Epidemiology and Severity of Medical Events for Mountain Bikers and Hikers Transported by Ambulance in Western Australia, 2015 to 2020.

INTRODUCTION: Outdoor activities offer physical and mental health benefits. However, incidents can occur requiring ambulance transport to hospital. This study aimed to describe the epidemiology and severity of traumatic and medical incidents for mountain bikers and hikers transported by ambulance within Western Australia. METHODS: This was a retrospective cohort study of ambulance-transported mountain bikers and hikers within Western Australia from 2015 to 2020. Data were extracted from ambulance electronic patient care records. Multivariable analyses were undertaken to identify variables associated with higher patient severity based on the National Early Warning Score 2 (NEWS2). RESULTS: A total of 610 patients required ambulance transport to hospital while mountain biking (n=329; 54%) or hiking (n = 281; 46%). Median age of mountain bikers and hikers was 38 (24-48) y and 49 (32-63) y, respectively. Paramedics reported a fracture in 92 (28%) mountain bikers and 78 (28%) hikers. The predominant injury locations for mountain bikers were upper limbs and for hikers, lower limbs. Cases were trauma related in 92% of mountain bikers and 55% of hikers. A significant association (P<0.001) between the etiology of the ambulance callout and patient severity was found. In trauma etiology cases, the frequency of medium-risk+ NEWS2 severity was 21.4%. In medical cases, the frequency of medium-risk+ severity was 40.8%. CONCLUSION: Both mountain bikers and hikers experienced incidents requiring ambulance transport to hospital. Incidents of a medical etiology had a higher clinical risk, as determined by the NEWS2 scores, regardless of activity being undertaken.

Emergency Medical Service Attendances for Adults with Repeat Falls in Western Australia: A State-Wide Retrospective Cohort Study.

OBJECTIVES: The risk of falls increases with age and often requires an emergency medical service (EMS) response. We compared the characteristics of patients attended by EMS in response to repeat falls within 30 days and 12 months of their first EMS-attended fall; and explored the number of days between the index fall and the subsequent fall(s). METHODS: This retrospective cohort study included all adults (> =18 years of age) who experienced their first EMS-attended fall between 1 January 2016 and 31 December 2020, followed up until 31 December 2021. Patients who experienced > =1 subsequent fall, following their first recorded fall, were defined as experiencing repeat falls. Multivariable logistic regression was used to identify the factors associated with repeat falls; and Kaplan-Meier analysis was used to estimate the time (in days) between consecutive EMS-attended falls. RESULTS: A total of 128,588 EMS-attended fall-related incidents occurred involving 77,087 individual patients. Most patients, 54,554 (71%) were attended only once for a fall-related incident (30,280 females; median age 73 years, inter-quartile range (IQR): 55-84). A total of 22,533 (29%) patients experienced repeat EMS-attended falls (13,248 females; median age 83 years, IQR: 74-89, at first call). These 22,533 patients accounted for 58% (74,034 attendances) of all EMS-attendances to fall-related incidents. Time between EMS-attended falls decreased significantly the more falls a patient sustained. Among the 22,533 patients who experienced repeat falls, 13,363 (59%) of repeat falls occurred within 12 months: 3,103 (14%) of patients sustained their second fall within 30 days of their index fall, and 10,260 (46%) between 31 days to 12 months. Patients who were transported to the hospital, via any urgency, at their first EMS-attended fall, had a reduced odds of sustaining a second EMS-attended fall within both 30 days and 31 days to 12 months, compared to non-transported patients. CONCLUSION: Nearly 30% of all patients attended by EMS for a fall, sustained repeat falls, which collectively accounted for nearly 60% of all EMS-attendances to fall-related incidents. Further exploration of the role EMS clinicians play in identifying and referring patients who sustain repeat falls into alternative pathways is needed.

"Mind the gap": An exploratory qualitative study of paramedics' experiences attending older adults who fall in Western Australia.

