracranial Hypertension Prediction Algorithms: A Narrative Review

Traumatic intracranial hypertension (tIH) is a common and potentially lethal complication of moderate to severe traumatic brain injury (m-sTBI). It often develops with little warning and is managed reactively with the tiered application of intracranial pressure (ICP)-lowering interventions administered in response to an ICP rising above a set threshold. For over 45 years, a variety of research groups have worked toward the development of technology to allow for the preemptive management of tIH in the hope of improving patient outcomes. In 2022, the first operationalizable tIH prediction system became a reality. With such a system, ICP lowering interventions could be administered prior to the rise in ICP, thus protecting the patient from potentially damaging tIH episodes and limiting the overall ICP burden experienced. In this review, we discuss related approaches to ICP forecasting and IH prediction algorithms, which collectively provide the foundation for the successful development of an operational tIH prediction system. We also discuss operationalization and the statistical assessment of tIH algorithms. This review will be of relevance to clinicians and researchers interested in development of this technology as well as those with a general interest in the bedside application of machine learning (ML) technology.

The Monitoring with Advanced Sensors, Transmission and E-Resuscitation in Traumatic Brain Injury (MASTER-TBI) collaborative: bringing data science to the ICU bedside

Background: With the adoption of multimodal neuromonitoring techniques, a large amount of high resolution neurophysiological data is generated during the treatment of patients with moderate to severe traumatic brain injury (m-sTBI) that is available for further analysis. The Monitoring with Advanced Sensors, Transmission and E-Resuscitation in Traumatic Brain Injury (MASTER-TBI) collaborative was formed in 2020 to facilitate analysis of these data. Objective: The MASTER-TBI collaborative curates m-sTBI patient data for the purposes of comparative effectiveness research, machine learning algorithm development, and neuropathophysiological phenomena analysis. Design, setting and participants: The MASTER-TBI collaborative is a multicentre longitudinal cohort study which utilises a novel hybrid cloud platform and other data science-informed techniques to collect and analyse data from patients with m-sTBI in whom both intracranial pressure monitoring and ICM+ (Cambridge Enterprise, Cambridge, UK) neuromonitoring software are utilised. MASTER-TBI enrols patients with m-sTBI from three participating Australian trauma intensive care units (ICUs). Main outcome measures: Captured outcome measures available for analysis include pathophysiological events (intracranial hypertension, cerebral perfusion pressure variations etc), surgical interventions, ICU and hospital length of stay, patient discharge status, and, where available, Glasgow Outcome Score-Extended (GOS-E) at 6 months. Results and conclusion: MASTER-TBI continues to develop data science-informed systems and techniques to maximise the use of captured high resolution m-sTBI patient neuromonitoring data. The highly innovative systems provide a world-class platform which aims to enhance the search for improved m-sTBI care and outcomes. This article provides an overview of the MASTER-TBI project's developed systems and techniques as well as a rationale for the approaches taken.

182 QUALITY IMPROVEMENT OF THE REFERRAL SYSTEM TO EDITH (EMERGENCY DEPARTMENT IN THE HOME) SERVICE

Background

Our department has been providing an Emergency Department in the Home (EDITH) service since early 2020. The goal is to bring the emergency services to older people and prevent unnecessary attendances to the ED. With over 3,000 patients seen in its first 14 months, this heavily used service needs a proficient and safe referral system.

The previous referral system predominately involved handwritten referrals and phone calls. Our aim was to streamline this via the introduction of the Siilo Application as a solitary referral source. A referral proforma was also drawn up to ensure all relevant details were included.

Methods

A baseline survey was conducted to establish staff’s opinion on the initial referral system. The questions were.

1. Are you happy with the current system of referring patients to EDITH?

2. Do you think that some referrals are being missed or delayed secondary to the current system?

3. Rank your current satisfaction with the referral system out of ten?

There was also an area for feedback in the survey. The new system was then introduced using the Siilo Application. Staff were trained in its use and a referral proforma was put in place. After three months of use a second survey was conducted with the same questions.

Results

60% were happy with the new referral system, up from 11% on the first survey. Those who believed referrals were being missed had fallen from 88.9% to 70%. The average score out of ten for the current system was 6.9, improved from 5.7.

Conclusion

Having a safe, user friendly and efficient referral system for complex patients is a fundamental part on the service we provide. Staff satisfaction with the referral system, especially in an emergency setting, is paramount to ensure adequate and safe referrals. Satisfaction rates did improve with the introduction of the Siilo Application, but there is room for further improvement.

142 FRAILTY IDENTIFICATION AND INTERDISCIPLINARY ASSESSMENT OF OLDER PEOPLE IN THE EMERGENCY DEPARTMENT

Background

Older People are attending Emergency Departments (EDs) in increasing numbers but the optimal assessment measures to use have yet to be established. This study examined the clinical utility of different assessments of strength, functional mobility, sarcopenia, cognition and frailty used by the physiotherapist in an interdisciplinary team (IDT) in the ED and determined any associations with clinical outcomes.

Methods

This observational cross-sectional study recruited adults ≥70 years who were assessed by an IDT on weekdays during working hours. Demographic variables such as age, gender, social situation, baseline mobility, falls and clinical measures such as Clinical Frailty Scale (CFS), 4AT, hand-held dynamometry, calf circumference and functional mobility in ED were recorded. Clinical outcomes were admission to hospital, discharge from ED with onward referral (ambulatory care or community) and discharge from ED with no referral. Ethical approval was obtained and SPSS was used for statistical analysis.

Results

Two hundred and fifty four participants were recruited, 58.3% female, mean age 80.23 (SD 6.56). Median CFS was 4 (IRQ 2.0), range 1–7 with 32.7% (n = 83) considered frail. Sarcopenia prevalence was 89.3% using grip strength and 7.1% using calf circumference. Grip strength predicted frailty even after adjusting for age (p &lt; 0.0001), gender (p &lt; 0.0001) and falls (p = 0.043). Admission to hospital was predicted by major diagnostic category (p = 0.016) and inability to sit to stand independently in ED (p &lt; 0.0001). Seventy percent (n = 179) of participants were discharged from ED, with 27.6% referred to ambulatory care or community services. Onward referral was predicted by frailty (p = 0.016) and falls in the last six months (p = 0.028).

