Experiences and views of people who frequently call emergency ambulance services: A qualitative study of UK service users.

INTRODUCTION: People who call emergency ambulances frequently are often vulnerable because of health and social circumstances, have unresolved problems or cannot access appropriate care. They have higher mortality rates. Case management by interdisciplinary teams can help reduce demand for emergency services and is available in some UK regions. We report results of interviews with people who use emergency ambulance services frequently to understand their experiences of calling and receiving treatment. METHODS: We used a two-stage recruitment process. A UK ambulance service identified six people who were known to them as frequently calling emergency services. Through third-sector organisations, we also recruited nine individuals with healthcare experiences reflecting the characteristics of people who call frequently. We gained informed consent to record and transcribe all telephone interviews. We used thematic analysis to explore the results. RESULTS: People said they make frequent calls to emergency ambulance services as a last resort when they perceive their care needs are urgent and other routes to help have failed. Those with the most complex health needs generally felt their immediate requirements were not resolved and underlying mental and physical problems led them to call again. A third of respondents were also attended to by police and were arrested for behaviour associated with their health needs. Those callers receiving case management did not know they were selected for this. Some respondents were concerned that case management could label frequent callers as troublemakers. CONCLUSION: People who make frequent calls to emergency ambulance services feel their health and care needs are urgent and ongoing. They cannot see alternative ways to receive help and resolve problems. Communication between health professionals and service users appears inadequate. More research is needed to understand service users' motivations and requirements to inform design and delivery of accessible and effective services. PATIENT OR PUBLIC CONTRIBUTION: People with relevant experience were involved in developing, undertaking and disseminating this research. Two public contributors helped design and deliver the study, including developing and analysing service user interviews and drafting this paper. Eight public members of a Lived Experience Advisory Panel contributed at key stages of study design, interpretation and dissemination. Two more public contributors were members of an independent Study Steering Committee.

A Randomized Trial of Epinephrine in Out-of-Hospital Cardiac Arrest.

BACKGROUND: Concern about the use of epinephrine as a treatment for out-of-hospital cardiac arrest led the International Liaison Committee on Resuscitation to call for a placebo-controlled trial to determine whether the use of epinephrine is safe and effective in such patients. METHODS: In a randomized, double-blind trial involving 8014 patients with out-of-hospital cardiac arrest in the United Kingdom, paramedics at five National Health Service ambulance services administered either parenteral epinephrine (4015 patients) or saline placebo (3999 patients), along with standard care. The primary outcome was the rate of survival at 30 days. Secondary outcomes included the rate of survival until hospital discharge with a favorable neurologic outcome, as indicated by a score of 3 or less on the modified Rankin scale (which ranges from 0 [no symptoms] to 6 [death]). RESULTS: At 30 days, 130 patients (3.2%) in the epinephrine group and 94 (2.4%) in the placebo group were alive (unadjusted odds ratio for survival, 1.39; 95% confidence interval [CI], 1.06 to 1.82; P=0.02). There was no evidence of a significant difference in the proportion of patients who survived until hospital discharge with a favorable neurologic outcome (87 of 4007 patients [2.2%] vs. 74 of 3994 patients [1.9%]; unadjusted odds ratio, 1.18; 95% CI, 0.86 to 1.61). At the time of hospital discharge, severe neurologic impairment (a score of 4 or 5 on the modified Rankin scale) had occurred in more of the survivors in the epinephrine group than in the placebo group (39 of 126 patients [31.0%] vs. 16 of 90 patients [17.8%]). CONCLUSIONS: In adults with out-of-hospital cardiac arrest, the use of epinephrine resulted in a significantly higher rate of 30-day survival than the use of placebo, but there was no significant between-group difference in the rate of a favorable neurologic outcome because more survivors had severe neurologic impairment in the epinephrine group. (Funded by the U.K. National Institute for Health Research and others; Current Controlled Trials number, ISRCTN73485024 .).

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.

Facilitators and barriers to the delivery of the PARAMEDIC2 trial.

Background: PARAMEDIC2 was a medicines trial comparing adrenaline with placebo in out-of-hospital cardiac arrest (OHCA). At the time, United Kingdom (UK) Emergency Medical Systems (EMS) were inexperienced in delivering such research. Aim: To identify barriers and facilitators to delivery of the PARAMEDIC2 (Adrenaline) trial by five UK NHS EMS. Methods: This qualitative study took a grounded theory approach to thematic analysis of workshop data. Members of the trial teams from each service attended a workshop in November 2018 and discussed their experiences in answer to two prompt questions. Data were coded and themes presented. Results: Three main themes were identified: professionalism, organisational investment and unique features of EMS. The study provided an opportunity for recruiting paramedics and research paramedics to demonstrate their professionalism. Research paramedics felt it was part of their professional duty to initiate discussions with the patient/family regarding the trial rather than leave this task to the hospital teams as would usually happen. Organisational investment was reflected by prioritising trial training and further development of research paramedics. By these means, research culture was developed. The unique features of EMS such as geographical challenges were often addressed with technological solutions and through building relationships with internal teams. Conclusion: Barriers to trial delivery included infrequent exposure to the condition of interest and lack of continuity in research paramedic roles. Facilitators identified included flexibility of the research protocol, and organisational investment in the development of research paramedics.Participating in PARAMEDIC2 was challenging for the EMS involved, but ultimately strengthened their research culture.

