Professor Richard Lyon MBE

Background: Early transfusion of packed red blood cells (PRBC) has been associated with improved survival in patients with haemorrhagic shock. This study aims to describe the characteristics of patients receiving pre-hospital blood transfusion and evaluate their subsequent need for in-hospital transfusion and surgery. Methods: The decision to administer a pre-hospital PRBC transfusion was based on clinical judgment. All patients transfused pre-hospital PRBC between February 2013 and December 2014 were included. Pre-hospital and in-hospital records were retrospectively reviewed. Results: One hundred forty-seven patients were included. 142 patients had traumatic injuries and 5 patients had haemorrhagic shock from a medical origin. Median Injury Severity Score was 30. 90% of patients receiving PRBC had an ISS of >15. Patients received a mean of 2.4(±1.1) units of PRBC in the pre-hospital phase. Median time from initial emergency call to hospital arrival was 114 min (IQR 103–140). There was significant improvement in systolic (p < 0.001), diastolic (p < 0.001) and mean arterial pressures (p < 0.001) with PRBC transfusion but there was no difference in HR (p = 0.961). Patients received PRBC significantly faster in the field than waiting until hospital arrival. At the receiving hospital 57% required an urgent surgical or interventional radiology procedure. At hospital arrival, patients had a mean lactate of 5.4(±4.4) mmol/L, pH of 6.9(±1.3) and base deficit of −8.1(±6.7). Mean initial serum adjusted calcium was 2.26(±0.29) mmol/L. 89% received further blood products in hospital. No transfusion complications or significant incidents occurred and 100% traceability was achieved. Discussion: Pre-hospital transfusion of packed red cells has the potential to improvde outcome for trauma patients with major haemorrhage. The pre-hospital time for trauma patients can be several hours, suggesting transfusion needs to start in the pre-hospital phase. Hospital transfusion research suggests a 1:1 ratio of packed red blood cells to plasma improves outcome and further research into pre-hospital adoption of this strategy is needed. Conclusion: Pre-hospital PRBC transfusion significantly reduces the time to transfusion for major trauma patients with suspected major haemorrhage. The majority of patients receiving pre-hospital PRBC were severely injured and required further transfusion in hospital. Further research is warranted to determine which patients are most likely to have outcome benefit from pre-hospital blood products and what triggers should be used for pre-hospital transfusion.

Background The COVID-19 pandemic has placed exceptional demand on Intensive Care Units, necessitating the critical care transfer of patients on a regional and national scale. Performing these transfers required specialist expertise and involved moving patients over significant distances. Air Ambulance Kent Surrey Sussex created a designated critical care transfer team and was one of the first civilian air ambulances in the United Kingdom to move ventilated COVID-19 patients by air. We describe the practical set up of such a service and the key lessons learned from the first 50 transfers. Methods Retrospective review of air critical care transfer service set up and case review of first 50 transfers. Results We describe key elements of the critical care transfer service, including coordination and activation; case interrogation; workforce; training; equipment; aircraft modifications; human factors and clinical governance. A total of 50 missions are described between 18 December 2020 and 1 February 2021. 94% of the transfer missions were conducted by road. The mean age of these patients was 58 years (29–83). 30 (60%) were male and 20 (40%) were female. The mean total mission cycle (time of referral until the time team declared free at receiving hospital) was 264 min (range 149–440 min). The mean time spent at the referring hospital prior to leaving for the receiving unit was 72 min (31–158). The mean transfer transit time between referring and receiving units was 72 min (9–182). Conclusion Critically ill COVID-19 patients have highly complex medical needs during transport. Critical care transfer of COVID-19-positive patients by civilian HEMS services, including air transfer, can be achieved safely with specific planning, protocols and precautions. Regional planning of COVID-19 critical care transfers is required to optimise the time available of critical care transfer teams.

Background Major haemorrhage is a leading cause of mortality following major trauma. Increasingly, Helicopter Emergency Medical Services (HEMS) in the United Kingdom provide pre-hospital transfusion with blood products, although the evidence to support this is equivocal. This study compares mortality for patients with suspected traumatic haemorrhage transfused with pre-hospital packed red blood cells (PRBC) compared to crystalloid. Methods A single centre retrospective observational cohort study between 1 January 2010 and 1 February 2015. Patients triggering a pre-hospital Code Red activation were eligible. The primary outcome measure was all-cause mortality at 6 hours and 28 days, including a sub-analysis of patients receiving a major and massive transfusion. Multivariable regression models predicted mortality. Multiple Imputation (MI) was employed, and logistic regression models were constructed for all imputed datasets. Results The crystalloid (n= 103) and PRBC (n= 92) group were comparable for demographics, Injury Severity Score (p= 0.67) and mechanism of injury (p= 0.74). Observed 6 hour mortality was smaller in the PRBC group (n= 10, 10%) compared to crystalloid group (n= 19, 18%). Adjusted OR was not statistically significant (OR 0.48, CI 0.19-1.19, p= 0.11). Observed mortality at 28 days was smaller in the PRBC group (n= 21, 27%) compared to crystalloid group (n= 31, 40%), p= 0.09. Adjusted OR was not statistically significant (OR 0.66, CI 0.32-1.35, p= 0.26). A statistically significant greater proportion of the crystalloid group required a major transfusion (n= 62, 63%) compared to the PRBC group (n= 41, 46%), p= 0.02. For patients requiring a massive transfusion observed mortality was smaller in the PRBC group at 28 days (p= 0.07). Conclusion In a single centre UK HEMS study, in patients with suspected traumatic haemorrhage who received a PRBC transfusion there was an observed, but non-significant, reduction in mortality at 6 hours and 28 days, also reflected in a massive transfusion subgroup. Patients receiving pre-hospital PRBC were significantly less likely to require an in-hospital major transfusion. Further adequately powered multi-centre prospective research is required to establish the optimum strategy for pre-hospital volume replacement in patients with traumatic haemorrhage.