PURPOSE: To explore paramedics' experiences and perspectives about attending and managing older adults who had fallen. PROCEDURES: This qualitative, exploratory study used a purposive sample of paramedics in Western Australia. Participants had at least one year of clinical experience. Semi-structured interviews were undertaken. Data were analysed via an inductive thematic approach. FINDINGS: Fourteen paramedics were interviewed (Median age: 38 years, n = 5 females). The main theme identified that experiences were positive when attending patients with high-acuity medical problems or injuries following falls because binary decision-making (transport vs non-transport) was appropriate. Themes highlighted that decision-making for low-acuity falls attendances was a complex balance between 1) patient context, 2) risk management, 3) paramedic reactions, and 4) the lack of alternate referral pathways available. Experiences could be stressful and frustrating when attending falls call-outs for older adults with no injuries or medical problems. Participants concurred that when transport to hospital was not required there were no available, alternative pathways to refer onwards for appropriate health or social care. CONCLUSION: Attending low-acuity call-outs for falls was often frustrating and required complex decision-making, with gaps in services identified. Further exploration of alternative referral pathways for health care for pre-hospital management of adults who fall is required.

Analgesic agents administered by ambulance personnel to mountain bikers and hikers on trails in Western Australia.

Objective: To describe the types of analgesic medications administered to patients who were attended by ambulance on recreational trails while mountain biking or hiking and report on the reduction in pain by these agents. Methods: This is a retrospective cohort study of patients attended by ambulance (2015-2021) after mountain biking or hiking, on Western Australia (WA) trails. All data were extracted from electronic patient care records created by ambulance personnel who attended the patient. We compared patient and case characteristics between mountain bikers and hikers and the reduction in pain scores achieved by different analgesics. Results: A total of 717 patients were included. Paramedics reported traumatic aetiology for mountain bikers in 92 % of cases and hikers in 58 % of cases. A pain score out of 10 was recorded for 538 (75 %) patients. The median (inter-quartile range) initial pain score was 6 (2-8) and the median final pain score was 3 (1-5). Around 48 % of these 538 patients reported ≥25 % reduction in their pain score. A reduction of ≥25 % in their pain score was greatest in those patients who received intravenous fentanyl (81 %), followed by patients administered multiple analgesics (72 %) and methoxyflurane only (52 %). Even 37 % of 134 patients who received no analgesia still reported ≥25 % reduction in their pain score by hospital arrival. Conclusion: Trauma was the most common reason mountain bikers and hikers on trails called an ambulance and a large proportion of these patients were in pain on ambulance arrival. Further work assessing the effectiveness of safe, non-opioid analgesics, additional to methoxyflurane, is needed to ensure non-registered practitioners such as first aid providers and event medical teams can offer suitable safe analgesics to these patients. Additionally, among patients given no pharmacological analgesic agent, almost half still achieved a >25 % reduction in their pain scores which reiterates the importance of non-pharmacological pain reduction strategies.

Epidemiology of ambulance-attended adults who fell in Western Australia 2015 - 2021: An increasing incidence in an ageing population.

BACKGROUND: Emergency Medical Services (EMS) are attending an increasing number of adults who fall. This study aimed to describe the incidence, patient characteristics, treatments and disposition of ambulance attended patients who fell in Western Australia (WA). METHODS: An ordinal logistic regression (using STATA) was conducted in this retrospective cohort study, analysing predictors of lower compared to higher transport urgency levels. Participants were adults ( ≥ 18 years) who fell and required ambulance attendance in WA between 1st January 2015 - 31st December 2021. RESULTS: A total of 188,720 patients (female = 107,811, 57 %) were attended by ambulances after falls, (median age = 80 years [IQR 67-87]). The age-standardized incidence rate of ambulance attended falls increased from 115 cases/100,000 person-years to 161 cases/100,000 person-years between 2015 and 2021. A total of 89,140 (47 %) patients had an injury recorded by paramedics, most often lacerations or suspected fractures. The electronic patient care record showed, 50,044 (26.5 %) patients received medication and 30,954 (16.4 %) patients received other intervention, e.g., ECG. A total of 148,050 (78 %) patients were transported to hospital with the following urgency levels: 2,371 (2 %) via urgency one; 27,882 (19 %) via urgency two, 93,447 (63 %) via urgency three and 22,584 (15 %) via urgency four and five ( < 1 % unknown urgency). Positive predictors of lower level transport urgency to hospital included being female and older than 65 years of age. CONCLUSION: Older, female patients had higher odds of being transported via a lower urgency, with 50 % of this cohort transported via urgency three. While 19 % of patients were attended via a Priority one, only 1 % were transported to hospital via urgency one. The incidence rate of falls requiring ambulance attendance has increased over time, increasing the demand placed on EMS annually.