Termination of Resuscitation Rules and Survival Among Patients With Out-of-Hospital Cardiac Arrest: A Systematic Review and Meta-Analysis.

Importance: Termination of resuscitation (TOR) rules may help guide prehospital decisions to stop resuscitation, with potential effects on patient outcomes and health resource use. Rules with high sensitivity risk increasing inappropriate transport of nonsurvivors, while rules without excellent specificity risk missed survivors. Further examination of the performance of TOR rules in estimating survival of out-of-hospital cardiac arrest (OHCA) is needed. Objective: To determine whether TOR rules can accurately identify patients who will not survive an OHCA. Data Sources: For this systematic review and meta-analysis, the MEDLINE, Embase, CINAHL, Cochrane Library, and Web of Science databases were searched from database inception up to January 11, 2024. There were no restrictions on language, publication date, or time frame of the study. Study Selection: Two reviewers independently screened records, first by title and abstract and then by full text. Randomized clinical trials, case-control studies, cohort studies, cross-sectional studies, retrospective analyses, and modeling studies were included. Systematic reviews and meta-analyses were reviewed to identify primary studies. Studies predicting outcomes other than death, in-hospital studies, animal studies, and non-peer-reviewed studies were excluded. Data Extraction and Synthesis: Data were extracted by one reviewer and checked by a second. Two reviewers assessed risk of bias using the Revised Quality Assessment Tool for Diagnostic Accuracy Studies. Cochrane Screening and Diagnostic Tests Methods Group recommendations were followed when conducting a bivariate random-effects meta-analysis. This review followed the Preferred Reporting Items for a Systematic Review and Meta-Analysis of Diagnostic Test Accuracy Studies (PRISMA-DTA) statement and is registered with the International Prospective Register of Systematic Reviews (CRD42019131010). Main Outcomes and Measures: Sensitivity and specificity tables with 95% CIs and bivariate summary receiver operating characteristic (SROC) curves were produced. Estimates of effects at different prevalence levels were calculated. These estimates were used to evaluate the practical implications of TOR rule use at different prevalence levels. Results: This review included 43 nonrandomized studies published between 1993 and 2023, addressing 29 TOR rules and involving 1 125 587 cases. Fifteen studies reported the derivation of 20 TOR rules. Thirty-three studies reported external data validations of 17 TOR rules. Seven TOR rules had data to facilitate meta-analysis. One clinical study was identified. The universal termination of resuscitation rule had the best performance, with pooled sensitivity of 0.62 (95% CI, 0.54-0.71), pooled specificity of 0.88 (95% CI, 0.82-0.94), and a diagnostic odds ratio of 20.45 (95% CI, 13.15-31.83). Conclusions and Relevance: In this review, there was insufficient robust evidence to support widespread implementation of TOR rules in clinical practice. These findings suggest that adoption of TOR rules may lead to missed survivors and increased resource utilization.

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.

Acute respiratory failure is a life-threatening medical emergency. It occurs when heart or lung disease suddenly develops, or deteriorates, and leads to the patient being unable to maintain oxygen levels in their blood. Continuous positive airway pressure is a potentially useful treatment that could be used by paramedics. It involves delivering oxygen under increased pressure through a tight-fitting face mask. However, it is uncertain whether or not it could work effectively in NHS ambulance services, or if it represents value for money. The Ambulance continuous positive airway pressure (CPAP): Use, Treatment Effect and economics (ACUTE) trial investigated whether or not it is possible and worthwhile to undertake a full-scale study comparing continuous positive airway pressure with normal paramedic treatment. Paramedics identified adults with acute respiratory failure when attending 999 emergency calls. Half were randomly assigned to receive continuous positive airway pressure, whereas the other half were treated normally. Patients were then followed up to see what happened to them. Fewer patients than expected were entered into the trial, but paramedics were able to provide treatment with continuous positive airway pressure, and most patients were successfully followed up. It therefore seems possible to do a full-scale trial. A cost-effectiveness model also showed that it is uncertain whether or not continuous positive airway pressure represents value for money for the NHS, so further research might be worthwhile, if continuous positive airway pressure is thought to be effective. However, examination of patients recruited to the trial uncovered important doubts about whether or not continuous positive airway pressure would help them. One-quarter of patients were not able to tolerate the tight continuous positive airway pressure mask. Some of the patients had conditions that are not usually treated by continuous positive airway pressure, or had severe underlying disease that could not be helped by this treatment. Others had collapsed lungs that could have been made worse by continuous positive airway pressure. This means that, although a full-scale trial may be possible, it is difficult to see how continuous positive airway pressure could save enough lives to make a trial worthwhile.

