Mass casualty, intentional vehicular trauma and anaesthesia.

The use of motor vehicles to initiate mass casualty incidents is increasing in frequency and such events are called intentional vehicular assaults. Perpetrators are inspired by a range of terrorist ideologies or have extremist views, criminal intent, or mental health issues. Assaults using a motor vehicle as the principal weapon of attack are easy to launch and require little to no forward planning. This makes them difficult for police and security agencies to predict, prevent, or interdict. With the increasing frequency of intentional vehicular assaults, anaesthesiologists in various settings may be involved in caring for victims and should be engaged in preparing for them. This narrative review examines the literature on vehicle assaults committed around the world and provides an overview of the unique injury patterns and considerations for the pre-hospital, perioperative, and critical care management of victims of these mass casualty events. The article discusses planning, education, and training in an attempt to reduce the mortality and morbidity of intentional vehicular assaults.

Near real-time marine mammal monitoring from gliders: Practical challenges, system development, and management implications.

In 2017, an endangered North Atlantic right whale mortality event in the Gulf of St. Lawrence, Canada, triggered the implementation of dynamic mitigation measures that required real-time information on whale distribution. Underwater glider-based acoustic monitoring offers a possible solution for collecting near real-time information but has many practical challenges including self-noise, energy restrictions, and computing capacity, as well as limited glider-to-shore data transfer bandwidth. This paper describes the development of a near real-time baleen whale acoustic monitoring glider system and its evaluation in the Gulf of St. Lawrence in 2018. Development focused on identifying and prioritizing important acoustic events and on sending contextual information to shore for human validation. The system performance was evaluated post-retrieval, then the trial was simulated using optimized parameters. Trial simulation evaluation revealed that the validated detections of right, fin, and blue whales produced by the system were all correct; the proportion of species occurrence missed varied depending on the timeframe considered. Glider-based near real-time monitoring can be an effective and reliable technique to inform dynamic mitigation strategies for species such as the North Atlantic right whale.

Propofol for migraine in the emergency department: A pilot randomised controlled trial.

OBJECTIVE: To test the administration of intravenous (i.v.) propofol at a procedural sedation dose compared to standard therapy for initial management of migraine in the ED. METHODS: This was an open label, randomised controlled pilot trial. Eligible patients were adults with a diagnosis of migraine and planned for treatment with i.v. medications. Patients were randomised to propofol or standard therapy groups. The primary outcome variable was time to discharge (TTD) defined as time from intervention to discharge from the ED. Secondary outcomes were safety of propofol administration and change in pain scores. A reduction of pain by ≥50% or discharge from the ED was defined as favourable. All analyses were performed on an intention-to-treat basis. RESULTS: Data from 29 patients were analysed, with 15 patients in the propofol group and 14 patients in the standard therapy group. TTD was significantly lower in the propofol group with median of 290 (interquartile range 162-500) min compared to 554.5 (interquartile range 534-639) min in the standard therapy group (P = 0.021). The hazard ratio for the defined favourable outcome of reduction of pain scores or discharge from the ED was 1.54 (95% CI 0.69-3.41). CONCLUSIONS: Initial management of migraine with i.v. propofol at procedural sedation doses significantly reduced TTD compared to standard therapy. We did not detect any significant safety concerns although the study was not adequately powered to detect safety of the intervention and requires validation.

Finger thoracostomy in patients with chest trauma performed by paramedics on a helicopter emergency medical service.

OBJECTIVE: To determine the frequency of finger thoracostomy performed by intensive care flight paramedics after the introduction of a training programme in this procedure and complications of the procedure that were diagnosed after hospital arrival. METHODS: This was a retrospective cohort study of adult and paediatric trauma patients undergoing finger thoracostomy performed by paramedics on a helicopter emergency medical service between June 2015 and May 2018. Hospital data were obtained through a manual search of the medical records at each of the three receiving major trauma services. Additional data were sourced from the Victorian State Trauma Registry. RESULTS: The final analysis included 103 cases, of which 73.8% underwent bilateral procedures with a total of 179 finger thoracostomies performed. The mean age of patients was 42.8 (standard deviation 21.4) years and 73.8% were male. Motor vehicle collision was the most common mechanism of injury accounting for 54.4% of cases. The median Injury Severity Score was 41 (interquartile range 29-54). There were 30 patients who died pre-hospital, with most (n = 25) having finger thoracostomy performed in the setting of a traumatic cardiac arrest. A supine chest X-ray was performed prior to intercostal catheter insertion in 38 of 73 patients arriving at hospital; of these, none demonstrated a tension pneumothorax. There were three cases of potential complications related to the finger thoracostomy. CONCLUSION: Finger thoracostomy was frequently performed by intensive care flight paramedics. It was associated with a low rate of major complications and given the deficiencies of needle thoracostomy, should be the preferred approach for chest decompression.

