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.

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.

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.

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.

Time to amiodarone administration and survival outcomes in refractory ventricular fibrillation

OBJECTIVE

International guidelines recommend amiodarone for out-of-hospital cardiac arrest (OHCA) in refractory ventricular fibrillation (VF). While early appropriate interventions have been shown to improve OHCA survival, the association between time to amiodarone and survival remains to be established.

METHODS

Included were adult OHCA in refractory VF, between January 2015 and December 2019, who received a resuscitation attempt with amiodarone from Queensland Ambulance Service paramedics. Patient characteristics and survival outcomes were described. Factors associated with survival were investigated, with a focus on time from arrest to amiodarone administration. Optimal time window for amiodarone administration was determined, and factors influencing whether amiodarone was given within the optimal time window were examined.

RESULTS

A total of 502 patients were included. The average (range) time from arrest to amiodarone was 25 (4-83) min. Time to amiodarone was negatively associated with survival (adjusted odds ratio 0.93 for event survival; 95% confidence interval 0.89-0.97). The optimal time window for amiodarone was within 23 min following arrest. Patients receiving amiodarone within the optimal time had significantly better survival than those receiving it outside this window (event survival 38.3% vs 20.6%, P < 0.001; discharge survival 25.5% vs 9.7%, P < 0.001; 30-day survival 25.1% vs 9.7%, P < 0.001). Paramedic response time (adjusted odds ratio 0.96; 95% confidence interval 0.92-0.99) and time from arrest to intravenous access (0.71; 0.67-0.76) were independent factors determining whether patients received amiodarone within the optimal time.

CONCLUSIONS

Earlier amiodarone administration was associated with improved survival. Strategies aimed at reducing delay to amiodarone administration have the potential to improve outcome.

Trauma by-pass guideline: A data-driven conformance analysis for road trauma cases in Queensland

OBJECTIVE

Study objectives were to (i) develop and test a whole-of-system method for identifying patients who meet a major trauma by-pass guideline definition; (ii) apply this method to assess conformance to the current 2006 guideline for a road trauma cohort; and (iii) leverage relevant findings to propose improvements to the guideline.

METHODS

Retrospective analysis of existing, routinely collected data relating to Queensland road trauma patients July 2015 to June 2017. Data from ambulance, aero-medical retrievals, ED, hospital and death registers were linked and used for analysis. Processes of care measured included: frequency of pre-hospital triage criteria, distribution of destination (trauma service level), compliance with guideline (recommended vs actual destination), trauma service level by threat to life (injury severity) (all modes of transport and aero-medical in particular), proportion of patients requiring only ED, transport pathway (direct vs inter-hospital transfer).

RESULTS

3847 cases were identified from data as meeting criteria for major trauma by-pass. The top five most frequently used criteria for qualifying patients as meeting the major trauma by-pass guideline were pulse rate, vehicle rollover, possible spinal cord injury, respiration rate and entrapment. The study demonstrates a 65% conformance to the clinical guideline. Overtriaged patients (transported to higher trauma service than recommended) generally reveal International Classification of Disease Injury Severity Score representing a high threat to life.

CONCLUSION

Overall, the present study found good conformance, with overtriage rate as expected by clinicians. It is recommended to include data values to capture paramedics assessment of trauma level to enable more accurate assessment of conformance to guideline and future revision of the thresholds.

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.

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.

