New South Wales Ambulance Research Articles

Evaluating the effectiveness of the maximum permitted dose of midazolam in seizure termination: Insights from New South Wales, Australia.

Out-of-hospital seizures demand rapid management. Midazolam plays a key role in stopping seizures. At times the first dose of midazolam proves insufficient, necessitating additional doses. Within the New South Wales Ambulance (NSWA) service, the upper limit for midazolam administration is set at 15 mg. However, the outcomes and safety of using midazolam at this maximum dosage have not been thoroughly investigated. A retrospective analysis of out of hospital electronic health records from New South Wales, Australia, over the year 2022, was conducted. The study manually reviewed cases where adult patients received the maximum dose of midazolam for seizure management by paramedics. It focused on seizure cessation success rates and the incidence of adverse effects to evaluate the clinical implications of high-dose midazolam administration. Of 818 790 individual attendances by NSWA clinicians, a total of 11 392 (1.4%) adults had seizures noted, of which midazolam was administered in 2565 (22.5%). An algorithm shows that in 2352 (91.7%) instances the midazolam was associated with the apparent termination of seizures. Analysis revealed that 176 (1.5%) proportion of all adult's seizure patients required the maximum dose of midazolam for seizure control. These higher doses successfully terminate seizures in about half of the instances. AEs following the maximum dose of midazolam included hypoxia in 26.7% of patients and respiratory depression in 9.7%, indicating significant side effects at higher dosages. In New South Wales, Australia, administering the maximum dose of midazolam to seizure patients is rare but proves effective in approximately half of the refractory seizure cases. Therefore, assessing the potential for additional doses of midazolam or the use of a second-line agent is advisable.

The New South Wales Sudden Cardiac Arrest Registry: A Data Linkage Cohort Study.

Sudden cardiac arrest (SCA) in young people aged 1 to 50 years often occurs with no presenting symptoms or risk factors prompting screening for cardiovascular disease prior to their cardiac arrest. Approximately 3,000 young Australians suffer from sudden cardiac death (SCD) each year, making this a major public health issue. However, there is significant variation in the way incidence is estimated resulting in discrepancy across reporting which impacts our ability to understand and prevent these devastating events. We describe the New South Wales (NSW) Sudden Cardiac Arrest Registry: a retrospective, data linkage study which will identify all SCAs in the young in NSW from 2009 through to June2022. To determine the incidence, demographic characteristics and causes of SCA in young people. We will develop an NSW-based registry that will contribute to a greater understanding of SCA including risk factors and outcomes. The cohort will include all people who experience a SCA in the NSW community aged between 1 to 50 years. Cases will be identified using the following three datasets: the Out of Hospital Cardiac Arrest Register housed at NSW Ambulance, the NSW Emergency Department Data Collection, and the National Coronial Information System. Data from eight datasets will be collected, anonymised and linked for the entire cohort. Analysis will be undertaken and reported using descriptive statistics. The NSW SCA registry will be an important resource for the improved understanding of SCA and inform the widespread impacts it has on individuals, their families and society.

Prehospital times and outcomes of patients transported using an ambulance trauma transport protocol: A data linkage analysis from New South Wales Australia