Conclusion

Grip strength in addition to a validated tool such as CFS may assist an experienced IDT in identifying frailty, which can in turn inform decision-making regarding ED disposition and pathways of care for older people. Functional assessment in the ED is also important to determine the need for hospital admission.

215 WHAT IMPACT CAN ‘EMERGENCY DEPARTMENT IN THE HOME’ (EDITH) HAVE ON THE OLDER ADULT POPULATION PRESENTING WITH FALLS?

Background

EDITH is a frailty response service providing medical and occupational therapy input to older adults living within the catchment area of a level 4 acute hospital. EDITH aims to reduce avoidable Emergency Department (ED) attendances and utilise alternative care pathways. Falls are common among older people and are often associated with poorer outcomes. Traditionally, older patients who have had a fall and contact emergency services for assistance are transferred to the ED and this can be associated with elevated risks. Additionally, older patients who have had a fall and are discharged on scene by the emergency services are at greater risk of recurring falls in the absence of immediate onward referral to community falls prevention services (Nowak and Hubbard 2009).

Methods

Paper count method data collection was completed. Inclusion criteria included referrals from the National Ambulance Service within the last 6 months.

Results

75 patients met the inclusion criteria; 34 males, 41 females with an average age of 82. 11 patients were conveyed to hospital, giving a conveyance rate of 14.6%, the average conveyance rate for the EDITH service is 7.2%. 3 patients were conveyed to ED, while 8 patients were conveyed to the Medical Assessment Unit (MAU) in the local level 3 hospital. This resulted in 72% of patients that required hospital conveyance being streamed to the MAU; traditionally 100% of these patients would have presented to ED. Overall, 85.4% of patients seen remained at home.

Conclusion

EDITH are providing targeted medical and occupational therapy assessment(s) for older adults in their homes with successful outcomes. Implementation of alternative care pathways, reduction in avoidable ED attendances and prolonged independence in the home for this patient profile are some of the favourable findings.

Reference

1. Nowak A, Hubbard RE. (2009) Falls and frailty: lessons from complex systems. Journal of the Royal Society of Medicine. 102(3):98–102.

249 A SURVEY OF IRISH DOCTORS VIEWS ON FLEXIBLE TRAINING

Background

We aimed to establish the views of non consultant hospital doctors working in Ireland on the options available for ‘Flexible Training’ or ‘Less-Than-Full-Time-Training’. Our population is ageing rapidly, and an expanding workforce will be required. Difficulties with doctor retention and recruitment are growing challenges in Ireland.

Methods

An anonymised survey of 9 questions was carried out using Survey Monkey®. Question format included multiple choice, yes/no or a free text box. This was disseminated via the Royal College of Physicians of Ireland to 1,557 trainees of the Institute of Medicine, the national postgraduate body for medical specialties. It was also circulated to members of the Irish Medical Organisation, the national medical organisation, and to approximately 200 doctors across two hospitals on social media.

Results

There were 674 (84.3%) respondents in training- 46.3% BST, 53.7% HST; and 125 (15.6%) non-training respondents. Doctors overwhelmingly felt trainees should have access to flexible training (n = 849, 99.41%), with 82.39% reporting they would apply (n = 702). Most (92.5%) felt that 16 WTE positions was inadequate (n = 789). Reasons chosen for not applying for flexible training included- 36.1% (n = 169) felt it could impact their career, 25.4% (n = 119) identified they did not meet the criteria, 14.32% (n = 67) reported no interest, while 24.1% (n = 113) gave ‘other’ reasons including lengthy training, salary impacts, and not having a requirement for flexible training. When asked about suggestions for improving flexible training, 19.7% chose ‘offer more places’, 6.7%-‘remove eligibility criteria’, 19.6% -‘offer job sharing options’, 9.5%- ‘allow more flexible training years’, 17.7% -‘regional based training’, 22.5% -‘all of the above’, 4.9%—‘other’.

Conclusion

Our survey suggests non consultant hospital doctors in Ireland strongly desire an expansion of current flexible training options. This is essential to ensure Ireland is an attractive place for doctors to work, to support their health and wellbeing, and to ensure an adequate workforce to care for an ageing population.

188 IMPROVING THE ASSESSMENT AND MANAGEMENT OF FALLS IN OLDER PEOPLE BY THE EMERGENCY DEPARTMENT IN THE HOME

Background

Falls among older adults are the injury pattern that causes the most morbidity and mortality. Assessing and managing these in the patients’ homes is challenging; it requires a comprehensive, systematic approach. This quality Improvement Project used a Comprehensive Geriatric Assessment for older adults who have suffered fall, carried out by an Emergency Department in the Home (EDITH) practitioner in the patient’s home.

Aim: To improve the evaluation and management of older people who have fallen and are attended to by the Emergency Department in the Home.

Methods

This OD project was carried out using the HSE People’s Needs Defining Change model. A new, streamlined version of the Comprehensive Geriatric Assessment tool was developed and introduced, and this was implemented and altered over two PDSA cycles.

Results

Documentation of falls improved dramatically, from a median of three out of 12 domains included to a median of 11 domains included. Users’ feedback helped the CGA evolve and was incredibly positive about the change.

Conclusion

This project shows that a CGA can be used successfully in patients’ own homes to assess risk factors for falling. The HSE’s People’s Needs Defining Change can be used to implement community-based projects. The community CGA tool could be explored by other areas and organisations in the future.

51 TO EXPLORE EMERGENCY MEDICINE SPRS UNDERSTANDING, IDENTIFICATION AND MANAGEMENT OF FRAILTY WITHIN THE EMERGENCY DEPARTMENT

Background

Our frail cohort of older adults represent a large proportion of those presenting to our Emergency Departments. This has led to the introduction of diverse teams in many Emergency Departments to support their complex care needs. However, it is not known if Emergency Clinicians have a clear understanding of frailty identification and management or feel this is part of their own role.

The aim of this study was to engage with Emergency Medicine Senior Trainees on the national training scheme in Ireland to explore their understanding of frailty and what they feel their role is in its identification and management.