Types and anatomical locations of injuries among mountain bikers and hikers: A systematic review.

BACKGROUND: Mountain biking and hiking continue to grow in popularity. With new participants to these sports, it is likely the number of injuries will increase. To assist medical personnel in the management of these patients we attempted to quantify the types and locations of injuries sustained by mountain bikers and hikers. Objective The objective of this systematic review is to identify the type and anatomical location of injuries for both mountain bikers and hikers. METHODS: A systematic search was undertaken using CINAHL, Cochrane, ProQuest, PubMed and Scopus databases. Reviewers assessed the eligibility of articles by a title/abstract review and final full-text review. Studies were included if the types of injuries were reported by medical personnel and contained anatomical locations. Studies were excluded if it did not take place on a trail or if the injuries were self-reported. Risk of bias was assessed utilising the Joanna Briggs Institute (JBI) checklists for study quality. No meta-analysis or comparison between mountain bikers and hikers was possible due to the high heterogeneity of the definition of injury. RESULTS: A total of 24 studies met the inclusion criteria, 17 covering mountain biking and 7 hiking. This represented 220,935 injured mountain bikers and 17,757 injured hikers. The most common type of injuries sustained by mountain bikers included contusions, abrasions and minor lacerations, which made up between 45-74% of reported injuries in studies on competitive racing and 8-67% in non-competitive studies. Fractures represented between 1.5-43% of all reported injuries. The most injured region was the upper limbs reported in 10 of 17 studies. For hikers the most common injuries included blisters and ankle sprains with blisters representing 8-33% of all reported injuries. The most common body location to be injured by hikers was a lower limb in all 7 studies. CONCLUSIONS: This is the first systematic review to report on the injury epidemiology of the two most common trail users; mountain bikers and hikers. For participants in both activities the majority of injuries were of minor severity. Despite this, the high proportions of upper limb fractures in mountain bikers and ankle sprains in hikers cannot be ignored. TRIAL REGISTRATION: Registration: This systematic review was prospectively registered with the University of York PROSPERO database on the 12/4/2021 (CRD42021229623) https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42021229623.

Effect of a national awareness campaign on ambulance attendances for chest pain and out-of-hospital cardiac arrest.

AIM: Awareness of heart attack symptoms may enhance health-seeking behaviour and prevent premature deaths from out-of-hospital cardiac arrest (OHCA). We sought to investigate the impact of a national awareness campaign on emergency medical service (EMS) attendances for chest pain and OHCA. METHODS: Between January 2005 and December 2017, we included registry data for 97,860 EMS-attended OHCA cases from 3 Australian regions and dispatch data for 1,631,217 EMS attendances for chest pain across 5 Australian regions. Regions were exposed to between 11 and 28 months of television, radio, and print media activity. Multivariable negative binomial models were used to explore the effect of campaign activity on the monthly incidence of EMS attendances for chest pain and OHCA. RESULTS: Months with campaign activity were associated with an 8.8% (IRR 1.09, 95% CI: 1.07, 1.11) increase in the incidence of EMS attendances for chest pain and a 5.6% (IRR 0.94, 95% CI: 0.92, 0.97) reduction in OHCA attendances. Larger intervention effects were associated with increasing months of campaign activity, increasing monthly media spending and media exposure in 2013. In stratified analyses of OHCA cases, the largest reduction in incidence during campaign months was observed for unwitnessed arrests (IRR 0.93, 95% CI: 0.90, 0.96), initial non-shockable arrests (IRR 0.93, 95% CI: 0.90, 0.97) and arrests occurring in private residences (IRR 0.95, 95% CI: 0.91, 0.98). CONCLUSION: A national awareness campaign targeting knowledge of heart attack symptoms was associated with an increase in EMS use for chest pain and a reduction in OHCA incidence and may serve as an effective primary prevention strategy for OHCA.