IntroductionPrehospital trauma systems are designed to ensure optimal survival from critical injuries by triaging and transporting such patients to the most appropriate hospital in a timely manner. ObjectivesWe sought to evaluate whether prehospital time and location (metropolitan versus non-metropolitan) were associated with 30-day mortality in a cohort of patients transported by road ambulance using a trauma transport protocol. MethodsData linkage analysis of routinely collected ambulance and hospital data across all public hospitals in New South Wales (NSW). The data linkage cohort included adult patients (age ≥ 16years) transported by NSW Ambulance, where a T1 Major Trauma Transport Protocol was documented by paramedic crews and transported by road to a public hospital emergency department in NSW for two years between January 2019 and December 2020. The outcomes of interest were prehospital times (response time, scene time and transport time) and 30-day mortality due to injury. Results9012 cases were identified who were transported to an emergency department with T1 protocol indication. Median prehospital transport times were longer in non-metropolitan road transports [n = 3,071, 98 min (71–126)] compared to metropolitan transports [n = 5,941, 65 min (53–80), p < 0.001]. There was no significant difference in 30-day mortality between the two groups (1.24% vs 1.65%, p = 0.13). In the subgroup of patients with abnormal vital signs, the only predictors of mortality were increasing age, presence of severe injury (OR 24.87, 95%CI 11.02, 56.15, p < 0.001), and arrival at a non-trauma facility (OR 3.01, 95%CI 1.26, 7.20, p < 0.05). Increasing transport times were not found to increase the odds of 30-day mortality. DiscussionIn the context of an inclusive trauma system and an established prehospital major trauma protocol, increasing prehospital transport times and scene location were not associated with increased mortality.

Machine learning algorithms to classify self-harm behaviours in New South Wales Ambulance electronic medical records: A retrospective study

BackgroundThere is increasing interest in suicide surveillance solutions to identify non-fatal suicidal and self-harming behaviours in the Australian community not currently captured through national administrative datasets. ObjectiveThe aim of the present study was to develop machine learning models to classify self-harm related behaviours using unstructured clinical note text from New South Wales (NSW) Ambulance data and compare their performance via traditional methods. MethodsPrimary data were derived from NSW Ambulance electronic medical records (eMRs) for potential self-harm related NSW Ambulance attendances for the period 2013–2019. Data included paramedic clinical notes detailing the nature of the attendance, clinical outcome, and narrative information. We assessed sensitivity, specificity, positive predictive value, negative predictive value, F-score, and the Matthews correlation coefficient (MCC) for four algorithms (Support Vector Machine, random forest, decision tree, and logistic regression). ResultsThe performance of these algorithms was compared using the MCC measure. In a test sample of 3157 ambulance attendances (1349 self-harm related behaviours and 1808 unrelated), the MCC for classification of self-harm related behaviour ranged from +0.681 to +0.730. The Support Vector Machine (sensitivity = 82.7%, specificity = 89.6%, MCC = 0.730) and the logistic regression (sensitivity = 83.1%, specificity = 89.3%, MCC = 0.727) models performed best. ConclusionsThis study demonstrates that machine learning models can be applied to paramedic notes within unstructured medical records to classify self-harm related behaviours. The resulting model could be used to compliment current manual abstraction of self-harm behaviours and provide more timely approximations to be used for self-harm surveillance.

Description and prediction of outcome of drowning patients in New South Wales, Australia: protocol for a data linkage study

IntroductionDespite being a preventable cause of death, drowning is a global public health threat. Australia records an average of 288 unintentional drowning deaths per year; an estimated annual economic burden...

Prehospital care and transport costs of severely injured children in NSW Australia

BackgroundInjury is the leading cause of childhood death and disability in Australia. Prehospital emergency services in New South Wales (NSW) are provided by NSW Ambulance. The incidence, pre-hospital care provided and outcomes of children suffering major injury in NSW has not previously been described. MethodsThis retrospective study was conducted between July 2015 and September 2016 and included children <16 years with an injury severity score (ISS) >9, or requiring intensive care admission, or deceased following injury and treated in NSW. Children were identified through the three NSW Paediatric Trauma Centres, the NSW Trauma Registry, NSW Medical Retrieval Registry (AirMaestro, Avinet, Australia). ResultsThere were 359 majorly injured children treated by NSW-based emergency service providers, the majority were male (73.3%) with a mean (SD) age of 8.0 (5.2) years. The median (IQR) injury severity score (ISS) for those transported via NSW emergency medical services was 10 (9-17), with almost half (44.1%) treated prehospital having an ISS >12. The most common documented interventions were intravenous access (44.1%) and oxygen therapy (39.6%). Intubation and chest decompression were recorded in 15.3% and 3.1% of cases respectively. The calculated median (IQR) transport charges for NSW Emergency Services was AUD $942 ($841.3-$1184.6). ConclusionCritical interventions are performed infrequently in children with major injuries in the pre-hospital environment. The monitoring of the incidence and success rates for staff performing these interventions is not readily available from all prehospital emergency medical services operating in NSW. The capacity and processes to monitor and audit all critical interventions in the paediatric population should be resourced and clearly defined.

