Prehospital Tranexamic Acid for Severe Trauma.

BACKGROUND: Whether prehospital administration of tranexamic acid increases the likelihood of survival with a favorable functional outcome among patients with major trauma and suspected trauma-induced coagulopathy who are being treated in advanced trauma systems is uncertain. METHODS: We randomly assigned adults with major trauma who were at risk for trauma-induced coagulopathy to receive tranexamic acid (administered intravenously as a bolus dose of 1 g before hospital admission, followed by a 1-g infusion over a period of 8 hours after arrival at the hospital) or matched placebo. The primary outcome was survival with a favorable functional outcome at 6 months after injury, as assessed with the use of the Glasgow Outcome Scale-Extended (GOS-E). Levels on the GOS-E range from 1 (death) to 8 ("upper good recovery" [no injury-related problems]). We defined survival with a favorable functional outcome as a GOS-E level of 5 ("lower moderate disability") or higher. Secondary outcomes included death from any cause within 28 days and within 6 months after injury. RESULTS: A total of 1310 patients were recruited by 15 emergency medical services in Australia, New Zealand, and Germany. Of these patients, 661 were assigned to receive tranexamic acid, and 646 were assigned to receive placebo; the trial-group assignment was unknown for 3 patients. Survival with a favorable functional outcome at 6 months occurred in 307 of 572 patients (53.7%) in the tranexamic acid group and in 299 of 559 (53.5%) in the placebo group (risk ratio, 1.00; 95% confidence interval [CI], 0.90 to 1.12; P = 0.95). At 28 days after injury, 113 of 653 patients (17.3%) in the tranexamic acid group and 139 of 637 (21.8%) in the placebo group had died (risk ratio, 0.79; 95% CI, 0.63 to 0.99). By 6 months, 123 of 648 patients (19.0%) in the tranexamic acid group and 144 of 629 (22.9%) in the placebo group had died (risk ratio, 0.83; 95% CI, 0.67 to 1.03). The number of serious adverse events, including vascular occlusive events, did not differ meaningfully between the groups. CONCLUSIONS: Among adults with major trauma and suspected trauma-induced coagulopathy who were being treated in advanced trauma systems, prehospital administration of tranexamic acid followed by an infusion over 8 hours did not result in a greater number of patients surviving with a favorable functional outcome at 6 months than placebo. (Funded by the Australian National Health and Medical Research Council and others; PATCH-Trauma ClinicalTrials.gov number, NCT02187120.).

Suicide-Related Out-of-Hospital Cardiac Arrests in Queensland, Australia: Temporal Trends of Characteristics and Outcomes over 14 Years.

BACKGROUND: Research into suicide-related out-of-hospital cardiac arrests (OHCA) using OHCA registries is scant. A more complete understanding of methods, patient characteristics, and outcomes is essential to inform prehospital management strategies and public health interventions. METHODS: Included were all OHCA attended by Queensland Ambulance Service (Australia) paramedics between 1 January 2007 and 31 December 2020, where suicide-related causes could be identified. Age- and sex-standardized incidence rates were calculated. Suicide methods, patient characteristics, and survival outcomes were described. Factors associated with survival outcomes were investigated. RESULTS: Seven thousand three hundred and fifty-six suicide-related OHCA cases were included. The incidence rates increased from 9.0 per 100,000 population in 2007 to 12.4 in 2020. The incidence rates for males were four times those for females; however, incidence rates for females have increased faster than for males. Hanging was the most common suicide method (63%). Twenty-three percent of patients received resuscitation attempts by paramedics. Among those, the rates of return of spontaneous circulation (ROSC) sustained to hospital arrival, survival to hospital discharge, and survival to 30 days were 28.6, 8.5, and 8.0%, respectively. Over time, the rates of ROSC upon hospital arrival increased, whereas the rates of survival to discharge and 30-day survival remained stable. CONCLUSION: The incidence of prehospital-identified suicide-related OHCA in Queensland has increased over time. The prognosis of suicide-related OHCA is poor. Prevention measures should focus on early identification and treatment of individuals having a high risk of suicide. Emergency medical services need to have sufficient training for telecommunicators and paramedics in suicide risk assessment and identification.

Acute Opioid Withdrawal Following Intramuscular Administration of Naloxone 1.6 mg: A Prospective Out-Of-Hospital Series.