The Pre-Hospital Initial Fluid Therapy Estimate in Early Nasty Burns (PHIFTEEN B, 15-B) Guideline applied to a retrospective cohort of Intensive Care Unit patients with major burns

BACKGROUND

Appropriate fluid administration in severe burns is a cornerstone of early burns management. The American Burns Association's (ABA) recommendation is to administer 2 mL-4 mL × burnt Body Surface Area (BSA) × weight in the first 24 h with half administered in the first eight hours. Unfortunately, the calculations involved are complex and clinicians do not estimate the BSA or weight well, which can lead to errors in the amount of fluid administered. To simplify cognitive load to calculate the fluid resuscitation of early burns, the investigators derived the PHIFTEEN B (15-B) guideline. The 15-B guideline estimates the initial hourly fluid for adults ≥ 50 kg to be: 15 mL × BSA (to the nearest 10%) AIMS: To model and determine the accuracy of the 15-B calculated based on the characteristics of a retrospective cohort of patients admitted with ≥ 20% BSA to the Royal Brisbane and Women's Hospital (RBWH) Intensive Care Unit (ICU).

METHODS

The 15-B formula was retrospectively calculated on the prehospital BSA estimate on patients admitted to the RBWH ICU. In addition, the 15-B guideline was modelled against a variety of weights and BSAs. The fluid volume was deemed to be clinically significant if it was greater than 250 mL/h outside the ABA's recommendations.

RESULTS

The ICU cohort consisted of 107 patients (63.2% male, median age 37 years), with a median ICU estimated BSA of 40% and a median ICU weight estimation of 80 kg. In 43.9% of the cohort, the magnitude of the proportional difference between prehospital and ICU BSA estimate was greater than 25%. The 15-B formula accurately estimated the hourly fluid for all BSA (20%-100%) and weight combinations (50 kg-140 kg) in a BSA- weight matrix. When prehospital BSA estimate was utilized, 15-B guideline accurately estimated the fluid to be given within clinically significant limits for 97.2% of cases.

CONCLUSIONS

The 15-B formula is a simple, easy to calculate guideline which approximates the early fluid estimates in severely burned patients despite inaccuracy in prehospital BSA estimates.

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.

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 1^st January 2018 and 31^st 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.

Prehospital study of survival outcomes from out-of-hospital cardiac arrest in ST-elevation myocardial infarction in Queensland, Australia (the PRAISE study)

AIM

Patients that experience an out-of-hospital cardiac arrest in the context of a paramedic-identified ST-segment elevation myocardial infarction are a unique cohort. This study identifies the survival outcomes and determinants of survival in these patients.

METHODS

A retrospective analysis was undertaken of all patients, attended between 1 January 2013 and 31 December 2017 by the Queensland Ambulance Service, who had a ST-segment elevation myocardial infarction identified by the attending paramedic prior to deterioration into out-of-hospital cardiac arrest. We described the 'survived event' and 'survived to discharge' outcomes of patients and performed univariate analysis and multivariate logistic regression to identify factors associated with survival.

RESULTS

In total, 287 patients were included. Overall, high rates of survival were reported, with 77% of patients surviving the initial out-of-hospital cardiac arrest event and 75% surviving to discharge. Predictors of event survival were the presence of an initial shockable rhythm (adjusted odds ratio 8.60, 95% confidence interval (CI) 4.16-17.76; P < 0.001) and the administration of prehospital medication for subsequent primary percutaneous coronary intervention (adjusted odds ratio 2.54, 95% CI 1.17-5.50; P = 0.020). These factors were also found to be associated with survival to hospital discharge, increasing the odds of survival by 13.74 (95% CI 6.02-31.32; P < 0.001) and 6.96 (95% CI 2.50-19.41; P < 0.001) times, respectively. The administration of prehospital fibrinolytic medication was also associated with survival in a subgroup analysis.

CONCLUSION

This subset of out-of-hospital cardiac arrest patients was found to be highly salvageable and responsive to resuscitative measures, having arrested in the presence of paramedics and presented with an identified reversible cause.

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.

Statistical analysis plan for the POLAR-RCT: The Prophylactic hypOthermia trial to Lessen trAumatic bRain injury-Randomised Controlled Trial

Background

The Prophylactic hypOthermia to Lessen trAumatic bRain injury-Randomised Controlled Trial (POLAR-RCT) will evaluate whether early and sustained prophylactic hypothermia delivered to patients with severe traumatic brain injury improves patient-centred outcomes.