Use of ketamine wafer for pain management by volunteer emergency medical technicians in rural Western Australia.

OBJECTIVE: To describe the use of sublingual ketamine wafers administered by volunteer emergency medical technicians (EMTs) for pain management to patients in rural Western Australia (WA). METHODS: This retrospective cohort study included patients older than 12 years who were attended by volunteer EMTs in Esperance, Lancelin and Kalbarri, WA and received analgesic medications from 2018 to 2021. Patients who received ketamine wafers with/without other analgesics were compared to (i) patients who received only oral paracetamol and (ii) patients who received inhalational methoxyflurane without ketamine wafers with/without paracetamol. RESULTS: The present study included 826 patients, among whom 149 patients received ketamine wafer with/without other analgesics, 82 paracetamol only and 595 methoxyflurane with/without paracetamol. Patients who received ketamine wafers were younger (median age 49 years vs 54 years for the paracetamol group vs 58 years for the methoxyflurane group), required a longer median transport interval (56 min vs 20 min vs 8 min), trauma-related (73% vs 35% vs 54%), and presented higher median initial pain score (9 vs 3 vs 8 out of 10) than those who received paracetamol and those who received methoxyflurane, respectively. Eight in the ketamine wafers group (5.4%) had a record of nausea/vomiting after the administration of ketamine wafers. CONCLUSIONS: Sublingual ketamine wafer was administered by volunteer EMTs without any evidence of major adverse events in rural WA and deemed useful as an additional pain management option when long transport to hospital was needed. No other symptoms that may be associated with the use of ketamine were recorded.

The prehospital management of ambulance-attended adults who fell: A scoping review.

BACKGROUND: The ageing population is requiring more ambulance attendances for falls. This scoping review aimed to map and synthesise the evidence for the prehospital management of Emergency Medical Services (EMS) attended adult patients who fall. METHODS: The Joanna Briggs Institute methods for scoping reviews were used. Six databases were searched (Medline, Scopus, CINAHL, Cochrane, EMBASE, ProQuest), 1st August 2021. Included sources reported: ambulance attended (context), adults who fell (population), injuries, interventions or disposition data (concept). Data were narratively synthesised. RESULTS: One-hundred and fifteen research sources met the inclusion criteria. Detailed information describing prehospital delivered EMS interventions, transport decisions and alternative care pathways was limited. Overall, adults< 65 years were less likely than older adults to be attended repeatedly and/or not transported. Being male, falling from height and sustaining severe injuries were associated with transport to major trauma centres. Older females, falling from standing/low height with minor injuries were less likely to be transported to major trauma centres. CONCLUSION: The relationship between patient characteristics, falls and resulting injuries were well described in the literature. Other evidence about EMS management in prehospital settings was limited. Further research regarding prehospital interventions, transport decisions and alternative care pathways in the prehospital setting is recommended.

Ambulance dispatch prioritisation for traffic crashes using machine learning: A natural language approach.

