Identifying prehospital trauma patients from ambulance patient care records; comparing two methods using linked data in New South Wales, Australia.

BACKGROUND: Linked datasets for trauma system monitoring should ideally follow patients from the prehospital scene to hospital admission and post-discharge. Having a well-defined cohort when using administrative datasets is essential because they must capture the representative population. Unlike hospital electronic health records (EHR), ambulance patient-care records lack access to sources beyond immediate clinical notes. Relying on a limited set of variables to define a study population might result in missed patient inclusion. We aimed to compare two methods of identifying prehospital trauma patients: one using only those documented under a trauma protocol and another incorporating additional data elements from ambulance patient care records. METHODS: We analyzed data from six routinely collected administrative datasets from 2015 to 2018, including ambulance patient-care records, aeromedical data, emergency department visits, hospitalizations, rehabilitation outcomes, and death records. Three prehospital trauma cohorts were created: an Extended-T-protocol cohort (patients transported under a trauma protocol and/or patients with prespecified criteria from structured data fields), T-protocol cohort (only patients documented as transported under a trauma protocol) and non-T-protocol (extended-T-protocol population not in the T-protocol cohort). Patient-encounter characteristics, mortality, clinical and post-hospital discharge outcomes were compared. A conservative p-value of 0.01 was considered significant RESULTS: Of 1 038 263 patient-encounters included in the extended-T-population 814 729 (78.5 %) were transported, with 438 893 (53.9 %) documented as a T-protocol patient. Half (49.6 %) of the non-T-protocol sub-cohort had an International Classification of Disease 10th edition injury or external cause code, indicating 79644 missed patients when a T-protocol-only definition was used. The non-T-protocol sub-cohort also identified additional patients with intubation, prehospital blood transfusion and positive eFAST. A higher proportion of non-T protocol patients than T-protocol patients were admitted to the ICU (4.6% vs 3.6 %), ventilated (1.8% vs 1.3 %), received in-hospital transfusion (7.9 vs 6.8 %) or died (1.8% vs 1.3 %). Urgent trauma surgery was similar between groups (1.3% vs 1.4 %). CONCLUSION: The extended-T-population definition identified 50 % more admitted patients with an ICD-10-AM code consistent with an injury, including patients with severe trauma. Developing an EHR phenotype incorporating multiple data fields of ambulance-transported trauma patients for use with linked data may avoid missing these patients.

Toxicological analysis of serious drug-related harm among electronic dance music festival attendees in New South Wales, Australia: A consecutive case series.

BACKGROUND: A substantial increase in drug-related harm was observed during the 2018-2019 music festival season in New South Wales, Australia, including the deaths of five young people. As part of a rapid public health response, the New South Wales Ministry of Health referred samples from patients with suspected severe drug-related illness for forensic toxicological testing to identify the type and concentration of substances associated with the presentations. METHODS: Cases were identified through a variety of active and passive surveillance systems, and selected consecutively based on indicators of clinical severity. Comprehensive toxicology testing of blood and urine samples was expedited for all cases. Demographic and clinical characteristics were collated, together with quantitative toxicology results. Results were analysed using descriptive statistics. RESULTS: Forty cases from eleven different music festivals were included. The majority of cases (80.0%) were aged 25 years and under. There were five fatalities, and 62.5% of cases were admitted to intensive care units. MDMA was the most frequent substance, detected in 87.5% of cases. In 82.9% of cases with MDMA, blood concentrations were above thresholds that have been associated with toxicity. Multiple substances were detected in 60.0% of cases. Novel psychoactive substances were not detected. CONCLUSIONS: Our findings strongly suggest that MDMA-related toxicity was a major factor in the severity of the clinical presentations among these cases. Other substances may have enhanced MDMA toxicity but appear unlikely to have caused severe toxicity in isolation. These findings have important implications for harm reduction strategies targeted to music festival settings.

Decision support tool and suggestions for the development of guidelines for the helicopter transport of patients with COVID-19.