Methods

The POLAR-RCT is a multicentre, randomised, parallel group, phase III trial of early, prophylactic cooling in critically ill patients with severe traumatic brain injury, conducted in Australia, New Zealand, France, Switzerland, Saudi Arabia and Qatar. A total of 511 patients aged 18–60 years have been enrolled with severe acute traumatic brain injury.

The trial intervention of early and sustained prophylactic hypothermia to 33 °C for 72 h will be compared to standard normothermia maintained at a core temperature of 37 °C.

The primary outcome is the proportion of favourable neurological outcomes, comprising good recovery or moderate disability, observed at six months following randomisation utilising a midpoint dichotomisation of the Extended Glasgow Outcome Scale (GOSE). Secondary outcomes, also assessed at six months following randomisation, include the probability of an equal or greater GOSE level, mortality, the proportions of patients with haemorrhage or infection, as well as assessment of quality of life and health economic outcomes. The planned sample size will allow 80% power to detect a 30% relative risk increase from 50% to 65% (equivalent to a 15% absolute risk increase) in favourable neurological outcome at a two-sided alpha of 0.05.

Discussion

Consistent with international guidelines, a detailed and prospective analysis plan has been developed for the POLAR-RCT. This plan specifies the statistical models for evaluation of primary and secondary outcomes, as well as defining covariates for adjusted analyses and methods for exploratory analyses. Application of this statistical analysis plan to the forthcoming POLAR-RCT trial will facilitate unbiased analyses of these important clinical data.

Trial registration

ClinicalTrials.gov, NCT00987688 (first posted 1 October 2009); Australian New Zealand Clinical Trials Registry, ACTRN12609000764235. Registered on 3 September 2009.

Electronic supplementary material

The online version of this article (10.1186/s13063-018-2610-y) contains supplementary material, which is available to authorized users.

Protocol for a multicentre randomised controlled trial of early and sustained prophylactic hypothermia in the management of traumatic brain injury

INTRODUCTION

Traumatic brain injury (TBI) is a leading cause of death and disability worldwide. Prophylactic hypothermia is effective in laboratory models, but clinical studies to date have been inconclusive, partly because of methodological limitations. Our Prophylactic Hypothermia Trial to Lessen Traumatic Brain Injury (POLAR) randomised controlled trial is currently underway comparing early, sustained hypothermia versus standard care in patients with severe TBI. We describe our study protocol and the challenges in conducting prophylactic hypothermia research in TBI.

DESIGN

We aim to randomise 500 patients to either prophylactic 33°C hypothermia initiated within 3 hours of injury and continued for at least 72 hours, or standard normothermic management. Patients will be enrolled by paramedic services in the prehospital setting, or by emergency department staff at participating sites in Australia, New Zealand and Europe. The primary outcome will be the eight-level extended Glasgow outcome scale (GOSE), dichotomised to favourable and unfavourable outcomes at 6 months after injury. Secondary outcomes will include mortality at hospital discharge and at 6 months, ordinal analyses of 6-month GOSE outcomes, quality of life with health economic evaluations and the differential proportion of adverse events. We will predefine subgroup and interaction analyses.

DISCUSSION

After a run-in phase, recruitment for our main study began in December 2010. When the study is completed, we aim to provide evidence on the efficacy of prophylactic hypothermia in TBI to guide clinicians in their management of this devastating condition.

Tranexamic acid for trauma: filling the 'GAP' in evidence

Following findings of the Clinical Randomisation of an Antifibrinolytic in Significant Haemorrhage (CRASH-2) trial, tranexamic acid (TxA) use post trauma is becoming widespread. However, issues of generalisability, applicability and predictability beyond the context of study sites remain unresolved. Internal and external validity of the CRASH-2 trial are currently lacking and therefore incorporation of TxA into routine trauma resuscitation guidelines appears premature. The Pre-hospital Antifibrinolytics for Traumatic Coagulopathy and Haemorrhage (PATCH)-Trauma study is a National Health and Medical Research Council-funded randomised controlled trial of early administration of TxA in severely injured patients likely to have acute traumatic coagulopathy. The study population chosen has high mortality and morbidity and is potentially most likely to benefit from TxA's known mechanisms of action. This and further trials involving appropriate sample populations are required before evidence based guidelines on TxA use during trauma resuscitation can be developed.