STUDY OBJECTIVE: Large doses of intramuscular (IM) naloxone are commonly used in out-of-hospital settings to reverse opioid toxicity; however, they are used less commonly in hospitals because of concerns about opioid withdrawal, particularly agitation. We aimed to determine the frequency of severe agitation following a single 1.6 mg IM naloxone dose. METHODS: We undertook a prospective study of adult (>15 years) patients treated by an Australian state ambulance service with 1.6 mg IM administration of naloxone for respiratory depression (respiratory rate <11 breaths/min and/or oxygen saturation <93% in room air) caused by presumed opioid poisoning. The primary outcome was the proportion of presentations with severe agitation (Sedation Assessment Tool score >1) within 1 hour of naloxone administration. Secondary outcomes were the proportion of presentations with acute opioid withdrawal (tachycardia [pulse rate >100 beats/min], hypertension [systolic >140 mm Hg], vomiting, agitation, seizure, myocardial infarction, arrhythmia, or pulmonary edema), and reversal of respiratory depression (respiratory rate >10 breaths/min and saturation >92% or Glasgow Coma Scale score 15). RESULTS: From October 2019 to July 2021, there were 197 presentations in 171 patients, with a median age of 41 years (range, 18 to 80 years); of the total patients, 119 were men (70%). The most common opioids were heroin (131 [66%]), oxycodone (14 [7%]), and morphine (11 [6%]). Severe agitation occurred in 14 (7% [95% confidence interval {CI} 4% to 12%]) presentations. Opioid withdrawal occurred in 76 presentations (39% [95% CI 32% to 46%]), most commonly in the form of tachycardia (18%), mild agitation/anxiety (18%) and hypertension (14%). Three presentations (1.5%) received chemical sedation for severe agitation within 1 hour of naloxone administration. A single 1.6 mg dose of naloxone reversed respiratory depression in 192 (97% [95% CI: 94% to 99%]) presentations. CONCLUSION: Severe agitation was uncommon following the administration of 1.6 mg IM naloxone and rarely required chemical sedation.

Survival after Resuscitated Out-of-Hospital Cardiac Arrest in Patients with Paramedic-Identified ST-Segment Elevation Myocardial Infarction Treated with Primary Percutaneous Coronary Intervention.

Background: ST-segment elevation myocardial infarction (STEMI) is a common cause of out-of-hospital cardiac arrest (OHCA). For these patients, urgent angiography and revascularization is an important treatment goal. There is a lack of data on the prognosis of STEMI patients after OHCA, who are diagnosed and treated by paramedics prior to hospital transport for primary percutaneous coronary intervention (PCI). Methods: Included were adult STEMI patients identified and treated by paramedics in Queensland (Australia) from January 2016 to December 2019, transported to a hospital for primary PCI, and receiving primary PCI. Patients were grouped into those with resuscitated OHCA and those without OHCA. Clinically-important time intervals, angiographic and clinical profiles, and survival were described. Results: Patients with OHCA had longer time intervals from prehospital STEMI identification to reperfusion than those without OHCA (median 97 versus 87 mins, p = 0.001). The former had higher rates of cardiac arrhythmia history (50.5 versus 12.4%, p < 0.001), classified low left ventricular ejection fraction on admission (64.9 versus 50.1%, p = 0.006), and cardiogenic shock (5.2 versus 1.2%, p = 0.011) than the latter. A significantly higher proportion of patients with OHCA had multiple diseased vessels (16.9 versus 8.3%, p = 0.005). In-hospital, 30-day, and one-year mortality was low, being 4.1%, 4.1% and 5.2%, respectively, for STEMI patients with OHCA. The corresponding figures for those without OHCA were 1.6%, 1.8% and 3.3%, respectively. Conclusions: Survival in paramedic-identified STEMI patients treated with primary PCI following OHCA resuscitation was high. Rapid angiography and reperfusion are critical in these patients.

Epidemiology, management and survival outcomes of adult out-of-hospital traumatic cardiac arrest due to blunt, penetrating or burn injury.

