Ben Beck

Trends in traumatic out-of-hospital cardiac arrest in Perth, Western Australia from 1997 to 2014

AIM This study aims to describe and compare traumatic and medical out-of-hospital cardiac arrest (OHCA) occurring in Perth, Western Australia, between 1997 and 2014. METHODS The St John Ambulance Western Australia (SJA-WA) OHCA Database was used to identify all adult (≥ 16 years) cases. We calculated annual crude and age-sex standardised incidence rates (ASIRs) for traumatic and medical OHCA and investigated trends over time. RESULTS Over the study period, SJA-WA attended 1,354 traumatic OHCA and 16,076 medical OHCA cases. The mean annual crude incidence rate of traumatic OHCA in adults attended by SJA-WA was 6.0 per 100,000 (73.9 per 100,000 for medical cases), with the majority resulting from motor vehicle collisions (56.7%). We noted no change to either incidence or mechanism of injury over the study period (p>0.05). Compared to medical OHCA, traumatic OHCA cases were less likely to receive bystander cardiopulmonary resuscitation (CPR) (20.4% vs. 24.5%, p=0.001) or have resuscitation commenced by paramedics (38.9% vs. 44.8%, p<0.001). However, rates of bystander CPR and resuscitation commenced by paramedics increased significantly over time in traumatic OHCA (p<0.001). In cases where resuscitation was commenced by paramedics there was no difference in the proportion who died at the scene (37.2% traumatic vs. 34.3% medical, p=0.17), however, fewer traumatic OHCAs survived to hospital discharge (1.7% vs. 8.7%, p<0.001). CONCLUSIONS Despite temporal increases in rates of bystander CPR and paramedic resuscitation, traumatic OHCA survival remains poor with only nine patients surviving from traumatic OHCA over the 18-year period.

Establishing the Aus-ROC Australian and New Zealand out-of-hospital cardiac arrest Epistry.

Introduction Out-of-hospital cardiac arrest (OHCA) is a global health problem with low survival. Regional variation in survival has heightened interest in combining cardiac arrest registries to understand and improve OHCA outcomes. While individual OHCA registries exist in Australian and New Zealand ambulance services, until recently these registries have not been combined. The aim of this protocol paper is to describe the rationale and methods of the Australian Resuscitation Outcomes Consortium (Aus-ROC) OHCA epidemiological registry (Epistry). Methods and analysis The Aus-ROC Epistry is designed as a population-based cohort study. Data collection started in 2014. Six ambulance services in Australia (Ambulance Victoria, SA Ambulance Service, St John Ambulance Western Australia and Queensland Ambulance Service) and New Zealand (St John New Zealand and Wellington Free Ambulance) currently contribute data. All OHCA attended by ambulance, regardless of aetiology or patient age, are included in the Epistry. The catchment population is approximately 19.3 million persons, representing 63% of the Australian population and 100% of the New Zealand population. Data are collected using Utstein-style definitions. Information incorporated into the Epistry includes demographics, arrest features, ambulance response times, treatment and patient outcomes. The primary outcome is ‘survival to hospital discharge’, with ‘return of spontaneous circulation’ as a key secondary outcome. Ethics and dissemination Ethics approval was independently sought by each of the contributing registries. Overarching ethics for the Epistry was provided by Monash University HREC (Approval No. CF12/3938—2012001888). A population-based OHCA registry capturing the majority of Australia and New Zealand will allow risk-adjusted outcomes to be determined, to enable benchmarking across ambulance providers, facilitate the identification of system-wide strategies associated with survival from OHCA, and allow monitoring of temporal trends in process and outcomes to improve patient care. Findings will be shared with participating ambulance services and the academic community.

