Prehospital Partial Resuscitative Endovascular Balloon Occlusion of the Aorta for Exsanguinating Subdiaphragmatic Hemorrhage.

Importance: Hemorrhage is the most common cause of preventable death after injury. Most deaths occur early, in the prehospital phase of care. Objective: To establish whether prehospital zone 1 (supraceliac) partial resuscitative endovascular balloon occlusion of the aorta (Z1 P-REBOA) can be achieved in the resuscitation of adult trauma patients at risk of cardiac arrest and death due to exsanguination. Design, Setting, and Participants: This was a prospective observational cohort study (Idea, Development, Exploration, Assessment and Long-term follow-up [IDEAL] 2A design) with recruitment from June 2020 to March 2022 and follow-up until discharge from hospital, death, or 90 days evaluating a physician-led and physician-delivered, urban prehospital trauma service in the Greater London area. Trauma patients aged 16 years and older with suspected exsanguinating subdiaphragmatic hemorrhage, recent or imminent hypovolemic traumatic cardiac arrest (TCA) were included. Those with unsurvivable injuries or who were pregnant were excluded. Of 2960 individuals attended by the service during the study period, 16 were included in the study. Exposures: ZI REBOA or P-REBOA. Main Outcomes and Measures: The main outcome was the proportion of patients in whom Z1 REBOA and Z1 P-REBOA were achieved. Clinical end points included systolic blood pressure (SBP) response to Z1 REBOA, mortality rate (1 hour, 3 hours, 24 hours, or 30 days postinjury), and survival to hospital discharge. Results: Femoral arterial access for Z1 REBOA was attempted in 16 patients (median [range] age, 30 [17-76] years; 14 [81%] male; median [IQR] Injury Severity Score, 50 [39-57]). In 2 patients with successful arterial access, REBOA was not attempted due to improvement in clinical condition. In the other 14 patients (8 [57%] of whom were in traumatic cardiac arrest [TCA]), 11 successfully underwent cannulation and had aortic balloons inflated in Z1. The 3 individuals in whom cannulation was unsuccessful were in TCA (failure rate = 3/14 [21%]). Median (IQR) pre-REBOA SBP in the 11 individuals for whom cannulation was successful (5 [46%] in TCA) was 47 (33-52) mm Hg. Z1 REBOA plus P-REBOA was associated with a significant improvement in BP (median [IQR] SBP at emergency department arrival, 101 [77-107] mm Hg; 0 of 10 patients were in TCA at arrival). The median group-level improvement in SBP from the pre-REBOA value was 52 (95% CI, 42-77) mm Hg (P < .004). P-REBOA was feasible in 8 individuals (8/11 [73%]) and occurred spontaneously in 4 of these. The 1- and 3-hour postinjury mortality rate was 9% (1/11), 24-hour mortality was 27% (3/11), and 30-day mortality was 82% (9/11). Survival to hospital discharge was 18% (2/11). Both survivors underwent early Z1 P-REBOA. Conclusions and Relevance: In this study, prehospital Z1 P-REBOA is feasible and may enable early survival, but with a significant incidence of late death. Trial Registration: ClinicalTrials.gov Identifier: NCT04145271.

Diagnostic accuracy of clinical examination to identify life- and limb-threatening injuries in trauma patients.