Methods

Following a literature review based on defined criteria, a number of focus groups were held with ED PGY4 and above doctors working in various Emergency Departments throughout the country, with thematic analysis of the transcripts of the focus groups.

Results

In total, 13 Emergency Medicine PGY4 and above doctors partook in the focus groups with an overall view that frailty identification was part of their role within the Emergency Department; however there was agreement they have limited insight into the core principles of frailty identification and management. There was also an overall desire for future formal education on frailty to be provided. Three themes in the form of frailty recognition and assessment, education on frailty, and the role of the multidisciplinary team were identified as well as a number of subthemes for further exploration.

Conclusion

The consequences of frailty often lead to presentation to the Emergency Department. There is an increased awareness of its presentation but the core providers of emergency care feel there is a lack of the education required for them to manage the consequences of frailty which they encounter on daily basis and they have a clear desire to increase the knowledge base and skill set.

186 OPTIMAL MANAGEMENT OF COVID-19 IN NURSING HOME PATIENTS: A QUALITY IMPROVEMENT PROJECT IN AN IRISH UNIVERSITY HOSPITAL EMERGENCY DEPARTMENT

Background

The Sars-CoV-2 global pandemic placed an unprecedented demand on acute health services and led to significant morbidity and mortality in older populations. Nearly half of attendances to this ED are over the age of 65 years and there are over 80 nursing homes in the catchment area. A pilot study in January 2021 showed that nursing home attendances increased significantly during the third wave of COVID-19 with many of these attendances potentially avoidable and suitable for optimised care in the nursing home.

The primary objective of this quality improvement project was to enhance the older person’s care and experience when presenting to ED or being reviewed in the community with symptoms and signs of COVID-19. Secondary aims were reduced nursing home attendances to ED and subsequent admissions from these attendances.

Methods

A guideline was constructed based on the RCEM standard for Quality Care for Older People and using the HSE guidelines for managing COVID-19 in nursing home patients. The guideline was introduced to staff and implemented in ED and via the EDITH service.

Results

Two PDSA cycles were undertaken post guideline implementation. There were substantial improvements in the frequency of discussion and documentation of advanced directives with increased numbers of patients being discharged directly back to the nursing home or treated in the nursing home using the guideline. There was a decrease in the number of nursing home attendances throughout the project.

Conclusion

This successful QIP shows the importance of manging older patients appropriately, while considering their wishes. Post-COVID work should centre on managing all older patients with optimised treatment and considering how they will benefit most from their attendance to ED.

Providing care for older adults in the Emergency Department: expert clinical recommendations from the European Task Force on Geriatric Emergency Medicine

Aim

The aim was to develop expert clinical recommendations on Geriatric Emergency Medicine to be disseminated across Europe.

Findings

Eight posters with expert clinical guidelines on the most important topics in Geriatric Emergency Medicine are now available through https://posters.geriemeurope.eu/.

Message

Expert clinical recommendations for Geriatric Emergency Medicine in Europe were created and are ready for dissemination across Europe.

Supplementary Information

The online version contains supplementary material available at 10.1007/s41999-021-00578-1.

Purpose

Despite the rapidly expanding knowledge in the field of Geriatric Emergency Medicine in Europe, widespread implementation of change is still lacking. Many opportunities in everyday clinical care are missed to improve care for this susceptible and growing patient group. The aim was to develop expert clinical recommendations on Geriatric Emergency Medicine to be disseminated across Europe.

Methods

A group of multi-disciplinary experts in the field of Geriatric Emergency Medicine in Europe was assembled. Using a modified Delphi procedure, a prioritized list of topics related to Geriatric Emergency Medicine was created. Next, a multi-disciplinary group of nurses, geriatricians and emergency physicians performed a review of recent guidelines and literature to create recommendations. These recommendations were voted upon by a group of experts and placed on visually attractive posters. The expert group identified the following eight subject areas to develop expert recommendations on: Comprehensive Geriatric Assessment in the Emergency Department (ED), age/frailty adjusted risk stratification, delirium and cognitive impairment, medication reviews in the ED for older adults, family involvement, ED environment, silver trauma, end of life care in the acute setting.

Results

Eight posters with expert clinical recommendations on the most important topics in Geriatric Emergency Medicine are now available through https://posters.geriemeurope.eu/.

Conclusion

Expert clinical recommendations for Geriatric Emergency Medicine may help to improve care for older patients in the Emergency Department and are ready for dissemination across Europe.

Supplementary Information

The online version contains supplementary material available at 10.1007/s41999-021-00578-1.

Use of Machine Learning Models to Predict Death After Acute Myocardial Infarction

Importance

Accurate prediction of adverse outcomes after acute myocardial infarction (AMI) can guide the triage of care services and shared decision-making, and novel methods hold promise for using existing data to generate additional insights.

Objective

To evaluate whether contemporary machine learning methods can facilitate risk prediction by including a larger number of variables and identifying complex relationships between predictors and outcomes.

Design, Setting, and Participants

This cohort study used the American College of Cardiology Chest Pain-MI Registry to identify all AMI hospitalizations between January 1, 2011, and December 31, 2016. Data analysis was performed from February 1, 2018, to October 22, 2020.

Main Outcomes and Measures

Three machine learning models were developed and validated to predict in-hospital mortality based on patient comorbidities, medical history, presentation characteristics, and initial laboratory values. Models were developed based on extreme gradient descent boosting (XGBoost, an interpretable model), a neural network, and a meta-classifier model. Their accuracy was compared against the current standard developed using a logistic regression model in a validation sample.

Results

A total of 755 402 patients (mean [SD] age, 65 [13] years; 495 202 [65.5%] male) were identified during the study period. In independent validation, 2 machine learning models, gradient descent boosting and meta-classifier (combination including inputs from gradient descent boosting and a neural network), marginally improved discrimination compared with logistic regression (C statistic, 0.90 for best performing machine learning model vs 0.89 for logistic regression). Nearly perfect calibration in independent validation data was found in the XGBoost (slope of predicted to observed events, 1.01; 95% CI, 0.99-1.04) and the meta-classifier model (slope of predicted-to-observed events, 1.01; 95% CI, 0.99-1.02), with more precise classification across the risk spectrum. The XGBoost model reclassified 32 393 of 121 839 individuals (27%) and the meta-classifier model reclassified 30 836 of 121 839 individuals (25%) deemed at moderate to high risk for death in logistic regression as low risk, which were more consistent with the observed event rates.