Feasibility study for implementation of resuscitative balloon occlusion of the aorta in peri-arrest, exsanguinating trauma at an adult level 1 Australian trauma centre.

OBJECTIVE: This prospective, observational, interventional study sought to determine if the introduction of resuscitative balloon occlusion of the aorta (REBOA) at an Australian adult major trauma centre would improve survival for major trauma patients. METHODS: Patients aged 18-60 years, transported directly from scene with exsanguinating, sub-diaphragmatic haemorrhage and hypovolaemic shock (systolic BP <70 mmHg or hypovolaemic cardiac arrest) were eligible for recruitment and followed up until hospital discharge (ACTRN12618000550202). RESULTS: During the 14-month study period (17 January 2015 to 12 March 2016) 3032 patients were admitted direct from scene with an overall mortality of 97 (3.71%). Of these patients 3019 had trauma centre vital signs recorded in the data set (99.57%) and 1523 were between the ages of 18-60, including 143 patients with a shock index of >1.0 (4.74%). There were 13 (0.43%) patients with a systolic BP <70 mmHg and/or cardiorespiratory arrest on arrival. The mortality in this group was six out of 13 (46.15%). Of these 13 patients, there were two (0.07% of the total cohort) where REBOA was attempted. There were no eligible patients for whom REBOA was achieved. None of the six patients who died would have benefited from REBOA deployment. CONCLUSIONS: Despite considerable training and resource allocation to ensure 24-h availability, the introduction of REBOA failed to effectively demonstrate any impact on patient outcome. Despite retrospective literature supporting the introduction of REBOA, in this 14-month prospective study there was no evidence of benefit. Further studies may define indications and subgroups of patients who may benefit.

Triage in Complex, Coordinated Terrorist Attacks.

INTRODUCTION: Terror attacks have increased in frequency, and tactics utilized have evolved. This creates significant challenges for first responders providing life-saving medical care in their immediate aftermath. The use of coordinated and multi-site attack modalities exacerbates these challenges. The use of triage is not well-validated in mass-casualty settings, and in the setting of intentional mass violence, new and innovative approaches are needed. METHODS: Literature sourced from gray and peer-reviewed sources was used to perform a comparative analysis on the application of triage during the 2011 Oslo/Utoya Island (Norway), 2015 Paris (France), and 2015 San Bernardino (California USA) terrorist attacks. A thematic narrative identifies strengths and weaknesses of current triage systems in the setting of complex, coordinated terrorist attacks (CCTAs). DISCUSSION: Triage systems were either not utilized, not available, or adapted and improvised to the tactical setting. The complexity of working with large numbers of patients, sensory deprived environments, high physiological stress, and dynamic threat profiles created significant barriers to the implementation of triage systems designed around flow charts, physiological variables, and the use of tags. Issues were identified around patient movement and "tactical triage." CONCLUSION: Current triage tools are inadequate for use in insecure environments, such as the response to CCTAs. Further research and validation are required for novel approaches that simplify tactical triage and support its effective application. Simple solutions exist in tactical triage, patient movement, and tag use, and should be considered as part of an overall triage system.

A new paradigm for retrieval medicine.

A number of new time critical medical interventions are highly specialised. As such, they are not available in many hospitals and EDs. This necessitates transfer to another facility, which is often associated with some degree of delay. Processes to facilitate timely access to these interventions should aim to replicate or improve on that which would have been available should the patient have been in the community, and responded to, primarily, by an emergency medical service.

Telementoring with project ECHO: a pilot study in Europe.

