Unmanned aerial vehicles and pre-hospital emergency medicine.

Unmanned aerial vehicles (UAVs) are used in many industrial and commercial roles and have an increasing number of medical applications. This article reviews the characteristics of UAVs and their current applications in pre-hospital emergency medicine. The key roles are transport of equipment and medications and potentially passengers to or from a scene and the use of cameras to observe or communicate with remote scenes. The potential hazards of UAVs both deliberate or accidental are also discussed.

Practical psychosocial care for providers of pre-hospital care: a summary of the report 'valuing staff, valuing patients'.

BACKGROUND: Caring for people who are ill or injured in pre-hospital environments is emotionally draining and physically demanding. This article focuses on the Psychosocial and Mental Health Programme commissioned by the Faculty of Pre-Hospital Care (FPHC) at the Royal College of Surgeons of Edinburgh (RCSEd) in 2018 to investigate the experiences and needs of responders to pre-hospital emergencies and make recommendations. It summarises the report to FPHC published in 2022, and adds material from research published subsequently. METHOD: FPHC appointed a team to undertake the work. Team members conducted a literature review, and a systematic review of the literature concerning the impacts on the mental health of pre-hospital practitioners. They conducted fieldwork, participated in training and had conversations with trainees and established practitioners, and took evidence from the Pre-hospital Emergency Medicine Trainees Association (PHEMTA). RESULTS: The Results summarise the evidence-based theoretical background derived from the programme and practical guidance for practitioners, professional organisations, and employers who deliver pre-hospital care on the implications of, preventing and intervening with pre-hospital providers who experience psychosocial and mental health problems. CONCLUSION: This paper summarises the outputs from a multidisciplinary programme of scholarship, research, and fieldwork. The authors condense the findings and the guidance developed by the Programme Team to provide a summary of the report and guidance on implementation. They believe that the recommendations are applicable to all healthcare organisations and particularly those that employ responders to emergencies and provide pre-hospital care.

Major trauma presentations and patient outcomes in English hospitals during the COVID-19 pandemic: An observational cohort study.

BACKGROUND: Single-centre studies suggest that successive Coronavirus Disease 2019 (COVID-19)-related "lockdown" restrictions in England may have led to significant changes in the characteristics of major trauma patients. There is also evidence from other countries that diversion of intensive care capacity and other healthcare resources to treating patients with COVID-19 may have impacted on outcomes for major trauma patients. We aimed to assess the impact of the COVID-19 pandemic on the number, characteristics, care pathways, and outcomes of major trauma patients presenting to hospitals in England. METHODS AND FINDINGS: We completed an observational cohort study and interrupted time series analysis including all patients eligible for inclusion in England in the national clinical audit for major trauma presenting between 1 January 2017 and 31 of August 2021 (354,202 patients). Demographic characteristics (age, sex, physiology, and injury severity) and clinical pathways of major trauma patients in the first lockdown (17,510 patients) and second lockdown (38,262 patients) were compared to pre-COVID-19 periods in 2018 to 2019 (comparator period 1: 22,243 patients; comparator period 2: 18,099 patients). Discontinuities in trends for weekly estimated excess survival rate were estimated when lockdown measures were introduced using segmented linear regression. The first lockdown had a larger associated reduction in numbers of major trauma patients (-4,733 (21%)) compared to the pre-COVID period than the second lockdown (-2,754 (6.7%)). The largest reductions observed were in numbers of people injured in road traffic collisions excepting cyclists where numbers increased. During the second lockdown, there were increases in the numbers of people injured aged 65 and over (665 (3%)) and 85 and over (828 (9.3%)). In the second week of March 2020, there was a reduction in level of major trauma excess survival rate (-1.71%; 95% CI: -2.76% to -0.66%) associated with the first lockdown. This was followed by a weekly trend of improving survival until the lifting of restrictions in July 2020 (0.25; 95% CI: 0.14 to 0.35). Limitations include eligibility criteria for inclusion to the audit and COVID status of patients not being recorded. CONCLUSIONS: This national evaluation of the impact of COVID on major trauma presentations to English hospitals has observed important public health findings: The large reduction in overall numbers injured has been primarily driven by reductions in road traffic collisions, while numbers of older people injured at home increased over the second lockdown. Future research is needed to better understand the initial reduction in likelihood of survival after major trauma observed with the implementation of the first lockdown.

Maintaining Prehospital Intubation Success with COVID-19 Personal Protective Precautions.

