How consistent are pre-alert guidelines? A review of UK ambulance service guidelines

Aims

Ambulance pre-alerts are used to inform receiving emergency departments (EDs) of the arrival of critically unwell or rapidly deteriorating patients who need time-critical assessment or treatment immediately upon arrival. Inappropriate use of pre-alerts can lead to EDs diverting resources from other critically ill patients. However, there is limited guidance about how pre-alerts should be undertaken, delivered or communicated. We aimed to map existing pre-alert guidance from UK NHS ambulance services to explore consistency and accessibility of existing guidance.

Methods

We contacted all UK ambulance services to request documentation containing guidance about pre-alerts. We reviewed and mapped all guidance to understand which conditions were recommended for a pre-alert and alignment with Association of Ambulance Chief Executives (AACE) and Royal College of Emergency Medicine (RCEM) pre-alert guidance. We reviewed the language and accessibility of guidance using the AGREE II tool.

Results

We received responses from 15/19 UK ambulance services and 10 stated that they had specific pre-alert guidance. We identified noticeable variations in conditions declared suitable for pre-alerts in each service, with a lack of consistency within each ambulance service's own guidance, and a lack of alignment with the AACE/RCEM pre-alert guidance. Services listed between four and 45 different conditions suitable for pre-alert. There were differences in physiological thresholds and terminology, even for conditions with established care pathways (e.g. hyperacute stroke, ST segment elevation myocardial infarction). Pre-alert criteria were typically listed in several short sections in lengthy handover procedure policy documents. Documents appraised were of poor quality with low scores below 35% for applicability and overall.

Implications

There is a clear need for ambulance services to have both policies and tools that complement each other and incorporate the same list of pre-alertable conditions. Clinicians need a single, easily accessible document to refer to in a time-critical situation to reduce the risk of making an incorrect pre-alert decision.

Prehospital early warning scores for adults with suspected sepsis: the PHEWS observational cohort and decision-analytic modelling study

Background

Guidelines for sepsis recommend treating those at highest risk within 1 hour. The emergency care system can only achieve this if sepsis is recognised and prioritised. Ambulance services can use prehospital early warning scores alongside paramedic diagnostic impression to prioritise patients for treatment or early assessment in the emergency department.

Objectives

To determine the accuracy, impact and cost-effectiveness of using early warning scores alongside paramedic diagnostic impression to identify sepsis requiring urgent treatment.

Design

Retrospective diagnostic cohort study and decision-analytic modelling of operational consequences and cost-effectiveness.

Setting

Two ambulance services and four acute hospitals in England.

Participants

Adults transported to hospital by emergency ambulance, excluding episodes with injury, mental health problems, cardiac arrest, direct transfer to specialist services, or no vital signs recorded.

Interventions

Twenty-one early warning scores used alongside paramedic diagnostic impression, categorised as sepsis, infection, non-specific presentation, or other specific presentation.

Main outcome measures

Proportion of cases prioritised at the four hospitals; diagnostic accuracy for the sepsis-3 definition of sepsis and receiving urgent treatment (primary reference standard); daily number of cases with and without sepsis prioritised at a large and a small hospital; the minimum treatment effect associated with prioritisation at which each strategy would be cost-effective, compared to no prioritisation, assuming willingness to pay £20,000 per quality-adjusted life-year gained.

Results

Data from 95,022 episodes involving 71,204 patients across four hospitals showed that most early warning scores operating at their pre-specified thresholds would prioritise more than 10% of cases when applied to non-specific attendances or all attendances. Data from 12,870 episodes at one hospital identified 348 (2.7%) with the primary reference standard. The National Early Warning Score, version 2 (NEWS2), had the highest area under the receiver operating characteristic curve when applied only to patients with a paramedic diagnostic impression of sepsis or infection (0.756, 95% confidence interval 0.729 to 0.783) or sepsis alone (0.655, 95% confidence interval 0.63 to 0.68). None of the strategies provided high sensitivity (> 0.8) with acceptable positive predictive value (> 0.15). NEWS2 provided combinations of sensitivity and specificity that were similar or superior to all other early warning scores. Applying NEWS2 to paramedic diagnostic impression of sepsis or infection with thresholds of > 4, > 6 and > 8 respectively provided sensitivities and positive predictive values (95% confidence interval) of 0.522 (0.469 to 0.574) and 0.216 (0.189 to 0.245), 0.447 (0.395 to 0.499) and 0.274 (0.239 to 0.313), and 0.314 (0.268 to 0.365) and 0.333 (confidence interval 0.284 to 0.386). The mortality relative risk reduction from prioritisation at which each strategy would be cost-effective exceeded 0.975 for all strategies analysed.

Limitations

We estimated accuracy using a sample of older patients at one hospital. Reliable evidence was not available to estimate the effectiveness of prioritisation in the decision-analytic modelling.

Conclusions

No strategy is ideal but using NEWS2, in patients with a paramedic diagnostic impression of infection or sepsis could identify one-third to half of sepsis cases without prioritising unmanageable numbers. No other score provided clearly superior accuracy to NEWS2. Research is needed to develop better definition, diagnosis and treatments for sepsis.

Study registration

This study is registered as Research Registry (reference: researchregistry5268).

Funding

This award was funded by the National Institute for Health and Care Research (NIHR) Health Technology Assessment programme (NIHR award ref: 17/136/10) and is published in full in Health Technology Assessment; Vol. 28, No. 16. See the NIHR Funding and Awards website for further award information.

The COVID-19 ambulance response assessment (CARA) study: a national survey of ambulance service healthcare professionals' preparedness and response to the COVID-19 pandemic

Background

The COVID-19 pandemic placed significant demand on the NHS, including ambulance services, but it is unclear how this affected ambulance service staff and paramedics in other clinical settings (e.g. urgent and primary care, armed services, prisons). This study aimed to measure the self-perceived preparedness and impact of the first wave of the pandemic on paramedics' psychological stress and perceived ability to deliver care.

Methods

Ambulance clinicians and paramedics working in other healthcare settings were invited to participate in a three-phase sequential online survey during the acceleration (April 2020), peak (May 2020) and deceleration (September/October 2020) phases of the first wave of COVID-19 in the United Kingdom. Recruitment used social media, Trust internal bulletins and the College of Paramedics' communication channels, employing a convenience sampling strategy. Data were collected using purposively developed open- and closed-ended questions and the validated general health questionnaire-12 (GHQ-12). Data were analysed using multi-level linear and logistic regression models.

Results

Phase 1 recruited 3717 participants, reducing to 2709 (73%) by phase 2 and 2159 (58%) by phase 3. Participants were mostly male (58%, n = 2148) and registered paramedics (n = 1992, 54%). Mean (standard deviation) GHQ-12 scores were 16.5 (5.2) during phase 1, reducing to 15.2 (6.7) by phase 3. A total of 84% of participants (n = 3112) had a GHQ-12 score ≥ 12 during the first phase, indicating psychological distress. Participants that had higher GHQ-12 scores were feeling unprepared for the pandemic, and reported a lack of confidence in using personal protective equipment and managing cardiac arrests in confirmed or suspected COVID-19 patients.

Conclusions

Most participants reported psychological distress, the reasons for which are multi-factorial. Ambulance managers need to be aware of the risks to staff mental health and take action to mitigate these, to support staff in the delivery of unscheduled, emergency and urgent care under these additional pressures.

Prehospital early warning scores for adults with suspected sepsis: retrospective diagnostic cohort study

BACKGROUND

Ambulance services need to identify and prioritise patients with sepsis for early hospital assessment. We aimed to determine the accuracy of early warning scores alongside paramedic diagnostic impression to identify sepsis that required urgent treatment.

METHODS

We undertook a retrospective diagnostic cohort study involving adult emergency medical cases transported to Sheffield Teaching Hospitals ED by Yorkshire Ambulance Service in 2019. We used routine ambulance service data to calculate 21 early warning scores and categorise paramedic diagnostic impressions as sepsis, infection, non-specific presentation or other presentation. We linked cases to hospital records and identified those meeting the sepsis-3 definition who received urgent hospital treatment for sepsis (reference standard). Analysis determined the accuracy of strategies that combined early warning scores at varying thresholds for positivity with paramedic diagnostic impression.

RESULTS

We linked 12 870/24 955 (51.6%) cases and identified 348/12 870 (2.7%) with a positive reference standard. None of the strategies provided sensitivity greater than 0.80 with positive predictive value greater than 0.15. The area under the receiver operating characteristic curve for the National Early Warning Score, version 2 (NEWS2) applied to patients with a diagnostic impression of sepsis or infection was 0.756 (95% CI 0.729, 0.783). No other early warning score provided clearly superior accuracy to NEWS2. Paramedic impression of sepsis or infection had sensitivity of 0.572 (0.519, 0.623) and positive predictive value of 0.156 (0.137, 0.176). NEWS2 thresholds of >4, >6 and >8 applied to patients with a diagnostic impression of sepsis or infection, respectively, provided sensitivities and positive predictive values of 0.522 (0.469, 0.574) and 0.216 (0.189, 0.245), 0.447 (0.395, 0.499) and 0.274 (0.239, 0.313), and 0.314 (0.268, 0.365) and 0.333 (0.284, 0.386).