Bicycling crash characteristics: an in-depth crash investigation study

The aim of this study was to describe the crash characteristics and patient outcomes of a sample of patients admitted to hospital following bicycle crashes. Injured cyclists were recruited from the two major trauma services for the state of Victoria, Australia. Enrolled cyclists completed a structured interview, and injury details and patient outcomes were extracted from the Victorian State Trauma Registry (VSTR) and the Victorian Orthopaedic Trauma Outcomes Registry (VOTOR). 186 cyclists consented to participate in the study. Crashes commonly occurred during daylight hours and in clear weather conditions. Two-thirds of crashes occurred on-road (69%) and were a combination of single cyclist-only events (56%) and multi-vehicle crashes (44%). Of the multi-vehicle crashes, a motor vehicle was the most common impact partner (72%) and distinct pre-crash directional interactions were observed between the cyclist and motor vehicle. Nearly a quarter of on-road crashes occurred when the cyclist was in a marked bicycle lane. Of the 31% of crashes that were not on-road, 28 (15%) occurred on bicycle paths and 29 (16%) occurred in other locations. Crashes on bicycle paths commonly occurred on shared bicycle and pedestrian paths (83%) and did not involve another person or vehicle. Other crash locations included mountain bike trails (39%), BMX parks (21%) and footpaths (18%). While differences in impact partners and crash characteristics were observed between crashes occurring on-road, on bicycle paths and in other locations, injury patterns and severity were similar. Most cyclists had returned to work at 6 months post-injury, however only a third of participants reported a complete functional recovery. Further research is required to develop targeted countermeasures to address the risk factors identified in this study.

Predicting outcomes in traumatic out-of-hospital cardiac arrest: the relevance of Utstein factors

Background Given low survival rates in cases of traumatic out-of-hospital cardiac arrest (OHCA), there is a need to identify factors associated with outcomes. We aimed to investigate Utstein factors associated with achieving return of spontaneous circulation (ROSC) and survival to hospital in traumatic OHCA. Methods The Victorian Ambulance Cardiac Arrest Registry (VACAR) was used to identify cases of traumatic OHCA that received attempted resuscitation and occurred between July 2008 and June 2014. We excluded cases aged <16 years or with a mechanism of hanging or drowning. Results Of the 660 traumatic OHCA patients who received attempted resuscitation, ROSC was achieved in 159 patients (24%) and 95 patients (14%) survived to hospital (ROSC on hospital handover). Factors that were positively associated with achieving ROSC in multivariable logistic regression models were age ≥65 years (adjusted OR (AOR)=1.56, 95% CI: 1.01 to 2.43) and arresting rhythm (shockable (AOR=3.65, 95% CI: 1.64 to 8.11) and pulseless electrical activity (AOR=2.15, 95% CI: 1.36 to 3.39) relative to asystole). Similarly, factors positively associated with survival to hospital were arresting rhythm (shockable (AOR=3.92, 95% CI: 1.64 to 9.41) relative to asystole), and the mechanism of injury (falls (AOR=2.16, 95% CI: 1.03 to 4.54) relative to motor vehicle collisions), while trauma type (penetrating (AOR=0.27, 95% CI: 0.08 to 0.91) relative to blunt trauma) and event region (rural (AOR=0.39, 95% CI: 0.19 to 0.80) relative to urban) were negatively associated with survival to hospital. Conclusions Few patient and arrest characteristics were associated with outcomes in traumatic OHCA. These findings suggest there is a need to incorporate additional information into cardiac arrest registries to assist prognostication and the development of novel interventions in these trauma patients.

Description of the ambulance services participating in the Aus-ROC Australian and New Zealand out-of-hospital cardiac arrest Epistry

The present study aimed to describe and examine similarities and differences in the current service provision and resuscitation protocols of the ambulance services participating in the Aus‐ROC Australian and New Zealand out‐of‐hospital cardiac arrest (OHCA) Epistry. Understanding these similarities and differences is important in identifying ambulance service factors that might explain regional variation in survival of OHCA in the Aus‐ROC Epistry.