Conclusions and Relevance

In this cohort study using a large national registry, none of the tested machine learning models were associated with substantive improvement in the discrimination of in-hospital mortality after AMI, limiting their clinical utility. However, compared with logistic regression, XGBoost and meta-classifier models, but not the neural network, offered improved resolution of risk for high-risk individuals.

Effect of Hydrocortisone on Mortality and Organ Support in Patients With Severe COVID-19: The REMAP-CAP COVID-19 Corticosteroid Domain Randomized Clinical Trial

IMPORTANCE

Evidence regarding corticosteroid use for severe coronavirus disease 2019 (COVID-19) is limited.

OBJECTIVE

To determine whether hydrocortisone improves outcome for patients with severe COVID-19.

DESIGN, SETTING, AND PARTICIPANTS

An ongoing adaptive platform trial testing multiple interventions within multiple therapeutic domains, for example, antiviral agents, corticosteroids, or immunoglobulin. Between March 9 and June 17, 2020, 614 adult patients with suspected or confirmed COVID-19 were enrolled and randomized within at least 1 domain following admission to an intensive care unit (ICU) for respiratory or cardiovascular organ support at 121 sites in 8 countries. Of these, 403 were randomized to open-label interventions within the corticosteroid domain. The domain was halted after results from another trial were released. Follow-up ended August 12, 2020.

INTERVENTIONS

The corticosteroid domain randomized participants to a fixed 7-day course of intravenous hydrocortisone (50 mg or 100 mg every 6 hours) (n = 143), a shock-dependent course (50 mg every 6 hours when shock was clinically evident) (n = 152), or no hydrocortisone (n = 108).

MAIN OUTCOMES AND MEASURES

The primary end point was organ support-free days (days alive and free of ICU-based respiratory or cardiovascular support) within 21 days, where patients who died were assigned -1 day. The primary analysis was a bayesian cumulative logistic model that included all patients enrolled with severe COVID-19, adjusting for age, sex, site, region, time, assignment to interventions within other domains, and domain and intervention eligibility. Superiority was defined as the posterior probability of an odds ratio greater than 1 (threshold for trial conclusion of superiority >99%).

RESULTS

After excluding 19 participants who withdrew consent, there were 384 patients (mean age, 60 years; 29% female) randomized to the fixed-dose (n = 137), shock-dependent (n = 146), and no (n = 101) hydrocortisone groups; 379 (99%) completed the study and were included in the analysis. The mean age for the 3 groups ranged between 59.5 and 60.4 years; most patients were male (range, 70.6%-71.5%); mean body mass index ranged between 29.7 and 30.9; and patients receiving mechanical ventilation ranged between 50.0% and 63.5%. For the fixed-dose, shock-dependent, and no hydrocortisone groups, respectively, the median organ support-free days were 0 (IQR, -1 to 15), 0 (IQR, -1 to 13), and 0 (-1 to 11) days (composed of 30%, 26%, and 33% mortality rates and 11.5, 9.5, and 6 median organ support-free days among survivors). The median adjusted odds ratio and bayesian probability of superiority were 1.43 (95% credible interval, 0.91-2.27) and 93% for fixed-dose hydrocortisone, respectively, and were 1.22 (95% credible interval, 0.76-1.94) and 80% for shock-dependent hydrocortisone compared with no hydrocortisone. Serious adverse events were reported in 4 (3%), 5 (3%), and 1 (1%) patients in the fixed-dose, shock-dependent, and no hydrocortisone groups, respectively.

CONCLUSIONS AND RELEVANCE

Among patients with severe COVID-19, treatment with a 7-day fixed-dose course of hydrocortisone or shock-dependent dosing of hydrocortisone, compared with no hydrocortisone, resulted in 93% and 80% probabilities of superiority with regard to the odds of improvement in organ support-free days within 21 days. However, the trial was stopped early and no treatment strategy met prespecified criteria for statistical superiority, precluding definitive conclusions.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT02735707.

Effect of Hydrocortisone on Mortality and Organ Support in Patients With Severe COVID-19: The REMAP-CAP COVID-19 Corticosteroid Domain Randomized Clinical Trial

IMPORTANCE

Evidence regarding corticosteroid use for severe coronavirus disease 2019 (COVID-19) is limited.

OBJECTIVE

To determine whether hydrocortisone improves outcome for patients with severe COVID-19.

DESIGN, SETTING, AND PARTICIPANTS

An ongoing adaptive platform trial testing multiple interventions within multiple therapeutic domains, for example, antiviral agents, corticosteroids, or immunoglobulin. Between March 9 and June 17, 2020, 614 adult patients with suspected or confirmed COVID-19 were enrolled and randomized within at least 1 domain following admission to an intensive care unit (ICU) for respiratory or cardiovascular organ support at 121 sites in 8 countries. Of these, 403 were randomized to open-label interventions within the corticosteroid domain. The domain was halted after results from another trial were released. Follow-up ended August 12, 2020.

INTERVENTIONS

The corticosteroid domain randomized participants to a fixed 7-day course of intravenous hydrocortisone (50 mg or 100 mg every 6 hours) (n = 143), a shock-dependent course (50 mg every 6 hours when shock was clinically evident) (n = 152), or no hydrocortisone (n = 108).

MAIN OUTCOMES AND MEASURES

The primary end point was organ support-free days (days alive and free of ICU-based respiratory or cardiovascular support) within 21 days, where patients who died were assigned -1 day. The primary analysis was a bayesian cumulative logistic model that included all patients enrolled with severe COVID-19, adjusting for age, sex, site, region, time, assignment to interventions within other domains, and domain and intervention eligibility. Superiority was defined as the posterior probability of an odds ratio greater than 1 (threshold for trial conclusion of superiority >99%).