CONCLUSION

No strategy is ideal but using NEWS2 alongside paramedic diagnostic impression of infection or sepsis could identify one-third to half of sepsis cases without prioritising unmanageable numbers. No other score provided clearly superior accuracy to NEWS2.

TRIAL REGISTRATION NUMBER

researchregistry5268, https://www.researchregistry.com/browse-the-registry%23home/registrationdetails/5de7bbd97ca5b50015041c33/.

Diagnostic Accuracy of Clinical Pathways for Suspected Acute Myocardial Infarction in the Out-of-Hospital Environment

STUDY OBJECTIVE

Chest pain is one of the most common reasons for emergency ambulance calls. Patients are routinely transported to the hospital to prevent acute myocardial infarction (AMI). We evaluated the diagnostic accuracy of clinical pathways in the out-of-hospital environment. The Troponin-only Manchester Acute Coronary Syndromes decision aid and History, ECG, Age, Risk Factors, Troponin score require cardiac troponin (cTn) measurement, whereas the History and ECG-only Manchester Acute Coronary Syndromes decision aid and History, ECG, Age, Risk Factors score do not.

METHODS

We conducted a prospective diagnostic accuracy study at 4 ambulance services and 12 emergency departments between February 2019 and March 2020. We included patients who received an emergency ambulance response in whom paramedics suspected AMI. Paramedics recorded the data required to calculate each decision aid and took venous blood samples in the out-of-hospital environment. Samples were tested using a point-of-care cTn assay (Roche cobas h232) within 4 hours. The target condition was a diagnosis of type 1 AMI, adjudicated by 2 investigators.

RESULTS

Of 817 included participants, 104 (12.8%) had AMI. Setting the cutoff at the lowest risk group, Troponin-only Manchester Acute Coronary Syndromes had 98.3% sensitivity (95% confidence interval 91.1% to 100%) and 25.5% specificity (21.4% to 29.8%) for type 1 AMI. History, ECG, Age, Risk Factors, Troponin had 86.4% sensitivity (75.0% to 98.4%) and 42.2% specificity (37.5% to 47.0%); History and ECG-only Manchester Acute Coronary Syndromes had 100% sensitivity (96.4% to 100%) and 3.1% specificity (1.9% to 4.7%), whereas History, ECG, Age, Risk Factors had 95.1% sensitivity (88.9% to 98.4%) and 12.1% specificity (9.8% to 14.8%).

CONCLUSION

With point-of-care cTn testing, decision aids can identify patients at a low risk of type 1 AMI in the out-of-hospital environment. When used alongside clinical judgment, and with appropriate training, such tools may usefully enhance out-of-hospital risk stratification.

External validation of the Manchester Acute Coronary Syndromes ECG risk model within a pre-hospital setting

OBJECTIVES

The Manchester Acute Coronary Syndromes ECG (MACS-ECG) prediction model calculates a score based on objective ECG measurements to give the probability of a non-ST elevation myocardial infarction (NSTEMI). The model showed good performance in the emergency department (ED), but its accuracy in the pre-hospital setting is unknown. We aimed to externally validate MACS-ECG in the pre-hospital environment.

METHODS

We undertook a secondary analysis from the Pre-hospital Evaluation of Sensitive Troponin (PRESTO) study, a multi-centre prospective study to validate decision aids in the pre-hospital setting (26 February 2019 to 23 March 2020). Patients with chest pain where the treating paramedic suspected acute coronary syndrome were included. Paramedics collected demographic and historical data and interpreted ECGs contemporaneously (as 'normal' or 'abnormal'). After completing recruitment, we analysed ECGs to calculate the MACS-ECG score, using both a pre-defined threshold and a novel threshold that optimises sensitivity to differentiate AMI from non-AMI. This was compared with subjective ECG interpretation by paramedics. The diagnosis of AMI was adjudicated by two investigators based on serial troponin testing in hospital.

RESULTS

Of 691 participants, 87 had type 1 AMI and 687 had complete data for paramedic ECG interpretation. The MACS-ECG model had a C-index of 0.68 (95% CI: 0.61 to 0.75). At the pre-determined cut-off, MACS-ECG had 2.3% (95% CI: 0.3% to 8.1%) sensitivity, 99.5% (95% CI: 98.6% to 99.9%) specificity, 40.0% (95% CI: 10.2% to 79.3%) positive predictive value (PPV) and 87.6% (87.3% to 88.0%) negative predictive value (NPV). At the optimal threshold for sensitivity, MACS-ECG had 50.6% sensitivity (39.6% to 61.5%), 83.1% specificity (79.9% to 86.0%), 30.1% PPV (24.7% to 36.2%) and 92.1% NPV (90.4% to 93.5%). In comparison, paramedics had a sensitivity of 71.3% (95% CI: 60.8% to 80.5%) with 53.8% (95% CI: 53.8% to 61.8%) specificity, 19.7% (17.2% to 22.45%) PPV and 93.3% (90.8% to 95.1%) NPV.

CONCLUSION

Neither MACS-ECG nor paramedic ECG interpretation had a sufficiently high PPV or NPV to 'rule in' or 'rule out' NSTEMI alone.

PP45 ‘Every day was a learning curve’: the experience of implementing COVID-19 triage protocols in UK ambulance services – a qualitative study

Background

TRIM is an evaluation of the models used to triage and manage emergency ambulance service care for patients with suspected Covid-19 during the first wave of the pandemic in 2020. We aimed to understand experiences and concerns of clinical and managerial staff about implementation of triage protocols in call centre and on-scene.

Methods

Research paramedics in four study sites across England interviewed purposively selected stakeholders from ambulance services (call handlers, clinical advisors in call centres, clinicians providing emergency response, managers) and ED clinical staff from one hospital per site. Interviews (n=23) were conducted remotely using MS Teams, recorded, and transcribed in full. Analysis generated themes from the implicit and explicit ideas within participants’ accounts, following the six stages of analysis described by Braun and Clarke, conducted by a group of researchers and PPI partners working together.

Results

We identified the following themes:

Constantly changing guidelines – at some points, updates several times a day

The ambulance service as part of the wider healthcare system - changes in other parts of the healthcare system left ambulance services as the default option

Peaks and troughs of demand - demand fluctuated greatly over time, with workload varying across the ambulance service, including an increased role for clinical advisors

A stretched system - resources to respond to patient demand were stretched thinner by staff sickness and isolation, longer job times, and increased handover delays at ED

Emotional load of responding to the pandemic - particularly for call centre staff

Doing the best they can in the face of uncertainty - in the face of a rapidly evolving situation unlike any which ambulance services had faced before

Discussion

Implementing triage protocols in response to the Covid-19 pandemic was a complex and process which had to be actively managed by a range of front line staff, dealing with external pressures and a heavy emotional load.

PP26 Exploring the use of pre-hospital pre-alerts and their impact on patients, ambulance service and emergency department staff: protocol for a mixed methods study

Background

Ambulance clinicians use pre-alert calls to inform receiving emergency departments (EDs) of the arrival of a critically unwell patient that will require a specialised response. Little is known about how a decision to pre-alert is made and how this is communicated and acted upon in the receiving ED. Whilst appropriate use of pre-alerts benefits patient care, their overuse carries a risk of harm or opportunity costs. The impact of pre-alerts on ambulance clinicians, ED staff and patients is not currently well understood.

Methods

We are conducting a mixed methods study with five inter-related work packages. We will analyse 12 months of routine data from ambulance pre-alerts in three regions to identify factors in the variation of pre-alert use, including pre-hospital decision-making. We will undertake a national online Qualtrics survey of ambulance clinician perspectives and experience of pre-alerts. We will explore the impacts of a pre-alert on staff, ED facilities and the patient using semi-structured interviews with ambulance clinicians, ED staff, patients and carers and undertake non-participant observation of ED pre-alert response.

Expected Results

We will describe current pre-alert practice using 12 months’ data for 3 Ambulance Services, including volume and types of pre-alerts. We will identify specific conditions or patient groups for whom pre-alerts are most likely to lead to change in clinical practice, or for whom action is unlikely to provide benefit. We will hold a feedback workshop in which we will share and discuss our findings with key stakeholders.

Conclusions

Current variation in pre-alert processes, both pre-hospital and in-hospital and the impact on patient care is not understood. The outputs of this study will establish an evidence base to update national guidance for pre-alert practice and identify areas of good pre-alert practice for both ambulance service and Emergency Department staff.