BACKGROUND: Timely and accurate identification of life- and limb-threatening injuries (LLTIs) is a fundamental objective of trauma care that directly informs triage and treatment decisions. However, the diagnostic accuracy of clinical examination to detect LLTIs is largely unknown, due to the risk of contamination from in-hospital diagnostics in existing studies. Our aim was to assess the diagnostic accuracy of initial clinical examination for detecting life- and limb-threatening injuries (LLTIs). Secondary aims were to identify factors associated with missed injury and overdiagnosis, and determine the impact of clinician uncertainty on diagnostic accuracy. METHODS: Retrospective diagnostic accuracy study of consecutive adult (≥ 16 years) patients examined at the scene of injury by experienced trauma clinicians, and admitted to a Major Trauma Center between 01/01/2019 and 31/12/2020. Diagnoses of LLTIs made on contemporaneous clinical records were compared to hospital coded diagnoses. Diagnostic performance measures were calculated overall, and based on clinician uncertainty. Multivariate logistic regression analyses identified factors affecting missed injury and overdiagnosis. RESULTS: Among 947 trauma patients, 821 were male (86.7%), median age was 31 years (range 16-89), 569 suffered blunt mechanisms (60.1%), and 522 (55.1%) sustained LLTIs. Overall, clinical examination had a moderate ability to detect LLTIs, which varied by body region: head (sensitivity 69.7%, positive predictive value (PPV) 59.1%), chest (sensitivity 58.7%, PPV 53.3%), abdomen (sensitivity 51.9%, PPV 30.7%), pelvis (sensitivity 23.5%, PPV 50.0%), and long bone fracture (sensitivity 69.9%, PPV 74.3%). Clinical examination poorly detected life-threatening thoracic (sensitivity 48.1%, PPV 13.0%) and abdominal (sensitivity 43.6%, PPV 20.0%) bleeding. Missed injury was more common in patients with polytrauma (OR 1.83, 95% CI 1.62-2.07) or shock (systolic blood pressure OR 0.993, 95% CI 0.988-0.998). Overdiagnosis was more common in shock (OR 0.991, 95% CI 0.986-0.995) or when clinicians were uncertain (OR 6.42, 95% CI 4.63-8.99). Uncertainty improved sensitivity but reduced PPV, impeding diagnostic precision. CONCLUSIONS: Clinical examination performed by experienced trauma clinicians has only a moderate ability to detect LLTIs. Clinicians must appreciate the limitations of clinical examination, and the impact of uncertainty, when making clinical decisions in trauma. This study provides impetus for diagnostic adjuncts and decision support systems in trauma.

Prehospital Care: An International Comparison of Independently Developed Training Courses.

OBJECTIVE: Prehospital and retrieval medicine (PHRM) occurs in a complex work environment. Appropriate training is essential to ensure high standards of clinical care and logistic decision making. Before commencing the role, PHRM doctors have varying levels of experience. This narrative review article aims to describe and compare 6 internationally accepted PHRM courses. METHODS: Six PHRM course directors were asked to describe their course in terms of education methods used, course content, and assessment processes. Each of the directors contributed to the discussion process. RESULTS: Although developed independently, all 6 courses use a comparable combination of lectures, simulations, and discussion groups. The amount of each pedagogical modality varies between the courses. CONCLUSION: We have identified significant similarities and some important differences among some well-accepted independently developed PHRM courses worldwide. Differences in content and the methods of delivery appear linked to the background of participants and service case mix. The authors believe that even in the small niche of PHRM, courses need to be tailored to the participants and the "destination of the participants" (ie, where they are going to use their skills).

Provision of pre-hospital medical care for terrorist attacks.

The delivery of medical care to the severely injured during major incidents and mass casualty events has been a recurring challenge for decades across the world. From events in resource-poor developing countries, through richly funded military conflicts, to the most equipped of developed nations, the provision of rapid medical care to the severely injured during major incidents and mass casualty events has been a priority for healthcare providers. This is often under the most difficult of circumstances.1,2 Whilst mass casualty events are a persistent global challenge, it is clear in developed countries that patients and their families demand and expect a high standard of care from their rescuers, that this care should be delivered rapidly, and this should be of the highest quality possible.3 Whilst there is respect afforded to those who 'run towards danger' during a high-threat situation, first responders are subjected to a high degree of scrutiny for their actions, even when the circumstances they are presented with are considered to be extraordinary.4 Likewise, even for those who are catastrophically injured beyond salvage, society expects the response to be dignified, calculated, and thorough.3.

Prospective Randomized Trial of Standard Left Anterolateral Thoracotomy Versus Modified Bilateral Clamshell Thoracotomy Performed by Emergency Physicians.