INTRODUCTION: Demand for emergency ambulances is increasing, therefore it is important that ambulance dispatch is prioritised appropriately. This means accurately identifying which incidents require a lights and sirens (L&S) response and those that do not. For traffic crashes, it can be difficult to identify the needs of patients based on bystander reports during the emergency phone call; as traffic crashes are complex events, often with multiple patients at the same crash with varying medical needs. This study aims to determine how well the text sent to paramedics en-route to the traffic crash scene by the emergency medical dispatcher (EMD), in combination with dispatch codes, can predict the need for a L&S ambulance response to traffic crashes. METHODS: A retrospective cohort study was conducted using data from 2014 to 2016 traffic crashes attended by emergency ambulances in Perth, Western Australia. Machine learning algorithms were used to predict the need for a L&S response or not. The features were the Medical Priority Dispatch System (MPDS) determinant codes and EMD text. EMD text was converted for computation using natural language processing (Bag of Words approach). Machine learning algorithms were used to predict the need for a L&S response, defined as where one or more patients (a) died before hospital admission, (b) received L&S transport to hospital, or (c) had one or more high-acuity indicators (based on an a priori list of medications, interventions or observations. RESULTS: There were 11,971 traffic crashes attended by ambulances during the study period, of which 22.3 % were retrospectively determined to have required a L&S response. The model with the highest accuracy was using an Ensemble machine learning algorithm with a score of 0.980 (95 % CI 0.976-0.984). This model predicted the need for an L&S response using both MPDS determinant codes and EMD text. DISCUSSION: We found that a combination of EMD text and MPDS determinate codes can predict which traffic crashes do and do not require a lights and sirens ambulance response to the scene with a high degree of accuracy. Emergency medical services could deploy machine learning algorithms to improve the accuracy of dispatch to traffic crashes, which has the potential to result in improved system efficiency.

A predictive ambulance dispatch algorithm to the scene of a motor vehicle crash: the search for optimal over and under triage rates.

BACKGROUND: Calls for emergency medical assistance at the scene of a motor vehicle crash (MVC) substantially contribute to the demand on ambulance services. Triage by emergency medical dispatch systems is therefore important, to ensure the right care is provided to the right patient, in the right amount of time. A lights and sirens (L&S) response is the highest priority ambulance response, also known as a priority one or hot response. In this context, over triage is defined as dispatching an ambulance with lights and sirens (L&S) to a low acuity MVC and under triage is not dispatching an ambulance with L&S to those who require urgent medical care. We explored the potential for crash characteristics to be used during emergency ambulance calls to identify those MVCs that required a L&S response. METHODS: We conducted a retrospective cohort study using ambulance and police data from 2014 to 2016. The predictor variables were crash characteristics (e.g. road surface), and Medical Priority Dispatch System (MPDS) dispatch codes. The outcome variable was the need for a L&S ambulance response. A Chi-square Automatic Interaction Detector technique was used to develop decision trees, with over/under triage rates determined for each tree. The model with an under/over triage rate closest to that prescribed by the American College of Surgeons Committee on Trauma (ACS COT) will be deemed to be the best model (under triage rate of ≤ 5% and over triage rate of between 25-35%. RESULTS: The decision tree with a 2.7% under triage rate was closest to that specified by the ACS COT, had as predictors-MPDS codes, trapped, vulnerable road user, anyone aged 75 + , day of the week, single versus multiple vehicles, airbag deployment, atmosphere, surface, lighting and accident type. This model had an over triage rate of 84.8%. CONCLUSIONS: We were able to derive a model with a reasonable under triage rate, however this model also had a high over triage rate. Individual EMS may apply the findings here to their own jurisdictions when dispatching to the scene of a MVC.

Prehospital continuous positive airway pressure (CPAP) for acute respiratory distress: a randomised controlled trial.