BACKGROUND: Survival from out-of-hospital traumatic cardiac arrest (TCA) is poor. Regional variation exists regarding epidemiology, management and outcomes. Data on prognostic factors are scant. A better understanding of injury patterns and outcome determinants is key to identifying opportunities for survival improvement. METHODS: Included were adult (≥18 years) out-of-hospital TCA due to blunt, penetrating or burn injury, who were attended by Queensland Ambulance Service paramedics between 1 January 2007 and 31 December 2019. We compared the characteristics of patients who were pronounced dead on paramedic arrival and those receiving resuscitation from paramedics. Intra-arrest procedures were described for attempted-resuscitation patients. Survival up to 6 months postarrest was reported, and factors associated with survival were investigated. RESULTS: 3891 patients were included; 2394 (61.5%) were pronounced dead on paramedic arrival and 1497 (38.5%) received resuscitation from paramedics. Most arrests (79.8%) resulted from blunt trauma. Motor vehicle collision (42.4%) and gunshot wound (17.7%) were the most common injury mechanisms in patients pronounced dead on paramedic arrival, whereas the most prevalent mechanisms in attempted-resuscitation patients were motor vehicle (31.3%) and motorcycle (20.6%) collisions. Among attempted-resuscitation patients, rates of transport and survival to hospital handover, to hospital discharge and to 6 months were 31.9%, 15.3%, 9.8% and 9.8%, respectively. Multivariable model showed that advanced airway management (adjusted OR 1.84; 95% CI 1.06 to 3.17), intravenous access (OR 5.04; 95% CI 2.43 to 10.45) and attendance of high acuity response unit (highly trained prehospital care clinicians) (OR 2.54; 95% CI 1.25 to 5.18) were associated with improved odds of survival to hospital handover. CONCLUSIONS: By including all paramedic-attended patients, this study provides a more complete understanding of the epidemiology of out-of-hospital TCA. Contemporary survival rates from adult out-of-hospital TCA who receive resuscitation from paramedics may be higher than historically thought. Factors identified in this study as associated with survival may be useful to guide prognostication and treatment.

Ambient temperatures, heatwaves and out-of-hospital cardiac arrest in Brisbane, Australia.

BACKGROUND: The health impacts of temperatures are gaining attention in Australia and worldwide. While a number of studies have investigated the association of temperatures with the risk of cardiovascular diseases, few examined out-of-hospital cardiac arrest (OHCA) and none have done so in Australia. This study examined the exposure-response relationship between temperatures, including heatwaves and OHCA in Brisbane, Australia. METHODS: A quasi-Poisson regression model coupled with a distributed lag non-linear model was employed, using OHCA and meteorological data between 1 January 2007 and 31 December 2019. Reference temperature was chosen to be the temperature of minimum risk (21.4°C). Heatwaves were defined as daily average temperatures at or above a heat threshold (90th, 95th, 98th, 99th percentile of the yearly temperature distribution) for at least two consecutive days. RESULTS: The effect of any temperature above the reference temperature was not statistically significant; whereas low temperatures (below reference temperature) increased OHCA risk. The effect of low temperatures was delayed for 1 day, sustained up to 3 days, peaking at 2 days following exposures. Heatwaves significantly increased OHCA risk across the operational definitions. When a threshold of 95th percentile of yearly temperature distribution was used to define heatwaves, OHCA risk increased 1.25 (95% CI 1.04 to 1.50) times. When the heat threshold for defining heatwaves increased to 99th percentile, the relative risk increased to 1.48 (1.11 to 1.96). CONCLUSIONS: Low temperatures and defined heatwaves increase OHCA risk. The findings of this study have important public health implications for mitigating strategies aimed at minimising temperature-related OHCA.

Epidemiology of Oxytocin Administration in Out-of-Hospital Births Attended by Paramedics.

AIM: Primary postpartum hemorrhage (PPH) is a life-threatening obstetric emergency that can be mitigated through the administration of a uterotonic to actively manage the third stage of labor. This study describes the prehospital administration of oxytocin by paramedics following attendance of out-of-hospital (OOH) births. METHODS: A retrospective analysis was undertaken of all OOH births between the 1st January 2018 and 31st December 2018 attended by the Queensland Ambulance Service. The demographic and epidemiological characteristics of patients that were administered oxytocin and the occurrence of adverse side effects were described. RESULTS: In total, 350 OOH births were included in this study with the majority involving multigravidas women (94.3%) and all but two involving singleton pregnancies. Oxytocin was administered following 222 births (63.4%), while 67 patients (19.1%) declined administration preferring a physiological third stage of labor, and in 61 cases (17.4%) oxytocin was withheld by the attending paramedic. There were no documented adverse events or side effects following administration. Oxytocin administration occurred on average 14 minutes (interquartile range 9-25) following the time of birth. The median time from oxytocin administration to placenta delivery was 10 minutes (interquartile range 5-22). CONCLUSION: Oxytocin is well accepted and safe treatment adjunct for the management of the third stage of labor in OOH births and should be considered for routine practice by other emergency medical services.