STUDY OBJECTIVE: Resuscitative thoracotomy is a time-sensitive, lifesaving procedure that may be performed by emergency physicians. The left anterolateral thoracotomy (LAT) is the standard technique commonly used in the United States to gain rapid access to critical intrathoracic structures. However, the smaller incision and subsequent limited exposure may not be optimal for the nonsurgical specialist to complete time-sensitive interventions. The modified bilateral anterior clamshell thoracotomy (MCT) developed by Barts Health NHS Trust clinicians at London's Air Ambulance overcomes these inherent difficulties, maximizes thoracic cavity visualization, and may be the ideal technique for the nonsurgical specialist. The aim of this study is to identify the optimal technique for the nonsurgical-specialist-performed resuscitative thoracotomy. Secondary aims of the study are to identify technical difficulties, procedural concerns, and physician preferences. METHODS: Emergency medicine staff and senior resident physicians were recruited from an academic Level I trauma center. Subjects underwent novel standardized didactic and skills-specific training on both the MCT and LAT techniques. Later, subjects were randomized to the order of intervention and performed both techniques on separate fresh, nonfrozen human cadaver specimens. Success was determined by a board-certified surgeon and defined as complete delivery of the heart from the pericardial sac and subsequent 100% occlusion of the descending thoracic aorta with a vascular clamp. The primary outcome was time to successful completion of the resuscitative thoracotomy technique. Secondary outcomes included successful exposure of the heart, successful descending thoracic aortic cross clamping, successful procedural completion, time to exposure of the heart, time to descending thoracic aortic cross-clamp placement, number and type of iatrogenic injuries, correct anatomic structure identification, and poststudy participant questionnaire. RESULTS: Sixteen emergency physicians were recruited; 15 met inclusion criteria. All participants were either emergency medicine resident (47%) or emergency medicine staff (53%). The median number of previously performed training LATs was 12 (interquartile range 6 to 15) and the median number of previously performed MCTs was 1 (interquartile range 1 to 1). The success rates of our study population for the MCT and LAT techniques were not statistically different (67% versus 40%; difference 27%; 95% confidence interval -61% to 8%). However, staff emergency physicians were significantly more successful with the MCT compared with the LAT (88% versus 25%; difference 63%; 95% CI 9% to 92%). Overall, the MCT also had a significantly higher proportion of injury-free trials compared with the LAT technique (33% versus 0%; difference 33%; 95% CI 57% to 9%). Physician procedure preference favored the MCT over the LAT (87% versus 13%; difference 74%; 95% CI 23% to 97%). CONCLUSION: Resuscitative thoracotomy success rates were lower than expected in this capable subject population. Success rates and procedural time for the MCT and LAT were similar. However, the MCT had a higher success rate when performed by staff emergency physicians, resulted in less periprocedural iatrogenic injuries, and was the preferred technique by most subjects. The MCT is a potentially feasible alternative resuscitative thoracotomy technique that requires further investigation.

Deliberate release: Plague - A review.

Yersinia pestis is the causative agent of plague and is considered one of the most likely pathogens to be used as a bioweapon. In humans, plague is a severe clinical infection that can rapidly progress with a high mortality despite antibiotic therapy. Therefore, early treatment of Y. pestis infection is crucial. This review provides an overview of its clinical manifestations, diagnosis, treatment, prophylaxis, and protection requirements for the use of clinicians. We discuss the likelihood of a deliberate release of plague and the feasibility of obtaining, isolating, culturing, transporting and dispersing plague in the context of an attack aimed at a westernized country. The current threat status and the medical and public health responses are reviewed. We also provide a brief review of the potential prehospital treatment strategy and vaccination against Y. pestis. Further, we discuss the plausibility of antibiotic resistant plague bacterium, F1-negative Y. pestis, and also the possibility of a plague mimic along with potential strategies of defense against these. An extensive literature search on the MEDLINE, EMBASE, and Web of Science databases was conducted to collate papers relevant to plague and its deliberate release. Our review concluded that the deliberate release of plague is feasible but unlikely to occur, and that a robust public health response and early treatment would rapidly halt the transmission of plague in the population. Front-line clinicians should be aware of the potential of a deliberate release of plague and prepared to instigate early isolation of patients. Moreover, front-line clinicians should be weary of the possibility of suicide attackers and mindful of the early escalation to public health organizations.