The novel coronavirus SARS-CoV2 emerged in December 2019 and is now pandemic. Initial analysis suggests that 5% of infected patients will require critical care, and that respiratory failure requiring intubation is associated with high mortality.Sick patients are geographically dispersed: most patients will remain in situ until they are in need of critical care. Additionally, there are likely to be patients who require retrieval for other reasons but who are co-incidentally infected with SARS-CoV-2 or shedding virus.The COVID-19 pandemic therefore poses a challenge to critical care retrieval systems, which often depend on small teams of specialists who live and work together closely. The infection or quarantining of a small absolute number of these staff could catastrophically compromise service delivery.Avoiding occupational exposure to COVID-19, and thereby ensuring service continuity, is the primary objective of aeromedical retrieval services during the pandemic. In this discussion paper we collaborated with helicopter emergency medical services(HEMS) worldwide to identify risks in retrieving COVID-19 patients, and develop strategies to mitigate these.Simulation involving the whole aeromedical retrieval team ensures that safety concerns can be addressed during the development of a standard operating procedure. Some services tested personal protective equipment and protocols in the aeromedical environment with simulation. We also incorporated experiences, standard operating procedures and approaches across several HEMS services internationally.As a result of this collaboration, we outline an approach to the safe aeromedical retrieval of a COVID-19 patient, and describe how this framework can be used to develop a local standard operating procedure.

Prospective observational study of mechanical cardiopulmonary resuscitation, extracorporeal membrane oxygenation and early reperfusion for refractory cardiac arrest in Sydney: the 2CHEER study.

BACKGROUND: Patients with prolonged cardiac arrest that is not responsive to conventional cardiopulmonary resuscitation have poor outcomes. The use of extracorporeal membrane oxygenation (ECMO) in refractory cardiac arrest has shown promising results in carefully selected cases. We sought to validate the results from an earlier extracorporeal cardiopulmonary resuscitation (ECPR) study (the CHEER trial). METHODS: Prospective, consecutive patients with refractory in-hospital (IHCA) or out-of-hospital cardiac arrest (OHCA) who met predefined inclusion criteria received protocolised care, including mechanical cardiopulmonary resuscitation, initiation of ECMO, and early coronary angiography (if an acute coronary syndrome was suspected). RESULTS: Twenty-five patients were enrolled in the study (11 OHCA, 14 IHCA); the median age was 57 years (interquartile range [IQR], 39-65 years), and 17 patients (68%) were male. ECMO was established in all patients, with a median time from arrest to ECMO support of 57 minutes (IQR, 38-73 min). Percutaneous coronary intervention was performed on 18 patients (72%). The median duration of ECMO support was 52 hours (IQR, 24-108 h). Survival to hospital discharge with favourable neurological recovery occurred in 11/25 patients (44%, of which 72% had IHCA and 27% had OHCA). When adjusting for lactate, arrest to ECMO flow time was predictive of survival (odds ratio, 0.904; P = 0.035). CONCLUSION: ECMO for refractory cardiac arrest shows promising survival rates if protocolised care is applied in conjunction with predefined selection criteria.

Does end-tidal capnography confirm tracheal intubation in fresh-frozen cadavers?