OBJECTIVE: To compare the efficacy of continuous positive airway pressure (CPAP) versus usual care for prehospital patients with severe respiratory distress. METHODS: We conducted a parallel group, individual patient, non-blinded randomised controlled trial in Western Australia between March 2016 and December 2018. Eligible patients were aged ≥40 years with acute severe respiratory distress of non-traumatic origin and unresponsive to initial treatments by emergency medical service (EMS) paramedics. Patients were randomised (1:1) to usual care or usual care plus CPAP. The primary outcomes were change in dyspnoea score and change in RR at ED arrival, and hospital length of stay. RESULTS: 708 patients were randomly assigned (opaque sealed envelope) to usual care (n=346) or CPAP (n=362). Compared with usual care, patients randomised to CPAP had a greater reduction in dyspnoea scores (usual care -1.0, IQR -3.0 to 0.0 vs CPAP -3.5, IQR -5.2 to -2.0), median difference -2.0 (95% CI -2.5 to -1.6); and RR (usual care -4.0, IQR -9.0 to 0.0 min-1 vs CPAP -8.0, IQR -14.0 to -4.0 min-1), median difference -4.0 (95% CI -5.0 to -4.0) min-1. There was no difference in hospital length of stay (usual care 4.2, IQR 2.1 to 7.8 days vs CPAP 4.8, IQR 2.5 to 7.9 days) for the n=624 cases admitted to hospital, median difference 0.36 (95% CI -0.17 to 0.90). CONCLUSIONS: The use of prehospital CPAP by EMS paramedics reduced dyspnoea and tachypnoea in patients with acute respiratory distress but did not impact hospital length of stay. TRIAL REGISTRATION NUMBER: ACTRN12615001180505.

Machine learning and natural language processing to identify falls in electronic patient care records from ambulance attendances.

We derived machine learning models utilizing features generated by natural language processing (NLP) of free-text data from an ambulance services provider to identify fall cases. The data comprised samples of electronic patient care records care records (ePCRs) from St John Western Australia (WA), the sole ambulance services provider in most of WA. We manually labeled fall cases by reviewing the free-text summary. The models used features including case characteristics (e.g., age) and text frequency-inverse document frequency (tf-idf) of each word of the free-text generated by NLP. Support vector machine (SVM) and random forest were used as classifiers. We compared the performance of the models against the manual identification of falls by recall, precision, and F-measure. A total of 9,447 cases (1%) were randomly sampled, of which 1,648 (17%) were labeled as fall. The best model was an SVM model using case characteristics and tf-idf's of the first 100 words of free-text, with recall of 0.84, precision of 0.86, and F-measure of 0.85. This performance was better than an SVM model with only case characteristics. Machine-learning models incorporated with features generated by NLP improved the performance of classifying fall cases compared with models without such features. Scope remains for further improvement.

No apparent effect of the COVID-19 pandemic on out-of-hospital cardiac arrest incidence and outcome in Western Australia.

BACKGROUND: We examined the incidence, patient and arrest characteristics, and survival outcomes of out-of-hospital cardiac arrest (OHCA) in Western Australia (WA) in the first wave of the COVID-19 pandemic. METHODS: Adult OHCA cases attended by St John WA Emergency Medical Service (EMS) between 16th March and 17th May 2020 ('COVID-19 period') were compared with those for the same period in 2017-9. We calculated crude OHCA incidence for all OHCA cases and modelled the effect of the 'COVID-19 period' on 30-day survival for OHCA cases with EMS attempted resuscitation; comparing our results with those published for Victoria (Australia), which had a higher incidence of COVID-19. RESULTS: In WA there was no significant difference between the 2020 'COVID-19 period' (n = 423) and the same period in 2017-9 (n = 1,334) in the OHCA incidence in adults (117.9 vs 126.1 per 100,000 person-years, p = 0.23). In OHCA cases with EMS-resuscitation attempted, there was no change in bystander cardiopulmonary resuscitation rates. Despite an increase in EMS response time, neither the crude nor risk-adjusted odds ratio (aOR) for 30-day survival in 2020 was significantly different to 2017-9 (11.7% vs 9.6%; p = 0.45) (aOR = 1.19, 95% confidence interval 0.57-2.51, p = 0.65). This contrasts with a significant reduction in survival to hospital discharge reported in Victoria. CONCLUSION: In WA, with a relatively low incidence of COVID-19, OHCA incidence and survival was not significantly different during the initial wave of the COVID-19 pandemic compared to the three previous years. Our study suggests that OHCA survival may be more closely related to the incidence of COVID-19 in the community, rather than COVID-19 restrictions per se.

