The Role of Integrated Air Transport System in Managing Patients with Abdominal Aortic Aneurysm Rupture.

OBJECTIVE: Ruptured abdominal aortic aneurysms (rAAAs) are highly morbid emergencies. Not all hospitals are equipped to repair them, and an air ambulance network may aid in regionalising specialty care to quaternary referral centres. The association between travel distance by air ambulance and rAAA mortality in patients transferred as an emergency for repair was examined. METHODS: A retrospective review of institutional data. Adults with rAAA (2002 - 2019) transferred from an outside hospital (OSH) to a single quaternary referral centre for repair via air ambulance were identified. Patients who arrived via ground transport or post-repair at an OSH for continued critical care were excluded. Patients were divided into near and far groups based on the 75th percentile of the straight line travel distance (> 72 miles) between hospitals. The primary outcome was 30 day mortality. Multivariable logistic regression was used to assess the association between distance and mortality after adjusting for age, sex, ethnicity, cardiovascular comorbidities, and repair type. RESULTS: A total of 290 patients with rAAA were transported a median distance of 40.4 miles (interquartile range 25.5, 72.7) with 215 (74.1%) near and 75 (25.9%) far patients. Both the near and far groups had similar ages, sex, and ethnicity. There was no difference in pre-operative loss of consciousness, intubation, or cardiac arrest between groups. Endovascular aneurysm repair utilisation and intra-operative aortic occlusion balloon use were also similar. Neither the observed (26.8% vs. 23.9%, p = .61) nor the adjusted odds ratio (0.70, 95% confidence interval 0.36 - 1.39, p = .32) 30 day mortality rate differed significantly between the near and far groups. CONCLUSION: Increasing distance travelled during transfer by air ambulance was not associated with worse outcomes in patients with rAAA. The findings support the regionalisation of rAAA repair to large quaternary centres via an integrated and robust air ambulance network.

Prehospital invasive arterial blood pressure monitoring in critically ill patients attended by a UK helicopter emergency medical service- a retrospective observational review of practice.

BACKGROUND: Accurate haemodynamic monitoring in the prehospital setting is essential. Non-invasive blood pressure measurement is susceptible to vibration and motion artefact, especially at extremes of hypotension and hypertension: invasive arterial blood pressure (IABP) monitoring is a potential solution. This study describes the largest series to date of cases of IABP monitoring being initiated prehospital. METHODS: This retrospective observational study was conducted at East Anglian Air Ambulance (EAAA), a UK helicopter emergency medical service (HEMS). It included all patients attended by EAAA who underwent arterial catheterisation and initiation of IABP monitoring between 1st February 2015 and 20th April 2023. The following data were retrieved for all patients: sex; age; aetiology (medical cardiac arrest, other medical emergency, trauma); site of arterial cannulation; operator role (doctor/paramedic); time of insertion and, where applicable, times of pre-hospital emergency anaesthesia, and return of spontaneous circulation following cardiac arrest. Descriptive analyses were performed to characterise the sample. RESULTS: 13,556 patients were attended: IABP monitoring was initiated in 1083 (8.0%) cases, with a median age 59 years, of which 70.8% were male. 546 cases were of medical cardiac arrest: in 22.4% of these IABP monitoring was initiated during cardiopulmonary resuscitation. 322 were trauma cases, and the remaining 215 were medical emergencies. The patients were critically unwell: 981 required intubation, of which 789 underwent prehospital emergency anaesthesia; 609 received vasoactive medication. In 424 cases IABP monitoring was instituted en route to hospital. CONCLUSION: This study describes over 1000 cases of prehospital arterial catheterisation and IABP monitoring in a UK HEMS system and has demonstrated feasibility at scale. The high-fidelity of invasive arterial blood pressure monitoring with the additional benefit of arterial blood gas analysis presents an attractive translation of in-hospital critical care to the prehospital setting.

Characteristics and critical care interventions in drowning patients treated by the Danish Air Ambulance from 2016 to 2021: a nationwide registry-based study with 30-day follow-up.