Are sociodemographic characteristics associated with spatial variation in the incidence of OHCA and bystander CPR rates? A population-based observational study in Victoria, Australia

Background Rates of out-of-hospital cardiac arrest (OHCA) and bystander cardiopulmonary resuscitation (CPR) have been shown to vary considerably in Victoria. We examined the extent to which this variation could be explained by the sociodemographic and population health characteristics of the region. Methods Using the Victorian Ambulance Cardiac Arrest Registry, we extracted OHCA cases occurring between 2011 and 2013. We restricted the calculation of bystander CPR rates to those arrests that were witnessed by a bystander. To estimate the level of variation between Victorian local government areas (LGAs), we used a two-stage modelling approach using random-effects modelling. Results Between 2011 and 2013, there were 15 830 adult OHCA in Victoria. Incidence rates varied across the state between 41.9 to 104.0 cases/100 000 population. The proportion of the population over 65, socioeconomic status, smoking prevalence and education level were significant predictors of incidence in the multivariable model, explaining 93.9% of the variation in incidence among LGAs. Estimates of bystander CPR rates for bystander witnessed arrests varied from 62.7% to 73.2%. Only population density was a significant predictor of rates in a multivariable model, explaining 73% of the variation in the odds of receiving bystander CPR among LGAs. Conclusions Our results show that the regional characteristics which underlie the variation seen in rates of bystander CPR may be region specific and may require study in smaller areas. However, characteristics associated with high incidence and low bystander CPR rates can be identified and will help to target regions and inform local interventions to increase bystander CPR rates.

Variations in Rear Seat Cushion Properties and the Effects on Submarining

Objective: This study aims to investigate the effects of seating posture and seat cushion properties on submarining risk for rear seated children. Methods: An instrumented 6-year-old Hybrid III dummy restrained by an inertial-reel 3-point seat belt was subjected to simulated frontal impacts (Δv = 28.8 km/h, peak acceleration = 16 g). Dummy motion was captured using high-speed digital video. Head acceleration, neck loads, chest deflection, pelvic rotation, and femur displacement were used to assess submarining. Factors investigated included pre-impact seating posture, seat cushion length, stiffness of the seat cushion foam, and the inclination of the seat cushion. Results: The most severe submarining was observed when the dummy was seated in a slouched posture where pelvic rotation was over 3 times greater than in the upright seating posture. Though the standard seat cushion with the dummy seated in the upright posture recorded the lowest values of pelvic rotation and femur displacement, it is unlikely that a child will sit in such a posture. The shortened seat cushion increased femur displacement by 19 percent compared to the standard test seat, but it offers good pre-impact belt position. Submarining occurred in cases where the front edge of the seat collapsed during interactions with the dummys buttocks. Conclusions: These data suggest that shortening the rear seat cushion alone will not necessarily prevent submarining, but this does allow improved seated posture of the occupant, thus reducing submarining risk. This study has also shown that the collapse of the front edge of the seat cushion is a critical factor in submarining risk.

Regional variation in the characteristics, incidence and outcomes of out-of-hospital cardiac arrest in Australia and New Zealand: Results from the Aus-ROC Epistry

INTRODUCTION The aim of this study was to investigate regional variation in the characteristics, incidence and outcomes of out-of-hospital cardiac arrest (OHCA) in Australia and New Zealand. METHODS This was a population-based cohort study of OHCA using data from the Aus-ROC Australian and New Zealand OHCA Epistry over the period of 01 January 2015-31 December 2015. Seven ambulance services contributed data to the Epistry with a capture population of 19.8 million people. All OHCA attended by ambulance, regardless of aetiology or patient age, were included. RESULTS In 2015, there were 19,722 OHCA cases recorded in the Aus-ROC Epistry with an overall crude incidence of 102.5 cases per 100,000 population (range: 51.0-107.7 per 100,000 population). Of all OHCA cases attended by EMS (excluding EMS-witnessed cases), bystander CPR was performed in 41% of cases (range: 36%-50%). Resuscitation was attempted (by EMS) in 48% of cases (range: 40%-68%). The crude incidence for attempted resuscitation cases was 47.6 per 100,000 population (range: 34.7-54.1 per 100,000 population). Of cases with attempted resuscitation, 28% survived the event (range: 21%-36%) and 12% survived to hospital discharge or 30 days (range: 9%-17%; data provided by five ambulance services). CONCLUSION In the first results of the Aus-ROC Australian and New Zealand OHCA Epistry, significant regional variation in the incidence, characteristics and outcomes was observed. Understanding the system-level and public health drivers of this variation will assist in optimisation of the chain of survival provided to OHCA patients with the aim of improving outcomes.

