The relationship between patient volume and mortality in NSW major trauma service hospitals.

INTRODUCTION: Conventional wisdom is that Major Trauma Services (MTS) treating larger volumes of severe trauma patients will have better outcomes than lower volume centres, but recent studies from Europe have questioned this relationship. We aimed to determine if there is a relationship between patient volume and outcome in New South Wales (NSW) MTS hospitals. MATERIALS AND METHODS: Retrospective observational study using data from the NSW State Trauma Registry from 2010 to 2019 inclusive. Adult patients with Injury Severity Score >15 transported directly to a NSW MTS were included. Outcome measures were mortality at hospital discharge, and intensive care unit and hospital length of stay. Generalised estimating equation models were created to determine the adjusted relationship between patient volume and the main outcome measures. RESULTS: The mean annual patient volume of the MTS ranged from 127.4 to 282.0 patients whilst the observed mortality rates p.a. ranged from 10.4 % to 17.19 %. Multivariate analysis, using low volume MTS as the reference, did not demonstrate a significant difference in mortality between high and low volume MTS (adjusted OR: 1.14 95 % CI: 0.98-1.25, P = 0.087). There was however a significant correlation between volume and length of hospital stay (adjusted ß; 0.024, 95 % CI, 0.182 - 1.089, P = 0.006). CONCLUSIONS: There was no mortality difference between high and low volume MTS demonstrated. Length of hospital stay significantly increased with increasing volume however.

First experience with the abdominal aortic and junctional tourniquet in prehospital traumatic cardiac arrest.

INTRODUCTION: The Abdominal Aortic and Junctional Tourniquet (AAJT) increased systemic vascular resistance, mean arterial pressure, carotid blood flow and rate of return of spontaneous circulation (ROSC) in animals with hypovolaemic traumatic cardiac arrest (TCA). The objective of this study was to report the first experience of the use of the AAJT as part of a pre-hospital TCA algorithm. METHODS: This is a descriptive case series of the use of the AAJT in patients with TCA in a civilian physician-led pre-hospital trauma service in Sydney, Australia between June 2015 to August 2019. Cases were identified and data sourced from routinely collected data sets within the retrieval service. RESULTS: During the study, 44 TCAs were attended, 22 with AAJT application. Mean time (standard deviation) to AAJT application since last signs of life was 16 (9) min. Eighteen (16 males, 2 females) patients, with median age (interquartile range) of 40 (25-58) years, were included for analysis. Seventeen patients (94%) had blunt trauma. Sixteen patients (89%) were in TCA at the time of service contact, 11 (61%) had a change in electrical activity, 4 (22%) had ROSC, and of the 6 with documented end-tidal carbon dioxide, the mean rise was 24.0 mmHg (95% CI 12.6-35.4) (P = 0.003). Three patients (17%) had sustained ROSC on arrival to the Emergency Department. No patients survived to hospital discharge. CONCLUSION: Physiological changes were demonstrated but there were no survivors. Further research focusing on faster application times may be associated with improved outcomes.

Success and complications by team composition for prehospital paediatric intubation: a systematic review and meta-analysis.

BACKGROUND: Clinical team composition for prehospital paediatric intubation may affect success and complication rates. We performed a systematic review and meta-analysis to determine the success and complication rates by type of clinical team. METHODS: We searched MEDLINE, EMBASE, and CINAHL for interventional and observational studies describing prehospital intubation attempts in children with overall success, first-pass success, and complication rates. Eligible studies, data extraction, and assessment of risk of bias were assessed independently by two reviewers. We performed a random-effects meta-analysis of proportions. RESULTS: Forty studies (1989 to 2019) described three types of clinical teams: non-physician teams with no relaxants (22 studies, n = 7602), non-physician teams with relaxants (12 studies, n = 2185), and physician teams with relaxants (12 studies, n = 1780). Twenty-two (n = 3747) and 18 (n = 7820) studies were at low and moderate risk of bias, respectively. Non-physician teams without relaxants had lower overall intubation success rate (72%, 95% CI 67-76%) than non-physician teams with relaxants (95%, 95% CI 93-98%) and physician teams (99%, 95% CI 97-100%). Physician teams had higher first-pass success rate (91%, 95% CI 86-95%) than non-physicians with (75%, 95% CI 69-81%) and without (55%, 95% CI 48-63%) relaxants. Overall airway complication rate was lower in physician teams (10%, 95% CI 3-22%) than non-physicians with (30%, 95% CI 23-38%) and without (39%, 95% CI 28-51%) relaxants. CONCLUSION: Physician teams had higher rates of intubation success and lower rates of overall airway complications than other team types. Physician prehospital teams should be utilised wherever practicable for critically ill children requiring prehospital intubation.