Survival in Patients with Paramedic-Identified ST-Segment Elevation Myocardial Infarction.

BACKGROUND: Field identification and treatment of ST-segment elevation myocardial infarction (STEMI) by paramedics is an important component of care for these patients. There is a paucity of studies in the setting of paramedic-identified STEMI. This study investigated mortality and factors associated with mortality in a large state-wide prehospital STEMI sample. Methods: Included were adult STEMI patients identified and treated with reperfusion therapy by paramedics in the field between January 2016 and December 2018 in Queensland, Australia. 30-day and one-year all-cause mortality was compared between two prehospital reperfusion pathways: prehospital fibrinolysis versus direct referral to a hospital for primary percutaneous coronary intervention (direct percutaneous coronary intervention [PCI] referral). For prehospital fibrinolysis patients, factors associated with failed fibrinolysis were investigated. For direct PCI referral patients, factors associated with mortality were examined. Results: The 30-day mortality was 2.2% for prehospital fibrinolysis group and 1.8% for direct PCI referral group (p = 0.661). One-year mortality for the two groups was 2.7% and 3.2%, respectively (p = 0.732). Failed prehospital fibrinolysis was observed in 20.1% of patients receiving this therapy, with male gender and history of heart failure being predictors. For direct PCI referral group, low left ventricular ejection fraction (LVEF) on admission and cardiogenic shock prior to PCI were predictors of both 30-day and one-year mortality. Aboriginal and Torres Strait Islander status, and impaired kidney function on admission, were associated with one-year but not 30-day mortality. Being overweight was associated with lower 30-day mortality. Conclusions: Mortality in STEMI patients identified and treated by paramedics was low, and the prehospital fibrinolysis treatment pathway was effective with a mortality rate comparable to that of patients undergoing primary PCI. Key words: prehospital; Queensland; cardiac reperfusion; STEMI.

Prehospital ST-Segment Elevation Myocardial Infarction (STEMI) in Queensland, Australia: Findings from 11 Years of the Statewide Prehospital Reperfusion Strategy.

Background: Field identification and treatment of ST-segment elevation myocardial infarction (STEMI) by paramedics is an important component of the continuum of care for these patients. This study described real-world clinical practice in prehospital management of STEMI patients in Queensland, Australia. Methods: Retrospective analysis of data sourced from the STEMI database of the Queensland Ambulance Service, Australia. Adult STEMI patients identified by paramedics between February 2008 and December 2018 in Queensland were included. Key aspects of prehospital STEMI care were described. Clinically-important time intervals from symptom onset to reperfusion were reported. Results: A total of 8,388 patients were included. The proportion of patients receiving prehospital reperfusion treatment has improved markedly, increasing from 34% in 2008 to 65% in 2018 (p < 0.001). Direct referral of patients to a hospital for primary percutaneous coronary intervention (pPCI), and administration of preparatory antiplatelet and anticoagulant medications, was the main reperfusion treatment pathway, accounting for 75% of patients receiving reperfusion treatment. Time from paramedic arrival at scene to first 12-lead electrocardiogram has significantly reduced, from 11 minutes in 2008 to 6 minutes from 2012 onwards (p < 0.001). Median (interquartile range, IQR) time from prehospital STEMI identification to reperfusion was 88 (74-103) minutes for patients referred by paramedics to a hospital for pPCI. Fifty-five percent of patients who underwent pPCI achieved time from STEMI identification to reperfusion within 90 minutes. For patients receiving prehospital fibrinolysis, median (IQR) time from STEMI identification to administration of a fibrinolytic agent was 21 (12-33) minutes. Conclusion: The implementation of a statewide prehospital reperfusion strategy has markedly improved the rate of prehospital reperfusion treatment and key time metrics. Ongoing quality improvement efforts are required to further reduce delays in reperfusion.

A Prospective Study of the Safety and Effectiveness of Droperidol in Children for Prehospital Acute Behavioral Disturbance.