Clinical review of prehospital trauma deaths—The missing piece of the puzzle

Traumatic injury has long been established as a global public health problem and remains the leading cause of death among persons aged 1–44 [1]. Reviewing preventable trauma deaths, a method first utilised by Moylan et al. [2] and Detmer et al. [3] in hospitalised major trauma patients in the 1970s, has been a mechanism used to examine quality of care and outcomes. This approach was used by West et al. [4] in Orange County in the late 1970s to demonstrate the effectiveness of a regionalised system of trauma care. Since this time, regionalised trauma systems have been shown to substantially improve outcomes for hospitalised trauma patients globally [5,6]. Within our region of Victoria, Australia, the work of the Consultative Committee of Road Traffic Fatalities, led by McDermott et al. [7], was instrumental in the introduction of the Victorian State Trauma System; a regionalised trauma system that has been demonstrated to significantly improve outcomes for major trauma patients [8,9]. However, the majority of trauma deaths will occur in the prehospital setting [10], and these deaths have not been subject to the same scrutiny as in-hospital deaths. Furthermore, in most trauma systems, prehospital care is not linked to in-hospital care. This is a critical limitation of modern trauma systems in evaluating the system of care provided to all trauma patients, not just those who are transported to hospital. Reviewing prehospital trauma deaths provide an opportunity to examine the entire system of care provided to trauma patients, including treatment in the prehospital setting. This is not limited to just determining whether optimal on-scene clinical management was provided, but also providing evidence for the potential of novel interventions to reduce trauma mortality. Reviews of combat casualties have provided evidence for novel clinical management in the military environment [11]; this opportunity also exists in reviewing prehospital trauma deaths. Such interventions may include intravascular devices and the use of procoagulants to reduce bleeding. Additionally, the response of the system can also be evaluated, such as time from injury event to emergency call and the response of the emergency medical system (EMS). Historically, reviewing prehospital trauma deaths has focussed on the clinical management of patients. However, in the age of rapid technological development, we now have the opportunity to provide insight into the role of novel technologies to improve outcomes for trauma patients. These may include early notification systems, such as the use of crash detection systems or smartphones to alert EMS in the

Predictors of recovery in cyclists hospitalised for orthopaedic trauma following an on-road crash

BACKGROUND As cycling-related injury rates are on the rise, there is a need to understand the long term outcomes of these patients in order to quantify the burden of injury and to inform injury prevention strategies. This study aimed to investigate predictors of return to work and functional recovery in a cohort of cyclists hospitalised for orthopaedic trauma from crashes occurring on-road. METHODS A retrospective analysis of data from the Victorian Orthopaedic Trauma Outcomes Registry (VOTOR) was conducted for patients who were hospitalised for orthopaedic trauma following a cycling crash that occurred on-road between July 2007 and June 2015. RESULTS There were 1787 injured cyclists admitted at the participating hospitals. Most cyclists were male (79%), resided in major cities (89%) and were in the highest socioeconomic quintile (52%). The majority of crashes were either non-collisions (41%) or collisions with a motor vehicle (35%). A smaller proportion of cyclists who collided with motor vehicles had returned to work and had returned to pre-injury functional levels at 12 months post-injury, when compared to collisions with other impact counterparts and non-collisions. Mixed effects logistic regression models revealed that compensable patients demonstrated lower odds of complete functional recovery and return to work when compared with non-compensable patients. CONCLUSION Cyclists who collided with motor vehicles had worse outcomes compared to crashes with other impact counterparts and non-collision events. These findings provide support for reducing the potential for interaction between cyclists and motor vehicles.