Motor Vehicle Crash Characteristics That Are Predictive of High Acuity Patients: An Analysis of Linked Ambulance and Crash Data.

BACKGROUND: Motor vehicle crashes (MVCs) comprise a significant component of emergency medical service workload. Due to the potential for life-threatening injuries, ambulances are often dispatched at the highest priority to MVCs. However, previous research has shown that only a small proportion of high-priority ambulance responses to MVCs encounter high acuity patients. Alternative methods for triaging patients over the phone are required to reduce the burden of over-triage. One method is to use information readily available at the scene (e.g. whether a person was a motorcyclist, ejection status or whether an airbag deployed) as potential predictors of high acuity. Methods: A retrospective cohort study was conducted of all MVC patients in Perth attended by St John Western Australia between 2014 and 2016. Ambulance data was linked with Police crash data. The outcome variable of interest was patient acuity, where high acuity was defined as where a patient (1) died on-scene or (2) was transported by ambulance on priority one (lights & sirens) from the scene to hospital. Crash characteristics that are predictive of high acuity patients were identified by estimating crude odds ratios and 95% confidence intervals. Results: Of the 18,917 MVC patients attended by SJ-WA paramedics, 6.4% were classified as high acuity patients. The odds of being a high acuity patient was greater for vulnerable road users (motorcyclists, pedestrians and cyclists) than for motor vehicle occupants (OR 3.19, 95% CI, 2.80-3.64). A 'not ambulant patient' (one identified by paramedics as unable to walk or having an injury incompatible with being able to walk) had 15 times the odds of being high acuity than ambulant patients (OR 15.34, 95% CI, 11.48-20.49). Those who were trapped in a vehicle compared to those not trapped (OR 4.68, 95% CI, 3.95-5.54); and those who were ejected (both partial and full) from the vehicle compared to those not ejected (OR 6.49, 95% CI, 4.62-9.12) had higher odds of being high acuity patients. Discussion: There were two important findings from this study: (1) few MVC patients were deemed to be high acuity; and (2) several crash scene characteristics were strong predictors of high acuity patients.

"Sorry, what did you say?" Communicating defibrillator retrieval and use in OHCA emergency calls.

BACKGROUND: The defibrillator prompt, which directs callers to retrieve a defibrillator during out-of-hospital cardiac arrest, is crucial to the emergency call because it can save lives. We evaluated communicative effectiveness of the prompt instated by the Medical Priority Dispatch System™ Version 13, namely: if there is a defibrillator (AED) available, send someone to get it now, and tell me when you have it. METHODS: Using Conversation Analysis and descriptive statistics, we examined linguistic features of the defibrillator sequences (call-taker prompt and caller response) in 208 emergency calls where non-traumatic out-of-hospital cardiac arrest was confirmed by the emergency medical services, and they attempted resuscitation, in the first six months of 2019. Defibrillator sequence durations were measured to determine impact on time to CPR prompt. The proportion of cases where bystanders retrieved defibrillators was also assessed. RESULTS: There was low call-taker adoption of the Medical Priority Dispatch System™ Version 13 prompt (99/208) compared to alternative prompts (86/208) or no prompt (23/208). Caller responses to the Version 13 prompt tended to be longer, more ambiguous or unrelated, and have more instances of repair (utterances to address comprehension trouble). Defibrillators were rarely brought to the scene irrespective of defibrillator prompt utilised. CONCLUSION: While the Version 13 prompt aims to ensure the use of an available automatic external defibrillator, its effectiveness is undermined by the three-clause composition of the prompt and exclusion of a question structure. We recommend testing of a re-phrased defibrillator prompt in order to maximise comprehension and caller action.

Variations in the care of agitated patients in Australia and New Zealand ambulance services.