BACKGROUND: Life-like end-tidal capnography (ETCO2) waveforms have been demonstrated in recently deceased and fresh-frozen cadavers following tracheal intubation, offering potential for high fidelity airway simulation training. As the mechanism for carbon dioxide production is not fully understood, it is possible that oesophageal intubation may also generate a capnograph. Our aim was to measure ETCO2 levels following (1) oesophageal and (2) tracheal intubation in fresh-frozen cadavers, and to observe the size, shape and duration of any capnographic waveform. METHODS: Four fresh frozen cadavers underwent oesophageal intubation by an emergency medicine specialist with confirmation by a second specialist. Hand ventilation with room air via a self-inflating resuscitation bag was provided at 12 breaths per minute for 2 min or until ETCO2 was zero for 10 consecutive breaths. ETCO2 and waveform morphology were examined and video recorded. The oesophagus was then extubated and the process was repeated for tracheal intubation. RESULTS: In no case was oesophageal ETCO2 detected. For two cadavers, life-like ETCO2 waveforms were achieved immediately after tracheal intubation, with maximum ETCO2 achieved by the second breath. In these cases waveform morphology was normal and persistent. CONCLUSIONS: Cadaveric oesophageal intubation did not result in a capnography waveform, simulating live patients. When present, ETCO2 following tracheal intubation showed normal morphology which was sustained for 2 min. However, ETCO2 was not present following tracheal intubation in all cadavers. These results represent instrumentation on the cadavers for the first time after thawing and further work should assess the repeatability of the findings with subsequent intubations.

Hemodynamic Response After Rapid Sequence Induction With Ketamine in Out-of-Hospital Patients at Risk of Shock as Defined by the Shock Index.

STUDY OBJECTIVE: Ketamine is considered a stable induction agent for rapid sequence induction; however, hypotension rates up to 24% are reported. The shock index (shock index=pulse rate/systolic blood pressure [SBP]) may identify patients at risk of adverse hemodynamic change. We investigate whether SBP and pulse rate response to ketamine induction differ when patients are classified as being at risk of shock by their shock index. METHODS: We conducted a prospective observational study of electronically collected vital sign data from patients undergoing rapid sequence induction with ketamine. Patients were grouped into low shock index (shock index <0.9) or high shock index (shock index ≥0.9) preinduction. Pulse rate and SBP were compared between 3 minutes preinduction and for 3 measurements postinduction (3-minute intervals) by repeated-measures ANOVA. Proportions of patients developing hypotension or hypertension are also reported. RESULTS: One hundred twelve patients were enrolled (81 low shock index, 31 high shock index). Low shock index patients had increased SBP after induction (16 mm Hg; 95% confidence interval [CI] 11 to 21 mm Hg), whereas high shock index patients did not (2 mm Hg; 95% CI -4 to 7 mm Hg). Pulse rate in low shock index patients increased after induction (20 beats/min; 95% CI 16 to 25 beats/min) and remained elevated, whereas in high shock index patients a difference occurred at the second postinduction measurement only (15 beats/min; 95% CI 11 to 18 beats/min). More high shock index patients became hypotensive (26%; 95% CI 12% to 45%) than low shock index ones (2%; 95% CI 0% to 9%), whereas more low shock index patients became hypertensive (40%; 95% CI 29% to 51%) than high shock index ones (13%; 95% CI 4% to 30%). CONCLUSION: After ketamine induction, high shock index patients exhibited blunted hypertensive responses and more frequent hypotension, whereas low shock index patients had sustained increases in pulse rate and SBP.

Difficult Intubation Factors in Prehospital Rapid Sequence Intubation by an Australian Helicopter Emergency Medical Service.

OBJECTIVE: Prehospital rapid sequence intubation (RSI) of critically ill trauma patients is a high-risk procedure that may be associated with an increased rate of severe complications such as failed intubation, failure of oxygenation, hypoxia, hypotension, or need for surgical airway. The objective of this study was to describe the factors associated with difficult intubation in prehospital RSI as defined by more than a single look at laryngoscopy to achieve tracheal intubation. METHODS: This is an observational study using prospectively collected data. RESULTS: Four hundred forty-three RSIs were performed. Paramedics were the initial laryngoscopist in 290 (65.5%). First-look laryngoscopy resulted in successful tracheal intubation (TI) in 372 (84.0%) (95% confidence interval, 80.3%-87.1%). Intubation was achieved on second look at laryngoscopy in 58 (13.1%). "First-pass" TI was achieved in 394 (88.9%). Overall, successful TI was achieved in 438 (98.9%) (95% confidence interval, 97.4%-99.5%). Complications occurred in 116 (26.2%), with desaturation the commonest in 77 (17.4%). CONCLUSION: Factors associated with more than 1 look at laryngoscopy before TI included paramedic laryngoscopist and the presence of at least 1 of the following indicators: blood/vomitus in the airway, limited mouth opening, and limited neck movement. Trauma to face/neck, obese body habitus, C-spine precautions, cricoid pressure, midline stabilization, and intubation on the ground did not influence the level of difficulty encountered.