The Extension of Community Healthcare Outcomes (ECHO) project is a novel educational intervention designed in New Mexico to transfer subspecialty knowledge about hepatitis C virus (HCV) to primary care providers, thereby increasing patient access to HCV care. The ECHO model has been shown to deliver educational benefits and to result in good treatment outcomes for HCV-infected individuals in the USA; however, this approach has not been assessed in a European setting. We sought to evaluate the feasibility, acceptability and implementation of the ECHO model in Ireland using a pilot study. We present a descriptive review of recruitment, participation, retention and cost of the intervention as well as a qualitative review of the views of participants on the barriers, benefits and acceptability of the ECHO model. In the original Project ECHO in New Mexico, geographical distance posed the greatest barrier to accessing HCV care. In Ireland, people who inject drugs (PWID) were identified by interviewees as the main group facing barriers to accessing specialist HCV care. State-employed doctors and nurses caring for large numbers of HCV-infected PWID in opiate substitution treatment centres and homeless hostels were successfully recruited to participate in the project. Self-employed general practitioners did not participate, due mainly to a lack of time and the absence of reimbursement for participation. Practitioners who participated in the pilot reported benefits to themselves and their patients and would like to continue to participate in similar multidisciplinary, multisite educational interventions in the future.

Anatomy and Physiology of Left Ventricular Suction Induced by Rotary Blood Pumps.

This study in five large greyhound dogs implanted with a VentrAssist left ventricular assist device focused on identification of the precise site and physiological changes induced by or underlying the complication of left ventricular suction. Pressure sensors were placed in left and right atria, proximal and distal left ventricle, and proximal aorta while dual perivascular and tubing ultrasonic flow meters measured blood flow in the aortic root and pump outlet cannula. When suction occurred, end-systolic pressure gradients between proximal and distal regions of the left ventricle on the order of 40-160 mm Hg indicated an occlusive process of variable intensity in the distal ventricle. A variable negative flow difference between end systole and end diastole (0.5-3.4 L/min) was observed. This was presumably mediated by variable apposition of the free and septal walls of the ventricle at the pump inlet cannula orifice which lasted approximately 100 ms. This apposition, by inducing an end-systolic flow deficit, terminated the suction process by relieving the imbalance between pump requirement and delivery from the right ventricle. Immediately preceding this event, however, unnaturally low end-systolic pressures occurred in the left atrium and proximal left ventricle which in four dogs lasted for 80-120 ms. In one dog, however, this collapse progressed to a new level and remained at approximately -5 mm Hg across four heart beats at which point suction was relieved by manual reduction in pump speed. Because these pressures were associated with a pulmonary capillary wedge pressure of -5 mm Hg as well, they indicate total collapse of the entire pulmonary venous system, left atrium, and left ventricle which persisted until pump flow requirement was relieved by reducing pump speed. We suggest that this collapse caused the whole vascular region from pulmonary capillaries to distal left ventricle to behave as a Starling resistance which further reduced right ventricular output thus contributing to a major reduction in pump flow. We contend that similar complications of manual speed control also occur in the human subject and remain a major unsolved problem in the clinical management of patients implanted with rotary blood pumps.

Potentially avoidable blood transfusion during trauma resuscitation.

INTRODUCTION: Red blood cell (RBC) transfusion is often essential during trauma resuscitation but is associated with high cost and potential adverse outcomes. This study aimed to determine the incidence of potentially avoidable RBC transfusions (PAT) among adult major trauma patients. MATERIALS AND METHODS: A retrospective review of data collected by Registry on patients presenting between Jan 2006 and Dec 2011 was conducted. Eligible patients received at least 1 unit of RBC in the first 24h following presentation to the Emergency Department (ED). Episodes of PAT were determined according to haemodynamic stability and post-transfusion haemoglobin levels. RESULTS: There were 621 patients included, of whom 224 (36.1%; 95% CI: 32.3-40.0) received PAT. Of them, 132 (58.9%) were haemodynamically stable on arrival and did not require a surgical procedure. Patients with PAT had significantly lower injury severity scores (30 vs 34, p<0.01), higher presenting systolic blood pressure (129 vs 112mm Hg, p<0.01) and a lower frequency of a shock index ≥1 (24.1 vs 65.0%, p<0.01), compared to those without PAT. They also had a significantly lower mortality (13.4 vs 21.7%, p<0.01). CONCLUSIONS: PAT after trauma was common and often delivered to haemodynamically stable patients who did not require surgical procedures. Clinical decision pathways for trauma resuscitation should aim to limit PAT.

"After-hours" staffing of trauma centres and outcomes among patients presenting with acute traumatic coagulopathy.