Study objective: Although uncommon, children (<16 years) with acute behavioral disturbance are a significant issue for emergency medical service providers. In this study, we aimed to investigate the safety and effectiveness of droperidol in children with prehospital acute behavioral disturbance. Methods: This was a prospective observational study over 1 year investigating the use of droperidol (0.1-0.2 mg/kg) for children (< 16 years) with acute behavioral disturbance. Inclusion criteria for acute behavioral disturbance were defined by a sedation assessment tool score of ≥2 determined by the attending paramedic. The primary outcome was the proportion of adverse effects (need for airway intervention, oxygen saturation <90% and/or respiratory rate <12, systolic blood pressure <90 mmHg, sedation assessment tool score of -3 and dystonic reactions). Secondary outcomes included time to sedation (sedation assessment tool score decreased by 2 or more, or a score of zero), requirement for additional sedation, failure to sedate and proportion of sedation success defined as the number of patients successfully sedated who did not suffer any adverse events or receive additional sedation. Results: There were 96 patients (males 51 [53%], median age 14 years [range 7-15 years]) who presented on 102 occasions over the one year study period. Self-harm and/or harm to others was the commonest (74/105 [70%]) cause of acute behavioral disturbance followed by alcohol (16/105 [15%]). There were 9 adverse events in 8 patients (8/102 [8%]; 95% confidence intervals [CI]: 3-13%) Five patients had hypotension, all asymptomatic and only one required treatment; 2 dystonic reactions managed with benztropine and one patient with respiratory depression. Median time to sedation was 14 min (interquartile range (IQR): 10-20 min; range: 3-85 min). There was no requirement for prehospital additional sedation (0/102 [0%]; 95% CI: 0-4%) and additional sedation in the first hour of arrival to hospital was required by 4 patients (4/102 [4%]; 95% CI: 1-10%). Overall successful sedation was achieved in 89 (87%) patients. Conclusions: The use of droperidol in children for acute behavioral disturbance in the prehospital setting is both safe and effective.

A Prospective Before and After Study of Droperidol for Prehospital Acute Behavioral Disturbance.

STUDY OBJECTIVE: Acute behavioral disturbance is a common problem for emergency medical services. We aimed to investigate the safety and effectiveness of droperidol compared to midazolam in the prehospital setting. METHODS: This was a prospective before and after study comparing droperidol to midazolam for prehospital acute behavioral disturbance, when the state ambulance service changed medications. The primary outcome was the proportion of adverse effects (airway intervention, oxygen saturation < 90%, respiratory rate < 12, systolic blood pressure < 90 mmHg, sedation assessment tool score -3 and dystonic reactions) in patients receiving sedation. Secondary outcomes included time to sedation, requirement for additional sedation, staff and patient injuries, and prehospital time. RESULTS: There were 141 patients administered midazolam and 149 patients administered droperidol in the study. Alcohol was the most common cause of acute behavioral disturbance. Fewer patient adverse events occurred with droperidol (11/149) compared to midazolam (33/141) (7% vs. 23%; absolute difference 16%; 95% confidence interval [CI]: 8% to 24%; p = 0.0001). Median time to sedation was 22 min (interquartile range [IQR]:18 to 35 min) for droperidol compared to 30 min (IQR:20 to 45 min) for midazolam. Additional prehospital sedation was required in 6/149 (4%) droperidol patients and 20/141 (14%) midazolam patients, and 11 (7%) droperidol and 59 (42%) midazolam patients required further sedation in the emergency department. There were no differences in patient or staff injuries, or prehospital time. CONCLUSIONS: The use of droperidol for acute behavioral disturbance in the prehospital setting is associated with fewer adverse events, a shorter time to sedation, and fewer requirements for additional sedation.

Effect of Early Sustained Prophylactic Hypothermia on Neurologic Outcomes Among Patients With Severe Traumatic Brain Injury: The POLAR Randomized Clinical Trial.