BACKGROUND: Improving oxygenation and ventilation in drowning patients early in the field is critical and may be lifesaving. The critical care interventions performed by physicians in drowning management are poorly described. The aim was to describe patient characteristics and critical care interventions with 30-day mortality as the primary outcome in drowning patients treated by the Danish Air Ambulance. METHODS: This retrospective cohort study with 30-day follow-up identified drowning patients treated by the Danish Air Ambulance from January 1, 2016, through December 31, 2021. Drowning patients were identified using a text-search algorithm (Danish Drowning Formula) followed by manual review and validation. Operational and medical data were extracted from the Danish Air Ambulance database. Descriptive analyses were performed comparing non-fatal and fatal drowning incidents with 30-day mortality as the primary outcome. RESULTS: Of 16,841 dispatches resulting in a patient encounter in the six years, the Danish Drowning Formula identified 138 potential drowning patients. After manual validation, 98 drowning patients were included in the analyses, and 82 completed 30-day follow-up. The prehospital and 30-day mortality rates were 33% and 67%, respectively. The National Advisory Committee for Aeronautics severity scores from 4 to 7, indicating a critical emergency, were observed in 90% of the total population. They were significantly higher in the fatal versus non-fatal group (p < 0.01). At least one critical care intervention was performed in 68% of all drowning patients, with endotracheal intubation (60%), use of an automated chest compression device (39%), and intraosseous cannulation (38%) as the most frequently performed interventions. More interventions were generally performed in the fatal group (p = 0.01), including intraosseous cannulation and automated chest compressions. CONCLUSIONS: The Danish Air Ambulance rarely treated drowning patients, but those treated were severely ill, with a 30-day mortality rate of 67% and frequently required critical care interventions. The most frequent interventions were endotracheal intubation, automated chest compressions, and intraosseous cannulation.

Helicopter emergency medical services (HEMS) response to out-of-hospital cardiac arrest (OHCA) in the United States.

Introduction: Helicopter emergency medical services (HEMS) are used in the United States and globally to respond to patients with critical illness and victims of traumatic injury. Relatively limited research has examined their role in responding to out-of-hospital cardiac arrests (OHCA) in the United States. In this study, we compared OHCA treated by HEMS units with cardiac arrests treated by ground ambulances. Methods: We queried a large national-level database of emergency medical services (EMS) activations in the United States (NEMSIS). Inclusion criteria were OHCA activations between January 1, 2022 and December 31, 2022 treated by either HEMS or ground ambulance. Key arrest data from both groups were then compared. Interfacility transfers and cardiac arrests after EMS arrival were excluded. Results: A total of 1,233 cardiac arrests treated by HEMS and 341,096 cardiac arrests treated by ground ambulances met inclusion criteria. Comparing the two groups, cardiac arrests with HEMS response were more likely to be male (66.7% vs. 62.8%, p < 0.01), White (50.2% vs. 45.7%, p < 0.01), under 18 years old (10.9% vs. 2.7%, p < 0.001), associated with traumatic injury (19.1% vs. 5.7%, p < 0.001), witnessed (72.7% vs. 37.3%, p < 0.001), and initially-shockable (24.7% vs. 11.1%, p < 0.001). Conclusion: Our comparison of cardiac arrests treated by HEMS with cardiac arrests treated by ground ambulance reveals significant differences between the two groups. Further research is needed to better characterize HEMS' ideal role in the response to OHCA as new prehospital resuscitative techniques for non-traumatic and traumatic cardiac arrest are developed.

The SEE-IT Trial: emergency medical services Streaming Enabled Evaluation In Trauma: a feasibility randomised controlled trial.