BACKGROUND: Tracheal intubation is a high-risk intervention for exposure to airborne infective pathogens, including the novel coronavirus disease 2019 (COVID-19). During the recent pandemic, personal protective equipment (PPE) was essential to protect staff during intubation but is recognized to make the practical conduct of anesthesia and intubation more difficult. In the early phase of the coronavirus pandemic, some simple alterations were made to the emergency anesthesia standard operating procedure (SOP) of a prehospital critical care service to attempt to maintain high intubation success rates despite the challenges posed by wearing PPE. This retrospective observational cohort study aims to compare first-pass intubation success rates before and after the introduction of PPE and an altered SOP. METHODOLOGY: A retrospective observational cohort study was conducted from January 1, 2019 through August 30, 2021. The retrospective analysis used prospectively collected data using prehospital electronic patient records. Anonymized data were held in Excel (v16.54) and analyzed using IBM SPSS Statistics (v28). Patient inclusion criteria were those of all ages who received a primary tracheal intubation attempt outside the hospital by critical care teams. March 27, 2020 was the date from which the SOP changed to mandatory COVID-19 SOP including Level 3 PPE - this date is used to separate the cohort groups. RESULTS: Data were analyzed from 1,266 patients who received primary intubations by the service. The overall first-pass intubation success rate was 89.7% and the overall intubation success rate was 99.9%. There was no statistically significant difference in first-pass success rate between the two groups: 90.3% in the pre-COVID-19 group (n = 546) and 89.3% in the COVID-19 group (n = 720); Pearson chi-square 0.329; P = .566. In addition, there was no statistical difference in overall intubation success rate between groups: 99.8% in the pre-COVID-19 group and 100.0% in the COVID-19 group; Pearson chi-square 1.32; P = .251.Non-drug-assisted intubations were more than twice as likely to require multiple attempts in both the pre-COVID-19 group (n = 546; OR = 2.15; 95% CI, 1.19-3.90; P = .01) and in the COVID-19 group (n = 720; OR = 2.5; 95% CI, 1.5-4.1; P = <.001). CONCLUSION: This study presents simple changes to a prehospital intubation SOP in response to COVID-19 which included mandatory use of PPE, the first intubator always being the most experienced clinician, and routine first use of video laryngoscopy (VL). These changes allowed protection of the clinical team while successfully maintaining the first-pass and overall success rates for prehospital tracheal intubation.

Use of a national trauma registry to target violence reduction initiatives.

BACKGROUND: The incidence of interpersonal violence resulting in penetrating traumatic injury has increased in the UK. Violence reduction initiatives vary across the world, from reactive diversionary schemes to proactive educational intervention. To be successful a collaborative public health approach to violence reduction is vital. We examined regional data collected in a trauma network area as part of mandatory national trauma data submission to establish whether useful data could be extracted from this type of registry to inform regional violence reduction initiatives. Key information required to accurately target initiatives includes: who are the victims? where do incidents occur? and when do incidents occur? METHODS: Data were obtained from the national Trauma Audit and Research Network (TARN). This study utilised TARN inclusion criteria. Data for penetrating trauma patients from hospital sites in the Severn Major Trauma Network over an eight-year period were included in the analysis (1 June 2012 to 5 April 2020). The data were analysed using SPSS Statistics V27 and TARN analytics software. Existing ethical approval for anonymised registry data (PIAG section 60) was used. RESULTS: Over the eight-year study period, 299 cases of penetrating trauma were registered in the Major Trauma Network. Overall, the incidence of penetrating trauma is increasing (R value +0.470, and +0.900 when 2020 excluded). Male victims account for 87.3% of cases (n=261). Younger individuals are more likely to be victims of penetrating trauma. The proportion of victims aged 13-18 years increased from 0% in 2012 to 21.6% in 2019. There were 43 (14.3%) incidents of victims presenting more than once during the study period. The early evening and hour after midnight had the highest numbers of penetrating trauma incidents. Most incidents occurred in a small proportion of postcodes. All the postcodes identified as having high incidence of penetrating injuries were also areas with high deprivation. CONCLUSION: This study demonstrated that national trauma registry data can be used to establish valuable information about serious penetrating trauma in a region. This data provides key information with which to target a proactive approach to violence reduction in our region with implications for public health, police, and clinical policymakers.

Multicentre observational study on practice of prehospital management of hypotensive trauma patients: the SPITFIRE study protocol.