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.

Adult cardiac arrest in general practice

BACKGROUND

Out of hospital cardiac arrest victims contribute significantly to adult mortality figures but are encountered infrequently by most general practitioners and their staff. A number of scientific organisations produce guidelines for the basic and advanced management of cardiac arrest.

OBJECTIVE

To review the management principles for basic and advanced adult cardiac life support measures for cardiac arrest.

DISCUSSION

General practitioners are required to manage cardiac arrest victims infrequently. The initiation of bystander cardiopulmonary resuscitation and the rapid defibrillation of suitable cardiac rhythms determine a favourable outcome. All staff working at a surgery must be skilled in basic life support. The GP needs an understanding of advanced life support principles.

Acute pleuritic chest pain

BACKGROUND

The differential diagnosis of acute pleuritic chest pain is large and includes a number of life threatening conditions. Clinical suspicion plays a major role in the choice of investigation and the interpretation of the results.

OBJECTIVE

To outline the clinical features and diagnostic workup of three acute causes of pleuritic chest pain--acute pulmonary embolism, pneumothorax and acute pericarditis.

DISCUSSION

The general practitioner plays an important role in the initiation of the investigative pathway for these conditions. Appropriate referral for ongoing assessment and care requires the primary care physician to be aware of the available investigations and their limitations.

Addition of physicians to paramedic helicopter services decreases blunt trauma mortality

BACKGROUND

The authors hypothesized that the addition of critical care physicians to the flight crew of paramedic helicopter services would decrease mortality in blunt trauma, and that this would be due to the greater procedural capability and clinical judgement of the physician.

METHODS

Retrospective comparison was undertaken of patients flown directly from the accident scene over a 28-month period by the paramedic-staffed Westpac Hunter region helicopter to John Hunter Hospital, and the physician-staffed NRMA CareFlight helicopter to Westmead or Nepean Hospitals. Inclusion criteria were blunt trauma and an Injury Severity Score of > 10. Mortality was compared by trauma score-injury severity score (TRISS) methodology.

RESULTS

There were 140 patients in the paramedic treatment group and 67 in the physician group. There were no significant differences between the groups in age, mechanism of injury, distance transported, response, scene or transport times. Physicians intubated a greater proportion of patients (51 vs 10%; P < 0.001) including all patients with a Glasgow Coma Score of < 9. Physicians gave significantly greater volumes of fluids to hypotensive patients (median: 5035 vs 1475 mL: P < 0.001) and performed thoracic decompressions on a larger proportion of patients (12 vs 1%; P < 0.01). The Z statistic for the physician treatment group was 2.72 (P < 0.01 ) compared with -1.16 (P = 0.25) in the paramedic group. The adjusted W statistic was 13.44 (95% CI: 7.80-19.08) suggesting that there would be between eight and 19 extra survivors per 100 patients treated in the physician group compared with the paramedic group.

CONCLUSIONS

Physicians perform a greater number of procedures at accident scenes without increasing scene time. This results in significantly lower mortality. Critical care physicians should be added to paramedic helicopter services for scene response to blunt trauma.

Emergency eye injuries

This study analyses all patients presenting with eye complaints to the casualty section of a Brisbane Hospital during a one month period. Eye complaints constituted 3.6 per cent of all patients. A foreign body was involved in 57 per cent of all eye injuries. The patients were subject to a trial assessing the effectiveness of antibiotic treatment following removal of the foreign body. There was no significant difference between antibiotic and placebo (sterile saline).