A systematic literature review and meta-analysis of the effectiveness of extracorporeal-CPR versus conventional-CPR for adult patients in cardiac arrest.

INTRODUCTION: The probability of surviving a cardiac arrest remains low. International resuscitation guidelines state that extracorporeal cardiopulmonary resuscitation (ECPR) may have a role in selected patients suffering refractory cardiac arrest. Identifying these patients is challenging. This project systematically reviewed the evidence comparing the outcomes of ECPR over conventional-CPR (CCPR), before examining resuscitation-specific parameters to assess which patients might benefit from ECPR. METHOD: Literature searches of studies comparing ECPR to CCPR and the clinical parameters of survivors of ECPR were performed. The primary outcome examined was survival at hospital discharge or 30 days. A secondary analysis examined the resuscitation parameters that may be associated with survival in patients who receive ECPR (no-flow and low-flow intervals, bystander-CPR, initial shockable cardiac rhythm, and witnessed cardiac arrest). RESULTS: Seventeen of 948 examined studies were included. ECPR demonstrated improved survival (OR 0.40 (0.27-0.60)) and a better neurological outcome (OR 0.10 (0.04-0.27)) over CCPR during literature review and meta-analysis. Characteristics that were associated with improved survival in patients receiving ECPR included an initial shockable rhythm and a shorter low-flow time. Shorter no-flow, the presence of bystander-CPR and witnessed arrests were not characteristics that were associated with improved survival following meta-analysis, although the quality of input data was low. All data were non-randomised, and hence the potential for bias is high. CONCLUSION: ECPR is a sophisticated treatment option which may improve outcomes in a selected patient population in refractory cardiac arrest. Further comparative research is needed clarify the role of this potential resuscitative therapy.

Pre-hospital Resuscitative Endovascular Balloon Occlusion of the Aorta (REBOA) for exsanguinating pelvic haemorrhage.

AIM: To report the initial experience and outcomes of Resuscitative Endovascular Balloon Occlusion of the Aorta (REBOA) as an adjunct to pre-hospital resuscitation of patients with exsanguinating pelvic haemorrhage. METHODS: Descriptive case series of consecutive adult patients, treated with pre-hospital Zone III REBOA by a physician-led pre-hospital trauma service, between January 2014 and July 2018. RESULTS: REBOA was attempted in 19 trauma patients (13 successful, six failed attempts) and two non-trauma patients (both successful) with exsanguinating pelvic haemorrhage. Trauma patients were severely injured (median ISS 34, IQR: 27-43) and profoundly hypotensive (median systolic blood pressure [SBP] 57, IQR: 40-68 mmHg). REBOA significantly improved blood pressure (Pre-REBOA median SBP 57, IQR: 35-67 mmHg versus Post- REBOA SBP 114, IQR: 86-132 mmHg; Median of differences 66, 95% CI: 25-74 mmHg; P < 0.001). REBOA was associated with significantly lower risk of pre-hospital cardiac arrest (REBOA 0/13 [0%] versus no REBOA 3/6 [50%], P = 0.021) and death from exsanguination (REBOA 0/13 [0%] versus no REBOA 4/6 [67%], P = 0.004), when compared to patients with a failed attempt. Successful REBOA was associated with improved survival (REBOA 8/13 [62%] versus no REBOA 2/6 [33%]; P = 0.350). Distal arterial thrombus requiring thrombectomy was common in the REBOA group (10/13, 77%). CONCLUSION: REBOA is a feasible pre-hospital resuscitation strategy for patients with exsanguinating pelvic haemorrhage. REBOA significantly improves blood pressure and may reduce the risk of pre-hospital hypovolaemic cardiac arrest and early death due to exsanguination. Distal arterial thrombus formation is common, and should be actively managed.

Counting the Cost of Cervical Collars.