Objectives Prehospital rapid sequence induction (RSI) of anaesthesia is an intervention with significant associated risk. In this study, we aimed to investigate the haemodynamic response over time of a prehospital RSI protocol of fentanyl, ketamine and rocuronium in a heterogeneous population of trauma patients. Design, setting and participant We performed a retrospective study of all trauma patients who received a prehospital RSI for trauma by a physician staffed Helicopter Emergency Medical Service in the UK between 1 June 2018 and 1 February 2020. Primary outcome measure Primary outcome was defined as the incidence of clinically relevant hypotensive (systolic blood pressure (SBP) or mean arterial pressure (MAP) >20% below baseline, with an absolute SBP

Background: The effective treatment of airway compromise in trauma and non-trauma patients is important. Hypoxia and hypotension are predictors of negative patient outcomes and increased mortality, and may be important quality indicators of care provided by emergency medical services. Excluding cardiac arrests, critical trauma and non-trauma patients remain the two major groups to which helicopter emergency medical services (HEMS) are dispatched. Several studies describe the impact of pre-hospital hypoxia or hypotension on trauma patients, but few studies compare this in trauma and non-trauma patients. The primary aim was to describe the incidence of pre-hospital hypoxia and hypotension in the two groups receiving pre-hospital tracheal intubation (TI) by physician-staffed HEMS. Methods: Data were collected prospectively over a 12-month period, using a uniform Utstein-style airway template. Twenty-one physician-staffed HEMS in Europe and Australia participated. We compared peripheral oxygen saturation and systolic blood pressure before and after definitive airway management. Data were analysed using Cochran–Mantel–Haenszel methods and mixed-effects models. Results: Eight hundred forty three trauma patients and 422 non-trauma patients receiving pre-hospital TI were included. Non-trauma patients had significantly lower predicted mean pre-intervention SpO2 compared to trauma patients. Post-intervention and admission SpO2 for the two groups were comparable. However, 3% in both groups were still hypoxic at admission. For hypotension, the differences between the groups were less prominent. However, 9% of trauma and 10% of non-trauma patients were still hypotensive at admission. There was no difference in short-term survival between trauma (97%) and non-trauma patients (95%). Decreased level of consciousness was the most frequent indication for TI, and was associated with increased survival to hospital (cOR 2.8; 95% CI: 1.4–5.4).Conclusions: Our results showed that non-trauma patients had a higher incidence of hypoxia before TI than trauma patients, but few were hypoxic at admission. The difference for hypotension was less prominent, but one in ten patients were still hypotensive at admission. Further investigations are needed to identify reversible causes that may be corrected to improve haemodynamics in the pre-hospital setting. We found high survival rates to hospital in both groups, suggesting that physician-staffed HEMS provide high-quality emergency airway management in trauma and non-trauma patients. Trial registration: Clinicaltrials.gov Identifier: NCT01502111. Registered 22 December 2011

Background: Poor communication during patient handover is recognised internationally as a root cause of a significant proportion of preventable deaths. Improving the accuracy and quality of handover may reduce associated mortality and morbidity. Although the practice of handover between Ambulance and Emergency Department clinicians has received some attention over recent years there is little evidence to support handover best practice within the prehospital domain. Further research is therefore urgently required to understand the most appropriate way to deliver clinical information exchange in the pre-hospital environment. We aimed to investigate current clinical information exchange practices, perceived challenges and the preferred handover mnemonic for use during transfer of high acuity patients between ambulance clinicians and specialist prehospital teams. Methods: A national, cross-sectional questionnaire study. Participants were road based ambulance clinicians (RBAC) or active members of specialist prehospital teams (SPHT) based in Scotland. Results: Over a three month study period there were 247 prehospital incidents involving specialist teams. One hundred ninety individuals completed the questionnaire; 61% [n = 116] RBAC and 39% [n = 74] SPHT. Median length of prehospital experience was 10 years (IQR 5–18). Overall current prehospital handover practices were perceived as being effective (Mdn 4.00; IQR 3–4 [1 = very ineffective - 5 = very effective]) although SPHT clinicians rated handover effectiveness slightly lower than RBAC’s (Mdn 3.00 vs 4.00, U = 1842.5, p = .03). ‘ATMIST’ (Age, Time of onset, Medical complaint/injury, Investigation, Signs and Treatment) was deemed the mnemonic of choice. The clinical variables perceived as essential for handover are not explicitly identified within the SBAR mnemonic. The most frequently reported method of recording and transferring information during handover was via memory (n = 112 and n = 120 respectively) and ‘interruptions’ were perceived as the most significant barrier to effective handover. Conclusion: While, overall, current prehospital handover practice is perceived as effective this study has identified a number of areas for improvement. These include the development of a shared mental model through system standardisation, innovations to support information recording and delivery, and the clear identification at incidents of a handover lead. Mnemonics must be carefully selected to ensure they explicitly contain the perceived essential clinical variables required for prehospital handover; the mnemonic ATMIST meets these requirements. New theoretically informed, evidence-based interventions, must be developed and tested within existing systems of care to minimise information loss and risk to patients.

Objectives The aim of this study is to describe the demographics of reported traumatic cardiac arrest (TCA) victims, prehospital resuscitation and survival to hospital rate. Setting Helicopter Emergency Medical Service (HEMS) in south-east England, covering a resident population of 4.5 million and a transient population of up to 8 million people. Participants Patients reported on the initial 999 call to be in suspected traumatic cardiac arrest between 1 July 2016 and 31 December 2016 within the trust’s geographical region were identified. The inclusion criteria were all cases of reported TCA on receipt of the initial emergency call. Patients were subsequently excluded if a medical cause of cardiac arrest was suspected. Outcome measures Patient records were analysed for actual presence of cardiac arrest, prehospital resuscitation procedures undertaken and for survival to hospital rates. Results 112 patients were reported to be in TCA on receipt of the 999/112 call. 51 (46%) were found not to be in TCA on arrival of emergency medical services. Of the ‘not in TCA cohort’, 34 (67%) received at least one advanced prehospital medical intervention (defined as emergency anaesthesia, thoracostomy, blood product transfusion or resuscitative thoracotomy). Of the 61 patients in actual TCA, 10 (16%) achieved return-of-spontaneous circulation. In 45 (88%) patients, the HEMS team escorted the patient to hospital. Conclusion A significant proportion of patients reported to be in TCA on receipt of the emergency call are not in actual cardiac arrest but are critically unwell requiring advanced prehospital medical intervention. Early activation of an enhanced care team to a reported TCA call allows appropriate advanced resuscitation. Further research is warranted to determine which interventions contribute to improved TCA survival.