BACKGROUND: Use of bystander video livestreaming from scene to Emergency Medical Services (EMS) is becoming increasingly common to aid decision making about the resources required. Possible benefits include earlier, more appropriate dispatch and clinical and financial gains, but evidence is sparse. METHODS: A feasibility randomised controlled trial with an embedded process evaluation and exploratory economic evaluation where working shifts during six trial weeks were randomised 1:1 to use video livestreaming during eligible trauma incidents (using GoodSAM Instant-On-Scene) or standard care only. Pre-defined progression criteria were: (1) ≥ 70% callers (bystanders) with smartphones agreeing and able to activate live stream; (2) ≥ 50% requests to activate resulting in footage being viewed; (3) Helicopter Emergency Medical Services (HEMS) stand-down rate reducing by ≥ 10% as a result of live footage; (4) no evidence of psychological harm in callers or staff/dispatchers. Observational sub-studies included (i) an inner-city EMS who routinely use video livestreaming to explore acceptability in a diverse population; and (ii) staff wellbeing in an EMS not using video livestreaming for comparison to the trial site. RESULTS: Sixty-two shifts were randomised, including 240 incidents (132 control; 108 intervention). Livestreaming was successful in 53 incidents in the intervention arm. Patient recruitment (to determine appropriateness of dispatch), and caller recruitment (to measure potential harm) were low (58/269, 22% of patients; 4/244, 2% of callers). Two progression criteria were met: (1) 86% of callers with smartphones agreed and were able to activate livestreaming; (2) 85% of requests to activate livestreaming resulted in footage being obtained; and two were indeterminate due to insufficient data: (3) 2/6 (33%) HEMS stand down due to livestreaming; (4) no evidence of psychological harm from survey, observations or interviews, but insufficient survey data from callers or comparison EMS site to be confident. Language barriers and older age were reported in interviews as potential challenges to video livestreaming by dispatchers in the inner-city EMS. CONCLUSIONS: Progression to a definitive RCT is supported by these findings. Bystander video livestreaming from scene is feasible to implement, acceptable to both 999 callers and dispatchers, and may aid dispatch decision-making. Further assessment of unintended consequences, benefits and harm is required. TRIAL REGISTRATION: ISRCTN 11449333 (22 March 2022). https://www.isrctn.com/ISRCTN11449333.

Critical hypertension in trauma patients following prehospital emergency anaesthesia: a multi-centre retrospective observational study.

BACKGROUND: Critical hypertension in major trauma patients is associated with increased mortality. Prehospital emergency anaesthesia (PHEA) is performed for 10% of the most seriously injured patients. Optimising oxygenation, ventilation, and cerebral perfusion, whilst avoiding extreme haemodynamic fluctuations are the cornerstones of reducing secondary brain injury. The aim of this study was to report the differential determinants of post-PHEA critical hypertension in a large regional dataset of trauma patients across three Helicopter Emergency Medical Service (HEMS) organisations. METHODS: A multi-centre retrospective observational study of consecutive adult trauma patients undergoing PHEA across three HEMS in the United Kingdom; 2015-2022. Critical hypertension was defined as a new systolic blood pressure (SBP) > 180mmHg within 10 min of induction of anaesthesia, or > 10% increase if the baseline SBP was > 180mmHg prior to induction. Purposeful logistical regression was used to explore variables associated with post-PHEA critical hypertension in a multivariable model. Data are reported as number (percentage), and odds ratio (OR) with 95% confidence interval (95%CI). RESULTS: 30,744 patients were attended by HEMS during the study period; 2161 received PHEA and 1355 patients were included in the final analysis. 161 (11.9%) patients had one or more new episode(s) of critical hypertension ≤ 10 min post-PHEA. Increasing age (compared with 16-34 years): 35-54 years (OR 1.76, 95%CI 1.03-3.06); 55-74 years (OR 2.00, 95%CI 1.19-3.44); ≥75 years (OR 2.38, 95%CI 1.31-4.35), pre-PHEA Glasgow Coma Scale (GCS) motor score four (OR 2.17, 95%CI 1.19-4.01) and five (OR 2.82, 95%CI 1.60-7.09), patients with a pre-PHEA SBP > 140mmHg (OR 6.72, 95%CI 4.38-10.54), and more than one intubation attempt (OR 1.75, 95%CI 1.01-2.96) were associated with post-PHEA critical hypertension. CONCLUSION: Delivery of PHEA to seriously injured trauma patients risks haemodynamic fluctuation. In adult trauma patients undergoing PHEA, 11.9% of patients experienced post-PHEA critical hypertension. Increasing age, pre-PHEA GCS motor score four and five, patients with a pre-PHEA SBP > 140mmHg, and more than intubation attempt were independently associated with post-PHEA critical hypertension.