INTRODUCTION: Major haemorrhage after injury is the leading cause of preventable death for trauma patients. Recent advancements in trauma care suggest damage control resuscitation (DCR) should start in the prehospital phase following major trauma. In Italy, Helicopter Emergency Medical Services (HEMS) assist the most complex injuries and deliver the most advanced interventions including DCR. The effect size of DCR delivered prehospitally on survival remains however unclear. METHODS AND ANALYSIS: This is an investigator-initiated, large, national, prospective, observational cohort study aiming to recruit >500 patients in haemorrhagic shock after major trauma. We aim at describing the current practice of hypotensive trauma management as well as propose the creation of a national registry of patients with haemorrhagic shock. PRIMARY OBJECTIVE: the exploration of the effect size of the variation in clinical practice on the mortality of hypotensive trauma patients. The primary outcome measure will be 24 hours, 7-day and 30-day mortality. Secondary outcomes include: association of prehospital factors and survival from injury to hospital admission, hospital length of stay, prehospital and in-hospital complications, hospital outcomes; use of prehospital ultrasound; association of prehospital factors and volume of first 24-hours blood product administration and evaluation of the prevalence of use, appropriateness, haemodynamic, metabolic and effects on mortality of prehospital blood transfusions. INCLUSION CRITERIA: age >18 years, traumatic injury attended by a HEMS team including a physician, a systolic blood pressure <90 mm Hg or weak/absent radial pulse and a confirmed or clinically likely diagnosis of major haemorrhage. Prehospital and in-hospital variables will be collected to include key times, clinical findings, examinations and interventions. Patients will be followed-up until day 30 from admission. The Glasgow Outcome Scale Extended will be collected at 30 days from admission. ETHICS AND DISSEMINATION: The study has been approved by the Ethics committee 'Comitato Etico di Area Vasta Emilia Centro'. Data will be disseminated to the scientific community by abstracts submitted to international conferences and by original articles submitted to peer-reviewed journals. TRIAL REGISTRATION NUMBER: NCT04760977.

Pre-hospital critical care at major incidents.

The identification, triage, and extrication of casualties followed by on-scene management and transport to an appropriate hospital after mass casualty incidents can be complicated, delivered to variable standards, and add significant delays to care. An effective pre-hospital pathway can both increase the chances of survival of individual patients and significantly influence the effectiveness of the entire emergency response.

Establishing quality indicators for pre-hospital advanced airway management: a modified nominal group technique consensus process.

BACKGROUND: Pre-hospital advanced airway management is a complex intervention composed of numerous steps, interactions, and variables that can be delivered to a high standard in the pre-hospital setting. Standard research methods have struggled to evaluate this complex intervention because of considerable heterogeneity in patients, providers, and techniques. In this study, we aimed to develop a set of quality indicators to evaluate pre-hospital advanced airway management. METHODS: We used a modified nominal group technique consensus process comprising three email rounds and a consensus meeting among a group of 16 international experts. The final set of quality indicators was assessed for usability according to the National Quality Forum Measure Evaluation Criteria. RESULTS: Seventy-seven possible quality indicators were identified through a narrative literature review with a further 49 proposed by panel experts. A final set of 17 final quality indicators composed of three structure-, nine process-, and five outcome-related indicators, was identified through the consensus process. The quality indicators cover all steps of pre-hospital advanced airway management from preoxygenation and use of rapid sequence induction to the ventilatory state of the patient at hospital delivery, prior intubation experience of provider, success rates and complications. CONCLUSIONS: We identified a set of quality indicators for pre-hospital advanced airway management that represent a practical tool to measure, report, analyse, and monitor quality and performance of this complex intervention.

Rapid sequence induction: where did the consensus go?

BACKGROUND: Rapid Sequence Induction (RSI) was introduced to minimise the risk of aspiration of gastric contents during emergency tracheal intubation. It consisted of induction with the use of thiopentone and suxamethonium with the application of cricoid pressure. This narrative review describes how traditional RSI has been modified in the UK and elsewhere, aiming to deliver safe and effective emergency anaesthesia outside the operating room environment. Most of the key aspects of traditional RSI - training, technique, drugs and equipment have been challenged and often significantly changed since the procedure was first described. Alterations have been made to improve the safety and quality of the intervention while retaining the principles of rapidly securing a definitive airway and avoiding gastric aspiration. RSI is no longer achieved by an anaesthetist alone and can be delivered safely in a variety of settings, including in the pre-hospital environment. CONCLUSION: The conduct of RSI in current emergency practice is far removed from the original descriptions of the procedure. Despite this, the principles - rapid delivery of a definitive airway and avoiding aspiration, are still highly relevant and the indications for RSI remain relatively unchanged.