Introduction Helicopter emergency medical services (HEMS) are often dispatched to patients in traumatic cardiac arrest (TCA) as they can provide treatments and advanced interventions in the pre-hospital environment that have the potential to contribute to an increased survival. This study, aimed to investigate the added value of HEMS in the treatment of TCA. Methods We performed a retrospective cohort study of all patients with a pre-hospital TCA who were attended by a non-urban HEMS (Kent, Surrey and Sussex Air Ambulance trust) between July 1st 2013 and May 1st 2018. We investigated how many patients got return of spontaneous circulation (ROSC) at scene, which HEMS specific advanced interventions were performed in these patients, and how these interventions were related to ROSC. Results During the study period 263 patients with a TCA were attended by HEMS with an average response time of 30 min [range 13–109]. 51 patients (20%) regained ROSC at scene (28 before- and 23 after arrival of HEMS). The HEMS specific interventions of blood product administration (OR 8.54 [2.84–25.72]), and RSI (2.95 [1.32–6.58]) were positively associated with ROSC. Most patients who had a ROSC had one or more HEMS specific interventions being performed – RSI (n = 19, 37%), blood product administration (n = 32, 62%), thoracostomies (n = 36, 71%) and thoracotomy (n = 1, 2%). HEMS also delivered other important interventions to these patients as IV/IO access (n = 20, 39.2%) and endotracheal intubation without drugs (n = 9, 17.6%). Conclusion HEMS teams should be involved in the treatment of patients with a TCA, even in non-urban areas with prolonged response times, as they provide knowledge and skills that contribute to regaining and maintaining a sustained ROSC in this critically ill and injured cohort of patients.

Background Helicopter Emergency Medical Services (HEMS) respond to serious trauma and medical emergencies. Geographical disparity and the regionalisation of trauma systems can complicate accurate HEMS dispatch. We sought to evaluate HEMS dispatch sensitivity in older trauma patients by analysing critical care interventions and conveyance in a well-established trauma system. Methods All trauma patients aged 65 years that were attended by the Air Ambulance Kent Surrey Sussex over a 6-year period from 1 July 2013 to 30 June 2019 were included. Patient characteristics, critical care interventions and hospital disposition were stratified by dispatch type (immediate, interrogate and crew request). Results 1321 trauma patients aged 65 were included. Median age was 75 years [IQR 69-89]. HEMS dispatch was by immediate (32.0%), interrogation (43.5%) and at the request of ambulance clinicians (24.5%). Older age was associated with a longer dispatch interval and was significantly longer in the crew request category (37 min [34-39]) compared to immediate dispatch (6 min [5-6] (p=.001). Dispatch by crew request was common in patients with falls 2m more often resulted in immediate dispatch (p=.001). Immediate dispatch to isolated head injured patients often resulted in pre-hospital emergency anaesthesia (PHEA) (39%). However, over a third of head injured patients attended after dispatch by crew request received PHEA (36%) and a large proportion were triaged to major trauma centres (69%). Conclusions Many patients who do not fulfil the criteria for immediate HEMS dispatch need advanced clinical interventions and subsequent tertiary level care at a major trauma centre. Further studies should evaluate if HEMS activation criteria, nuanced by age-dependant triggers for mechanism and physiological parameters, optimise dispatch sensitivity and HEMS utilisation.

Background Obtaining accurate information from a 112 caller is key to correct tasking of Helicopter Emergency Medical Services (HEMS). Being able to view the incident scene via video from a mobile phone may assist HEMS dispatch by providing more accurate information such as mechanism of injury and/or injuries sustained. The objective of this study is to describe the acceptability and feasibility of using live video footage from the mobile phone of a 112 caller as an HEMS dispatch aid. Methods Live footage is obtained via the 112 caller’s mobile phone camera through the secure GoodSAM app’s Instant-on-scene™ platform. Video footage is streamed directly to the dispatcher, and not stored. During the feasibility trial period, dispatchers noted the purpose for which they used the footage and rated ease of use and any technical- and operational issues they encountered. A subjective assessment of caller acceptance to use video was conducted. Results Video footage from scene was attempted for 21 emergency calls. The leading reasons listed by the dispatchers to use live footage were to directly assess the patient (18/21) and to obtain information about the mechanism of injury and the scene (11/21). HEMS dispatchers rated the ease of use with a 4.95 on a 5-point scale (range 4–5). All callers gave permission to stream from their telephone camera. Video footage from scene was successfully obtained in 19 calls, and was used by the dispatcher as an aid to send (5) or stand down (14) a Helicopter Emergency Medical Services team. Conclusion Live video footage from a 112 caller can be used to provide dispatchers with more information from the scene of an incident and the clinical condition of the patient(s). The use of mobile phone video was readily accepted by the 112 caller and the technology robust. Further research is warranted to assess the impact video from scene could have on HEMS dispatching.

Introduction Pre-hospital enhanced care teams like Helicopter Emergency Medical Services (HEMS) are often dispatched to major trauma patients, including patients with traumatic brain injuries and those with major haemorrhage. For these patients, minimizing the time to definitive care is vital. The aim of this study was to determine whether increased awareness of elapsed on scene time produces a relevant time performance improvement for major trauma patients attended by HEMS, and weather introducing such a timer was feasible and acceptable to clinicians. Methods We performed a prospective cohort study of all single casualty traumatic incidents attended by Air Ambulance Kent Surrey Sussex (AAKSS) between 15 October 2016 and 23 May 2017 to test if introduction of a prompting scene timer within the service resulted in a reduction in pre-hospital scene times. Results The majority of the patients attended were male (74%) and sustained blunt trauma (92%). Overall, median scene time was 25.5 [IQR16.3] minutes before introduction of the scene timer and 23.0 [11.0] minutes after introduction, p = 0.13). Scene times for patients with a GCS ˂ 8 and for patients requiring prehospital anaesthesia were significantly lower after introduction of the timer (28 [IQR 14] vs 25 [1], p = 0.017 and 34 [IQR 13] vs 28 [IQR11] minutes, p = 0.007 respectively). The majority of clinicians felt the timer made them more aware of passing time (91%) but that this had not made a difference to scene time (62%) or their practice (57%). Conclusion Audible scene timers may have the potential to reduce pre-hospital scene time for certain single casualty trauma patients treated by a HEMS team, particularly for those patients needing pre-hospital anaesthesia. Regular use of on-scene timers may improve outcomes by reducing time to definitive care for certain subgroups of trauma patients.