Evaluation of prognostic risk models for postoperative pulmonary complications in adult patients undergoing major abdominal surgery: a systematic review and international external validation cohort study

BACKGROUND

Stratifying risk of postoperative pulmonary complications after major abdominal surgery allows clinicians to modify risk through targeted interventions and enhanced monitoring. In this study, we aimed to identify and validate prognostic models against a new consensus definition of postoperative pulmonary complications.

METHODS

We did a systematic review and international external validation cohort study. The systematic review was done in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. We searched MEDLINE and Embase on March 1, 2020, for articles published in English that reported on risk prediction models for postoperative pulmonary complications following abdominal surgery. External validation of existing models was done within a prospective international cohort study of adult patients (≥18 years) undergoing major abdominal surgery. Data were collected between Jan 1, 2019, and April 30, 2019, in the UK, Ireland, and Australia. Discriminative ability and prognostic accuracy summary statistics were compared between models for the 30-day postoperative pulmonary complication rate as defined by the Standardised Endpoints in Perioperative Medicine Core Outcome Measures in Perioperative and Anaesthetic Care (StEP-COMPAC). Model performance was compared using the area under the receiver operating characteristic curve (AUROCC).

FINDINGS

In total, we identified 2903 records from our literature search; of which, 2514 (86·6%) unique records were screened, 121 (4·8%) of 2514 full texts were assessed for eligibility, and 29 unique prognostic models were identified. Nine (31·0%) of 29 models had score development reported only, 19 (65·5%) had undergone internal validation, and only four (13·8%) had been externally validated. Data to validate six eligible models were collected in the international external validation cohort study. Data from 11 591 patients were available, with an overall postoperative pulmonary complication rate of 7·8% (n=903). None of the six models showed good discrimination (defined as AUROCC ≥0·70) for identifying postoperative pulmonary complications, with the Assess Respiratory Risk in Surgical Patients in Catalonia score showing the best discrimination (AUROCC 0·700 [95% CI 0·683-0·717]).

INTERPRETATION

In the pre-COVID-19 pandemic data, variability in the risk of pulmonary complications (StEP-COMPAC definition) following major abdominal surgery was poorly described by existing prognostication tools. To improve surgical safety during the COVID-19 pandemic recovery and beyond, novel risk stratification tools are required.

FUNDING

British Journal of Surgery Society.

STRategies to manage Emergency ambulance Telephone Callers with sustained High needs: an Evaluation using linked Data (STRETCHED) - a study protocol

INTRODUCTION

UK ambulance services have identified a concern with high users of the 999 service and have set up 'frequent callers' services, ranging from within-service management to cross-sectoral multidisciplinary case management approaches. There is little evidence about how to address the needs of this patient group.

AIM

To evaluate effectiveness, safety and efficiency of case management approaches to the care of people who frequently call the emergency ambulance service, and gain an understanding of barriers and facilitators to implementation.

OBJECTIVES

(1) Develop an understanding of predicted mechanisms of change to underpin evaluation. (2) Describe epidemiology of sustained high users of 999 services. (3) Evaluate case management approaches to the care of people who call the 999 ambulance service frequently in terms of: (i) Further emergency contacts (999, emergency department, emergency admissions to hospital) (ii) Effects on other services (iii) Adverse events (deaths, injuries, serious medical emergencies and police arrests) (iv) Costs of intervention and care (v) Patient experience of care. (4) Identify challenges and opportunities associated with using case management models, including features associated with success, and develop theories about how case management works in this population.

METHODS AND ANALYSIS

We will conduct a multisite mixed-methods evaluation of case management for people who use ambulance services frequently by using anonymised linked routine data outcomes in a 'natural experiment' cohort design, in four regional ambulance services. We will conduct interviews and focus groups with service users, commissioners and emergency and non-acute care providers. The planned start and end dates of the study are 1 April 2019 and 1 September 2022, respectively ETHICS AND DISSEMINATION: The study received approval from the UK Health Research Authority (Confidentiality Advisory Group reference number: 19/CAG/0195; research ethics committee reference number: 19/WA/0216).We will collate feedback from our Lived Experience Advisory Panel, the Frequent Caller National Network and Research Management Group for targeted dissemination activities.

03 The prehospital 12 lead electrocardiogram is associated with improved outcomes in patients with acute coronary syndromes presenting to emergency medical services: a nationwide linked cohort study

Background

Use of the Pre-Hospital 12-lead Electrocardiogram (PHECG) is recommended in patients presenting to emergency medical services (EMS) with suspected acute coronary syndrome (ACS).

Objectives

To investigate differences in mortality between those who did/did not receive PHECG.

Methods

Population-based, linked cohort study using Myocardial Ischaemia National Audit Project (MINAP) data from 2010-2017.

Results

Of 330,713 patients, 263,420 (79.6%) had PHECG, 67,293 (20.3%) did not. 30-day mortality was 7.8% overall, 7.1% with PHECG vs 10.9% without PHECG (adjusted Odds Ratio [aOR] 0.772, 95% confidence interval [CI] 0.748-0.795, p<0.001). 1 year mortality was 16.1% overall, 14.2% with PHECG vs 23.2% without (aOR 0.692, 95% CI 0.676-0.708, p<0.001). 144,254 patients had ST segment elevation myocardial infarction (STEMI); 130,240 (90.2%) had PHECG, 30 day mortality 8.8% overall, 8.0% with PHECG vs 15.9% without (aOR 0.588, 95% CI 0.557-0.622, p<0.001), 1 year mortality 13.1% overall, 12.1% with PHECG vs 22.8% without (aOR 0.585, 95% CI 0.557-0.614, p<0.001). 186,459 patients had non-STEMI; 133,180 (71.4%) had PHECG. 30-day mortality 7.1% overall, 6.1% with PHECG vs 9.6% without (aOR 0.677, 95%CI 0.652-0.704, p<0.001), 1 year mortality 18.3% overall, 16.3% with PHECG vs 23.3% without (aOR 0.694, 95% CI 0.676-0.713, p<0.001). 110,571 STEMI patients received primary PCI, 103,741 (93.8%) had PHECG. 30 day mortality 5.4% overall, 5.3% with PHECG vs 7.0% without (aOR 0.739, 95% CI 0.667-0.829, p<0.001). 1 year mortality 8.5% overall, 8.4% with PHECG vs 9.8% without (aOR 0.833, 95% CI 0.762-0.911, p<0.001). 26,127 (18.1%) STEMI patients received no reperfusion; 19,873 (76%) had PHECG. Mortality at 30 days 22.1% overall, 21.3% with PHECG vs 24.7% without (aOR 0.911, 95% CI 0.847-0.980, p=0.013), 1 year mortality 32.2% overall, 30.9% with PHECG, 36.4% without (aOR 0.865, 95% CI 0.810-0.925, p<0.001).

Conclusion

PHECG was associated with lower mortality at 30 days and 1 year in both STEMI and non-STEMI patients.

05 Co-design of a logic model describing components, mechanisms of change and expected impacts of case management for people who frequently call ambulance services

Background

Multi-agency case management is being introduced by ambulance services and their partners in the UK to try to identify and address the needs of those who call 999 ambulance services frequently. However, there is a lack of evidence about what works well in this setting and how. Based on current nationally agreed definitions, calling frequently is defined as 5 or more times in a month, or 12 or more times in a three-month period. The STRETCHED study (STRategies to manage Emergency ambulance Telephone Callers with sustained High needs – an Evaluation using linked Data) study seeks to evaluate clinical and cost-effectiveness, safety, and efficiency of case management for people who frequently call the emergency ambulance service.

We developed a logic model to describe key components, mechanisms of change and expected impacts of cross-sectoral case management approaches to the management of people who call 999 frequently.

Method

We conducted a stakeholder event with 37 people from Wales, England and Northern Ireland including patient representatives and professional staff involved in commissioning, planning and delivering case management for people who call 999 services frequently. The aggregated responses from the participants was used as the basis for developing a logic model.

Results

Components: dedicated staff time for case management, availability and knowledge of relevant services for referral, multidisciplinary collaboration, organisational support, and clear information sharing protocols

Mechanisms: provision of space for a clear understanding of reasons for calling, tailoring of multi–sectoral management to individual needs, offering therapeutic support and assistance in development of self–efficacy

Impacts: improvement in access to appropriate and timely care, increase in efficiency and accessibility of the healthcare system, reduction in emergency calls, costs and mortality

Conclusion

Case management is a developing area of provision in prehospital emergency care for people who call ambulance services frequently. Our logic model provides a firm foundation for evaluation to build the urgently needed evidence base for case management of people who call ambulance services frequently.

Call volume, triage outcomes, and protocols during the first wave of the COVID-19 pandemic in the United Kingdom: Results of a national survey

OBJECTIVES

During the first wave of the COVID-19 pandemic in the United Kingdom (UK), to describe volume and pattern of calls to emergency ambulance services, proportion of calls where an ambulance was dispatched, proportion conveyed to hospital, and features of triage used.