Physician-staffed helicopter emergency medical services augment ground ambulance paediatric airway management in urban areas: a retrospective cohort study.

OBJECTIVES: Paediatric intubation is a high-risk procedure for ground emergency medical services (GEMS). Physician-staffed helicopter EMS (PS-HEMS) may bring additional skills, drugs and equipment to the scene including advanced airway management beyond the scope of GEMS even in urban areas with short transport times. This study aimed to evaluate prehospital paediatric intubation performed by a PS-HEMS when dispatched to assist GEMS in a large urban area and examine how often PS-HEMS provided airway intervention that was not or could not be provided by GEMS. METHODS: We performed a retrospective observational study from July 2011 to December 2016 of a PS-HEMS in a large urban area (Sydney, Australia), which responds in parallel to GEMS. GEMS intubate without adjuvant neuromuscular blockade, whereas the PS-HEMS use neuromuscular blockade and anaesthetic agents. We examined endotracheal intubation success rate, first-look success rate and complications for the PS-HEMS and contrasted this with the advanced airway interventions provided by GEMS prior to PS-HEMS arrival. RESULTS: Overall intubation success rate was 62/62 (100%) and first-look success was 59/62 (95%) in the PS-HEMS-treated group, whereas the overall success rate was 2/7 (29%) for the GEMS group. Peri-intubation hypoxia was documented in 5/65 (8%) of the PS-HEMS intubation attempts but no other complications were reported. However, 3/7 (43%) of the attempted intubations by GEMS were oesophageal intubations, two of which were unrecognised. CONCLUSIONS: PS-HEMS have high success with low complication rates in paediatric prehospital intubation. Even in urban areas with rapid GEMS response, PS-HEMS activated in parallel can provide safe and timely advanced prehospital airway management for seriously ill and injured children beyond the scope of GEMS practice. Review of GEMS airway management protocols and the PS-HEMS case identification and dispatch system in Sydney is warranted.

Locating helicopter emergency medical service bases to optimise population coverage versus average response time.

BACKGROUND: New South Wales (NSW), Australia has a network of multirole retrieval physician staffed helicopter emergency medical services (HEMS) with seven bases servicing a jurisdiction with population concentrated along the eastern seaboard. The aim of this study was to estimate optimal HEMS base locations within NSW using advanced mathematical modelling techniques. METHODS: We used high resolution census population data for NSW from 2011 which divides the state into areas containing 200-800 people. Optimal HEMS base locations were estimated using the maximal covering location problem facility location optimization model and the average response time model, exploring the number of bases needed to cover various fractions of the population for a 45 min response time threshold or minimizing the overall average response time to all persons, both in green field scenarios and conditioning on the current base structure. We also developed a hybrid mathematical model where average response time was optimised based on minimum population coverage thresholds. RESULTS: Seven bases could cover 98% of the population within 45mins when optimised for coverage or reach the entire population of the state within an average of 21mins if optimised for response time. Given the existing bases, adding two bases could either increase the 45 min coverage from 91% to 97% or decrease the average response time from 21mins to 19mins. Adding a single specialist prehospital rapid response HEMS to the area of greatest population concentration decreased the average state wide response time by 4mins. The optimum seven base hybrid model that was able to cover 97.75% of the population within 45mins, and all of the population in an average response time of 18 mins included the rapid response HEMS model. CONCLUSIONS: HEMS base locations can be optimised based on either percentage of the population covered, or average response time to the entire population. We have also demonstrated a hybrid technique that optimizes response time for a given number of bases and minimum defined threshold of population coverage. Addition of specialized rapid response HEMS services to a system of multirole retrieval HEMS may reduce overall average response times by improving access in large urban areas.

Hemodynamic Deterioration in Lateral Compression Pelvic Fracture After Prehospital Pelvic Circumferential Compression Device Application.