Introduction Major trauma can result in both life-threatening haemorrhage and traumatic brain injury (TBI). The pre-hospital management of these conditions, particularly in relation to the cardiovascular system, is very different. TBI can result in cardiovascular instability but the exact incidence remains poorly described. This study explores the incidence of cardiovascular instability in patients undergoing pre-hospital anaesthesia for suspected TBI. Methods Retrospective case series of all pre-hospital trauma patients attended by Kent, Surrey & Sussex Air Ambulance Trust (United Kingdom) trauma team during the period 1 January 2015–31 December 2016. Patients were included if they showed clinical signs of TBI, underwent pre-hospital anaesthesia and hospital computed tomography scanning subsequently confirmed an isolated TBI. Results Out of 121 patients with confirmed isolated TBI, 68 were cardiovascularly stable throughout the pre-anaesthesia phase, whilst 53 (44%) showed signs of instability (HR ˃ 100bpm and/or SBP ˂ 100 mmHg pre-anaesthesia). Hypotension (SBP ˂ 100) with or without tachycardia was present in 14 (12%) patients. 10 (8%) patients with isolated TBI received pre-hospital blood product transfusion. Conclusion Increased awareness that traumatic brain injury can cause significant derangement to heart rate and blood pressure, even in the absence of major haemorrhage, would allow the pre-hospital clinician to treat cardiovascular instability with the most appropriate means, such as crystalloid and vasopressors, to limit secondary brain injury.

Background: Poor communication during patient handover is recognised internationally as a root cause of a significant proportion of preventable deaths. Improving the accuracy and quality of handover may reduce associated mortality and morbidity. Although the practice of handover between Ambulance and Emergency Department clinicians has received some attention over recent years there is little evidence to support handover best practice within the prehospital domain. Further research is therefore urgently required to understand the most appropriate way to deliver clinical information exchange in the pre-hospital environment. We aimed to investigate current clinical information exchange practices, perceived challenges and the preferred handover mnemonic for use during transfer of high acuity patients between ambulance clinicians and specialist prehospital teams. Methods: A national, cross-sectional questionnaire study. Participants were road based ambulance clinicians (RBAC) or active members of specialist prehospital teams (SPHT) based in Scotland. Results: Over a three month study period there were 247 prehospital incidents involving specialist teams. One hundred ninety individuals completed the questionnaire; 61% [n = 116] RBAC and 39% [n = 74] SPHT. Median length of prehospital experience was 10 years (IQR 5–18). Overall current prehospital handover practices were perceived as being effective (Mdn 4.00; IQR 3–4 [1 = very ineffective - 5 = very effective]) although SPHT clinicians rated handover effectiveness slightly lower than RBAC’s (Mdn 3.00 vs 4.00, U = 1842.5, p = .03). ‘ATMIST’ (Age, Time of onset, Medical complaint/injury, Investigation, Signs and Treatment) was deemed the mnemonic of choice. The clinical variables perceived as essential for handover are not explicitly identified within the SBAR mnemonic. The most frequently reported method of recording and transferring information during handover was via memory (n = 112 and n = 120 respectively) and ‘interruptions’ were perceived as the most significant barrier to effective handover. Conclusion: While, overall, current prehospital handover practice is perceived as effective this study has identified a number of areas for improvement. These include the development of a shared mental model through system standardisation, innovations to support information recording and delivery, and the clear identification at incidents of a handover lead. Mnemonics must be carefully selected to ensure they explicitly contain the perceived essential clinical variables required for prehospital handover; the mnemonic ATMIST meets these requirements. New theoretically informed, evidence-based interventions, must be developed and tested within existing systems of care to minimise information loss and risk to patients.

Background: Since 2016, critical care paramedics from the South East Coast Ambulance Service have offered neuromuscular blockade to patients for ventilatory/airway control after cardiac arrest. Aims: To examine the first cases of paramedic-delivered neuromuscular blockade, and evaluate the prevalence of its use and safety. Methods: Retrospective service evaluation of patients receiving post-arrest paralysis during the study period from 1 April 2016 until 31 July 2017. Findings: The study included 127 patients. The mean age of administration was 63 years, mean weight was 80 kg (SD: 19 kg), dose was 1 mg/kg and median time from rocuronium administration to hospital was 32 minutes (IQR 20–43 minutes). Three patients (2.3%) experienced a minor adverse incident. There were no major airway complications, nor other significant adverse incidents. Thirty-seven patients (31%) survived to discharge. Conclusion: From this patient group, paramedic-administered rocuronium in intubated patients who have experienced a cardiac arrest and a return of spontaneous circulation appears to be safe, but further interventional research is required to determine whether this improves patient outcomes.

Background Early transfusion of patients with major traumatic haemorrhage may improve survival. This study aims to establish the feasibility of freeze-dried plasma transfusion in a Helicopter Emergency Medical Service in the United Kingdom. Method A retrospective observational study of major trauma patients attended by Kent, Surrey and Sussex Helicopter Emergency Medical Service and transfused freeze-dried plasma since it was introduced in April 2014. Results Of the 1873 patients attended over a 12-month period before its introduction, 79 patients received packed red blood cells (4.2%) with a total of 193 units transfused. Of 1881 patients after the introduction of freeze-dried plasma, 10 patients received packed red blood cells only and 66 received both packed red blood cells and freeze-dried plasma, with a total of 158 units of packed red blood cells transfused, representing an 18% reduction between the two 12-month periods. In the 20 months since its introduction, of 216 patients transfused with at least 1 unit of freeze-dried plasma, 116 (54.0%) patients received both freeze-dried plasma and packed red blood cells in a 1:1 ratio. Earlier transfusion was feasible, transferring the patient to hospital prior to transfusion would have incurred a delay of 71 minutes (IQR 59-90). Conclusion Pre-hospital freeze-dried plasma and packed red blood cell transfusion is feasible in a 1:1 ratio in patients with suspected traumatic haemorrhage. The use of freeze-dried plasma as a first line fluid bolus reduced the number of pre-hospital packed red blood cell units required and reduced the time to transfusion.