Sustained life-like waveform capnography after human cadaveric tracheal intubation.

INTRODUCTION: Fresh frozen cadavers are effective training models for airway management. We hypothesised that residual carbon dioxide (CO2) in cadaveric lung would be detectable using standard clinical monitoring systems, facilitating detection of tracheal tube placement and further enhancing the fidelity of clinical simulation using a cadaveric model. METHODS: The tracheas of two fresh frozen unembalmed cadavers were intubated via direct laryngoscopy. Each tracheal tube was connected to a self-inflating bag and a sidestream CO2 detector. The capnograph display was observed and recorded in high-definition video. The cadavers were hand-ventilated with room air until the capnometer reached zero or the waveform approached baseline. RESULTS: A clear capnographic waveform was produced in both cadavers on the first postintubation expiration, simulating the appearances found in the clinical setting. In cadaver one, a consistent capnographic waveform was produced lasting over 100 s. Maximal end-tidal CO2 was 8.5 kPa (65 mm Hg). In cadaver two, a consistent capnographic waveform was produced lasting over 50 s. Maximal end-tidal CO2 was 5.9 kPa (45 mm Hg). CONCLUSIONS: We believe this to be the first work to describe and quantify detectable end-tidal capnography in human cadavers. We have demonstrated that tracheal intubation of fresh frozen cadavers can be confirmed by life-like waveform capnography. This requires further validation in a larger sample size.

Pre-hospital emergency medicine.

Pre-hospital care is emergency medical care given to patients before arrival in hospital after activation of emergency medical services. It traditionally incorporated a breadth of care from bystander resuscitation to statutory emergency medical services treatment and transfer. New concepts of care including community paramedicine, novel roles such as emergency care practitioners, and physician delivered pre-hospital emergency medicine are re-defining the scope of pre-hospital care. For severely ill or injured patients, acting quickly in the pre-hospital period is crucial with decisions and interventions greatly affecting outcomes. The transfer of skills and procedures from hospital care to pre-hospital medicine enables early advanced care across a range of disciplines. The variety of possible pathologies, challenges of environmental factors, and hazardous situations requires management that is tailored to the patient's clinical need and setting. Pre-hospital clinicians should be generalists with a broad understanding of medical, surgical, and trauma pathologies, who will often work from locally developed standard operating procedures, but who are able to revert to core principles. Pre-hospital emergency medicine consists of not only clinical care, but also logistics, rescue competencies, and scene management skills (especially in major incidents, which have their own set of management principles). Traditionally, research into the hyper-acute phase (the first hour) of disease has been difficult, largely because physicians are rarely present and issues of consent, transport expediency, and resourcing of research. However, the pre-hospital phase is acknowledged as a crucial period, when irreversible pathology and secondary injury to neuronal and cardiac tissue can be prevented. The development of pre-hospital emergency medicine into a sub-specialty in its own right should bring focus to this period of care.

Apneic oxygenation was associated with decreased desaturation rates during rapid sequence intubation by an Australian helicopter emergency medicine service.