Importance: After severe traumatic brain injury, induction of prophylactic hypothermia has been suggested to be neuroprotective and improve long-term neurologic outcomes. Objective: To determine the effectiveness of early prophylactic hypothermia compared with normothermic management of patients after severe traumatic brain injury. Design, Setting, and Participants: The Prophylactic Hypothermia Trial to Lessen Traumatic Brain Injury-Randomized Clinical Trial (POLAR-RCT) was a multicenter randomized trial in 6 countries that recruited 511 patients both out-of-hospital and in emergency departments after severe traumatic brain injury. The first patient was enrolled on December 5, 2010, and the last on November 10, 2017. The final date of follow-up was May 15, 2018. Interventions: There were 266 patients randomized to the prophylactic hypothermia group and 245 to normothermic management. Prophylactic hypothermia targeted the early induction of hypothermia (33°C-35°C) for at least 72 hours and up to 7 days if intracranial pressures were elevated, followed by gradual rewarming. Normothermia targeted 37°C, using surface-cooling wraps when required. Temperature was managed in both groups for 7 days. All other care was at the discretion of the treating physician. Main Outcomes and Measures: The primary outcome was favorable neurologic outcomes or independent living (Glasgow Outcome Scale-Extended score, 5-8 [scale range, 1-8]) obtained by blinded assessors 6 months after injury. Results: Among 511 patients who were randomized, 500 provided ongoing consent (mean age, 34.5 years [SD, 13.4]; 402 men [80.2%]) and 466 completed the primary outcome evaluation. Hypothermia was initiated rapidly after injury (median, 1.8 hours [IQR, 1.0-2.7 hours]) and rewarming occurred slowly (median, 22.5 hours [IQR, 16-27 hours]). Favorable outcomes (Glasgow Outcome Scale-Extended score, 5-8) at 6 months occurred in 117 patients (48.8%) in the hypothermia group and 111 (49.1%) in the normothermia group (risk difference, 0.4% [95% CI, -9.4% to 8.7%]; relative risk with hypothermia, 0.99 [95% CI, 0.82-1.19]; P = .94). In the hypothermia and normothermia groups, the rates of pneumonia were 55.0% vs 51.3%, respectively, and rates of increased intracranial bleeding were 18.1% vs 15.4%, respectively. Conclusions and Relevance: Among patients with severe traumatic brain injury, early prophylactic hypothermia compared with normothermia did not improve neurologic outcomes at 6 months. These findings do not support the use of early prophylactic hypothermia for patients with severe traumatic brain injury. Trial Registration: clinicaltrials.gov Identifier: NCT00987688; Anzctr.org.au Identifier: ACTRN12609000764235.

Characteristics and outcomes of patients administered blood in the prehospital environment by a road based trauma response team.

OBJECTIVE: To describe the characteristics, clinical interventions and the outcomes of patients administered packed red blood cells (pRBCs) by a metropolitan, road based, doctor-paramedic trauma response team (TRT). METHODS: A retrospective cohort study examining 18 months of historical data collated by the Queensland Ambulance Service TRT, the Pathology Queensland Central Transfusion Laboratory, the Royal Brisbane and Women's Hospital and the Princess Alexandra Hospital Trauma Services was undertaken. RESULTS: Over an 18-month period (1 January 2011 to 30 June 2012), 71 trauma patients were administered pRBCs by the TRT. Seven patients (9.9%) died on scene and 39 of the 64 patients (60.9%) transported to hospital survived to hospital discharge. 57 (89.1%) of the transported patients had an Injury Severity Score (ISS) > 15, with a mean ISS, Revised Trauma Score (RTS) and Trauma-Injury Severity Score of 32.11, 4.70 and 0.57, respectively. No patients with an RTS < 2 survived to hospital discharge. 53 patients (82.8%) received additional pRBCs in hospital with 17 patients (26.6%) requiring greater than 10 units pRBCs in the first 24 h. 47 patients (73.4%) required surgical or interventional radiological procedures in the first 24 h. CONCLUSIONS: There is a potential role for prehospital pRBC transfusions in an integrated civilian trauma system. The RTS calculated using the initial set of observations may be a useful tool in determining in which patients the administration of prehospital pRBC transfusions would be futile.

The feasibility of civilian prehospital trauma teams carrying and administering packed red blood cells.

OBJECTIVE: To evaluate the feasibility, limitations and costs involved in providing prehospital trauma teams with packed red blood cells (pRBCs) for use in the prehospital setting. METHODS: A retrospective cohort study, examining 18 months of historical data collated by the Queensland Ambulance Service Trauma Response Team (TRT) and the Pathology Queensland Central Transfusion Laboratory was undertaken. RESULTS: Over an 18-month period (1 January 2011-30 June 2012), of 500 pRBC units provided to the TRT, 130 (26%) were administered to patients in the prehospital environment. Of the non-transfused units, 97.8% were returned to a hospital blood bank and were available for reissue. No instances of equipment failure directly contributed to wastage of pRBCs. The cost of providing pRBCs for prehospital use was $A551 (£361) for each unit transfused. CONCLUSIONS: It is feasible and practical to provide prehospital trauma teams with pRBCs for use in the field. Use of pRBCs in the prehospital setting is associated with similar rates of pRBC wastage to that reported in emergency departments.

Pre-hospital ambulance notification and initiation of treatment of ST elevation myocardial infarction is associated with significant reduction in door-to-balloon time for primary PCI.