RESULTS

After excluding 19 participants who withdrew consent, there were 384 patients (mean age, 60 years; 29% female) randomized to the fixed-dose (n = 137), shock-dependent (n = 146), and no (n = 101) hydrocortisone groups; 379 (99%) completed the study and were included in the analysis. The mean age for the 3 groups ranged between 59.5 and 60.4 years; most patients were male (range, 70.6%-71.5%); mean body mass index ranged between 29.7 and 30.9; and patients receiving mechanical ventilation ranged between 50.0% and 63.5%. For the fixed-dose, shock-dependent, and no hydrocortisone groups, respectively, the median organ support-free days were 0 (IQR, -1 to 15), 0 (IQR, -1 to 13), and 0 (-1 to 11) days (composed of 30%, 26%, and 33% mortality rates and 11.5, 9.5, and 6 median organ support-free days among survivors). The median adjusted odds ratio and bayesian probability of superiority were 1.43 (95% credible interval, 0.91-2.27) and 93% for fixed-dose hydrocortisone, respectively, and were 1.22 (95% credible interval, 0.76-1.94) and 80% for shock-dependent hydrocortisone compared with no hydrocortisone. Serious adverse events were reported in 4 (3%), 5 (3%), and 1 (1%) patients in the fixed-dose, shock-dependent, and no hydrocortisone groups, respectively.

CONCLUSIONS AND RELEVANCE

Among patients with severe COVID-19, treatment with a 7-day fixed-dose course of hydrocortisone or shock-dependent dosing of hydrocortisone, compared with no hydrocortisone, resulted in 93% and 80% probabilities of superiority with regard to the odds of improvement in organ support-free days within 21 days. However, the trial was stopped early and no treatment strategy met prespecified criteria for statistical superiority, precluding definitive conclusions.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT02735707.

Emergency Department Management of the Covid-19 Pandemic

BACKGROUND

Emergency departments (EDs) need to be prepared to manage crises and disasters in both the short term and the long term. The coronavirus disease 2019 (COVID-19) pandemic has necessitated a rapid overhaul of several aspects of ED operations in preparation for a sustained response.

OBJECTIVE

We present the management of the COVID-19 crisis in 3 EDs (1 large academic site and 2 community sites) within the same health care system.

DISCUSSION

Aspects of ED throughput, including patient screening, patient room placement, and disposition are reviewed, along with departmental communication procedures and staffing models. Visitor policies are also discussed. Special considerations are given to airway management and the care of psychiatric patients. Brief guidance around the use of personal protective equipment is also included.

CONCLUSIONS

A crisis like the COVID-19 pandemic requires careful planning to facilitate urgent restructuring of many aspects of an ED. By sharing our departments' responses to the COVID-19 pandemic, we hope other departments can better prepare for this crisis and the next.

Effects of Routine Position Changes and Tracheal Suctioning on Intracranial Pressure in Traumatic Brain Injury Patients

Patient position change and tracheal suctioning are routine interventions in mechanically ventilated traumatic brain injury (TBI) patients. We sought to better understand the impact of these interventions on intracranial pressure (ICP) and cerebral hemodynamics. We conducted a prospective study in TBI patients requiring ICP monitoring. The timing of position changes and suctioning episodes were recorded with concurrent blood pressure and ICP measurements. We collected data on 460 patient position changes and 204 suctioning episodes over 2404 h in 18 ventilated patients (mean age 34 [13] years, median Glasgow Coma Score 4 [3-7]). We recorded 24 (20-31) positioning and 11 (6-18) suctioning episodes per patient, with 54% and 39% of position changes associated with ICP ≥22 mm Hg and cerebral perfusion pressure (CPP) <60 mm Hg, respectively, and 22% and 27% of suctioning episodes associated with an ICP ≥22 mm Hg and CPP <60 mm Hg. The median change in ICP was 11 (6-16) mm Hg after position changes and 3 (1-9) mm Hg after suctioning. Reduction in CPP to <60 mm Hg lasted ≥10 min in 17% of positioning and 11% of suctioning episodes. The baseline ICP and its amplitude were both predictive of a rise in ICP ≥22 mm Hg after positioning and suctioning episodes, whereas cerebral autoregulation was not. Baseline CPP was predictive of a decrease in CPP <60 mm Hg after both interventions. Increases in ICP and reductions in CPP are common following patient positioning and tracheal suctioning episodes. Frequently, these changes are substantial and sustained.

Paediatric Head Injury and Traumatic Brain Injury

Aim To determine prevalence of head injury presenting to paediatric emergency departments (PEDs) and characterise by demographics, triage category, disposition neuroimaging or re-attendance. Methods Presentations in 2014 and 2015, with diagnoses of head injury, intracranial bleed, skull fracture including single or re-attendances within 28 days post head injury to all national PEDs, were analysed. Demographics, triage score, imaging rate, admission, mechanisms and representation rate were recorded. Results Head injury was diagnosed in 13,392 of 224,860 (5.9%), median (IQR) age 3.9 (1.4 - 8.3) years. Regionally 3% of children <5 years attend each year. The total admitted/transferred was 10.8% (n=1460). Neuroimaging rate was 4.3% (n= 570). Falls predominated. Sport accounted for 12.2%. Conclusion One in twenty children PED presentations are head injury, over half in preschool children. A sizeable number were symptomatic reflected by admission, transfer, imaging or re-attendance. Observational management was favoured over imaging reflected in the higher admission versus imaging rate.

Introduction of the low risk ankle rule to a paediatric emergency department

INTRODUCTION

Ankle injuries are a common presentation to the paediatric emergency department (PED), accounting for approximately 2% of presentations.¹ X-rays are ordered for 85-95% of patients but only 12% of x-rays reveal a fracture. Clinical prediction rules, such as The Low Risk Ankle Rule (LRAR) exist to help clinicians safely reduce the frequency of radiography in these injuries. The LRAR has been shown to reduce imaging by up to 60% without missing any clinically significant fractures. We sought to introduce The LRAR into our department and study its outcomes on our practice.

AIMS

To introduce the LRAR into our department and study its effects on our radiography rate and length of stay (LOS).

METHODS

An audit of x-ray rates in ankle injuries in 2016 was performed to determine our department's baseline rate of radiography and LOS. We then conducted education sessions and created x-ray ordering prompts to encourage clinicians to use the LRAR. We introduced the LRAR, with a pilot period initially, and gathered data prospectively.