OBJECTIVE: To examine the effect of the "after-hours" (18:00-07:00) model of trauma care on a high-risk subgroup - patients presenting with acute traumatic coagulopathy (ATC). DESIGN, PARTICIPANTS AND SETTING: Retrospective analysis of data from the Alfred Trauma Registry for patients with ATC presenting between 1 January 2006 and 31 December 2011. MAIN OUTCOME MEASURE: Mortality at hospital discharge, adjusted for potential confounders, describing the association between after-hours presentation and mortality. RESULTS: There were 398 patients with ATC identified during the study period, of whom 197 (49.5%) presented after hours. Mortality among patients presenting after hours was 43.1%, significantly higher than among those presenting in hours (33.1%; P = 0.04). Following adjustment for possible confounding variables of age, presenting Glasgow Coma Scale score, urgent surgery or angiography and initial base deficit, after-hours presentation was significantly associated with higher mortality at hospital discharge (adjusted odds ratio, 1.77; 95% CI, 1.10-2.87). CONCLUSION: The after-hours model of care was associated with worse outcomes among some of the most critically ill trauma patients. Standardising patient reception at major trauma centres to ensure a consistent level of care across all hours of the day may improve outcomes among patients who have had a severe injury.

Barriers to and facilitators of hepatitis C testing, management, and treatment among current and former injecting drug users: a qualitative exploration.

Hepatitis C (HCV) infection is common among injecting drug users (IDUs), yet accessing of HCV care, particularly HCV treatment, is suboptimal. There has been little in-depth study of IDUs experiences of what enables or prevents them engaging at every level of HCV care, including testing, follow-up, management and treatment processes. This qualitative study aimed to explore these issues with current and former IDUs in the greater Dublin area, Ireland. From September 2007 to September 2008 in-depth interviews were conducted with 36 service-users across a range of primary and secondary care services, including: two addiction clinics, a general practice, a community drop-in center, two hepatology clinics, and an infectious diseases clinic. Interviews were analyzed using a grounded theory approach. Barriers to HCV care included perceptions of HCV infection as relatively benign, fear of investigations and treatment, and feeling well. Perceptions were shaped by the discourse about HCV and "horror stories" about the liver biopsy and treatment within their peer networks. Difficulties accessing HCV care included limited knowledge of testing sites, not being referred for specialist investigations and ineligibility for treatment. Employment, education, and addiction were priorities that competed with HCV care. Relationships with health care providers influenced engagement with care: Trust in providers, concern for the service-user, and continuity of care fostered engagement. Education on HCV infection, investigations, and treatment altered perceptions. Becoming symptomatic, responsibilities for children, and wanting to move on from drug use motivated HCV treatment. In conclusion, IDUs face multiple barriers to HCV care. A range of facilitators were identified that could inform future interventions.

Black Saturday: the personal recollection of a doctor working during the worst bushfire in Australian history.

The date, 7 February 2009, will be known forever in Victoria, Australia as "Black Saturday". In the worst bushfires in Australian history, 173 lives were lost. Townships were razed. Over 1800 homes were destroyed, resulting in >7000 people being made homeless. The provision of health care to the injured, and then to the displaced communities, was provided by a range of health professionals, including paramedics, nurses, and doctors. This is a personal recollection of the related events.

Anesthetic management of thoracic trauma.

PURPOSE OF REVIEW: Trauma remains a leading cause of death across all age groups. Thoracic injury is a contributing cause in approximately half of these. Despite being potentially life threatening, most thoracic trauma is managed nonoperatively or with an intercostal catheter. Only 10% of thoracic trauma patients will require emergency thoracotomy. Many more will undergo emergency or urgent surgical intervention for coexisting injuries. Thoracic injuries are dynamic. It is crucial for the anesthesiologist to continually reassess the patient, so that the manifestations of evolving injuries may be detected as early as possible and appropriate management decisions made. Up-to-date knowledge of injury patterns, mechanisms, pathophysiology, and operative and nonoperative management will facilitate optimal management of these patients. RECENT FINDINGS: There is recent literature discussing the surgical, anesthetic and critical care management of a range of thoracic injuries resulting from either blunt or penetrating trauma. SUMMARY: Initial resuscitation and surgical management of patients with thoracic trauma continue to evolve. Improvements in prehospital care and diagnostic techniques as well as development of minimally invasive interventions mean that the anesthesiologist may be required to provide care to unstable patients in an expanded range of scenarios and environments.

Benzocaine-Induced Methemoglobinemia Complicating Transesophageal Echocardiography: A Case Report.

Methemoglobinemia is a rare but potentially serious complication occurring after the administration of the anesthetic agent benzocaine. We describe the findings and subsequent treatment of a patient who developed this complication after the use of benzocaine during the course of transesophageal echocardiography.