BACKGROUND: Mortality in ST elevation myocardial infarction (STEMI) is strongly predicted by the time from first medical contact to reperfusion. The aim of this study was to examine the impact of pre-hospital diagnosis by paramedics in the field on the door-to-balloon (DTB) times of patients with ST elevation myocardial infarction undergoing primary percutaneous intervention. METHODS: Paramedics in the field identified patients with ST elevation myocardial infarction on a 12-lead electrocardiograph, activated the cardiac catheter laboratory team from the field and initiated therapy with anticoagulants and antiplatelet agents in the pre-hospital setting. This cohort of patients was compared to a similar group of patients without pre-hospital diagnosis and notification. The primary outcome measure was DTB times. A secondary end point was mortality at 30 days and mortality at six months. RESULTS: A total of 281 patients, mean age of 61.1±12.9 years underwent primary percutaneous intervention with pre-hospital notification occurring in 63 cases. DTB times were lower in those with pre notification than in those without pre-hospital notification (40.4 vs. 75.6 minutes, p<0.001). This represented a 47.6% shorter DTB time. A non-statistically significant mortality reduction at one month and six months was observed in the pre-hospital notification group (1.6 versus 4.3%, p= 0.307 and 1.6 versus 6.4%, p= 0.203, respectively). CONCLUSION: Pre-hospital intervention at our centre had a powerful effect in reducing the time to reperfusion in patients with STEMI undergoing primary percutaneous intervention.

Cost-effectiveness analysis of an ambulance service-operated specialised cardiac vehicle with mobile extracorporeal cardiopulmonary resuscitation capacity for out-of-hospital cardiac arrests in Queensland, Australia.

OBJECTIVE: Extracorporeal CPR (E-CPR) has been primarily limited to the in-hospital setting. A few systems around the world have implemented pre-hospital mobile E-CPR in the form of a dedicated cardiac vehicle fitted with specialised equipment and clinicians required for the performance of E-CPR on-scene. However, evidence of the outcomes and cost-effectiveness of mobile E-CPR remain to be established. We evaluated the cost-effectiveness of a hypothetical mobile E-CPR vehicle operated by Queensland Ambulance Service in the state of Queensland, Australia. METHODS: We adapted our published mathematical model to estimate the cost-effectiveness of pre-hospital mobile E-CPR relative to current practice. In the model, a specialised cardiac vehicle with mobile E-CPR capability is deployed to selected OHCA patients, with eligible candidates receiving pre-hospital E-CPR in-field and rapid transport to the closest appropriate centre for in-hospital E-CPR. For comparison, non-candidates receive standard ACLS from a conventional ambulance response. Cost-effectiveness was expressed as Australian dollars ($, 2021 value) per quality-adjusted life year (QALY) gained. RESULTS: Pre-hospital mobile E-CPR improves outcomes compared to current practice at a cost of $27 323 per QALY gained. The cost-effectiveness of pre-hospital mobile E-CPR is sensitive to the assumption around the number of patients who are the targets of the vehicle, with higher patient volume resulting in improved cost-effectiveness. CONCLUSIONS: Pre-hospital E-CPR may be cost-effective. Successful implementation of a pre-hospital E-CPR programme requires substantial planning, training, logistics and operational adjustments.

Epidemiology of open limb fractures attended by ambulance clinicians in the out-of-hospital setting: A retrospective analysis.

BACKGROUND: Open limb fractures are a time-critical orthopaedic emergency that present to jurisdictional ambulance services. This study describes the demographic characteristics and epidemiological profile of these patients METHODS: We undertook a retrospective analysis of all patients that presented to Queensland Ambulance Service with an open limb fracture (fracture to the humerus, radius/ulna, tibia/fibula or femur) over a two-year period (January 2018 - December 2019). RESULTS: Overall, 1020 patients were included. Patients were mainly male (65.9%) and middle-aged (age 41 years, IQR 22-59). Fractures predominately occurred in the lower extremities (64.9%) with transport crashes the primary mechanism of injury (47.8%). The location of the fracture varied depending on the cause of injury, with femur fractures associated with motorcycle crashes, and fractures to the radius/ulna attributed to falls of greater than one metre (p = 0.001). The median prehospital episode of care was 83 min (IQR 62-144) with aeromedical air ambulance involvement and the attendance of a critical care paramedic or emergency physician, both independent factors that increased this time interval. CONCLUSION: Open limb fractures are a relatively infrequent injury presentation encountered by ambulance clinicians. The characteristics of these patients is consistent with previously described national and international out-of-hospital trauma cohorts.