METHODS

Semistructured electronic survey of all UK ambulance services (n = 13) and a request for routine service data on weekly call volumes for 22 weeks (February 1-July 3, 2020). Questionnaires and data request were emailed to chief executives and research leads followed by email and telephone reminders. The routine data were analyzed using descriptive statistics, and questionnaire data using thematic analysis.

RESULTS

Completed questionnaires were received from 12 services. Call volume varied widely between services, with a UK peak at week 7 at 13.1% above baseline (service range -0.5% to +31.4%). All services ended the study period with a lower call volume than at baseline (service range -3.7% to -25.5%). Suspected COVID-19 calls across the UK totaled 604,146 (13.5% of all calls), with wide variation between services (service range 3.7% to 25.7%), and in service peaks of 11.4% to 44.5%. Ambulances were dispatched to 478,638 (79.2%) of these calls (service range 59.0% to 100.0%), with 262,547 (43.5%) resulting in conveyance to hospital (service range 32.0% to 53.9%). Triage models varied between services and over time. Two primary call triage systems were in use across the UK. There were a large number of products and arrangements used for secondary triage, with services using paramedics, nurses, and doctors to support decision making in the call center and on scene. Frequent changes to triage processes took place.

CONCLUSIONS

Call volumes were highly variable. Case mix and workload changed significantly as COVID-19 calls displaced other calls. Triage models and prehospital outcomes varied between services. We urgently need to understand safety and effectiveness of triage models to inform care during further waves and pandemics.

Perceptions of anonymised data use and awareness of the NHS data opt-out amongst patients, carers and healthcare staff

BACKGROUND

England operates a National Data Opt-Out (NDOO) for the secondary use of confidential health data for research and planning. We hypothesised that public awareness and support for the secondary use of health data and the NDOO would vary by participant demography and healthcare experience. We explored patient/public awareness and perceptions of secondary data use, grouping potential researchers into National Health Service (NHS), academia or commercial. We assessed awareness of the NDOO system amongst patients, carers, healthcare staff and the public. We co-developed recommendations to consider when sharing unconsented health data for research.

METHODS

A patient and public engagement program, co-created and including patient and public workshops, questionnaires and discussion groups regarding anonymised health data use.

RESULTS

There were 350 participants in total. Central concerns for health data use included unauthorised data re-use, the potential for discrimination and data sharing without patient benefit. 94% of respondents were happy for their data to be used for NHS research, 85% for academic research and 68% by health companies, but less than 50% for non-healthcare companies and opinions varied with demography and participant group. Questionnaires showed that knowledge of the NDOO was low, with 32% of all respondents, 53% of all NHS staff and 29% of all patients aware of the NDOO. Recommendations to guide unconsented secondary health data use included that health data use should benefit patients; data sharing decisions should involve patients/public. That data should remain in close proximity to health services with the principles of data minimisation applied. Further, that there should be transparency in secondary health data use, including publicly available lists of projects, summaries and benefits. Finally, organisations involved in data access decisions should participate in programmes to increase knowledge of the NDOO, to ensure public members were making informed choices about their own data.

CONCLUSION

The majority of participants in this study reported that the use of healthcare data for secondary purposes was acceptable when accessed by NHS. Academic and health-focused companies. However, awareness was limited, including of the NDOO. Further development of publicly-agreed recommendations for secondary health data use may improve both awareness and confidence in secondary health data use.

Out-of-hospital cardiac arrest due to hanging: a retrospective analysis

BACKGROUND

There has been little research into the prehospital management of cardiac arrest following hanging despite it being among the most prevalent methods of suicide worldwide. The aim of this study was to report the characteristics, resuscitative treatment and outcomes of patients managed in the prehospital environment for cardiac arrest secondary to hanging and compare these with all-cause out-of-hospital cardiac arrest (OHCA).

METHODS

Data from a UK ambulance service cardiac arrest registry were extracted for all cases in which treatment was provided for OHCA due to hanging between 1 January 2013 and 30 June 2018. Cases were linked to outcome data obtained from the Trauma Audit and Research Network. Comparison of the cohort was made to previously published data from a UK study of all-cause OHCA with 95% CIs calculated for the proportional difference between the studies in selected presentation and outcome variables.

RESULTS

189 cases were identified. 95 patients were conveyed to hospital and four of these survived to discharge. 40 patients were conveyed despite absence of a spontaneous circulation and none of these patients survived. While only three patients were initially in a shockable rhythm, DC shocks were administered in 20 cases. There was one case of failed ventilation prompting front-of-neck access for oxygenation. By comparison with all-cause OHCA the proportion of patients with a spontaneous circulation at hospital handover was similar (27.0% vs 27.5%; 0.5% difference, 95% CI -5.9% to 6.8%, p=0.882) but survival to hospital discharge was significantly lower (2.2% vs 8.4%; 6.2% difference, 95% CI 4.1% to 8.3%, p=0.002).

CONCLUSION

Clinical outcomes following OHCA due to hanging are poor, particularly when patients are transported while in cardiac arrest. Failure to ventilate was uncommon, and clinicians should be alert to the possibility of shockable rhythms developing during resuscitation.

Infrastructure and operating processes of PIONEER, the HDR-UK Data Hub in Acute Care and the workings of the Data Trust Committee: a protocol paper

INTRODUCTION

Health Data Research UK designated seven UK-based Hubs to facilitate health data use for research. PIONEER is the Hub in Acute Care. PIONEER delivered workshops where patients/public citizens agreed key principles to guide access to unconsented, anonymised, routinely collected health data. These were used to inform the protocol.

METHODS

This paper describes the PIONEER infrastructure and data access processes. PIONEER is a research database and analytical environment that links routinely collected health data across community, ambulance and hospital healthcare providers. PIONEER aims ultimately to improve patient health and care, by making health data discoverable and accessible for research by National Health Service, academic and commercial organisations. The PIONEER protocol incorporates principles identified in the public/patient workshops. This includes all data access requests being reviewed by the Data Trust Committee, a group of public citizens who advise on whether requests should be supported prior to licensed access.

ETHICS AND DISSEMINATION

East Midlands-Derby REC (20/EM/0158): Confidentiality Advisory Group (20/CAG/0084). www.PIONEERdatahub.co.uk.

Adrenaline to improve survival in out-of-hospital cardiac arrest: the PARAMEDIC2 RCT

BACKGROUND

Adrenaline has been used as a treatment for cardiac arrest for many years, despite uncertainty about its effects on long-term outcomes and concerns that it may cause worse neurological outcomes.

OBJECTIVES

The objectives were to evaluate the effects of adrenaline on survival and neurological outcomes, and to assess the cost-effectiveness of adrenaline use.

DESIGN

This was a pragmatic, randomised, allocation-concealed, placebo-controlled, parallel-group superiority trial and economic evaluation. Costs are expressed in Great British pounds and reported in 2016/17 prices.

SETTING

This trial was set in five NHS ambulance services in England and Wales.

PARTICIPANTS

Adults treated for an out-of-hospital cardiac arrest were included. Patients were ineligible if they were pregnant, if they were aged < 16 years, if the cardiac arrest had been caused by anaphylaxis or life-threatening asthma, or if adrenaline had already been given.

INTERVENTIONS

Participants were randomised to either adrenaline (1 mg) or placebo in a 1 : 1 allocation ratio by the opening of allocation-concealed treatment packs.

MAIN OUTCOME MEASURES

The primary outcome was survival to 30 days. The secondary outcomes were survival to hospital admission, survival to hospital discharge, survival at 3, 6 and 12 months, neurological outcomes and health-related quality of life through to 6 months. The economic evaluation assessed the incremental cost per quality-adjusted life-year gained from the perspective of the NHS and Personal Social Services. Participants, clinical teams and those assessing patient outcomes were masked to the treatment allocation.

RESULTS

From December 2014 to October 2017, 8014 participants were assigned to the adrenaline (n = 4015) or to the placebo (n = 3999) arm. At 30 days, 130 out of 4012 participants (3.2%) in the adrenaline arm and 94 out of 3995 (2.4%) in the placebo arm were alive (adjusted odds ratio for survival 1.47, 95% confidence interval 1.09 to 1.97). For secondary outcomes, survival to hospital admission was higher for those receiving adrenaline than for those receiving placebo (23.6% vs. 8.0%; adjusted odds ratio 3.83, 95% confidence interval 3.30 to 4.43). The rate of favourable neurological outcome at hospital discharge was not significantly different between the arms (2.2% vs. 1.9%; adjusted odds ratio 1.19, 95% confidence interval 0.85 to 1.68). The pattern of improved survival but no significant improvement in neurological outcomes continued through to 6 months. By 12 months, survival in the adrenaline arm was 2.7%, compared with 2.0% in the placebo arm (adjusted odds ratio 1.38, 95% confidence interval 1.00 to 1.92). An adjusted subgroup analysis did not identify significant interactions. The incremental cost-effectiveness ratio for adrenaline was estimated at £1,693,003 per quality-adjusted life-year gained over the first 6 months after the cardiac arrest event and £81,070 per quality-adjusted life-year gained over the lifetime of survivors. Additional economic analyses estimated incremental cost-effectiveness ratios for adrenaline at £982,880 per percentage point increase in overall survival and £377,232 per percentage point increase in neurological outcomes over the first 6 months after the cardiac arrest.