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.

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.

Cardiac arrest is a medical emergency that happens when the heart suddenly stops pumping effectively. When cardiac arrest happens, awareness is lost within seconds. If emergency treatment is not started quickly, the person will die. The first treatments of cardiac arrest involve pressing on the chest, giving rescue breaths and defibrillation (electric shocks applied to the heart). If these treatments do not work, ambulance paramedics use a drug called adrenaline to try to restart the heart. Although this treatment has been used for many years, some recent research suggests that it may cause more harm than good. In this research study, we compared the effects of giving adrenaline with the effects of not giving adrenaline to people who had a cardiac arrest in the community. The research showed that adrenaline was effective at restarting the heart, so more people survived long enough to be admitted to hospital. Thirty days later, 130 out of 4012 patients (3.2%) who received adrenaline and 94 out of 3995 (2.4%) who did not receive adrenaline were alive. However, adrenaline did not improve the number of patients who went home from hospital having made a good recovery and were able to care for themselves. The evidence suggests that adrenaline represents a poor use of NHS funds on cost-effectiveness grounds. In a community survey, 95% of people who responded thought that long-term survival with good brain function was more important than just being alive. Further research exploring the opinions of patients and the public will help to understand the results of this research for the NHS.

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.

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 influence of time to adrenaline administration in the Paramedic 2 randomised controlled trial.

PURPOSE: To examine the time to drug administration in patients with a witnessed cardiac arrest enrolled in the Pre-Hospital Assessment of the Role of Adrenaline: Measuring the Effectiveness of Drug Administration in Cardiac Arrest (PARAMEDIC2) randomised controlled trial. METHODS: The PARAMEDIC2 trial was undertaken across 5 NHS ambulance services in England and Wales with randomisation between December 2014 and October 2017. Patients with an out-of-hospital cardiac arrest who were unresponsive to initial resuscitation attempts were randomly assigned to 1 mg intravenous adrenaline or matching placebo according to treatment packs that were identical apart from treatment number. Participants and study staff were masked to treatment allocation. RESULTS: 8016 patients were enrolled, 4902 sustained a witnessed cardiac arrest of whom 2437 received placebo and 2465 received adrenaline. The odds of return of spontaneous circulation decreased in both groups over time but at a greater rate in the placebo arm odds ratio (OR) 0.93 (95% CI 0.92-0.95) compared with the adrenaline arm OR 0.96 (95% CI 0.95-0.97); interaction OR: 1.03, 95% CI 1.01-1.05, p = 0.005. By contrast, although the rate of survival and favourable neurological outcome decreased as time to treatment increased, the rates did not differ between the adrenaline and placebo groups. CONCLUSION: The rate of return of spontaneous circulation, survival and favourable neurological outcomes decrease over time. As time to drug treatment increases, adrenaline increases the chances of return of spontaneous circulation. Longer term outcomes were not affected by the time to adrenaline administration. (ISRCTN73485024).

Education, Implementation, and Teams: 2020 International Consensus on Cardiopulmonary Resuscitation and Emergency Cardiovascular Care Science With Treatment Recommendations.

For this 2020 International Consensus on Cardiopulmonary Resuscitation and Emergency Cardiovascular Care Science With Treatment Recommendations, the Education, Implementation, and Teams Task Force applied the population, intervention, comparator, outcome, study design, time frame format and performed 15 systematic reviews, applying the Grading of Recommendations, Assessment, Development, and Evaluation guidance. Furthermore, 4 scoping reviews and 7 evidence updates assessed any new evidence to determine if a change in any existing treatment recommendation was required. The topics covered included training for the treatment of opioid overdose; basic life support, including automated external defibrillator training; measuring implementation and performance in communities, and cardiac arrest centers; advanced life support training, including team and leadership training and rapid response teams; measuring cardiopulmonary resuscitation performance, feedback devices, and debriefing; and the use of social media to improve cardiopulmonary resuscitation application.

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.

Characteristics of neighbourhoods with high incidence of out-of-hospital cardiac arrest and low bystander cardiopulmonary resuscitation rates in England.