Veljanoski D , Grier G , Wilson MH . Counting the cost of cervical collars. Prehosp Disaster Med. 2017;32(6):701-702.

Impact brain apnoea - A forgotten cause of cardiovascular collapse in trauma.

OBJECTIVE: Early death following cranial trauma is often considered unsurvivable traumatic brain injury (TBI). However, Impact Brain Apnoea (IBA), the phenomenon of apnoea following TBI, may be a significant and preventable contributor to death attributed to primary injury. This paper reviews the history of IBA, cites case examples and reports a survey of emergency responder experience. METHODS: Literature and narrative review and focused survey of pre-hospital physicians. RESULTS: IBA was first reported in the medical literature in 1705 but has been demonstrated in multiple animal studies and is frequently anecdotally witnessed in the pre-hospital arena following human TBI. It is characterised by the cessation of spontaneous breathing following a TBI and is commonly accompanied by a catecholamine surge witnessed as hypertension followed by cardiovascular collapse. This contradicts the belief that isolated traumatic brain injury cannot be the cause of shock, raising the possibility that brain injury may be misinterpreted and therefore mismanaged in patients with isolated brain injury. Current trauma management techniques (e.g. rolling patients supine, compression only cardiopulmonary resuscitation) could theoretically compound hypoxia and worsen the effects of IBA. Anecdotal examples from clinicians attending head injured patients within a few minutes of injury are described. Proposals for the study and intervention for IBA using advances in remote technology are discussed. CONCLUSION: IBA is a potential cause of early death in some head injured patients. The precise mechanisms in humans are poorly understood but it is likely that early, simple interventions to prevent apnoea could improve clinical outcomes.

Scenario based outdoor simulation in pre-hospital trauma care using a simple mannequin model.

INTRODUCTION: We describe a system of scenario-based training using simple mannequins under realistic circumstances for the training of pre-hospital care providers. METHODS: A simple intubatable mannequin or student volunteers are used together with a training version of the equipment used on a routine basis by the pre-hospital care team (doctor + paramedic).Training is conducted outdoors at the base location all year round. The scenarios are led by scenario facilitators who are predominantly senior physicians. Their role is to brief the training team and guide the scenario, results of patient assessment and the simulated responses to interventions and treatment. Pilots, fire-fighters and medical students are utilised in scenarios to enhance realism by taking up roles as bystanders, additional ambulance staff and police. These scenario participants are briefed and introduced to the scene in a realistic manner. After completion of the scenario, the training team would usually be invited to prepare and deliver a hospital handover as they would in a real mission. A formal structured debrief then takes place. RESULTS: This training method technique has been used for the training of all London Helicopter Emergency Medical Service (London HEMS) doctors and paramedics over the last 24 months. Informal participant feedback suggests that this is a very useful teaching method, both for improving motor skills, critical decision-making, scene management and team interaction. Although formal assessment of this technique has not yet taken place we describe how this type of training is conducted in a busy operational pre-hospital trauma service. DISCUSSION: The teaching and maintenance of pre-hospital care skills is essential to an effective pre-hospital trauma care system. Simple mannequin based scenario training is feasible on a day-to-day basis and has the advantages of low cost, rapid set up and turn around. The scope of scenarios is limited only by the imagination of the trainers. Significant effort is made to put the participants into "the Zone"--the psychological mindset, where they believe they are in a realistic setting and treating a real patient, so that they gain the most from each teaching session. The method can be used for learning new skills, communication and leadership as well as maintaining existing skills. CONCLUSION: The method described is a low technology, low cost alternative to high technology simulation which may provide a useful adjunct to delivering effective training when properly prepared and delivered. We find this useful for both induction and regular training of pre-hospital trauma care providers.

Introduction and use of the ProSeal laryngeal mask airway as a rescue device in a pre-hospital trauma anaesthesia algorithm.

We report the successful use of the Proseal laryngeal mask airway as a rescue device in three pre-hospital cases where tracheal intubation after induction of anaesthesia had failed. The ProSeal LMA allowed ventilation and oxygenation of all three patients under difficult circumstances.