Increased fracture displacement has previously been described with the application of pelvic circumferential compression devices (PCCDs) in patients with lateral compression-type pelvic fracture. We describe the first reported case of hemodynamic deterioration temporally associated with the prehospital application of a PCCD in a patient with a complex acetabular fracture with medial displacement of the femoral head. Active hemorrhage from a site adjacent to the acetabular fracture was subsequently demonstrated on angiography. Caution in the application of PCCDs to patients with lateral compression-type fractures is warranted.

Loss of Consciousness During Single Sling Helicopter Hoist Rescue Resulting in a Fatal Fall.

INTRODUCTION: Although harness suspension trauma has been documented since the 1960s, especially in the mountaineering setting, there is little robust medical research into the area. Helicopter hoist rescue shares similar risks and is reserved for those cases that cannot be accessed safely by other routes, where extrication may be hazardous or will take an unreasonable amount of time. The single sling or chest harness used for hoist rescue is a single harness around the upper torso and is easier and quicker to apply than a stretcher. However, the risks of a chest harness need to be balanced against the patient's condition, the environment, aircraft performance, and the urgency of the rescue. CASE REPORT: We report an adult male falling 80 ft to his death while being hoisted into a rescue helicopter for a likely fractured ankle. A single rescue sling harness technique was used, but the patient became unconscious, slipped out of the harness, and fell. He had significant comorbidities, including cardiomyopathy, obstructive sleep apnea, morbid obesity, and diabetes. DISCUSSION: A decrease in cardiac output secondary to thoracic compression was the presumed cause for his loss of consciousness and the potential physiological mechanisms and modifying factors are discussed. Further research into harness suspension trauma is required. Stretcher, double point harnesses, or rescue baskets are likely safer methods of hoisting, especially in a medically compromised patient. Biles J, Garner AA. Loss of consciousness during single sling helicopter hoist rescue resulting in a fatal fall. Aerosp Med Hum Perform. 2016; 87(9):821-824.

Physician staffed helicopter emergency medical service case identification - a before and after study in children.

BACKGROUND: Severely injured children may have better outcomes when transported directly to a Paediatric Trauma Centre (PTC). A case identification system using the crew of a physician staffed helicopter emergency medical service (P-HEMS) that identified severely injured children for P-HEMS dispatch was previously associated with high rates of direct transfer. It was theorised that discontinuation of this system may have resulted in deterioration of system performance. METHODS: Severe paediatric trauma cases were identified from a state based trauma registry over two time periods. In Period A the P-HEMS case identification system operated in parallel with a paramedic dispatcher (Rapid Launch Trauma Co-ordinator-RLTC) operating from a central control room (n = 71). In Period B the paramedic dispatcher operated in isolation (n = 126). Case identification and direct transfer rates were compared as was time to arrival at the PTC. RESULTS: After cessation of the P-HEMS system the rate of case identification fell from 62 to 31 % (P < 0.001), identification of fatal cases fell from 100 to 47 % (P < 0.001), the rate of direct transfer to a PTC fell from 66 to 53 % (P = 0.076) and the time to arrival in a PTC increased from a median 69 (interquartile range 52 - 104) mins to 97 (interquartile range 56 - 305) mins (P = 0.003). When analysing the rate of direct transfer to a PTC as a function of team composition, after adjusting for age and injury severity scores, there was no change in the rate between the physician and paramedic groups across the two time periods (relative risk 0.92, 95 % CI: 0.44 to 1.41). DISCUSSION: The parallel identification system improves case identification rates and decreases time to arrival at the PTC, whilst requiring RLTC authorisation preserves the safety and efficiency benefits of centralised dispatch. The model could be extended to adult patients with similar benefits. CONCLUSIONS: A case identification system relying solely on RLTC paramedics resulted in a significantly lower case identification rate and increased prehospital time with a non-significant fall in direct transfer rate to the PTC. The elimination of the P-HEMS input from the tasking system resulted in worse performance indicators and has the potential for poorer outcomes.

Performance comparison of improvised prehospital blood warming techniques and a commercial blood warmer.