LIMITATIONS

The estimate for survival with a favourable neurological outcome is imprecise because of the small numbers of patients surviving with a good outcome.

CONCLUSIONS

Adrenaline improved long-term survival, but there was no evidence that it significantly improved neurological outcomes. The incremental cost-effectiveness ratio per quality-adjusted life-year exceeds the threshold of £20,000-30,000 per quality-adjusted life-year usually supported by the NHS.

FUTURE WORK

Further research is required to better understand patients' preferences in relation to survival and neurological outcomes after out-of-hospital cardiac arrest and to aid interpretation of the trial findings from a patient and public perspective.

TRIAL REGISTRATION

Current Controlled Trials ISRCTN73485024 and EudraCT 2014-000792-11.

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. 25. See the NIHR Journals Library website for further project information.

Prehospital continuous positive airway pressure for acute respiratory failure: the ACUTE feasibility RCT

BACKGROUND

Acute respiratory failure is a life-threatening emergency. Standard prehospital management involves controlled oxygen therapy. Continuous positive airway pressure is a potentially beneficial alternative treatment; however, it is uncertain whether or not this treatment could improve outcomes in NHS ambulance services.

OBJECTIVES

To assess the feasibility of a large-scale pragmatic trial and to update an existing economic model to determine cost-effectiveness and the value of further research.

DESIGN

(1) An open-label, individual patient randomised controlled external pilot trial. (2) Cost-effectiveness and value-of-information analyses, updating an existing economic model. (3) Ancillary substudies, comprising an acute respiratory failure incidence study, an acute respiratory failure diagnostic agreement study, clinicians perceptions of a continuous positive airway pressure mixed-methods study and an investigation of allocation concealment.

SETTING

Four West Midlands Ambulance Service hubs, recruiting between August 2017 and July 2018.

PARTICIPANTS

Adults with respiratory distress and peripheral oxygen saturations below the British Thoracic Society's target levels were included. Patients with limited potential to benefit from, or with contraindications to, continuous positive airway pressure were excluded.

INTERVENTIONS

Prehospital continuous positive airway pressure (O-Two system, O-Two Medical Technologies Inc., Brampton, ON, Canada) was compared with standard oxygen therapy, titrated to the British Thoracic Society's peripheral oxygen saturation targets. Interventions were provided in identical sealed boxes.

MAIN OUTCOME MEASURES

Feasibility objectives estimated the incidence of eligible patients, the proportion recruited and allocated to treatment appropriately, adherence to allocated treatment, and retention and data completeness. The primary clinical end point was 30-day mortality.

RESULTS

Seventy-seven patients were enrolled (target 120 patients), including seven patients with a diagnosis for which continuous positive airway pressure could be ineffective or harmful. Continuous positive airway pressure was fully delivered to 74% of participants (target 75%). There were no major protocol violations/non-compliances. Full data were available for all key outcomes (target ≥ 90%). Thirty-day mortality was 27.3%. Of the 21 deceased participants, 14 (68%) either did not have a respiratory condition or had ceiling-of-treatment decision implemented that excluded hospital non-invasive ventilation and critical care. The base-case economic evaluation indicated that standard oxygen therapy was probably cost-effective (incremental cost-effectiveness ratio £5685 per quality-adjusted life-year), but there was considerable uncertainty (population expected value of perfect information of £16.5M). Expected value of partial perfect information analyses indicated that effectiveness of prehospital continuous positive airway pressure was the only important variable. The incidence rate of acute respiratory failure was 17.4 (95% confidence interval 16.3 to 18.5) per 100,000 persons per year. There was moderate agreement between the primary prehospital and final hospital diagnoses (Gwet's AC1 coefficient 0.56, 95% confidence interval 0.43 to 0.69). Lack of hospital awareness of the Ambulance continuous positive airway pressure (CPAP): Use, Treatment Effect and economics (ACUTE) trial, limited time to complete trial training and a desire to provide continuous positive airway pressure treatment were highlighted as key challenges by participating clinicians.

LIMITATIONS

During week 10 of recruitment, the continuous positive airway pressure arm equipment boxes developed a 'rattle'. After repackaging and redistribution, no further concerns were noted. A total of 41.4% of ambulance service clinicians not participating in the ACUTE trial indicated a difference between the control and the intervention arm trial boxes (115/278); of these clinician 70.4% correctly identified box contents.

CONCLUSIONS

Recruitment rate was below target and feasibility was not demonstrated. The economic evaluation results suggested that a definitive trial could represent value for money. However, limited compliance with continuous positive airway pressure and difficulty in identifying patients who could benefit from continuous positive airway pressure indicate that prehospital continuous positive airway pressure is unlikely to materially reduce mortality.

FUTURE WORK

A definitive clinical effectiveness trial of continuous positive airway pressure in the NHS is not recommended.

TRIAL REGISTRATION

Current Controlled Trials ISRCTN12048261.

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. 7. See the NIHR Journals Library website for further project information.

Cost-effectiveness of out-of-hospital continuous positive airway pressure for acute respiratory failure: decision analytic modelling using data from a feasibility trial

Background

Standard prehospital management for Acute respiratory failure (ARF) involves controlled oxygen therapy. Continuous positive airway pressure (CPAP) is a potentially beneficial alternative treatment, however, it is uncertain whether this could improve outcomes and provide value for money. This study aimed to evaluate the cost-effectiveness of prehospital CPAP in ARF.

Methods

A cost-utility economic evaluation was performed using a probabilistic decision tree model synthesising available evidence. The model consisted of a hypothetical cohort of patients in a representative ambulance service with undifferentiated ARF, receiving standard oxygen therapy or prehospital CPAP. Costs and quality adjusted life years (QALYs) were estimated using methods recommended by NICE.

Results

In the base case analysis, using CPAP effectiveness estimates form the ACUTE trial, the mean expected costs of standard care and prehospital CPAP were £15,201 and £14,850 respectively and the corresponding mean expected QALYs were 1.190 and 1.128, respectively. The mean ICER estimated as standard oxygen therapy compared to prehospital CPAP was £5685 per QALY which indicated that standard oxygen therapy strategy was likely to be cost-effective at a threshold of £20,000 per QALY (67% probability). The scenario analysis, using effectiveness estimates from an updated meta-analysis, suggested that prehospital CPAP was more effective (mean incremental QALYs of 0.157), but also more expensive (mean incremental costs of £1522), than standard care. The mean ICER, estimated as prehospital CPAP compared to standard care, was £9712 per QALY. At the £20,000 per QALY prehospital CPAP was highly likely to be the most cost-effective strategy (94%).

Conclusions

Cost-effectiveness of prehospital CPAP depends upon the estimate of effectiveness. When based on a small pragmatic feasibility trial, standard oxygen therapy is cost-effective. When based on meta-analysis of heterogeneous trials, CPAP is cost-effective. Value of information analyses support commissioning of a large pragmatic effectiveness trial, providing feasibility and plausibility conditions are met.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12873-021-00404-8.

The diagnostic accuracy of pre-hospital assessment of acute respiratory failure

Introduction:

Acute respiratory failure (ARF) is a common medical emergency. Pre-hospital management includes controlled oxygen therapy, supplemented by specific management options directed at the underlying disease. The aim of the current study was to characterise the accuracy of paramedic diagnostic assessment in acute respiratory failure.

Methods:

A nested diagnostic accuracy and agreement study comparing pre-hospital clinical impression to the final hospital discharge diagnosis was conducted as part of the ACUTE (Ambulance CPAP: Use, Treatment effect and Economics) trial. Adults with suspected ARF were recruited from the UK West Midlands Ambulance Service. The pre-hospital clinical impression of the recruiting ambulance service clinician was prospectively recorded and compared to the final hospital diagnosis at 30 days. Agreement between pre-hospital and hospital diagnostic assessments was evaluated using raw agreement and Gwets AC1 coefficient.

Results:

77 participants were included. Chronic obstructive pulmonary disease (32.9%) and lower respiratory tract infection (32.9%) were the most frequently suspected primary pre-hospital diagnoses for ARF, with secondary contributory conditions recorded in 36 patients (46.8%). There was moderate agreement between the primary pre-hospital and hospital diagnoses, with raw agreement of 58.5% and a Gwets AC1 coefficient of 0.56 (95% CI 0.43 to 0.69). In five cases, a non-respiratory final diagnosis was present, including: myocardial infarction, ruptured abdominal aortic aneurysm, liver failure and sepsis.

