Alan A. Garner

It is 15 years since the Head Injury Retrieval Trial recruited its last patient in Sydney, Australia. The trial remains the only randomised controlled trial of severely injured patients to directly compare an advanced clinical intervention team delivered by a helicopter emergency medical service to a paramedic ground response in the world medical literature. Issues with the conduct and confounding of the trial are reviewed, as well as the evolution of the Sydney prehospital trauma system in the 15 years since the trial concluded. The design of the Sydney prehospital trauma system remains suboptimal and non‐evidence based.

Background: It has been recommended that prehospital rapid sequence intubation (PH-RSI) be performed in locations that provide 360-degree access to the patient. We aimed to examine the success and complication rate of PH-RSI by location of intubation as well as the effect on scene time. Methods: We conducted a single-centre, retrospective cohort study of patients with attempted PH-RSI over a 96-month period. Locations compared were intubation within the road ambulance, outside the vehicle on a stretcher, on the ground and in other locations. The primary outcome was the occurrence of major intubation complications by location. Secondary outcomes were first-pass success, time to intubation from patient contact and total scene time. Modified Poisson with robust SE variance and quantile regressions was used to adjust for confounding variables. Results: Of 413 patients, major intubation complications occurred in 60 (14.5%, 95% CI 11.3% to 18.3%) patients. Patients intubated on the ground were twice as likely to have complications than patients intubated on a stretcher outside the vehicle (p=0.023) in the unadjusted analysis. First-pass success intubations occurred in 400 (96.9%, 95% CI 94.7% to 98.3%). Adjusted time from contact to intubation was not different (p=0.864) but total scene time was significantly shorter for patients intubated inside an ambulance compared with outside on a stretcher (median difference −4.0 min, 95% CI −6.5 to 1.5; p=0.002). Conclusions: Intubating selected patients within an ambulance had similar complication rates to intubation on a stretcher outside the vehicle but was associated with a small reduction in on-scene time.

Objective: This study aimed to compare the timeliness of single role versus multirole physician‐staffed prehospital models and construct an optimised capability‐based case allocation map for Sydney, Australia. Methods: We retrospectively compared response, scene, and total prehospital intervals over an 11‐year period. Generalized linear regression models with log function were used to control for confounders. An optimized case allocation map was derived from response time data. Results: For the single role service 672 helicopter responses were compared with 289 road and 208 helicopter multirole responses. Multirole patients were typically closer to their base (median 18.2 km vs. 23.4 km, p = 0.004). Response interval was shorter for the single role service (median 18 min vs. 24 min, p < 0.001). Scene and total prehospital intervals were shorter for the single role service (24 min vs. 32 min, p < 0.001 and 70 min vs. 80 min, p < 0.001, respectively). On multivariate analysis, multirole allocation was significantly associated with longer scene intervals (IRR = 1.176, [95% CI 1.133, 1.221], p < 0.001) and longer total prehospital intervals (IRR = 1.402 [95% CI 1.315, 1.495], p < 0.001). The optimised case allocation map indicates multirole road response is faster for a 9 km radius circle eccentrically centred on their base. All other locations are more rapidly served by the single role helicopter model. Conclusions: A single role model is associated with a shorter response, scene, and total prehospital intervals compared with a multirole model. Real‐world response time data rather than distance can be used to optimise case allocation when response capabilities are not equivalent.

Objective: The Inter‐Changeable Operator Model (ICOM) enables paramedics and flight nurses to perform intubations interchangeably with team physicians in prehospital critical care. However, literature on ICOM characteristics and performance is limited.Methods: We conducted a retrospective, observational study of an ICOM operating within an Australian Helicopter Emergency Medical Service over a nine‐year period. First pass success, major complication rates and clinically important time intervals were compared between first intubator groups.Results: A total of 413 patients met the inclusion criteria, with paramedics performing the majority of first intubation attempts (379/413, 91.8%). Physicians primarily conducted second intubation attempts and managed high‐risk patients. In unadjusted analysis, the risk of major complication in the paramedic/supervised registrar group was not lower than the most senior physician intubator group (relative risk [RR] 0.59, 95% confidence interval [CI]: 0.26–1.32; P = 0.198) and after adjustment the risk was also not lower (RR 0.60, 95% CI: 0.24–1.54; P = 0.289). First pass failure occurred in 12 (3.1%) and 1 (4.8%) patients intubated by paramedic/supervised registrar and most senior physician groups, respectively (P = 0.498). The median (95% CI) adjusted difference in contact to intubation time between paramedic/supervised registrar first intubator and most senior physician groups was −2 min (−7 to 3; P = 0.392). Total adjusted scene time was also not significantly different between groups (median difference 2 min, 95% CI: −3 to 7; P = 0.500).Conclusions: Paramedics conducting most intubations within an ICOM are both safe and efficient. Larger studies are required to examine differences between physician subgroups.

Objective: A 45‐min interval from injury to intubation has been proposed as a performance indicator for severe trauma patient management. In the Sydney pre‐hospital system a previous change in case identification systems was associated with activation delay. We aimed to determine if this also decreased the proportion of patients intubated within this benchmark.Methods: Retrospective cohort study of patients intubated by a helicopter emergency medical service (HEMS) over two time periods. Period 1 dispatch was via HEMS crew directly screening the computerised dispatch system, and period 2 was via paramedics in a central control room. Times from emergency call to intubation were compared.Results: In the HEMS crew screening period 46/58 (79.31%) intubations met the target, compared with 137/314 (43.6%) in the central control period (P < 0.001). The median (interquartile range) time to intubation in the direct crew screening period was 33 (25–41) min, versus the central control period at 47 (38–60) min (P < 0.001).On multivariate modelling, distance to the scene was related to time to intubation (P < 0.001; Incident Rate Ratio = 1.018, 95% confidence interval 1.015–1.020) as was dispatch system, entrapment/access difficulty and indication for intubation (all P < 0.001).Conclusions: Time from emergency call to intubation was significantly shorter in the HEMS screening period where all non‐trapped cases less than 50 km distant were intubated within the 45‐min benchmark. There was no distance where intubation within 45 min could be assured for non‐trapped patients in the central control period due to dispatch delays.

Objective: To survey the current structure, capability and operational scope of pre‐hospital and retrieval aeromedical teams across Australia.Methods: The medical directors of all Australian civilian adult aeromedical retrieval organisations with pre‐hospital teams and/or doctors for inter‐hospital critical care patient transport were contacted in a survey to qualitatively assess capacity and team structure.Results: All 17 organisations contacted completed the survey. While there is diversity in team structure with the pairing of doctors, paramedics and nurses, capacity for patient care is generally homogenous. A doctor/paramedic model is the more common team structure for rotary‐wing missions, and doctor/nurse for fixed‐wing. Differences are mostly due to state government controlled aspects of their health services. An advanced degree of intensive patient care occurs outside of the hospital. Land and sea rescue is an important aspect of Australian aeromedical work.Conclusion: Aeromedicine in Australia has many consistent elements, but variable contexts have resulted in a diversity of operational models.