Aims: The aim of the project was to identify the neighbourhood characteristics of areas in England where out-of-hospital cardiac arrest (OHCA) incidence was high and bystander cardiopulmonary resuscitation (BCPR) was low using registry data. Methods and results: Analysis was based on 67 219 cardiac arrest events between 1 April 2013 and 31 December 2015. Arrest locations were geocoded to give latitude/longitude. Postcode district was chosen as the proxy for neighbourhood. High-risk neighbourhoods, where OHCA incidence based on residential population was >127.6/100 000, or based on workday population was >130/100 000, and BCPR in bystander witnessed arrest was <60% were observed to have: a greater mean residential population density, a lower workday population density, a lower rural-urban index, a higher proportion of people in routine occupations and lower proportion in managerial occupations, a greater proportion of population from ethnic minorities, a greater proportion of people not born in UK, and greater level of deprivation. High-risk areas were observed in the North-East, Yorkshire, South-East, and Birmingham. Conclusion: The study identified neighbourhood characteristics of high-risk areas that experience a high incidence of OHCA and low bystander resuscitation rate that could be targeted for programmes of training in cardiopulmonary resuscitation and automated external defibrillator use.

The effects of adrenaline in out of hospital cardiac arrest with shockable and non-shockable rhythms: Findings from the PACA and PARAMEDIC-2 randomised controlled trials.

INTRODUCTION: Previous research suggests there may be differences in the effects of adrenaline related to the initial cardiac arrest rhythm. The aim of this study was to assess the effect of adrenaline compared with placebo according to whether the initial cardiac arrest rhythm was shockable or non-shockable. METHODS: Return of spontaneous circulation (ROSC), survival and neurological outcomes according to the initial arrest rhythm were compared amongst patients enrolled in the PARAMEDIC-2 randomised, placebo controlled trial. The results of the PARAMEDIC-2 and PACA out of hospital cardiac arrest trials were combined and meta-analysed. RESULTS: The initial rhythm was known for 3929 (98.2%) in the placebo arm and 3919 (97.6%) in the adrenaline arm. The effect on the rate of ROSC of adrenaline relative to placebo was greater in patients with non-shockable cardiac rhythms (1002/3003 (33.4%) versus 222/3005 (7.4%), adjusted OR: 6.5, (95% CI 5.6-7.6)) compared with shockable rhythms 349/716 (48.7%) versus (208/702 (29.6%), adjusted OR: 2.3, 95%CI: 1.9-2.9)). The adjusted odds ratio for survival at discharge for non-shockable rhythms was 2.5 (1.3, 4.8) and 1.3 (0.9, 1.8) for shockable rhythms (P value for interaction 0.065) and 1.8 (0.8-4.1) and 1.1 (0.8-1.6) respectively for neurological outcome at discharge (P value for interaction 0.295). Meta-analysis found similar results. CONCLUSION: Relative to placebo, the effects of adrenaline ROSC are greater for patients with an initially non-shockable rhythm than those with a shockable rhythms. Similar patterns are observed for longer term survival outcomes and favourable neurological outcomes, although the differences in effects are less pronounced. ISRCTN73485024.

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.

Data quality and 30-day survival for out-of-hospital cardiac arrest in the UK out-of-hospital cardiac arrest registry: a data linkage study.

OBJECTIVES: The Out-of-Hospital Cardiac Arrest Outcomes (OHCAO) project aims to understand the epidemiology and outcomes of out-of-hospital cardiac arrest (OHCA) across the UK. This data linkage study is a subproject of OHCAO. The aim was to establish the feasibility of linking OHCAO data to National Health Service (NHS) patient demographic data and Office for National Statistics (ONS) date of death data held on the NHS Personal Demographics Service (PDS) database to improve OHCAO demographic data quality and enable analysis of 30-day survival from OHCA. DESIGN AND SETTING: Data were collected from 1 January 2014 to 31 December 2014 as part of a prospective, observational study of OHCA attended by 10 English NHS Ambulance Services. 28 729 OHCA cases had resuscitation attempted by Emergency Medical Services and were included in the study. Data linkage was carried out using a data linkage service provided by NHS Digital, a national provider of health-related data. To assess data linkage feasibility a random sample of 3120 cases was selected. The sample was securely transferred to NHS Digital to be matched using OHCAO patient demographic data to return previously missing demographic data and provide ONS date of death data. RESULTS: A total of 2513 (80.5%) OHCAO cases were matched to patients in the NHS PDS database. Using the linkage process, missing demographic data were retrieved for 1636 (72.7%) out of 2249 OHCAO cases that had previously incomplete demographic data. Returned ONS date of death data allowed analysis of 30-day survival status. The results showed a 30-day survival rate of 9.3%, reducing unknown survival status from 46.1% to 8.5%. CONCLUSIONS: In this sample, data linkage between the OHCAO registry and NHS PDS database was shown to be feasible, improving demographic data quality and allowing analysis of 30-day survival status.