Conclusions:

Pre-hospital assessment of ARF is challenging, with limited accuracy compared to the final hospital diagnosis. A syndromic approach, providing general supportive care, rather than a specifically disease-orientated treatment strategy, is likely to be most appropriate for the pre-hospital environment.

The effect of airway management on CPR quality in the PARAMEDIC2 randomised controlled trial

INTRODUCTION

Good quality basic life support (BLS) is associated with improved outcome from cardiac arrest. Chest compression fraction (CCF) is a BLS quality indicator, which may be influenced by the type of airway used. We aimed to assess CCF according to the airway strategy in the PARAMEDIC2 study: no advanced airway, supraglottic airway (SGA), tracheal intubation, or a combination of the two. Our hypothesis was that tracheal intubation was associated with a decrease in the CCF compared with alternative airway management strategies.

METHODS

PARAMEDIC2 was a multicentre double-blinded placebo-controlled trial of adrenaline vs placebo in out-of-hospital cardiac arrest. Data showing compression rate and ratio from patients recruited by London Ambulance Service (LAS) as part of this study was collated and analysed according to the advanced airway used during the resuscitation attempt.

RESULTS

CPR process data were available from 286/ 2058 (13.9%) of the total patients recruited by LAS. The mean compression rate for the first 5 min of data recording was the same in all groups (P = 0.272) and ranged from 104.2 (95% CI of mean: 100.5, 107.8) min^-1 to 108.0 (95% CI of mean: 105.1, 108.3) min^-1. The mean compression fraction was also similar across all groups (P = 0.159) and ranged between 74.7% and 78.4%. There was no difference in the compression rates and fractions across the airway management groups, regardless of the duration of CPR.

CONCLUSION

There was no significant difference in the compression fraction associated with the airway management strategy.

PP27 What are emergency ambulance services doing to meet the needs of people who call frequently? A national survey of current practice in the united kingdom

Background

Emergency ambulance services are integral to providing a service for those with unplanned urgent and life-threatening health conditions. However, high use of the service by a small minority of patients is a concern.

Aims and Objectives

To describe: service-wide and local policies or pathways for people classified as Frequent Caller; call volume; and results of any audit or evaluation.

Methods

We conducted a national survey of current practice in ambulance services in relation to the management of people who call the emergency ambulance service frequently using a structured questionnaire, for completion by email and telephone interview. We analysed responses using a descriptive and thematic approach.

Results

Twelve of 13 UK ambulance services responded. Most services used nationally agreed definitions for ‘Frequent Caller’, with 600 – 900 people meeting this classification each month. Service-wide policies were in place, with local variations. Models of care varied from within-service care where calls are flagged in the call centre, contact made with callers and their GP with an aim of discouraging further calls; to case management through cross-service, multi-disciplinary team meetings aiming to resolve callers’ needs. No formal audits or evaluations were reported.

Conclusions

Ambulance services are under pressure to meet challenging response times for high acuity patients. Tensions are apparent in the provision of care to patients who have complex needs and call frequently. Within service care focused mainly on reducing calls whilst multi-disciplinary case management aimed to resolve clinical and emotional needs of patients. However, there is currently inadequate evidence to inform commissioning, policy or practice development.

PP16 A review of the annual case epidemiology and clinical exposure of 45 paramedics, in a UK ambulance service: a service evaluation

Introduction

Ambulance services are facing increased demand to provide both urgent and emergency care. Details of a paramedic’s case load, patient mix and interventions delivered during patient encounters within contemporary practice are rarely described within the literature. This paper provides insight into the work of paramedics within an NHS ambulance service within the UK; the frequency of low, medium and high acuity clinical presentations, amongst patients they care for and the utilisation of clinical interventions in practice.

Methods

A single site, retrospective service evaluation to describe the case load of 45 operational paramedics within a large regional English NHS ambulance service, over a full calendar year.

Results

A combined caseload of 33649 patients were attended by 45 paramedics. Paramedics attend 748 patients per year (95% CI, 705 – 790), 91.6% are adults. Aetiology of clinical presentations of patients attended by paramedics are 76.2% medical and 23.8% traumatic. 34.8% of patients receive a clinical intervention or administration of a medicine during their clinical management. Conveyance to hospital occurs in 63% of face to face interactions. Most patient interactions by paramedics are for low acuity clinical presentations. National Early Warning Score calculations of 25678 clinical records demonstrate that 74.1% of patients are LOW RISK, 16.5% are MEDIUM RISK and only 9.4% of patients are categorised as HIGH RISK. The distribution of NEWS seems not to be affected by rurality of the paramedic’s operational base. Musculoskeletal injury is the most common clinical impression with 7.0% of attendances.

Conclusion

Paramedics attend an extremely varied patient case mix; across the full life cycle. Most patients have low acuity clinical presentations. Patients with high acuity illness and in need of life saving critical interventions are seen infrequently, which may have implications for the education, exposure and skill retention in the management of this patient group.

Is a definitive trial of prehospital continuous positive airway pressure versus standard oxygen therapy for acute respiratory failure indicated? The ACUTE pilot randomised controlled trial

OBJECTIVES

To determine the feasibility of a large-scale definitive multicentre trial of prehospital continuous positive airway pressure (CPAP) in acute respiratory failure.

DESIGN

A single-centre, open-label, individual patient randomised, controlled, external pilot trial.

SETTING

A single UK Ambulance Service, between August 2017 and July 2018.

PARTICIPANTS

Adults with respiratory distress and peripheral oxygen saturations below British Thoracic Society target levels despite controlled oxygen treatment.

INTERVENTIONS

Patients were randomised to prehospital CPAP (O-Two system) versus standard oxygen therapy in a 1:1 ratio using simple randomisation.

PRIMARY AND SECONDARY OUTCOME MEASURES

Feasibility outcomes comprised recruitment rate, adherence to allocated treatment, retention and data completeness. The primary clinical outcome was 30-day mortality.

RESULTS

77 patients were enrolled (target 120), including 7 cases with a diagnosis where CPAP could be ineffective or harmful. CPAP was fully delivered in 74% (target 75%). There were no major protocol violations. Full data were available for all key outcomes (targets ≥90%). Overall 30-day mortality was 27.3%. Of these deceased patients, 14/21 (68%) either did not have a respiratory condition or had ceiling of treatment decisions implemented excluding hospital non-invasive ventilation and critical care.

CONCLUSIONS

Recruitment rate was below target and feasibility was not demonstrated. Limited compliance with CPAP, and difficulty in identifying patients who could benefit from CPAP, indicate that prehospital CPAP is unlikely to materially reduce mortality. A definitive effectiveness trial of CPAP is therefore not recommended.

TRIAL REGISTRATION NUMBER

ISRCTN12048261; Post-results.

What are emergency ambulance services doing to meet the needs of people who call frequently? A national survey of current practice in the United Kingdom

Background

Emergency ambulance services are integral to providing a service for those with unplanned urgent and life-threatening health conditions. However, high use of the service by a small minority of patients is a concern. Our objectives were to describe: service-wide and local policies or pathways for people classified as Frequent Caller; call volume; and results of any audit or evaluation.

Method

We conducted a national survey of current practice in ambulance services in relation to the management of people who call the emergency ambulance service frequently using a structured questionnaire for completion by email and telephone interview. We analysed responses using a descriptive and thematic approach.

Results

Twelve of 13 UK ambulance services responded. Most services used nationally agreed definitions for ‘Frequent Caller’, with 600–900 people meeting this classification each month. Service-wide policies were in place, with local variations. Models of care varied from within-service care where calls are flagged in the call centre; contact made with callers; and their General Practitioner (GP) with an aim of discouraging further calls, to case management through cross-service, multi-disciplinary team meetings aiming to resolve callers’ needs. Although data were available related to volume of calls and number of callers meeting the threshold for definition as Frequent Caller, no formal audits or evaluations were reported.

Conclusions

Ambulance services are under pressure to meet challenging response times for high acuity patients. Tensions are apparent in the provision of care to patients who have complex needs and call frequently. Multi-disciplinary case management approaches may help to provide appropriate care, and reduce demand on emergency services. However, there is currently inadequate evidence to inform commissioning, policy or practice development.

Use and impact of the prehospital 12-lead ECG in the primary PCI era (PHECG2): protocol for a mixed-method study

Introduction

Use of the prehospital 12-lead ECG (PHECG) is recommended in patients presenting to emergency medical services (EMS) with suspected acute coronary syndrome (ACS). Prior research found that although PHECG use was associated with improved 30-day survival, a third of patients (typically women, the elderly and those with comorbidities) under EMS care did not receive a PHECG.