INTRODUCTION: Prehospital transfusion of packed red blood cells (PRBC) may be life saving for hypovolaemic trauma patients. PRBCs should preferably be warmed prior to administration but practical prehospital devices have only recently become available. The effectiveness of purpose designed prehospital warmers compared with previously used improvised methods of warming has not previously been described. MATERIALS AND METHODS: Expired units of PRBCs were randomly assigned to a warming method in a bench study. Warming methods were exposure to body heat of an investigator, leaving the blood in direct sunlight on a dark material, wrapping the giving set around gel heat pads or a commercial fluid warmer (Belmont Buddy Lite). Methods were compared with control units that were run through the fluid circuit with no active warming strategy. RESULTS: The mean temperature was similar for all methods on removal from the fridge (4.5°C). The mean temperatures (degrees centigrade) for all methods were higher than the control group at the end of the circuit (all P≤0.001). For each method the mean (95% CI) temperature at the end of the circuit was; body heat 17.2 (16.4-18.0), exposure to sunlight 20.2 (19.4-21.0), gel heat pads 18.8 (18.0-19.6), Buddy Lite 35.2 (34.5-36.0) and control group 14.7 (13.9-15.5). CONCLUSIONS: All of the warming methods significantly warmed the blood but only the Buddy Lite reliably warmed the blood to a near normal physiological level. Improvised warming methods therefore cannot be recommended.

Retrospective evaluation of prehospital triage, presentation, interventions and outcome in paediatric drowning managed by a physician staffed helicopter emergency medical service.

BACKGROUND: Drowning patients may benefit from the advanced airway management capabilities that can be provided by physician staffed helicopter emergency medical services. The aim of this study is to describe paediatric drowning patients treated by such a service examining tasking systems, initial physiology at the incident scene, survival and neurological outcome. METHODS: Retrospective analysis of paediatric drowning victims over a 5- year period. Case identification system, patient age, site of drowning, presence or absence of cardiac output, first Glasgow Coma Scale (GCS) score and interventions were collected from prehospital notes, and survival and neurological outcomes from hospital and rehabilitation notes. RESULTS: The P-HEMS direct case identification system operating in parallel with a central control system identified all severe drowning cases but 3 of 7 cases (43%) were missed when the central control system operated in isolation. All severe drowning cases (22) identified for P-HEMS response were intubated and transported directly to a paediatric specialist centre. Intubation required adjuvant anaesthesia in 10 (45%) cases. All children with GCS greater than eight on arrival of the P-HEMS survived neurologically intact. Seven of eight children with a GCS between four and seven survived without neurological impairment and all children with a GCS greater than three survived. Four of twelve asystolic children survived including one child who at 18 months post drowning is neurologically normal. All children who survived had return of spontaneous circulation prior to arrival in the emergency department. CONCLUSIONS: P-HEMS played a significant role in the management of severe paediatric drowning in this case series. Requirement for P-HEMS only interventions were high and all identified cases were transferred directly to a paediatric specialist centre. Discontinuation of the P-HEMS direct case identication system that operated during the majority of the study period resulted in deterioration in system performance with some paediatric drowning cases subsequently not identified for P-HEMS response being transported to adult hospitals.

Prehospital response model and time to CT scan in blunt trauma patients; an exploratory analysis of data from the head injury retrieval trial.

BACKGROUND: It has been suggested that prehospital care teams that can provide advanced prehospital interventions may decrease the transit time through the ED to CT scan and subsequent surgery. This study is an exploratory analysis of data from the Head Injury Retrieval Trial (HIRT) examining the relationship between prehospital team type and time intervals during the prehospital and ED phases of management. METHODS: Three prehospital care models were compared; road paramedics, and two physician staffed Helicopter Emergency Medical Services (HEMS) - HIRT HEMS and the Greater Sydney Area (GSA) HEMS. Data on prehospital and ED time intervals for patients who were randomised into the HIRT were extracted from the trial database. Additionally, data on interventions at the scene and in the ED, plus prehospital entrapment rate was also extracted. Subgroups of patients that were not trapped or who were intubated at the scene were also specifically examined. RESULTS: A total of 3125 incidents were randomised in the trial yielding 505 cases with significant injury that were treated by road paramedics, 302 patients treated by the HIRT HEMS and 45 patients treated by GSA HEMS. The total time from emergency call to CT scan was non-significantly faster in the HIRT HEMS group compared with road paramedics (medians of 1.9 hours vs. 2.1 hours P = 0.43) but the rate of prehospital intubation was 41% higher in the HIRT HEMS group (46.4% vs. 5.3% P < 0.001). Most time intervals for the GSA HEMS were significantly longer with a regression analysis indicating that GSA HEMS scene times were 13 (95% CI, 7-18) minutes longer than the HIRT HEMS independent of injury severity, entrapment or interventions performed on scene. CONCLUSION: This study suggests that well-rehearsed and efficient interventions carried out on-scene, by a highly trained physician and paramedic team can allow earlier critical care treatment of severely injured patients without increasing the time elapsed between injury and hospital-based intervention. There is also indication that role specialisation improves time intervals in physician staffed HEMS which should be confirmed with purpose designed trials.