STUDY OBJECTIVE: The Greater Sydney Area Helicopter Emergency Medical Service undertakes in excess of 2,500 physician/paramedic out-of-hospital and interhospital retrievals each year, of which 8% require intubation. Emergency anesthesia of critically ill patients is associated with complications, including hypoxia. In July 2011, the service introduced apneic oxygenation with nasal cannulae to its emergency anesthesia standard operating procedure to reduce rates of desaturation during rapid sequence intubation. We evaluate the association between the introduction of apneic oxygenation and incidence of desaturation during rapid sequence intubation in both out-of-hospital and interhospital retrievals. METHODS: This was a retrospective study of prospectively collected airway registry data. Consecutive patients who underwent rapid sequence intubation by Greater Sydney Area Helicopter Emergency Medical Service personnel between September 2009 and July 2013, spanning the introduction of apneic oxygenation, were included for analysis (n=728). We compared patients who underwent rapid sequence intubation before the service introduced apneic oxygenation (n=310) with those who underwent it after its introduction (n=418). We evaluated the association between the introduction of apneic oxygenation and the incidence of desaturation. RESULTS: During the study period, 9,901 missions were conducted with 728 rapid sequence intubations (310 pre- and 418 postapneic oxygenation). The introduction of apneic oxygenation was followed by a decrease in desaturation rates from 22.6% to 16.5% (difference=6.1%; 95% confidence interval 0.2% to 11.2%). CONCLUSION: Introduction of apneic oxygenation was associated with decreased incidence of desaturation in patients undergoing rapid sequence intubation.

Are physicians required during winch rescue missions in an Australian helicopter emergency medical service?

BACKGROUND: A helicopter emergency medical service (HEMS) capable of winching offers several advantages over standard rescue operations. Little is known about the benefit of physician winching in addition to a highly trained paramedic. OBJECTIVE: To analyse the mission profiles and interventions performed during rescues involving the winching of a physician in the Greater Sydney Area HEMS (GSA-HEMS). METHODS: All winch missions involving a physician from August 2009 to January 2012 were identified from the prospectively completed GSA-HEMS electronic database. A structured case sheet review for a predetermined list of demographic data and physician-only interventions (POIs) was conducted. RESULTS: We identified 130 missions involving the winching of a physician, of which 120 case sheets were available for analysis. The majority of patients were traumatically injured (90%) and male (85%) with a median age of 37 years. Seven patients were pronounced dead at the scene. A total of 63 POIs were performed on 48 patients. Administration of advanced analgesia was the most common POI making up 68.3% of interventions. Patients with abnormal RTSc(2) scores were more likely to receive a POI than those with normal RTSc(2) (84.8% vs 15.2%; p=0.03). The performance of a POI had no effect on median scene times (45 vs 43 min; p=0.51). CONCLUSIONS: Our high POI rate of 40% (48/120) coupled with long rescue times and the occasional severe injuries support the argument for winching Physicians. Not doing so would deny a significant proportion of patients time-critical interventions, advanced analgesia and procedural sedation.

Algorithm for the resuscitation of traumatic cardiac arrest patients in a physician-staffed helicopter emergency medical service.

Survival rates following traumatic cardiac arrest (TCA) are known to be poor but resuscitation is not universally futile. There are a number of potentially reversible causes to TCA and a well-defined group of survivors. There are distinct differences in the pathophysiology between medical cardiac arrests and TCA. The authors present some of the key differences and evidence related to resuscitation in TCA, and suggest a separate algorithm for the management of out-of-hospital TCA attended by a highly trained physician and paramedic team.

Helicopter emergency medical service registrars do not comprehensively document primary surveys.

OBJECTIVES: In-hospital primary surveys undertaken on traumatically injured patients can be inaccurate and incomplete. This study examined the documentation of prehospital primary surveys conducted by Greater Sydney Area Helicopter Emergency Medical Service registrars on trauma patients. METHODS: A retrospective case sheet review of prehospital trauma primary surveys documented by Greater Sydney Area Helicopter Emergency Medical Service registrars was carried out using previously published methodologies. A 13-item prehospital primary survey score was created and analysed by registrar specialty. A linear mixed model was used to determine whether differences in prehospital primary survey score existed between specialties. A one-point difference in the mean scores was considered clinically significant. RESULTS: A total of 75 charts were reviewed. An unadjusted mean of 9.5±1.6 (SD) items, out of a possible 13, was documented. Documentation was found to be less complete for anaesthetic trainees (adjusted mean score=9.10) than for emergency medicine trainees (adjusted mean score=10.34). The difference in the mean scores was 1.24 (95% confidence interval, 0.25-2.23, t53d.f.=2.52, P=0.01). A significant clustering effect was identified for individual registrars (χ1d.f.=6.03, P=0.01). A very good level of agreement was obtained between the PPSS raters (κ=0.93, 95% confidence interval, 0.87-0.99). CONCLUSION: Helicopter emergency medical service registrars do not comprehensively document prehospital primary surveys on traumatically injured patients. However, emergency medicine trainees document more completely than anaesthetic trainees. Individual registrar variation contributes significantly towards the completeness of prehospital primary survey documentation.