Emergency scalpel cricothyroidotomy use in a prehospital trauma service: a 20-year review.

BACKGROUND: This study aimed to determine the rate of scalpel cricothyroidotomy conducted by a physician-paramedic prehospital trauma service over 20 years and to identify indications for, and factors associated with the intervention. METHODS: A retrospective observational study was conducted from 1 January 2000 to 31 December 2019 using clinical database records. This study was conducted in a physician-paramedic prehospital trauma service, serving a predominantly urban population of approximately 10 million in an area of approximately 2500 km2. RESULTS: Over 20 years, 37 725 patients were attended by the service, and 72 patients received a scalpel cricothyroidotomy. An immediate 'primary' cricothyroidotomy was performed in 17 patients (23.6%), and 'rescue' cricothyroidotomies were performed in 55 patients (76.4%). Forty-one patients (56.9%) were already in traumatic cardiac arrest during cricothyroidotomy. Thirty-two patients (44.4%) died on scene, and 32 (44.4%) subsequently died in hospital. Five patients (6.9%) survived to hospital discharge, and three patients (4.2%) were lost to follow-up. The most common indication for primary cricothyroidotomy was mechanical entrapment of patients (n=5, 29.4%). Difficult laryngoscopy, predominantly due to airway soiling with blood (n=15, 27.3%) was the most common indication for rescue cricothyroidotomy. The procedure was successful in 97% of cases. During the study period, 6570 prehospital emergency anaesthetics were conducted, of which 30 underwent rescue cricothyroidotomy after failed tracheal intubation (0.46%, 95% CI 0.31% to 0.65%). CONCLUSIONS: This study identifies a number of indications leading to scalpel cricothyroidotomy both as a primary procedure or after failed intubation. The main indication for scalpel cricothyroidotomy in our service was as a rescue airway for failed laryngoscopy due to a large volume of blood in the airway. Despite high levels of procedural success, 56.9% of patients were already in traumatic cardiac arrest during cricothyroidotomy, and overall mortality in patients with trauma receiving this procedure was 88.9% in our service.

Apnoeic oxygenation for emergency anaesthesia of pre-hospital trauma patients.

BACKGROUND: Efficient and timely airway management is universally recognised as a priority for major trauma patients, a proportion of whom require emergency intubation in the pre-hospital setting. Adverse events occur more commonly in emergency airway management, and hypoxia is relatively frequent. The aim of this study was to establish whether passive apnoeic oxygenation was effective in reducing the incidence of desaturation during pre-hospital emergency anaesthesia. METHODS: A prospective before-after study was performed to compare patients receiving standard care and those receiving additional oxygen via nasal prongs. The primary endpoint was median oxygen saturation in the peri-rapid sequence induction period, (2 minutes pre-intubation to 2 minutes post-intubation) for all patients. Secondary endpoints included the incidence of hypoxia in predetermined subgroups. RESULTS: Of 725 patients included; 188 patients received standard treatment and 537 received the intervention. The overall incidence of hypoxia (first recorded SpO2 < 90%) was 16.7%; 10.9% had SpO2 < 85%. 98/725 patients (13.5%) were hypoxic post-intubation (final SpO2 < 90% 10 minutes post-intubation). Median SpO2 was 100% vs. 99% for the standard vs. intervention group. There was a statistically significant benefit from apnoeic oxygenation in reducing the frequency of peri-intubation hypoxia (SpO2 < =90%) for patients with initial SpO2 > 95%, p = 0.0001. The other significant benefit was observed in the recovery phase for patients with severe hypoxia prior to intubation. CONCLUSION: Apnoeic oxygenation did not influence peri-intubation oxygen saturations, but it did reduce the frequency and duration of hypoxia in the post-intubation period. Given that apnoeic oxygenation is a simple low-cost intervention with a low complication rate, and that hypoxia can be detrimental to outcome, application of nasal cannulas during the drug-induced phase of emergency intubation may benefit a subset of patients undergoing emergency anaesthesia.

Reactivity, Formation, and Solubility of Polyoxometalates Probed by Calorimetry.