Background For the prehospital diagnosis of raised intracranial pressure (ICP), clinicians are reliant on clinical signs such as the Glasgow Coma Score (GCS), pupillary response and/or Cushing’s triad (hypertension, bradycardia and an irregular breathing pattern). This study aimed to explore the diagnostic accuracy of these signs as indicators of a raised ICP. Methods We performed a retrospective cohort study of adult patients attended by a Helicopter Emergency Medical Service (Air Ambulance Kent, Surrey Sussex), who had sustained a traumatic brain injury (TBI), requiring prehospital anaesthesia between 1 January 2016 and 1 January 2018. We established optimal cut-off values for clinical signs to identify patients with a raised ICP and investigated diagnostic accuracy for combinations of these values. Results Outcome data for 249 patients with TBI were available, of which 87 (35%) had a raised ICP. Optimal cut-off points for systolic blood pressure (SBP), heart rate (HR) and pupil diameter to discriminate patients with a raised ICP were, respectively, >160 mm Hg,5 mm. Cushing criteria (SBP >160 mm Hg and HR

Background Poor communication during patient handover is recognised internationally as a root cause of a significant proportion of preventable deaths. Improving the accuracy and quality of handover may reduce associated mortality and morbidity. Although the practice of handover between Ambulance and Emergency Department clinicians has received some attention over recent years there is little evidence to support handover best practice within the prehospital domain. Further research is therefore urgently required to understand the most appropriate way to deliver clinical information exchange in the pre-hospital environment. We aimed to investigate current clinical information exchange practices, perceived challenges and the preferred handover mnemonic for use during transfer of high acuity patients between ambulance clinicians and specialist prehospital teams. Methods A national, cross-sectional questionnaire study. Participants were road based ambulance clinicians (RBAC) or active members of specialist prehospital teams (SPHT) based in Scotland. Results Over a three month study period there were 247 prehospital incidents involving specialist teams. 190 individuals completed the questionnaire; 61% [n=116] RBAC and 39% [n=74] SPHT. Median length of prehospital experience was 10 years (IQR 5-18). Overall current prehospital handover practices were perceived as being effective (Mdn 4.00; IQR 3-4 [1= very ineffective - 5 = very effective]) although SPHT clinicians rated handover effectiveness slightly lower than RBAC's (Mdn 3.00 vs 4.00, U = 1842.5, p = .03). 'ATMIST' (Age, Time of onset, Medical complaint/injury, Investigation, Signs and Treatment) was deemed the mnemonic of choice. The clinical variables perceived as essential for handover are not explicitly identified within the SBAR mnemonic. The most frequently reported method of recording and transferring information during handover was via memory (n=112 and n=120 respectively) and ‘interruptions’ were perceived as the most significant barrier to effective handover. Conclusion While, overall, current prehospital handover practice is perceived as effective this study has identified a number of areas for handover improvement. These include the development of a shared mental model through system standardisation, innovations to support information recording and delivery, and the clear identification at incidents of a handover lead. Mnemonics must be carefully selected to ensure they explicitly contain the perceived essential clinical variables required for prehospital handover; the mnemonic ATMIST meets these requirements. New theoretically informed, evidence-based interventions, must be developed and tested within existing systems of care to minimise information loss and risk to patients.

Most trauma and out of hospital cardiac arrest (OHCA) deaths occur prior to arrival at hospital, with increased risk for rural compared to urban patients. Essex and Hertfordshire Air Ambulance Trust (EHAAT) and Kent Surrey Sussex Air Ambulance Trust (KSS) provide a physician-paramedic Helicopter Emergency Medical Service (HEMS) in two regions of the United Kingdom. We investigated whether an association exists between prehospital mortality and distance from care in HEMS patients. We performed a retrospective study using spatial statistics to investigate the geographic distribution of scene outcome (alive versus deceased). We also performed multiple logistic regression of outcome against quartiles of distance from base to scene and a relative risk (RR) estimation over the operational areas. Organisations were analysed separately to assess consistency of spatial relationships. 2680 EHAAT and 4213 KSS patients met the inclusion criteria. Ripley’s K and Cross K functions indicated that outcomes (death and leaving the scene alive) cluster together. For KSS distance was not associated with outcome, for EHAAT distance was a significant predictor of mortality at furthest distance (41 to 95 km; OR 5.82, 95%CI 1.63 to 37.18, p = 0.019). Only one area of KSS and no areas of EHAAT had an increased RR of mortality. In contrast to previous research of pre-hospital patients, we found little evidence of geographic difference in scene outcome for trauma patients attended by the two HEMS services. Increased mortality risk for OHCA at the furthest distance from helicopter base was found in one organisation; a single area of increased RR of mortality was found for the other organisation.

Objective This study sought to assess the impact of a helicopter emergency medical service (HEMS) capable of night operations. Methods This is a retrospective case review of all night HEMS missions attended by a charity air ambulance service in South East England over a 2-year period (October 1, 2013, to October 1, 2015). Results During the 2-year trial period, the HEMS service undertook a total of 5,004 missions and attended to 3,728 patients. Of these, 1,373 missions, or 27.4% of the total HEMS activity, were night missions. Night missions increased from year 1 (n = 617) to year 2 (n = 756). A mean of 1.9 missions per night were conducted, resulting in the treatment of 1.3 patients per night. A higher proportion of patients were transported to a major trauma center at night (64% vs. 51%, χ2 = 41.8, P < .0001). Weather conditions prevented HEMS from responding at night via air for 15% of the night operational hours. Conclusion A 2-year trial period of a night HEMS service in South East England showed the predicted activation rate, with a mean of 1.3 patients attended to per night. Patients transported to a major trauma center had a mean Injury Severity Score of 23. Further research is warranted to determine if the night HEMS service conveys a patient outcome benefit. Major trauma is a leading cause of serious morbidity and mortality.1,2 Advanced prehospital care can improve the outcome for major trauma patients.3,4 Kent, Surrey & Sussex Air Ambulance Trust (KSSAAT) delivers advanced prehospital care by deploying 2 doctor/paramedic teams by aircraft or response car. The 2 teams respond from 2 separate bases in South East England, 1 based in Surrey and 1 based in Kent. Historically, KSSAAT was operational between 0700 and 1900 hours 7 days per week. However, major trauma frequently occurs overnight, and the lack of a night helicopter emergency medical service (HEMS) was felt to be detrimental to enhanced patient care because no enhanced prehospital medical care was available overnight. Before any night HEMS service was available, KSSAAT undertook a prospective study in 2010 to explore the possible impact that a night HEMS service may have.5 This study showed the likely need of a night HEMS team being tasked 1.7 times per night during the hours of 1900 to 0700. The incidence of these predicted cases continued throughout the entire night period but with gradually decreasing frequency. Most nights of the week were predicted to have similar levels of activity with the exception of Saturday, which appeared to be the busiest night of the week. A high number of the cases identified resulted in the patient being transported to a major trauma center (MTC), indicating that HEMS activation may well have been warranted. Based on this study, KSSAAT made the decision to commit itself to exploring the options for night HEMS operations. This commitment was the start of a 3-year research, development, and training process, which culminated with the launch of a 2-year night HEMS operational trial on the night of September 26, 2013. At this point, KSSAAT became the first 24/7 helicopter-based HEMS in the United Kingdom. The purpose of this study is to review the activity, case mix, and demographics of the 2-year night HEMS trial period. We sought to compare the actual activity of the night HEMS service with the previously estimated need.