The Head Injury Retrieval Trial (HIRT): a single-centre randomised controlled trial of physician prehospital management of severe blunt head injury compared with management by paramedics only.

BACKGROUND: Advanced prehospital interventions for severe brain injury remains controversial. No previous randomised trial has been conducted to evaluate additional physician intervention compared with paramedic only care. METHODS: Participants in this prospective, randomised controlled trial were adult patients with blunt trauma with either a scene GCS score <9 (original definition), or GCS<13 and an Abbreviated Injury Scale score for the head region ≥3 (modified definition). Patients were randomised to either standard ground paramedic treatment or standard treatment plus a physician arriving by helicopter. Patients were evaluated by 30-day mortality and 6-month Glasgow Outcome Scale (GOS) scores. Due to high non-compliance rates, both intention-to-treat and as-treated analyses were preplanned. RESULTS: 375 patients met the original definition, of which 197 was allocated to physician care. Differences in the 6-month GOS scores were not significant on intention-to-treat analysis (OR 1.11, 95% CI 0.74 to 1.66, p=0.62) nor was the 30-day mortality (OR 0.91, 95% CI 0.60 to 1.38, p=0.66). As-treated analysis showed a 16% reduction in 30-day mortality in those receiving additional physician care; 60/195 (29%) versus 81/180 (45%), p<0.01, Number needed to treat =6. 338 patients met the modified definition, of which 182 were allocated to physician care. The 6-month GOS scores were not significantly different on intention-to-treat analysis (OR 1.14, 95% CI 0.73 to 1.75, p=0.56) nor was the 30-day mortality (OR 1.05, 95% CI 0.66 to 1.66, p=0.84). As-treated analyses were also not significantly different. CONCLUSIONS: This trial suggests a potential mortality reduction in patients with blunt trauma with GCS<9 receiving additional physician care (original definition only). Confirmatory studies which also address non-compliance issues are needed. TRIAL REGISTRATION NUMBER: NCT00112398.

The study protocol for the Head Injury Retrieval Trial (HIRT): a single centre randomised controlled trial of physician prehospital management of severe blunt head injury compared with management by paramedics.

BACKGROUND: The utility of advanced prehospital interventions for severe blunt traumatic brain injury (BTI) remains controversial. Of all trauma patient subgroups it has been anticipated that this patient group would most benefit from advanced prehospital interventions as hypoxia and hypotension have been demonstrated to be associated with poor outcomes and these factors may be amenable to prehospital intervention. Supporting evidence is largely lacking however. In particular the efficacy of early anaesthesia/muscle relaxant assisted intubation has proved difficult to substantiate. METHODS: This article describes the design and protocol of the Head Injury Retrieval Trial (HIRT) which is a randomised controlled single centre trial of physician prehospital care (delivering advanced interventions such as rapid sequence intubation and blood transfusion) in addition to paramedic care for severe blunt TBI compared with paramedic care alone. RESULTS: Primary endpoint is Glasgow Outcome Scale score at six months post injury. Issues with trial integrity resulting from drop ins from standard care to the treatment arm as the result of policy changes by the local ambulance system are discussed. CONCLUSION: This randomised controlled trial will contribute to the evaluation of the efficacy of advance prehospital interventions in severe blunt TBI. TRIAL REGISTRATION: ClinicalTrials.gov: NCT00112398.

Physician staffed helicopter emergency medical service dispatch via centralised control or directly by crew - case identification rates and effect on the Sydney paediatric trauma system.