Room temperature calorimetry methods were developed to describe the energy landscapes of six polyoxometalates (POMs), Li-U24, Li-U28, K-U28, Li/K-U60, Mo132, and Mo154, in terms of three components: enthalpy of dissolution (ΔHdiss), enthalpy of formation of aqueous POMs (ΔHf,(aq)), and enthalpy of formation of POM crystals (ΔHf,(c)). ΔHdiss is controlled by a combination of cation solvation enthalpy and the favorability of cation interactions with binding sites on the POM. In the case of the four uranyl peroxide POMs studied, clusters with hydroxide bridges have lower ΔHf,(aq) and are more stable than those containing only peroxide bridges. In general for POMs, the combination of calorimetric results and synthetic observations suggest that spherical topologies may be more stable than wheel-like clusters, and ΔHf,(aq) can be accurately estimated using only ΔHf,(c) values owing to the dominance of the clusters in determining the energetics of POM crystals.

Helicopter and ground emergency medical services transportation to hospital after major trauma in England: a comparative cohort study.

BACKGROUND: The utilization of helicopter emergency medical services (HEMS) in modern trauma systems has been a source of debate for many years. This study set to establish the true impact of HEMS in England on survival for patients with major trauma. METHODS: A comparative cohort design using prospectively recorded data from the UK Trauma Audit and Research Network registry. 279 107 patients were identified between January 2012 and March 2017. The primary outcome measure was risk adjusted in-hospital mortality within propensity score matched cohorts using logistic regression analysis. Subset analyses were performed for subjects with prehospital Glasgow Coma Scale <8, respiratory rate <10 or >29 and systolic blood pressure <90. RESULTS: The analysis was based on 61 733 adult patients directly admitted to major trauma centers: 54 185 ground emergency medical services (GEMS) and 7548 HEMS. HEMS patients were more likely male, younger, more severely injured, more likely to be victims of road traffic collisions and intubated at scene. Crude mortality was higher for HEMS patients. Logistic regression demonstrated a 15% reduction in the risk adjusted odds of death (OR=0.846; 95% CI 0.684 to 1.046) in favor of HEMS. When analyzed for patients previously noted to benefit most from HEMS, the odds of death were reduced further but remained statistically consistent with no effect. Sensitivity analysis on 5685 patients attended by a doctor on scene but transported by GEMS demonstrated a protective effect on mortality versus the standard GEMS response (OR 0.77; 95% CI 0.62 to 0.95). DISCUSSION: This prospective, level 3 cohort analysis demonstrates a non-significant survival advantage for patients transported by HEMS versus GEMS. Despite the large size of the cohort, the intrinsic mismatch in patient demographics limits the ability to statistically assess HEMS true benefit. It does, however, demonstrate an improved survival for patients attended by doctors on scene in addition to the GEMS response. Improvements in prehospital data and increased trauma unit reporting are required to accurately assess HEMS clinical and cost-effectiveness.

An observational study evaluating the demand of major trauma on different surgical specialities in a UK Major Trauma Centre.

INTRODUCTION: Major Trauma Centres (MTCs) should ideally have all key surgical specialities on site. This may not always be the case since trauma is only one factor influencing speciality location. The implications of this can only be understood when the demands on specific specialities are established and this is not well documented. We investigated surgical speciality demand by quantifying the frequency and urgency of surgical trauma interventions. PATIENTS AND METHODS: Data on adult trauma admissions for a UK MTC were retrieved from the UK Trauma Audit and Research Network for a 2-year period and analysed to establish the frequency and urgency of surgical interventions. RESULTS: Of 1285 trauma patients with an ISS > 15 presenting in the study year period 713 (55.5%) required surgery. Neurosurgical (59.9%) and orthopaedic (55.1%) operations were most frequent. Cardiothoracic, general surgery, plastic surgery and maxillofacial operations were required infrequently. General surgery was commonly needed urgently, 45% within 4 h of MTC arrival. Urgency was also common in interventional radiology and vascular surgery. Cardiothoracic interventions were mainly urgent interventions (thoracotomy 1/3) and less urgent (rib fixation 2/3). DISCUSSION: Neurosurgery and orthopaedic surgery are key on-site trauma specialities and required frequently. General surgery, interventional radiology and cardiothoracic interventions are required less frequently but often urgently. This confirms a need for MTC on-site capability and possibly training to maintain competency in occasional trauma operators, particularly in general surgery. Maxillofacial surgery, ENT and urology are required neither frequently nor urgently and on-site presence may be less critical. CONCLUSION: Demand for specific surgical specialities was reported in a cohort of UK trauma patients. This confirmed the need for rapid on-site capability in key specialities and highlights possible training requirements for occasional trauma operators in specialities with low frequency but high urgency.