Objective Pre-hospital emergency anaesthesia in the form of rapid sequence intubation (RSI) is a critical intervention delivered by advanced pre-hospital critical care teams. Our previous simulation study determined the feasibility of in-aircraft RSI. We now examine whether this feasibility is preserved in a simulated setting, when clinicians wear personal protective equipment (PPE) for aerosol-generating procedures (AGP) for in-aircraft, on-the-ground RSI. Methods Air Ambulance Kent Surrey Sussex is a Helicopter Emergency Medical Service (HEMS) which utilises an AW169 cabin simulator. Wearing full AGP PPE (eye protection, FFP3 mask, gown, gloves), 10 doctor-paramedic teams performed RSI in a standard “can intubate, can ventilate” scenario and a “can't intubate, can't oxygenate” (CICO) scenario. Pre-specified timings were reported, and participant feedback was sought by questionnaire. Results RSI was most commonly performed by direct laryngoscopy and was successfully achieved in all scenarios. Time to completed endotracheal intubation (ETI) was fastest (287s) in the standard scenario and slower (370s, p=.01) in the CICO scenario. Time to ETI was not significantly delayed by wearing PPE in the standard (p=.19) or CICO variant (p=.97). Communication challenges, equipment complications and PPE difficulties were reported, but ways to mitigate these also reported. Conclusion In-aircraft RSI (aircraft on-the-ground) whilst wearing PPE for AGPs had no significant impact on time to successful completion of ETI in a simulated setting. Patient safety is paramount in civilian HEMS, but the adoption of in-aircraft RSI could confer significant patient benefit in terms of pre-hospital time saving and further research is warranted.

Objectives Patients who sustain a head injury but maintain a Glasgow Coma Scale (GCS) of 13–15 may still be suffering from a significant brain injury. We aimed to assess the appropriateness of triage and decision to perform prehospital rapid sequence induction (RSI) in patients attended by a UK Helicopter Emergency Medical Service (HEMS) following head injury. Design A retrospective cohort study of patients attended by Kent Surrey & Sussex Air Ambulance Trust (KSSAAT) HEMS. Setting A mixed urban and rural area of 4.5 million people in South East England. Participants GCS score of 13, 14 or 15 on arrival of the HEMS team and clinical findings suggesting head injury. Patients accompanied by the HEMS team to hospital (‘Escorted’), and those that were ‘Assisted’ but conveyed by the ambulance service were reviewed. No age restrictions to inclusion were set. Primary outcome measure Significant brain injury. Secondary outcome measure Recognition of patients requiring prehospital anaesthesia for head injury. Results Of 517 patients, 321 had adequate follow-up, 69% of these were Escorted, 31% Assisted. There was evidence of intracranial injury in 13.7% of patients and clinically important brain injury in 7.8%. There was no difference in the rate of clinically important brain injury between Escorted and Assisted patients (p=0.46). Nineteen patients required an RSI by the HEMS team and this patient group was significantly more likely to have clinically important brain injury (p=0.04). Conclusion In patients attended by a UK HEMS service with a head injury and a GCS of 13–15, a small but significant proportion had a clinically important brain injury and a proportion were appropriately recognised as requiring prehospital RSI. For patients deemed not to need a HEMS intervention, differentiating between those with and without clinically important brain injury appears challenging.

Introduction: Rapid Sequence Induction of anaesthesia (RSI) is the recommended method to facilitate emergency tracheal intubation in trauma patients. In emergency situations, a simple and standardised RSI protocol may improve the safety and effectiveness of the procedure. A crucial component of developing a standardised protocol is the selection of induction agents. The aim of this study is to compare the safety and effectiveness of a traditional RSI protocol using etomidate and suxamethonium with a modified RSI protocol using fentanyl, ketamine and rocuronium. Methods: We performed a comparative cohort study of major trauma patients undergoing pre-hospital RSI by a physician-led Helicopter Emergency Medical Service. Group 1 underwent RSI using etomidate and suxamethonium and Group 2 underwent RSI using fentanyl, ketamine and rocuronium. Apart from the induction agents, the RSI protocol was identical in both groups. Outcomes measured included laryngoscopy view, intubation success, haemodynamic response to laryngoscopy and tracheal intubation, and mortality. Results: Compared to Group 1 (n = 116), Group 2 RSI (n = 145) produced significantly better laryngoscopy views (p = 0.013) and resulted in significantly higher first-pass intubation success (95% versus 100%; p = 0.007). A hypertensive response to laryngoscopy and tracheal intubation was less frequent following Group 2 RSI (79% versus 37%; p < 0.0001). A hypotensive response was uncommon in both groups (1% versus 6%; p = 0.05). Only one patient in each group developed true hypotension (SBP < 90 mmHg) on induction. Conclusions: In a comparative, cohort study, pre-hospital RSI using fentanyl, ketamine and rocuronium produced superior intubating conditions and a more favourable haemodynamic response to laryngoscopy and tracheal intubation. An RSI protocol using fixed ratios of these agents delivers effective pre-hospital trauma anaesthesia.

Objectives: The aim of this study was to establish if in patients who die at scene as a result of a traumatic cardiac arrest (TCA), their cause of death could be determined through coroners reports, and to ascertain the quality of the feedback provided. Methods: This is a retrospective study of all patients presenting in TCA who were attended by the Kent, Surrey and Sussex Air Ambulance trust between 1 January 2015 and 30 June 2016. Results: In total, 159 patients were attended during the study period. PM reports could not be obtained for 37 patients, mainly due to unestablished identities at scene. Forty of the 122 reports obtained were full PM reports, 3 were inquest reports and for 79 patients only their (presumed) cause of death was provided. A specific cause of death was provided for 68 patients, whereas in the remaining 54 patients the cause of death was given as “multiple injuries”. In 32% of the patients with a full PM report, injuries were identified during the post mortem examination that had not been noted on scene. Conclusion: Feedback from coroners to pre-hospital teams after patients die as a result of a TCA is important, but currently suboptimal.