The overall aim of the PHECG2 study is to update evidence on care and outcomes for patients eligible for PHECG, specifically addressing the following research questions: (1) Is there a difference in 30-day mortality, and in reperfusion rate, between those who do and those who do not receive PHECG? (2) Has the proportion of eligible patients who receive PHECG changed since the introduction of primary percutaneous coronary intervention networks? (3) Are patients that receive PHECG different from those that do not in terms of social and demographic factors, or prehospital clinical presentation? (4) What factors influence EMS clinicians’ decisions to perform PHECG?

Methods and analysis

This is an explanatory, mixed-method study comprising four work packages (WPs). WP1 is a population-based, linked-data analysis of a national ACS registry (Myocardial Ischaemia National Audit Project). WP2 is a retrospective chart review of patient records from three large regional EMS. WP3 comprises focus groups of EMS personnel. WP4 will synthesise findings from WP1–3 to inform the development of an intervention to increase PHECG uptake.

Ethics and dissemination

The study has been approved by the London-Hampstead Research Ethics Committee (ref: 18LO1679). Findings will be disseminated through feedback to participating EMS, conference presentations and publication in peer-reviewed journals.

Trial registration number

NCT03699137

Pre-hospital CPAP for acute respiratory failure: the ACUTE feasibility and pilot randomised controlled trial

Introduction:

Acute respiratory failure (ARF) is a common and life-threatening medical emergency. Continuous positive airway pressure (CPAP) is a potentially beneficial alternative treatment; however, it is uncertain whether this could improve important outcomes in NHS ambulance services. The ACUTE study aimed to assess the feasibility of a large-scale pragmatic trial of pre-hospital CPAP.

Methods:

The study was a pilot randomised controlled trial of the O-Two system CPAP mask versus standard oxygen therapy, with concealed allocation in identical sealed boxes. Feasibility objectives estimated the incidence of eligible patients; the proportion recruited and allocated to treatment appropriately; adherence to allocated treatment; and retention and data completeness. The primary clinical endpoint was 30-day mortality. Ancillary studies included an ARF incidence study, ARF diagnostic agreement study, clinician perceptions of CPAP mixed methods study and investigation of allocation concealment.

Results:

Over 12 months, 77 patients were enrolled (target 120). CPAP was fully delivered in 74% (target 75%). There were no major protocol violations/non-compliances. Full data were available for all key outcomes (targets ≥ 90%). Thirty-day mortality was 27.3%. Of deceased patients, 14/21 (68%) either did not have a respiratory condition or had ceiling of treatment decisions implemented excluding hospital NIV and critical care.

Conclusion:

The ACUTE trial recruitment rate was below the target rate and feasibility was not demonstrated. Identification of patients who might benefit from pre-hospital CPAP was challenging. It appeared difficult to exclude conditions where CPAP would not work, or might be harmful, and to select appropriate patients where there was a meaningful chance of success, or where the potential advantages of pre-hospital CPAP would outweigh the burdens of more advanced and aggressive treatment. The limited compliance with CPAP, and the difficulty in identifying patients who could benefit from CPAP, indicate that pre-hospital CPAP is unlikely to materially reduce mortality. A definitive effectiveness trial of CPAP in the NHS is therefore not recommended.

051 The ACUTE (ambulance CPAP: use, treatment effect and economics) feasibility study: a pilot randomised controlled trial of prehospital CPAP for acute respiratory failure

Background

Acute respiratory failure (ARF) is a common and life-threatening medical emergency. Continuous positive airway pressure (CPAP) is a potentially beneficial prehospital treatment, but it is uncertain whether this could improve important outcomes in NHS ambulance services.

Methods

An individually randomised, external pilot study was conducted to test the feasibility of a definitive pragmatic trial. Adults with respiratory distress and peripheral oxygen saturations below British Thoracic Society target levels were recruited from the West Midlands Ambulance Service between August 2017 and July 2018. Participants were randomised 1:1 to prehospital CPAP or standard oxygen therapy. Feasibility objectives estimated the: incidence of eligible patients; proportion recruited and allocated to treatment appropriately; adherence to allocated treatment; retention and data completeness; and 30-day mortality, as a potential primary outcome for a definitive trial.

Results

Over 12 months, 77 patients were enrolled (CPAP arm 42, standard oxygen arm 35 cases, target 120). CPAP was fully delivered as planned in 74% (target 75%). There were no major protocol violations/non-compliances (target 0%). Full data were available for key outcomes (target ≥90%). Mortality was higher than expected (overall 27.3%, CPAP arm 28.6% n=12/42, standard care arm 25.7% n=9/35). Of deceased patients, 14/21 (68%) either did not have a respiratory condition or had ceiling of treatment decisions excluding hospital non-invasive ventilation and critical care. Two patients required emergency department treatment for a pneumothorax, neither having received prehospital CPAP. There were no other serious adverse events.

Conclusions

The lower than expected recruitment rate, limited compliance with CPAP, and the difficulty in identifying patients who could benefit from CPAP, indicate limited potential for prehospital CPAP to reduce mortality. A definitive effectiveness trial is therefore not recommended. These findings also argue against routine implementation of CPAP into NHS ambulance services.

PRe-hospital Evaluation of Sensitive TrOponin (PRESTO) Study: multicentre prospective diagnostic accuracy study protocol

INTRODUCTION

Within the UK, chest pain is one of the most common reasons for emergency (999) ambulance calls and the most common reason for emergency hospital admission. Diagnosing acute coronary syndromes (ACS) in a patient with chest pain in the prehospital setting by a paramedic is challenging. The Troponin-only Manchester Acute Coronary Syndromes (T-MACS) decision rule is a validated tool used in the emergency department (ED) to stratify patients with suspected ACS following a single blood test.We are seeking to evaluate the diagnostic accuracy of the T-MACS decision aid algorithm to 'rule out' ACS when used in the prehospital environment with point-of-care troponin assays. If successful, this could allow paramedics to immediately rule out ACS for patients in the 'very low risk' group and avoid the need for transport to the ED, while also risk stratifying other patients using a single blood sample taken in the prehospital setting.

METHODS AND ANALYSIS

We will recruit patients who call emergency (999) ambulance services where the responding paramedic suspects cardiac chest pain. The data required to apply T-MACS will be prospectively recorded by paramedics who are responding to each patient. Paramedics will be required to draw a venous blood sample at the time of arrival to the patient. Blood samples will later be tested in batches for cardiac troponin, using commercially available troponin assays. The primary outcome will be a diagnosis of acute myocardial infarction, established at the time of initial hospital admission. The secondary outcomes will include any major adverse cardiac events within 30 days of enrolment.

ETHICS AND DISSEMINATION

The study obtained approval from the National Research Ethics Service (reference: 18/ES/0101) and the Health Research Authority. We will publish our findings in a high impact general medical journal.

TRIAL REGISTRATION NUMBER

Registration number: ClinicalTrials.gov, study ID: NCT03561051.

Recurrent tuberculosis in the pre-elimination era

Recurrent tuberculosis (TB), defined as TB that recurs after a patient has been considered cured, constitutes a challenge to TB control. In low TB burden countries, the underlying causes and consequences of recurrent TB are poorly understood. We conducted a literature review to summarise the evidence of recurrent TB in low-burden settings and to address current gaps in knowledge. We included peer-reviewed publications on studies conducted in countries with an estimated TB incidence of <100 cases per 100 000 population. The Newcastle-Ottawa scale was used to assess study quality. The review yielded 44 manuscripts, 39 of which were reports of observational studies and 5 of clinical trials. The median percentage of TB patients experiencing an episode of recurrent TB after treatment completion was 3.4% (interquartile range [IQR] 1.6-6.0, range 0.4-16.7) in studies with a median follow-up of 7.8 years (IQR 5-12, range 2-33). The median percentage of recurrences attributable to endogenous reactivation (rather than exogenous reinfection) was 81% (IQR 73.1-85.5, range 49-100). Commonly identified risk factors for recurrence in low-burden settings included infection by the human immunodeficiency virus, low socio-economic status, foreign birth and infection with drug-resistant TB. Current understanding of recurrence in low-burden settings is limited, in part due to substantial methodological differences between studies. Further research is required to delineate the mechanisms of TB recurrence, its health and clinical impact, as well as the implications for TB elimination efforts in low-burden countries.