RESULTS

969 patients presented in with an ankle injury in 2016, 90.7% of these patients had an x-ray. The median LOS was 109 min. 92 patients presented during  the LRAR implementation period with an ankle injury. Nine patients had exclusion criteria from using the LRAR and the attending physician did not use the LRAR in four patients. Of the remaining 79 patients, 49 had a LRAR positive exam. Only one of these patients went on to have an x-ray, which was normal. The 30 patients with a LRAR negative exam all had an x-ray. Overall, our x-ray rate during the study period was 40/92 (43.4%), a reduction of 47.3%. The average LOS during the study was 101 min. No clinically significant fractures were missed.

CONCLUSION

The LRAR can safely and effectively reduce the rate of radiography in ankle injuries, without missing any clinically significant fractures.

Trends in Mental Health Presentations to a Paediatric Emergency Department

Aims This study aimed to analyse trends in mental health presentations to the Emergency Department (ED), which anecdotally had increased over the past decade. Methods The ED's electronic 'Symphony' system was used to identify the annual number of presentations categorised as having a mental health complaint from 2006-2017. A detailed analysis was performed on presentations over a one-year period. Results The number of presentations increased from 69 in 2006 to a peak of 432 in 2016 (526% increase). The overall admission rate was 33.3%(n=99), while 52.5%(n=156) of presentations occurred outside of standard working hours. Similar increases were documented by other ED's worldwide, and the WHO estimate that neuropsychiatric disorders will become one of the top five causes of morbidity, mortality and disability among children by 2020. Conclusion With the number of mental health presentations dramatically increasing, carefully designed and integrated strategies are required to pro-actively tackle this growing epidemic.

Abstract 102: The Association of Patient Navigator Program Features and Hospital Strategies with Processes and Outcome Metrics in Acute Myocardial Infarction and Heart Failure

Background: Association between hospital site-led structure, system and process changes, number of site-initiated technologies, the perceived value of program-directed services aimed at promoting quality improvement and process and outcome metrics achieved are unknown after a 2-year acute myocardial infarction and heart failure (AMI-HF) quality program.

Methods: After participation in the Patient Navigator Program, hospitals (n=35) completed surveys on the implementation of structure, system and process changes, number of site-initiated technologies, and the perceived value of program directed educational calls and webinars, quality-focused site visits, use of a list-serv that facilitated site coordinator communication and data reports. Univariate analyses assessed the associations of each factor with 30-day unadjusted AMI-HF rehospitalization and in-hospital risk adjusted AMI death and 14 AMI-HF process metrics.

Results: When hospital structure, system and process changes were high, sites were more likely to improve 30-day HF re-hospitalization, p =0.014. The number of site-initiated technologies and the value of using a list-serv to communicate with other program sites were not associated with outcome or process metric changes from baseline to 2 years. Sites that rated program-led educational calls and webinars as a high value were more likely to improve AMI-HF self-care education documentation, p =0.049. Sites that rated quality-related site visits as high value were more likely to improve left ventricular systolic dysfunction evaluation, p =0.035 and 30-day unadjusted AMI-HF rehospitalization rates ( p =0.021 and 0.007, respectively). Sites who rated the value of data reports more highly were less likely to improve 30-day unadjusted AMI rehospitalization, p =0.006 and more likely to improve 30-day HF rehospitalization, p =0.033.

Conclusion: Hospital-initiated structure-system-process changes and Patient Navigator Program-directed services that were perceived as high value, especially site visits and data reports, were more likely to be associated with improved 30-day HF re-hospitalization rates and some process improvements compared to baseline.

Who's challenging who training for staff empathy towards adults with challenging behaviour: cluster randomised controlled trial

BACKGROUND

One in five adults with intellectual disabilities (ID) known to services display challenging behaviours (CBs), and these individuals are at risk for restrictive practices and poor care. Staff attitudes may contribute to the development and/or maintenance of CBs. We investigated the effectiveness of co-produced Who's Challenging Who? training delivered by people with ID to staff.

METHOD

This study involved a cluster randomised controlled trial (RCT) of Who's Challenging Who? training with follow-up at six and 20 weeks post-randomisation.

PARTICIPANTS

two staff from each of 118 residential care settings for adults with ID at least one of whom displayed aggressive CB.

PRIMARY OUTCOME

Self-reported Staff Empathy for people with Challenging Behaviour Questionnaire.

ANALYSIS

intention to treat of all randomised settings. ISCRTN registration: ISRCTN53763600.

RESULTS

118 residential settings (including 236 staff) were randomised to either receive training (59 settings) or to receive training after a delay (59 settings). The primary analysis included data from 121 staff in 76 settings (51% of staff, 64% of settings). The adjusted mean difference on the transformed (cubed) Staff Empathy for people with Challenging Behaviour Questionnaire score at the primary end point was 1073.2 (95% CI: -938.1 to 3084.5, P = 0.296) in favour of the intervention group (effect size Cohen's d = .19).

CONCLUSIONS

This is the first large-scale RCT of a co-produced training course delivered by people with ID. Findings indicated a small positive (but statistically non-significant) effect on increased staff empathy at 20 weeks, and small to moderate effects for staff reported secondary outcomes in favour of the intervention group.

Methaemoglobinaemia: A Blue Light Emergency

We present the case of a patient with severe methaemoglobinaemia secondary to “poppers”. She presented with decreased level of consciousness and cyanosis. A methaemoglobin level was not available prior to treatment but the patient responded well and the diagnosis was confirmed afterwards.

New hazards in paediatric poisoning presentations

Accidental ingestion is an important preventable cause of childhood morbidity. All accidental ingestion presentations (n = 478) to a tertiary paediatric ED from January 2010 to December 2011 were analysed. These results were compared with a similar study in the same institution ten years previously in 2001 and showed that while accidental ingestions constituted a higher proportion of presentations (0.5% in this study v 0.45% in 2001), fewer had investigations performed (21% v 35%) and fewer were admitted (7% v 20%). Accidental ingestions account for 0.5% of presentations and are an important focus of home safety information for parents and guardians. Paracetamol (n = 67, 14%) and liquid detergent capsules (n = 44, 9.2%) were the two most common substances implicated in these presentations, and have the potential to cause severe morbidity and mortality.