OBJECTIVE: The objective of the present study is to examine variations in paramedic care of the agitated patient, including verbal de-escalation, physical restraint and sedation, provided by ambulance services in Australia and New Zealand. METHODS: To examine the care of agitated patients, we first identified and reviewed all clinical practice guidelines for the management of agitated patients in Australian and New Zealand ambulance services between September and November 2018. We then conducted a structured questionnaire to obtain further information on the training, assessment and care of agitated patients by the ambulance services. Two authors extracted the data independently, and all interpretations and results were reviewed and confirmed by relevant ambulance services. RESULTS: There were 10 independent clinical practice guidelines for the care of agitated patients in the 10 ambulance services. All services reported training in the management of agitated patients, and two services used a validated tool to assess the level of agitation. All services used physical restraint, although six services required police presence to restrain the patient. All ambulance services used some form of sedation, typically divided into the management of mild to moderate, and severe agitation. The most common agent for sedation was midazolam, while ketamine was the most common agent for sedating severely agitated patients. The maximum dose was varied, and contraindications for sedating agents varied between services. CONCLUSIONS: There were wide variations across the ambulance services in terms of the assessment of agitation, as well as the use of physical restraint and sedation.

The EXACT protocol: A multi-centre, single-blind, randomised, parallel-group, controlled trial to determine whether early oxygen titration improves survival to hospital discharge in adult OHCA patients.

BACKGROUND: Experimental and observational research suggests hyperoxia following resuscitation from cardiac arrest is associated with neurological injury and worse clinical outcomes. This paper describes the rationale and design of the EXACT trial. EXACT aims to determine whether reducing oxygen in the acute phase of post-resuscitation care for out-of-hospital cardiac arrest (OHCA) improves survival. METHODS: EXACT is a multi-centre, randomised (1:1), single-blind, parallel trial. Presumed cardiac OHCA cases who achieve a return of spontaneous circulation will be eligible if they are comatose, with an advanced airway and have an oxygen saturation (SpO2) ≥95% on >10 L/min (or 100% oxygen). Paramedics will randomise 1416 eligible cases to receive oxygen therapy targeting an SpO2 of 90-94% (intervention) or 98-100% (control). Study treatment will continue until admission to an intensive care unit or hospital ward. The primary outcome is survival to hospital discharge. Secondary outcomes include 12-month survival and quality of life. RESULTS: The study has commenced in the Australian states of Victoria and South Australia, and has enrolled 167 eligible cases to date (80 intervention and 87 control). Further sites are due to commence in 2019, recruitment is expected to take three years. CONCLUSION: This study will determine if early reduction of oxygen leads to improved outcomes in OHCA. Such a finding may potentially change clinical practice with implications on future OHCA survival outcomes. TRIAL REGISTRATION NUMBER: NCT03138005.

'We're going to do CPR': A linguistic study of the words used to initiate dispatcher-assisted CPR and their association with caller agreement.

BACKGROUND: In emergency ambulance calls for out-of-hospital cardiac arrest (OHCA), dispatcher-assisted cardiopulmonary resuscitation (CPR) plays a crucial role in patient survival. We examined whether the language used by dispatchers to initiate CPR had an impact on callers' agreement to perform CPR. METHODS: We analysed 424 emergency calls relating to cases of paramedic-confirmed OHCA where OHCA was recognised by the dispatcher, the caller was with the patient, and resuscitation was attempted by paramedics. We investigated the linguistic choices used by dispatchers to initiate CPR, and the impact of those choices on caller agreement to perform CPR. RESULTS: Overall, CPR occurred in 85% of calls. Caller agreement was low (43%) when dispatchers used terms of willingness ("do you want to do CPR?"). Caller agreement was high (97% and 84% respectively) when dispatchers talked about CPR in terms of futurity ("we are going to do CPR") or obligation ("we need to do CPR"). In 38% (25/66) of calls where the caller initially declined CPR, the dispatcher eventually secured their agreement by making several attempts at initiating CPR. CONCLUSION: There is potential for increased agreement to perform CPR if dispatchers are trained to initiate CPR with words of futurity and/or obligation.