Prehospital Blood Transfusion in New South Wales, Australia: A Retrospective Cohort Study

Introduction Catastrophic hemorrhage remains the leading cause of preventable death. Not all New South Wales (NSW) hospitals stock blood products and, as such, blood products carried by NSW Ambulance retrieval teams are often the first available to critically unwell patients. Objective To describe the trends, characteristics and predictors of mortality prior to hospital treatment in patients receiving prehospital blood transfusion by NSW Ambulance retrieval teams attending primary missions from 2009–2018. Methods Retrospective review of all patients who received blood products with NSW Ambulance retrieval teams between 13/8/2009 and 31/12/2018. Results A total of 12,468 primary taskings were reviewed, identifying 1,043 (8.4%) cases of prehospital transfusion. The proportion of missions administering blood transfusions doubled between 2009 and 2018. Road traffic incidents were the predominant etiology. Eighty per cent of patients (n = 842) reached hospital alive following transfusion. Retrieval missions had a median time of 117 minutes (IQR 74–168). An initial blood pressure <100mmHg and reduced GCS were strongly associated with prehospital mortality. The median shock index of patients prior to transfusion was 1.2, which reduced to 1.0 after transfusion. Conclusion The use of prehospital blood transfusion for suspected bleeding in NSW Australia has more than doubled since 2010. Patients who received prehospital transfusion arrived at hospital with improved hemodynamic observations.

Lived experience of involuntary transport under mental health legislation.

Police have historically been responsible for transporting people during a mental health crisis in Australia. A major change to the New South Wales (NSW) Mental Health Act (MHA) in 2007 expanded the range of coercive transportation agencies to include NSW Ambulance (paramedics) and NSW Health (mental health nurses). Anecdotal reports, however, describe a lack of clarity around how these changes should be implemented in practice. This research aims to explore this lack of clarity through qualitative analysis of interviews with people with the lived experience of involuntary transport under the MHA. Sixteen interviews were conducted; most (n=14) interviews in northern NSW regions: six with people who had been transported (consumers), four with carers, and six with service providers (two police, one paramedic, and three mental health nurses). For consumers and carers, the police response was often perceived as too intense, particularly if the person was not violent. Carers were often conflicted by having to call for emergency intervention. Service providers were frustrated by a lack of a coordinated interagency response, resourcing issues, delays at emergency departments, and lack of adequate training. A central theme across all groups was the importance of communication styles. As one participant (consumer) said: 'Everybody needs a lesson in kindness'. All groups agreed that high-risk situations necessitate police involvement. However, invocation of the MHA during a high-risk situation is fraught with stress and difficulties, leaving little room for empathetic communications. Effective and diverse, evidence-based, early intervention strategies - both consensual and non-consensual - are necessary to reduce the requirement for police involvement in mental health transports.