Cost-effectiveness of extracorporeal cardiopulmonary resuscitation for refractory out-of-hospital cardiac arrest: A modelling study.

Background: Extracorporeal cardiopulmonary resuscitation (E-CPR) is a method of CPR that passes the patient's blood through an extracorporeal membrane oxygenation (ECMO) device to provide mechanical haemodynamic and oxygenation support in cardiac arrest patients who are not responsive to conventional CPR (C-CPR). E-CPR is being adopted rapidly worldwide despite the absence of high quality trial data and its substantial cost. Published cost-effectiveness data for E-CPR are scarce. Methods: We developed a mathematical model to estimate the cost-effectiveness of E-CPR relative to C-CPR in adult patients with refractory out-of-hospital cardiac arrest (OHCA). The model was a combination of a decision tree for the acute treatment phase and a Markov model for long-term periods. Cost-effectiveness was evaluated from the Australian health system perspective over lifetime. Cost-effectiveness was expressed as Australian dollars (AUD, 2021 value) per quality-adjusted life year (QALY) gained. Variables were parameterised using published data. Probabilistic and univariate sensitivity analyses were performed. Results: The incremental cost-effectiveness ratio (ICER) of E-CPR was estimated to be AUD 45,716 per QALY gained over lifetime (95% uncertainty range 22,102-292,904). The cost-effectiveness of E-CPR was most sensitive to the outcome of the therapy. Conclusion: E-CPR has median ICER that is below common accepted willingness-to-pay thresholds. Local factors within the health care system need to be considered to determine the feasibility of implementing an effective E-CPR program.

Spatiotemporal variation in the risk of out-of-hospital cardiac arrests in Queensland, Australia.

BACKGROUND: Spatiotemporal analysis of out-of-hospital cardiac arrest (OHCA) risk is essential to design targeted public health strategies. Such information is lacking in the state of Queensland and Australia more broadly. METHODS: We developed a spatiotemporal Bayesian model accounting for spatial and temporal dimensions, space-time interactions, and demographic factors. The model was fit to data of all OHCA cases attended by paramedics in Queensland between January 2007 and December 2019. Parameter inference was performed using the integrated nested Laplace approximation method. We estimated and thematically mapped area-year risk of OHCA occurrence for all 78 local government areas (LGAs) in Queensland. RESULTS: We observed spatial variability in OHCA risk among the LGAs. Areas in the north half of the state and two areas in the south exhibited the highest risk; whereas OHCA risk was lowest in the west and south west parts of the state. Demographic factors did not have significant impact on the heterogeneity of risk between the LGAs. An overall trend of modestly decreasing risk of OHCA was found. CONCLUSIONS: This study identified areas of high OHCA risk in Queensland, providing valuable information to guide public health policy and optimise resource allocation. Further research is needed to investigate the specifics of the areas that may explain their risk profile.

Assessing need for extracorporeal cardiopulmonary resuscitation for out-of-hospital cardiac arrest using Power BI for data visualisation.

OBJECTIVE: To estimate the number of patients in refractory out-of-hospital cardiac arrest (OHCA) potentially suitable for transport to an extracorporeal cardiopulmonary resuscitation (ECPR)-capable hospital in Brisbane, Queensland, Australia, based on outcome predictors for ECPR, ambulance geolocation and patient data. METHODS: A retrospective cohort study was performed using data from all patients in OHCA attended by Queensland Ambulance Service between 1 January 2014 and 31 December 2018. The number of refractory arrest patients who could potentially be transferred to an ECPR-capable centre within 45 min of the time of arrest was modelled using theoretical on-scene treatment times. RESULTS: Of 25 518 ambulance-attended OHCA in Queensland during the study period, 540 (2%) patients met criteria of refractory arrest for study inclusion. Further age and arrest rhythm criteria for transport to an ECPR-capable hospital were met in 253 (47%) study patients, an average of 51 patients per year. In 2018, 72 patients met study criteria for transport to an ECPR-capable centre. Based on theoretical on-scene treatment times of 12 and 20 min, in 2018 only 14 (19%) and 11 (15%) patients respectively would potentially arrive at an ECPR-capable hospital within accepted timeframes for ECPR. CONCLUSIONS: Retrospective data collected from existing ambulance databases can be used to model patient suitability for ECPR. Relatively few patients with refractory OHCA in Queensland, Australia, could be attended and transported to an ECPR-capable centre within clinically acceptable timeframes. Further studies of the transport logistics and economic implications of providing ECPR services for OHCA are required to better inform decisions around this intervention.