Correlations of inflammatory gene pathways, corticolimbic functional activities, and aggression in pediatric bipolar disorder: a preliminary study

The mechanisms underlying aggression in adolescents with bipolar disorder have been poorly understood. The present study has investigated the associations among TNF gene expressions, functional brain activations under the frustrative non-reward task, and aggression in adolescents with bipolar disorder. Baseline gene expressions and aggressive tendencies were measured with the RNA-sequencing and Brief Rating of Aggression by Children and Adolescents (BRACHA), respectively. Our results show that activity levels of left subgenual anterior cingulate gyrus (ACG), right amygdala, left Brodmann area 10 (orbitofrontal cortex), and right thalamus were inversely correlated with BRACHA scores and were activated with frustrative non-reward during the affective Posner Task. In addition, 11 TNF related gene expressions were significantly correlated with activation of amygdala or ACG during the affective Posner Task. Three TNF gene expressions were inversely correlated with BRACHA score while one TNF gene (TNFAIP3) expression was positively correlated with BRACHA score. Therefore, TNF-related inflammatory cytokine genes may play a role in neural activity associated with frustrative non-reward and aggressive behaviors in pediatric bipolar disorder.

Use of lean principals to improve flow of patients with fractured neck of femur--the HOPE study

We describe the implementation of a care pathway for patients with fractured neck of femur (NOF) using Lean and Six Sigma principles. After introduction of the Lean pathway, 32 patients out a total of 86 (37%) with fractured NOF were admitted to the Trauma Ward within 4 hours of presentation to the hospital; prior to implementation this was 16 patients out of a total of 59 (27%). Post-Lean an earlier mean theatre start time of 8.40am was achieved, resulting in a 38 minute increase in daily theatre time. An additional 52 patients (12%) received surgery within 24 hours of admission, resulting in 1 night length of stay reduction. Lean methodology proved an effective method to guide change resulting in an improved journey for the patient and significant workflow gains.

Epidemiology of high falls from windows in children

Falls from a height result in significant morbidity and mortality worldwide. Targeted prevention strategies in the US combined data collection, publicity campaigns and building regulation and reduced high falls in New York by 93%. This retrospective cohort study describes children who fell from a height presenting or referred to Children's University Hospital Temple St. over a 2 year period. Case ascertainment was through the Emergency Department Symphony registration system and the Trauma Area Research Network (TARN) database. Forty five falls were identified, 33 falls (73.3%) were in children less than 5 with boys being three times more likely to fall. Forty four falls were from windows, 31 from < 12 feet and 7 were witnessed. Injury severity Scores (ISS) correlated to height of fall; both deaths fells from > 24ft. A publicity campaign is warranted to highlight the frequency of injury following falls from windows. Building legislation is required to safeguard high windows and balconies. A post fall questionnaire would enable the collection of unbiased forensic data.

Caffeine provokes adverse interactions with 3,4-methylenedioxymethamphetamine (MDMA, 'ecstasy') and related psychostimulants: mechanisms and mediators

Concomitant consumption of caffeine with recreational psychostimulant drugs of abuse can provoke severe acute adverse reactions in addition to longer term consequences. The mechanisms by which caffeine increases the toxicity of psychostimulants include changes in body temperature regulation, cardiotoxicity and lowering of the seizure threshold. Caffeine also influences the stimulatory, discriminative and reinforcing effects of psychostimulant drugs. In this review, we consider our current understanding of such caffeine-related drug interactions, placing a particular emphasis on an adverse interaction between caffeine and the substituted amphetamine, 3,4-methylenedioxymethamphetamine (MDMA, 'ecstasy'), which has been most recently described and characterized. Co-administration of caffeine profoundly enhances the acute toxicity of MDMA in rats, as manifested by high core body temperature, tachycardia and increased mortality. In addition, co-administration of caffeine enhances the long-term serotonergic neurotoxicity induced by MDMA. Observations to date support an interactive model of drug-induced toxicity comprising MDMA-related enhancement of dopamine release coupled to a caffeine-mediated antagonism of adenosine receptors in addition to inhibition of PDE. These experiments are reviewed together with reports of caffeine-related drug interactions with cocaine, d-amphetamine and ephedrine where similar mechanisms are implicated. Understanding the underlying mechanisms will guide appropriate intervention strategies for the management of severe reactions and potential for increased drug-related toxicity, resulting from concomitant caffeine consumption.

Development and evaluation by a cluster randomised trial of a psychosocial intervention in children and teenagers experiencing diabetes: the DEPICTED study

OBJECTIVE

To develop and evaluate a health-care communication training programme to help diabetes health-care professionals (HCPs) counsel their patients more skilfully, particularly in relation to behaviour change.

DESIGN

The HCP training was assessed using a pragmatic, cluster randomised controlled trial. The primary and secondary analyses were intention-to-treat comparisons of outcomes using multilevel modelling to allow for cluster (service) and individual effects, and involved two-level linear models.

SETTING

Twenty-six UK paediatric diabetes services.

PARTICIPANTS

The training was delivered to HCPs (doctors, nurses, dietitians and psychologists) working in paediatric diabetes services and the effectiveness of this training was measured in 693 children aged 4-15 years and families after 1 year (95.3% follow-up).

INTERVENTIONS

A blended learning programme was informed by a systematic review of the literature, telephone and questionnaire surveys of professional practice, focus groups with children and parents, experimental consultations and three developmental workshops involving a stakeholder group. The programme focused on agenda-setting, flexible styles of communication (particularly guiding) and a menu of strategies using web-based training and practical workshops.