Best practice advice on pre-hospital emergency anaesthesia & advanced airway management.

BACKGROUND: Effective and timely airway management is a priority for sick and injured patients. The benefit and conduct of pre-hospital emergency anaesthesia (PHEA) and advanced airway management remains controversial but there are a proportion of critically ill and injured patients who require urgent advanced airway management prior to hospital arrival. This document provides current best practice advice for the provision of PHEA and advanced airway management. METHOD: This best practice advice was developed from EHAC Medical Working Group enforced by pre-hospital critical care experts. The group used a nominal group technique to establish the current best practice for the provision of PHEA and advanced airway management. The group met on three separate occasions to discuss and develop the guideline. All members of the working party were able to access and edit the guideline online. RESULTS: This EHAC best practice advice covers all areas of PHEA and advanced airway management and provides up to date evidence of current best practice. CONCLUSION: PHEA and advanced airway management are complex interventions that should be delivered by appropriately trained personnel using a well-rehearsed approach and standardised equipment. Where advanced airway interventions cannot be delivered, careful attention should be given to applying basic airway interventions and ensuring their effectiveness at all times.

Effect of Prehospital Red Blood Cell Transfusion on Mortality and Time of Death in Civilian Trauma Patients.

BACKGROUND: Current management principles of hemorrhagic shock after trauma emphasize earlier transfusion therapy to prevent dilution of clotting factors and correct coagulopathy. London's Air Ambulance (LAA) was the first UK civilian prehospital service to routinely offer prehospital red blood cell (RBC) transfusion (phRTx). We investigated the effect of phRTx on mortality. METHODS: Retrospective trauma database study comparing mortality before implementation with after implementation of phRTx in exsanguinating trauma patients. Univariate logistic regression was performed for the unadjusted association between phRTx and mortality was performed, and multiple logistic regression adjusting for potential confounders. RESULTS: We identified 623 subjects with suspected major hemorrhage. We excluded 84 (13.5%) patients due to missing data on survival status. Overall 187 (62.3%) patients died in the before phRTx period and 143 (59.8%) died in the after phRTx group. There was no significant improvement in overall survival after the introduction of phRTx (P = 0.554). Examination of prehospital mortality demonstrated 126 deaths in the pre-phRTx group (42.2%) and 66 deaths in the RBC administered group (27.6%). There was a significant reduction in prehospital mortality in the group who received RBC (P < 0.001). CONCLUSIONS: phRTx was associated with increased survival to hospital, but not overall survival. The "delay death" effect of phRTx carries an impetus to further develop inhospital strategies to improve survival in severely bleeding patients.

Prehospital emergency anaesthesia: an updated survey of UK practice with emphasis on the role of standardisation and checklists.

INTRODUCTION: Prehospital emergency anaesthesia (PHEA or 'prehospital rapid sequence intubation') is a high-risk procedure. Standard operating procedures (SOPs) and checklists within healthcare systems have been demonstrated to reduce human error and improve patient safety. We aimed to describe the current practice of PHEA in the UK, determine the use of checklists for PHEA and describe the content, format and layout of any such checklists currently used in the UK. METHOD: A survey of UK prehospital teams was conducted to establish the incidence and conduct of PHEA practice. Results were grouped into systems delivering a high volume of PHEA per year (>50 PHEAs) and low volume (≤50 PHEAs per annum). Standard and 'crash' (immediate) induction checklists were reviewed for length, content and layout. RESULTS: 59 UK physician-led prehospital services were identified of which 43 (74%) participated. Thirty services (70%) provide PHEA and perform approximately 1629 PHEAs annually. Ten 'high volume' services deliver 84% of PHEAs per year with PHEA being performed on a median of 11% of active missions. The most common indication for PHEA was trauma. 25 of the 30 services (83%) used a PHEA checklist prior to induction of anaesthesia and 24 (80%) had an SOP for the procedure. 19 (76%) of the 'standard' checklists and 5 (50%) of the 'crash' induction checklists used were analysed. On average, standard checklists contained 169 (range: 52-286) words and 41 (range: 28-70) individual checks. The style and language complexity varied significantly between different checklists. CONCLUSION: PHEA is now performed commonly in the UK. The use of checklists for PHEA is relatively common among prehospital systems delivering this intervention. Care must be taken to limit checklist length and to use simple, unambiguous language in order to maximise the safety of this high-risk intervention.