Background: Maintaining effective oxygenation throughout the process of Pre-Hospital Emergency Anaesthesia (PHEA) is critical. There are multiple strategies available to clinicians to oxygenate patients both prior to and during PHEA. The optimal pre-oxygenation technique remains unclear, and it is unknown what techniques are being used by United Kingdom Helicopter Emergency Medical Services (HEMS). This study aimed to determine the current pre-and peri-PHEA oxygenation strategies used by UK HEMS services. Methods: An electronic questionnaire survey was delivered to all UK HEMS services between 05 July and 26 December 2019. Questions investigated service standard operating procedures (SOPs) and individual clinician practice regarding oxygenation strategies prior to airway instrumentation (pre-oxygenation) and oxygenation strategies during airway instrumentation (apnoeic oxygenation). Service SOPs were obtained to corroborate questionnaire replies.

Objective Prehospital rapid sequence intubation (RSI) is an important aspect of prehospital care for helicopter emergency medical services (HEMS). This study examines the feasibility of in-aircraft (aircraft on the ground) RSI in different simulated settings. Methods Using an AW169 aircraft cabin simulator at Air Ambulance Kent Surrey Sussex, 3 clinical scenarios were devised. All required RSI in a “can intubate, can ventilate” (easy variant) and a “can't intubate, can't ventilate” scenario (difficult variant). Doctor-paramedic HEMS teams were video recorded, and elapsed times for prespecified end points were analyzed. Results Endotracheal intubation (ETI) was achieved fastest outside the simulator for the easy variant (median = 231 seconds, interquartile range = 28 seconds). Time to ETI was not significantly longer for in-aircraft RSI compared with RSI outside the aircraft, both in the easy (p = .14) and difficult variant (p = .50). Wearing helmets with noise distraction did not impact the time to intubation when compared with standard in-aircraft RSI, both in the easy (p = .28) and difficult variant (p = .24). Conclusion In-aircraft, on-the-ground RSI had no significant impact on the time to successful completion of ETI. Future studies should prospectively examine in-cabin RSI and explore the possibilities of in-flight RSI in civilian HEMS services.

Background For the prehospital diagnosis of raised intracranial pressure (ICP), clinicians are reliant on clinical signs such as the Glasgow Coma Score (GCS), pupillary response and/or Cushing’s triad (hypertension, bradycardia and an irregular breathing pattern). This study aimed to explore the diagnostic accuracy of these signs as indicators of a raised ICP. Methods We performed a retrospective cohort study of adult patients attended by a Helicopter Emergency Medical Service (Air Ambulance Kent, Surrey Sussex), who had sustained a traumatic brain injury (TBI), requiring prehospital anaesthesia between 1 January 2016 and 1 January 2018. We established optimal cut-off values for clinical signs to identify patients with a raised ICP and investigated diagnostic accuracy for combinations of these values. Results Outcome data for 249 patients with TBI were available, of which 87 (35%) had a raised ICP. Optimal cut-off points for systolic blood pressure (SBP), heart rate (HR) and pupil diameter to discriminate patients with a raised ICP were, respectively, ˃160 mm Hg,˂60 bpm and ˃5 mm. Cushing criteria (SBP ˃160 mm Hg and HR ˂60 bpm) and pupillary response and size were complimentary in their ability to detect patients with a raised ICP. The presence of a fixed blown pupil or a Cushing’s response had a specificity of 93.2 (88.2–96.6)%, and a positive likelihood ratio (LR+) of 5.4 (2.9–10.2), whereas sensitivity and LR− were only 36.8 (26.7–47.8)% and 0.7 (0.6–0.8), respectively, (Area Under the Curve (AUC) 0.65 (0.57–0.73)). Sensitivity analysis revealed that optimal cut-off values and resultant accuracy were dependent on injury pattern. Conclusion Traditional clinical signs of raised ICP may under triage patients to prehospital treatment with hyperosmolar drugs. Further research should identify more accurate clinical signs or alternative non-invasive diagnostic aids in the prehospital environment.

Background Quality of manual cardiopulmonary resuscitation (CPR) during extrication and transport of out-of-hospital cardiac arrest victims is known to be poor. Performing manual CPR during ambulance transport poses significant risk to the attending emergency medical services crew. We sought to use pre-hospital video recording to objectively analyse the impact of introducing mechanical CPR with an extrication sheet (Autopulse, Zoll) to an advanced, second-tier cardiac arrest response team. Methods The study was conducted prospectively using defibrillator downloads and analysis of pre-hospital video recording to measure the quality of CPR during extrication from scene and ambulance transport of the OHCA patient. Adult patients with non-traumatic OHCA were included. The interruption to manual CPR to during extrication and to deploy the mechanical CPR device was analysed. Results In the manual CPR group, 53 OHCA cases were analysed for quality of CPR during extrication. The median time that chest compression was interrupted to allow the patient to be carried from scene to the ambulance was 270 s (IQR 201–387 s). 119 mechanical CPR cases were analysed. The median time interruption from last manual compression to first Autopulse compression was 39 s (IQR 29–47 s). The range from last manual compression to first Autopulse compression was 14–118 s. Conclusion Mechanical CPR used in combination with an extrication sheet can be effectively used to improve the quality of resuscitation during extrication and ambulance transport of the refractory OHCA patient. The time interval to deploy the mechanical CPR device can be shortened with regular simulation training.

Following the return of spontaneous circulation after cardiac arrest, neurological dysfunction, airway or ventilatory compromise can impede transport to early percutaneous coronary intervention, necessitating pre-hospital or emergency department anaesthesia to facilitate this procedure. There are no published reports of the ideal induction agents in these patients. We sought to describe haemodynamic changes associated with a midazolam (0.1mg/kg) fentanyl (2mcg/kg) rocuronium (1mg/kg) regimen developed from expert opinion, and adherence to the protocol by our pre-hospital teams. We performed a retrospective review of electronic vital-signs recorded during induction of return of spontaneous circulation patients over a 30-month period. We analysed the changes in systolic blood pressure and heart rate using a repeated-measures design, and the rate of new hypotension or hypertension. Sixty four patients had four consecutive measurements for analysis (one pre-induction and three post-induction). Systolic blood pressure was significantly lower than the pre-induction value at all three post-induction measurements. Heart rate did not differ between any time-point. New episodes of hypotension (systolic pressure

We read the article “The effect of pre-hospital critical care on survival following out of hospital cardiac arrest: A prospective observational study”1 with great interest. The authors should be complimented for their effort to answer the question whether or not pre-hospital critical care teams contribute to the survival of out-of-hospital cardiac arrest (OHCA) patients. In their study, they could not demonstrate a positive association between pre-hospital critical care and survival to hospital discharge, which was their primary endpoint. Although a couple of reasons for the lack of benefit from pre-hospital critical care for OHCA are provided, we think several important explanations remain unmentioned in the article.