MAIN OUTCOME MEASURES

The primary trial outcome was a change in glycosylated haemoglobin (HbA1c) levels between the start and finish of a 12-month study period. Secondary trial outcomes included change in quality of life, other clinical [including body mass index (BMI)] and psychosocial measures (assessed at participant level as listed above) and cost (assessed at service level). In addition, patient details (HbA1c levels, height, weight, BMI, insulin regimen), health service contacts and patient-borne costs were recorded at each clinic visit, along with details of who patients consulted with, for how long, and whether or not patients consulted on their own at each visit. Patients and carers were also asked to complete an interim questionnaire assessing patient enablement (or feelings towards clinic visit for younger patients aged 7-10 years) at their first clinic visit following the start of the trial. The cost of the intervention included the cost of training intervention teams.

RESULTS

Trained staff showed better skills than control subjects in agenda-setting and consultation strategies, which waned from 4 to 12 months. There was no effect on HbA1c levels (p = 0.5). Patients in intervention clinics experienced a loss of confidence in their ability to manage diabetes, whereas controls showed surprisingly reduced barriers (p = 0.03) and improved adherence (p = 0.05). Patients in intervention clinics reported short-term increased ability (p = 0.04) to cope with diabetes. Parents in the intervention arm experienced greater excitement (p = 0.03) about clinic visits and improved continuity of care (p = 0.01) without the adverse effects seen in their offspring. The mean cost of training was £13,145 per site or £2163 per trainee. There was no significant difference in total NHS costs (including training) between groups (p = 0.1).

CONCLUSIONS

Diabetes HCPs can be trained to improve consultation skills, but these skills need reinforcing. Over 1 year, no benefits were seen in children, unlike parents, who may be better placed to support their offspring. Further modification of this training is required to improve outcomes that may need to be measured over a longer time to see effects.

TRIAL REGISTRATION

Current Controlled Trials ISRCTN61568050.

FUNDING

This project was funded by the NIHR Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 15, No. 29. See the HTA programme website for further project information.

Approach to acute abdominal pain

Evaluation of the emergency department patient with acute abdominal pain may be challenging. Many factors can obscure the clinical findings leading to incorrect diagnosis and subsequent adverse outcomes. Clinicians must consider multiple diagnoses with limited time and information, giving priority to life-threatening conditions that require expeditious management to avoid morbidity and mortality. This article seeks to provide the clinician with the clinical tools to achieve these goals by reviewing the anatomic and physiological basis of abdominal pain and key components of the history and the physical examination. In addition, this article discusses the approach to unstable patients with abdominal pain.

Mechanisms mediating the ability of caffeine to influence MDMA ('Ecstasy')-induced hyperthermia in rats

BACKGROUND AND PURPOSE

Caffeine exacerbates the hyperthermia associated with an acute exposure to 3,4 methylenedioxymethamphetamine (MDMA, 'Ecstasy') in rats. The present study investigated the mechanisms mediating this interaction.

EXPERIMENTAL APPROACH

Adult male Sprague-Dawley rats were treated with caffeine (10 mg x kg(-1); i.p.) and MDMA (15 mg x kg(-1); i.p.) alone and in combination. Core body temperatures were monitored before and after drug administration.

KEY RESULTS

Central catecholamine depletion blocked MDMA-induced hyperthermia and its exacerbation by caffeine. Caffeine provoked a hyperthermic response when the catecholamine releaser d-amphetamine (1 mg x kg(-1)) was combined with the 5-HT releaser D-fenfluramine (5 mg x kg(-1)) or the non-selective dopamine receptor agonist apomorphine (1 mg x kg(-1)) was combined with the 5-HT(2) receptor agonist DOI (2 mg x kg(-1)) but not following either agents alone. Pretreatment with the dopamine D(1) receptor antagonist Schering (SCH) 23390 (1 mg x kg(-1)), the 5-HT(2) receptor antagonist ketanserin (5 mg x kg(-1)) or alpha(1)-adreno- receptor antagonist prazosin (0.2 mg x kg(-1)) blocked MDMA-induced hyperthermia and its exacerbation by caffeine. Co-administration of a combination of MDMA with the PDE-4 inhibitor rolipram (0.025 mg x kg(-1)) and the adenosine A(1/2) receptor antagonist 9-chloro-2-(2-furanyl)-[1,2,4]triazolo[1,5-C]quinazolin-5-amine 15943 (10 mg x kg(-1)) or the A(2A) receptor antagonist SCH 58261 (2 mg x kg(-1)) but not the A(1) receptor antagonist DPCPX (10 mg x kg(-1)) exacerbated MDMA-induced hyperthermia.

CONCLUSIONS AND IMPLICATIONS

A mechanism comprising 5-HT and catecholamines is proposed to mediate MDMA-induced hyperthermia. A combination of adenosine A(2A) receptor antagonism and PDE inhibition can account for the exacerbation of MDMA-induced hyperthermia by caffeine.

Requirements for calibration in noninvasive glucose monitoring by Raman spectroscopy

BACKGROUND

In the development of noninvasive glucose monitoring technology, it is highly desirable to derive a calibration that relies on neither person-dependent calibration information nor supplementary calibration points furnished by an existing invasive measurement technique (universal calibration).

METHOD

By appropriate experimental design and associated analytical methods, we establish the sufficiency of multiple factors required to permit such a calibration. Factors considered are the discrimination of the measurement technique, stabilization of the experimental apparatus, physics-physiology-based measurement techniques for normalization, the sufficiency of the size of the data set, and appropriate exit criteria to establish the predictive value of the algorithm.

RESULTS

For noninvasive glucose measurements, using Raman spectroscopy, the sufficiency of the scale of data was demonstrated by adding new data into an existing calibration algorithm and requiring that (a) the prediction error should be preserved or improved without significant re-optimization, (b) the complexity of the model for optimum estimation not rise with the addition of subjects, and (c) the estimation for persons whose data were removed entirely from the training set should be no worse than the estimates on the remainder of the population. Using these criteria, we established guidelines empirically for the number of subjects (30) and skin sites (387) for a preliminary universal calibration. We obtained a median absolute relative difference for our entire data set of 30 mg/dl, with 92% of the data in the Clarke A and B ranges.

CONCLUSIONS

Because Raman spectroscopy has high discrimination for glucose, a data set of practical dimensions appears to be sufficient for universal calibration. Improvements based on reducing the variance of blood perfusion are expected to reduce the prediction errors substantially, and the inclusion of supplementary calibration points for the wearable device under development will be permissible and beneficial.