Do emergency physicians and radiologists reliably interpret pelvic radiographs obtained as part of a trauma series?

INTRODUCTION: Interpretation of pelvic radiography is an important component of the primary survey and is commonly performed by emergency physicians. Radiologists bring unique skills to trauma care, including choice of imaging modality and image interpretation. It is not clear if this limited resource is most efficiently used in the resuscitation room. No studies have compared radiologists and trauma clinicians in their ability to interpret pelvic radiographs following trauma. OBJECTIVE: To determine the sensitivity and specificity of trauma experienced and trauma inexperienced emergency physicians in detecting pelvic fractures compared with radiologists, the latter subgroup combined report being used as the gold standard. SETTING AND METHODS: Prospective cohort study conducted in two large teaching hospitals in central London. All participants reviewed 144 consecutive pelvic radiographs performed each as part of a 'trauma series' and known to have undergone concomitant pelvic CT imaging. RESULTS: No statistically significant difference was found between radiologists and emergency physicians from a trauma centre in pelvic radiograph interpretation. Radiologist reporting was associated with an improved specificity compared with emergency physicians working in a non-trauma hospital (p=0.049). The study population missed 30% of fractures on plain radiography against the gold standard of CT. DISCUSSION: The ability to interpret trauma series pelvic radiographs is comparable between emergency physicians and radiologists. If this were also true of trauma chest radiographs, then the most valuable use of the radiologist may not be the resuscitation room but in rapid reporting of more complex imaging techniques. However, plain radiography is insensitive for pelvic fracture detection compared with CT, even in expert hands.

Review of aeromedical intra-aortic balloon pump retrieval in New South Wales.

OBJECTIVES: The intra-aortic balloon pump (IABP) was first introduced in 1968 to augment cardiac output in the haemodynamically unstable patient and serve as a bridge to treatment options such as coronary artery bypass grafting and cardiac transplantation. Transfer of IABP-dependent patients for upgrade of clinical care is increasingly common and safe. In Australia, percutaneous coronary intervention centres can be located outside cardiothoracic surgical centres. This study reviews IABP medical retrieval by a doctor/paramedic team after implementation of a standardized protocol. METHODS: This was a retrospective case series review, using descriptive statistics. RESULTS: Greater Sydney Area Helicopter Emergency Service carried out 22 cases from 1 May 2007 to 31 December 2009. Median age was 62 years [interquartile range (IQR) 51-83], 67% were male. In all, 63% of patients were retrieved on inotropic support, 29% overall received invasive ventilation. Highest frequency indications were myocardial infarction, cardiogenic shock and bridge to coronary artery bypass grafts. There were complications during 18% of all retrievals and no adverse outcomes. Of the patients, 67% (14/21) were retrieved by road and 33% (7/21) by helicopter (longest distance 500 km). Median stabilization time by a retrieval team was 1 h 15 min (IQR 50 min to 3 h 30 min). Median mission time was 4 h 55 min (IQR 3 h 50 min to 8 h 54 min). CONCLUSION: Our system offers a safe method of IABP medical retrieval. The doctor and paramedic combination complements strengths in logistics and critical care. This serves as a guide to other systems looking to put in place a similar model of care.