BACKGROUND: Severe paediatric trauma patients benefit from direct transport to dedicated Paediatric Trauma Centres (PTC). Parallel case identification systems utilising paramedics from a centralised dispatch centre versus the crew of a physician staffed Helicopter Emergency Medical Service (HEMS) allowed comparison of the two systems for case identification rates and subsequent timeliness of direct transfer to a PTC. METHODS: Paediatric trauma patients over a two year period from the Sydney region with an Injury Severity Score (ISS) > 15 were retrospectively identified from a state wide trauma registry. Overall paediatric trauma system performance was assessed by comparisons of the availability of the physician staffed HEMS for patient characteristics, transport mode (direct versus indirect) and the times required for the patient to arrive at the paediatric trauma centre. The proportion of patients transported directly to a PTC was compared between the times that the HEMS service was available versus the time that it was unavailable to determine if the HEMS system altered the rate of direct transport to a PTC. Analysis of variance was used to compare the identifying systems for various patient characteristics when the HEMS was available. RESULTS: Ninety nine cases met the inclusion criteria, 44 when the HEMS system was operational. Patients identified for physician response by the HEMS system were significantly different to those that were not identified with higher median ISS (25 vs 18, p = 0.011), and shorter times to PTC (67 vs 261mins, p = 0.015) and length of intensive care unit stays (2 vs 0 days, p = 0.045). Of the 44 cases, 21 were not identified, 3 were identified by the paramedic system and 20 were identified by the HEMS system, (P < 0.001). Direct transport to a PTC was more likely to occur when the HEMS dispatch system was available (RR 1.81, 95% CI 1.20-2.73). The median time (minutes) to arrival at the PTC was shorter when HEMS available (HEMS available 92, IQR 50-261 versus HEMS unavailable 296, IQR 84-583, P < 0.01). CONCLUSIONS: Physician staffed HEMS crew dispatch is significantly more likely to identify cases of severe paediatric trauma and is associated with a greater proportion of transports directly to a PTC and with faster times to arrival.

Early post-tsunami disaster medical assistance to Banda Aceh: a personal account.

The south Asian tsunami on 26 December, 2004, saw Australia deploy civilian teams to an international disaster in large numbers for the first time. The logistics of supporting such teams in both a self sustainability capacity and medical equipment had not previously been planned for or tested. For the first Australian team deployed to Banda Aceh, which arrived on the fourth day after the tsunami, equipment sourced from the New South Wales Fire Brigades Urban Search and Rescue (US&R) cache supplied all food, water, tents, generators and sleeping equipment. The medical equipment was largely sourced from the CareFlight US&R medical cache. There were significant deficits in surgical equipment as the medical cache had not been designed to provide a stand alone surgical capability. This resulted in the need for substantial improvisation by the surgical teams during the deployment. Despite this, the team performed nearly 140 major procedures in austere circumstances and significantly contributed to the early international response to this major humanitarian disaster.

Safety of emergency medical service helicopters.

Robust safety specifications and funding arrangements are needed.

The role of physician staffing of helicopter emergency medical services in prehospital trauma response.

The crewing of Helicopter Emergency Medical Service (HEMS) for scene response to trauma patients is generally considered to be controversial, particularly regarding the role of physicians. This is reflected in HEMS in Australia with some services utilizing physician crewing for all prehospital missions. Others however, use physicians for selected missions only whilst others do not use physicians at all. This review seeks to determine whether the literature supports using physicians in addition to paramedics in HEMS teams for prehospital trauma care. Studies were excluded if they compared physician teams with basic life support teams (BLS) teams rather than paramedics. Ambulance officers were considered to be paramedics where they were able to administer intravenous fluids and use a method of airway management beyond bag-valve-mask ventilation. Studies were excluded if the skill set of the ambulance team was not defined, the level of staffing of the helicopter service was not stated, team composition varied without reporting outcomes for each team type, patient outcome data were not reported, or the majority of the transports were interhospital rather than prehospital transports.

The Bali bombing: civilian aeromedical evacuation.

After the Bali bombing on 12 October 2002, many injured Australians required evacuation to Darwin, and then to burns units around Australia. Many patients were evacuated from Denpasar by Qantas, with assistance from staff of civilian medical retrieval services. The transport of patients from Darwin to specialist burns units involved a coordinated response of civilian and military services. Some issues in responding to such disasters were identified, and a national coordinating network could improve future responses.