Automated Assessment of Movement Impairment in Huntington's Disease

Quantitative assessment of movement impairment in Huntington's disease (HD) is essential to monitoring of disease progression. This paper aimed to develop and validate a novel low cost, objective automated system for the evaluation of upper limb movement impairment in HD in order to eliminate the inconsistency of the assessor and offer a more sensitive, continuous assessment scale. Patients with genetically confirmed HD and healthy controls were recruited to this observational study. Demographic data, including age (years), gender, and unified HD rating scale total motor score (UHDRS-TMS), were recorded. For the purposes of this paper, a modified upper limb motor impairment score (mULMS) was generated from the UHDRS-TMS. All participants completed a brief, standardized clinical assessment of upper limb dexterity while wearing a tri-axial accelerometer on each wrist and on the sternum. The captured acceleration data were used to develop an automatic classification system for discriminating between healthy and HD participants and to automatically generate a continuous movement impairment score (MIS) that reflected the degree of the movement impairment. Data from 48 healthy and 44 HD participants was used to validate the developed system, which achieved 98.78% accuracy in discriminating between healthy and HD participants. The Pearson correlation coefficient between the automatic MIS and the clinician rated mULMS was 0.77 with a p-value < 0.01. The approach presented in this paper demonstrates the possibility of an automated objective, consistent, and sensitive assessment of the HD movement impairment.

The ACUTE (Ambulance CPAP: Use, Treatment effect and economics) feasibility study: a pilot randomised controlled trial of prehospital CPAP for acute respiratory failure

Background

Acute respiratory failure (ARF) is a common and life-threatening medical emergency. Standard prehospital management involves controlled oxygen therapy and disease-specific ancillary treatments. Continuous positive airway pressure (CPAP) is a potentially beneficial alternative treatment that could be delivered by emergency medical services. However, it is uncertain whether this treatment could work effectively in United Kingdom National Health Service (NHS) ambulance services and if it represents value for money.

Methods

An individual patient randomised controlled external pilot trial will be conducted comparing prehospital CPAP to standard oxygen therapy for ARF. Adults presenting to ambulance service clinicians will be eligible if they have respiratory distress with peripheral oxygen saturation below British Thoracic Society (BTS) target levels, despite titrated supplemental oxygen. Enrolled patients will be allocated (1:1 simple randomisation) to prehospital CPAP (O_two system) or standard oxygen therapy using identical sealed boxes. Feasibility outcomes will include incidence of recruited eligible patients, number of erroneously recruited patients and proportion of cases adhering to allocation schedule and treatment, followed up at 30 days and with complete data collection. Effectiveness outcomes will comprise survival at 30 days (definitive trial primary end point), endotracheal intubation, admission to critical care, length of hospital stay, visual analogue scale (VAS) dyspnoea score, EQ-5D-5L and health care resource use at 30 days. The cost-effectiveness of CPAP, and of conducting a definitive trial, will be evaluated by updating an existing economic model. The trial aims to recruit 120 patients over 12 months from four regional ambulance hubs within the West Midlands Ambulance Service (WMAS). This sample size will allow estimation of feasibility outcomes with a precision of < 5%. Feasibility and effectiveness outcomes will be reported descriptively for the whole trial population, and each trial arm, together with their 95% confidence intervals.

Discussion

This study will determine if it is feasible, acceptable and cost-effective to undertake a full-scale trial comparing CPAP and standard oxygen treatment, delivered by ambulance service clinicians for ARF. This will inform NHS practice and prevent inappropriate prehospital CPAP adoption on the basis of limited evidence and at a potentially substantial cost.

Trial registration

ISRCTN12048261. Registered on 30 August 2017. http://www.isrctn.com/ISRCTN12048261

The societal cost of Huntington's disease: are we underestimating the burden?

Background and purpose

Approximately 9000 people in the UK are affected by Huntington's disease (HD). People with HD require ongoing health and social care support. There is a knowledge gap about costs of health and social care use associated with HD in the UK. This paper estimates the economic cost in the UK.

Methods

Data on UK patients for the year 2013 were extracted from the European Huntington's Disease Network REGISTRY study, a full clinical dataset, including the full medical history and medication history for patients with HD. National unit costs for the price year 2013 were applied to health and social care services.

Results

Data were available for 131 people. The mean annual cost per person with HD was £21 605. The largest proportion of this cost (65%) was due to informal care (£14 085).

Conclusions

Informal care was the largest driver of costs across all stages of HD; thus there is a need to also consider the needs of carers when planning services for people with HD.

Prevalence and predictors of hospital prealerting in acute stroke: a mixed methods study

Background

Thrombolysis can significantly reduce the burden of stroke but the time window for safe and effective treatment is short. In patients travelling to hospital via ambulance, the sending of a ‘prealert’ message can significantly improve the timeliness of treatment.

Objective

Examine the prevalence of hospital prealerting, the extent to which prealert protocols are followed and what factors influence emergency medical services (EMS) staff's decision to send a prealert.

Methods

Cohort study of patients admitted to two acute stroke units in West Midlands (UK) hospitals using linked data from hospital and EMS records. A logistic regression model examined the association between prealert eligibility and whether a prealert message was sent. In semistructured interviews, EMS staff were asked about their experiences of patients with suspected stroke.

Results

Of the 539 patients eligible for this study, 271 (51%) were recruited. Of these, only 79 (29%) were eligible for prealerting according to criteria set out in local protocols but 143 (53%) were prealerted. Increasing number of Face, Arm, Speech Test symptoms (1 symptom, OR 6.14, 95% CI 2.06 to 18.30, p=0.001; 2 symptoms, OR 31.36, 95% CI 9.91 to 99.24, p<0.001; 3 symptoms, OR 75.84, 95% CI 24.68 to 233.03, p<0.001) and EMS contact within 5 h of symptom onset (OR 2.99, 95% CI 1.37 to 6.50 p=0.006) were key predictors of prealerting but eligibility for prealert as a whole was not (OR 1.92, 95% CI 0.85 to 4.34 p=0.12). In qualitative interviews, EMS staff displayed varying understanding of prealert protocols and described frustration when their interpretation of the prealert criteria was not shared by ED staff.

Conclusions

Up to half of the patients presenting with suspected stroke in this study were prealerted by EMS staff, regardless of eligibility, resulting in disagreements with ED staff during handover. Aligning the expectations of EMS and ED staff, perhaps through simplified prealert protocols, could be considered to facilitate more appropriate use of hospital prealerting in acute stroke.

Isothermal Recombinase Polymerase amplification (RPA) of Schistosoma haematobium DNA and oligochromatographic lateral flow detection

Background

Accurate diagnosis of urogenital schistosomiasis is vital for surveillance/control programs. Amplification of schistosome DNA in urine by PCR is sensitive and specific but requires infrastructure, financial resources and skilled personnel, often not available in endemic areas. Recombinase Polymerase Amplification (RPA) is an isothermal DNA amplification/detection technology that is simple, rapid, portable and needs few resources.

Findings

Here a Schistosoma haematobium RPA assay was developed and adapted so that DNA amplicons could be detected using oligochromatographic Lateral Flow (LF) strips. The assay successfully amplified S. haematobium DNA at 30–45 °C in 10 mins and was sensitive to a lower limit of 100 fg of DNA. The assay was also successful with the addition of crude urine, up to 5 % of the total reaction volume. Cross amplification occurred with other schistosome species but not with other common urine microorganisms.

Conclusion

The LF-RPA assay developed here can amplify and detect low levels of S. haematobium DNA. Reactions are rapid, require low temperatures and positive reactions are interpreted using lateral flow strips, reducing the need for infrastructure and resources. This together with an ability to withstand inhibitors within urine makes RPA a promising technology for further development as a molecular diagnostic tool for urogenital schistosomiasis.

Exercise testing and training in people with Huntington's disease

OBJECTIVE

To explore exercise response in people with Huntington's disease (HD).

DESIGN

Experimental observational study with a randomly allocated subgroup before/after interventional study.

SETTING

Community.

SUBJECTS

People with HD (n=30) and a healthy comparator group (n=20). Thirteen people from the HD group were randomly allocated to an exercise training program.

MAIN MEASURES

Heart rate (HR) and perceived exertion on the Borg-CR10 scale (RPE) during a submaximal cycle ergometer exercise test (three minute unloaded and nine minute 65%-75%HRmaximum phase). Expired air and lactate measures were available for 8 people with HD during the exercise.

INTERVENTION

A 12 week gym and home walking exercise programme (n=13).

RESULTS

People with HD achieved a lower work rate at nine minutes (82±42(0-195) v 107±35(50 -185) Watts (p<0.05)), but higher RPE at both three (3±2(0-7) v 1±1(0-4)) and nine minutes (7±3(1-10) v 5± 2(2-9)) both p<0.01, compared to the healthy group and did not achieve a steady state HR during unloaded cycling. People with HD also demonstrated higher than expected lactate at three 2.5±2.5(1.1-8)mmo.L-1 and nine 3.8±1.9(1.2-6.6)mmo.L-1 minutes and respiratory exchange ratio at three 0.78±0.03 (0.74-0.81) and nine minutes 0.94±0.11(0.81-1.15). After exercise training there were no changes observed in HR or RPE responses during the exercise test.

CONCLUSIONS

There was a large variability in the observed metabolic and physiological responses to exercise in people with HD. The observed exercise responses suggest that altered exercise prescription parameters may be required for people with HD and that exercise response and factors' affecting this requires further investigation.