Quantification of NSW Ambulance Record Linkages with Multiple External Datasets

This study has two aims: 1) to describe linkage rates between ambulance data and external datasets for “episodes of care” and “patient only” linkages in New South Wales (NSW), Australia; and 2) to detect and report any systematic issues with linkage that relate to patients, and operational or clinical variables that may introduce bias in subsequent studies if not adequately addressed. During 2010–11, the Centre for Health Record Linkage (CHeReL) in NSW, linked the records for patients attended by NSW Ambulance paramedics for the period July 2006 to June 2009, with four external datasets: Emergency Department Data Collection; Admitted Patient Data Collection; NSW Registry of Births, Deaths and Marriages death registration data; and the Australian Bureau of Statistics mortality data. This study reports linkage rates in terms of those “expected” to link and those who were “not expected” to link with external databases within 24 hours of paramedic attendance. Following thorough data preparation processes, 2,041,728 NSW Ambulance care episodes for 1,116,509 patients fulfilled the inclusion criteria. The overall episode-specific hospital linkage rate was 97.2%. Where a patient was not transported to hospital following paramedic care, 8.6% of these episodes resulted in an emergency department attendance within 24 hours. For all care episodes, 5.2% linked to a death record at some time within the 3-year period, with 2.4% of all death episodes occurring within 7 days of a paramedic encounter. For NSW Ambulance episodes of care that were expected to link to an external dataset but did not, nonlinkage to hospital admission records tended to decrease with age. For all other variables, issues relating to rates of linkage and nonlinkage were more indiscriminate. This quantification of the limitations of this large linked dataset will underpin the interpretation and results of ensuing studies that will inform future clinical and operational policies and practices at NSW Ambulance. Key words: emergency medical services, epidemiologic methods, medical record linkage, research design

Standardising paediatric resuscitation training in New South Wales, Australia: RESUS4KIDS

A key competency for all health-care workers (HCWs) who care for children is the ability to respond to a child in respiratory or cardiorespiratory arrest. However, evidence suggests that medical and nursing staff may not have the knowledge and clinical skills to respond to these emergencies. The aim of this project was to create a standardised, evidence-based, paediatric life support course that would be available free to all HCWs in New South Wales (NSW), including NSW Ambulance. A paediatric life support course was designed along current education principles. It used e-learning as pre-learning and a face-to-face short practical course, combining team work and communication with practical paediatric resuscitation skills training. The programme was designed to empower local trainers to deliver a standardised course to local participants. A total of 14,000 participants have completed the mandatory e-learning component, and over 8600 participants have completed the short practical course, across all NSW Local Health Districts, including NSW Ambulance. RESUS4KIDS has also been adopted by the universities of Sydney and Newcastle undergraduate medical and nursing programmes. Outside of NSW and ACT, over 400 participants have completed the course in facilities in Queensland, South Australia, Victoria and the Northern Territory. We have developed a course that is available, at no cost to individuals or facilities, to all HCWs in NSW, including students, paramedics and general practitioners. We would encourage all other jurisdictions to consider adopting the programme.

An investigation into the cost, coverage and activities of Helicopter Emergency Medical Services in the state of New South Wales, Australia

Background and context Helicopter Emergency Medical Services (HEMS) have been incorporated into modern health systems for their speed and coverage. In the state of New South Wales (NSW), nine HEMS operate from various locations around the state and currently there is no clear picture of their resource implications. The aim of this study was to assess the cost of HEMS in NSW and investigate the factors linked with the variation in the costs, coverage and activities of HEMS. Methods We undertook a survey of HEMS costs, structures and operations in NSW for the 2008/2009 financial year. Costs were estimated from annual reports and contractual agreements. Data related to the structure and operation of services was obtained by face-to-face interviews, from operational data extracted from individual HEMS, from the NSW Ambulance Computer Aided Despatch system and from the Aeromedical Operations Centre database. In order to estimate population coverage for each HEMS, we used GIS mapping techniques with Australian Bureau of Statistics census information. Results Across HEMS, cost per mission estimates ranged between $9300 and $19,000 and cost per engine hour estimates ranged between $5343 and $15,743. Regarding structural aspects, six HEMS were run by charities or not-for-profit companies (with partial government funding) and three HEMS were run (and fully funded) by the state government through NSW Ambulance. Two HEMS operated as ‘hub’ services in conjunction with three associated ‘satellite’ services and in contrast, four services operated independently. Variation also existed between the HEMS in the type of helicopter used, the clinical staffing and the hours of operation. The majority of services undertook both primary scene responses and secondary inter-facility transfers, although the proportion of each type of transport contributing to total operations varied across the services. Interpretation This investigation highlighted the cost of HEMS operations in NSW which in total equated to over $50 million per annum. Across services, we found large variation in the cost estimates which was underscored by variation in the structure and operations of HEMS.