Background Previous studies have demonstrated an association between hyperoxia and increased mortality in various patient groups. Critically unwell and injured patients are routinely given high concentration oxygen in the pre-hospital phase of care. We aim to investigate the incidence of hyperoxia in major trauma patients receiving pre-hospital emergency anesthesia (PHEA) in the pre-hospital setting and determine factors that may help guide clinicians with pre-hospital oxygen administration in these patients. Methods A retrospective cohort study was performed of all patients who received PHEA by a single helicopter emergency medical service (HEMS) between 1 October 2014 and 1 May 2019 and who were subsequently transferred to one major trauma centre (MTC). Patient and treatment factors were collected from the electronic patient records of the HEMS service and the MTC. Hyperoxia was defined as a PaO2 > 16 kPA on the first arterial blood gas analysis upon arrival in the MTC. Results On arrival in the MTC, the majority of the patients (90/147, 61.2%) had severe hyperoxia, whereas 30 patients (20.4%) had mild hyperoxia and 26 patients (19.7%) had normoxia. Only 1 patient (0.7%) had hypoxia. The median PaO2 on the first arterial blood gas analysis (ABGA) after HEMS handover was 36.7 [IQR 18.5–52.2] kPa, with a range of 7.0–86.0 kPa. SpO2 pulse oximetry readings before handover were independently associated with the presence of hyperoxia. An SpO2 ≥ 97% was associated with a significantly increased odds of hyperoxia (OR 3.99 [1.58–10.08]), and had a sensitivity of 86.7% [79.1–92.4], a specificity of 37.9% [20.7–57.8], a positive predictive value of 84.5% [70.2–87.9] and a negative predictive value of 42.3% [27.4–58.7] for the presence of hyperoxemia. Conclusion Trauma patients who have undergone PHEA often have profound hyperoxemia upon arrival at hospital. In the pre-hospital setting, where arterial blood gas analysis is not readily available a titrated approach to oxygen therapy should be considered to reduce the incidence of potentially harmful tissue hyperoxia.

Background Helicopter Emergency Medical Services (HEMS) are a scarce resource that can provide advanced emergency medical care to unwell or injured patients. Accurate tasking of HEMS is required to incidents where advanced pre-hospital clinical care is needed. We sought to evaluate any association between non-clinically trained dispatchers, following a bespoke algorithm, compared with HEMS paramedic dispatchers with respect to incidents requiring a critical HEMS intervention. Methods Retrospective analysis of prospectively collected data from two 12-month periods was performed (Period one: 1st April 2014 – 1st April 2015; Period two: 1st April 2016 – 1st April 2017). Period 1 was a Paramedic-led dispatch process. Period 2 was a non-clinical HEMS dispatcher assisted by a bespoke algorithm. Kent, Surrey & Sussex HEMS (KSS HEMS) is tasked to approximately 2500 cases annually and operates 24/7 across south-east England. The primary outcome measure was incidence of a HEMS intervention. Results A total of 4703 incidents were included; 2510 in period one and 2184 in period two. Variation in tasking was reduced by introducing non-clinical dispatchers. There was no difference in median time from 999 call to HEMS activation between period one and two (period one; median 7 min (IQR 4–17) vs period two; median 7 min (IQR 4–18). Non-clinical dispatch improved accuracy of HEMS tasking to a mission where a critical care intervention was required (OR 1.25, 95% CI 1.04–1.51, p = 0.02). Conclusion The introduction of non-clinical, HEMS-specific dispatch, aided by a bespoke algorithm improved accuracy of HEMS tasking. Further research is warranted to explore where this model could be effective in other HEMS services.

Background: Sudden loss of consciousness (LOC) in the prehospital setting in the absence of cardiac arrest and seizure activity may be a challenge from a dispatcher's perspective: The aetiology is varied, with many causes being transient and mostly self-limiting, whereas other causes are potentially life threatening. In this study we aim to evaluate the dispatch of HEMS to patients with LOC of medical origin, by exploring to which patients with a LOC HEMS is dispatched, which interventions HEMS teams perform in these patients, and whether HEMS interventions can be predicted by patient characteristics. Methods: We performed retrospective cohort study of all patients with a reported unexplained LOC (e.g. not attributable to a circulatory arrest or seizures) attended by the Air Ambulance Kent, Surrey & Sussex (AAKSS), over a 4-year period (July 2013-December 2017). Primary outcome was defined as the number of HEMS-specific interventions performed in patients with unexplained LOC. Secondary outcome was the relation of clinical-and dispatch criteria with HEMS interventions being performed. Results: During the study period, 127 patients with unexplained LOC were attended by HEMS. HEMS was dispatched directly to 25.2% of the patients, but mostly (74.8%) on request of the ground ambulance crews. HEMS interventions were performed in 65% of the patients (Prehospital Emergency Anaesthesia 56%, hyperosmolar therapy 21%, antibiotic/antiviral therapy 8%, vasopressor therapy 6%) and HEMS conveyed most patients (77%) to hospital. Acute neurological pathology was a prevalent underlying cause of unexplained LOC: 38% had gross pathology on their CT-scan upon arrival in hospital. Both GCS (r=-0.60, p

Background Although the merit of pre-hospital critical care teams such as Helicopter Emergency Medical Services (HEMS) has been universally recognized for patients with penetrating torso injuries who present with unstable physiology, the potential merit in patients initially presenting with stable physiology is largely undetermined. The ability to predict the required pre-hospital interventions patients may have important implications for HEMS tasking, especially when transport times to definitive care are prolonged. Methods We performed a retrospective cohort study of patients who sustained a penetrating torso injury and were attended by the Air Ambulance Kent Surrey Sussex (AAKSS) over a 6-year period. Primary outcome was defined as the percentage of patients with penetrating torso injuries requiring HEMS-specific interventions anytime between HEMS arrival and arrival at hospital. Secondary outcomes were the association of individual patient- and injury characteristics with the requirement for HEMS interventions. Results During the study period 363 patients met inclusion criteria. 90% of patients were male with a median age of 30 years. 99% of penetrating trauma incident occurred more than 10-min drive from a Major Trauma Centre (MTC). Presenting GCS was > 13 in 83% of patients. Significant hemodynamic- or ventilatory compromise was present in more than 25% of the patients. Traumatic cardiac arrest was present in 34 patients (9.4%), profound hypotension with SBP