Traslado aéreo civil de pacientes / Patients being transported by civil airline companies

Objetivo Las operaciones aéreas iniciaron en Colombia en 1919 pero no hay conocimiento sobre el traslado aéreo de pacientes en el país. El estudio fue realizado con empresas en Bogotá que realizaron traslados aéreos de pacientes durante los años 2005 a 2007. El objetivo es mejorar el conocimiento sobre las operaciones de traslado aéreo de pacientes en Colombia. Método Estudio descriptivo de los traslados aéreos de pacientes realizados por tres empresas durante los tres años seleccionados. La escala de valoración del riesgo para el transporte de pacientes fue usada en cada uno de los registros. Resultados Solo tres empresas autorizaron el acceso a los registros médicos, encontrando 98 en total, 24 en 2005, 28 en 2006, y 46 en 2007, pero solo se realizaron 96 traslados, debido a que dos fueron cancelados por malas condiciones médicas del paciente. Todos fueron traslados secundarios (entre hospitales) realizados en ala fija, es decir en avión, 61 % hombres, 38 % mujeres, 51 % adultos y 49 % fueron menores de 18 años (57 % neonatos). De acuerdo con la escala 27 % de los pacientes estaban inestables, 48 % moderadamente inestables y 25 % estables. El 90 % de los traslados fueron realizados por personal médico, 14 casos tuvieron complicaciones durante el vuelo pero la mortalidad fue solo del 4 %. Conclusiones El traslado aéreo de pacientes requiere una valoración y un registro completos de todas las variables relacionadas con el traslado y de personal entrenado en la atención de pacientes críticos de todas las edades.

Objective Colombian aviation operations began in 1919; however, no knowledge is currently available concerning medical air transport in the country. This study involved local companies in Bogota which provided air medical transfer for patients from 2005 to 2007; it was aimed at improving knowledge regarding air transport for patients in Colombia. Method This was a descriptive study of patient air transfer by three companies during the aforementioned three-year period. The Risk Score for Transport Patients' (RSTP) scale was used in each report. Results Only three companies authorized access to their medical reports; 98 reports were found, 24 in 2005, 28 in 2006 and 46 in 2007 but only 96 patients were transferred because two flights were cancelled because of the patients' poor medical condition. All the records dealt with secondary air transfer (between facilities) in fixed-wing aircraft. 61 % of the patients so transferred were male and 38 % female; 51 % were adults and 49 % were less than 18 years old (57 % of the latter being newborn). According to the RSTP scale, 27 % of the patients were unstable, 48 % moderately unstable and 25 % were stable. 90 % of the transfers were accompanied by medical staff, 14 cases had complications during their flights but mortality was just 4 %. Conclusion Patients' air transfer requires complete assessment and a complete record of all the variables related to transporting patients by air and personnel trained in dealing with critically-ill patients of all ages.

Avaliação inicial do Serviço de Atendimento Móvel de Urgência na Cidade de Porto Alegre / Initial evaluation of the Mobile Emergency Medical Services in the city of Porto Alegre, Brazil / Evaluación inicial del servicio de atención móvil de urgencia en la ciudad de Porto Alegre

FUNDAMENTO: Os Serviços de Atendimento Móvel de Urgência (SAMU) no Brasil têm resultados imediatos pouco conhecidos. OBJETIVO: Avaliar os preditores clínicos de sobrevida dos pacientes em parada cardiorrespiratória (PCR) no ambiente não hospitalar atendidos pelo SAMU de Porto Alegre. MÉTODOS: Estudo observacional e prospectivo. Os desfechos avaliados foram sobrevida em 30 dias e até a alta hospitalar, além de escore do Cerebral Performance Category (CPC) I-II. RESULTADOS: De janeiro a outubro de 2008, foram atendidos 593 pacientes em PCR não traumática e foram realizadas 260 tentativas de ressuscitação cardiopulmonar (RCP). Houve sucesso inicial em 52 (20,0 por cento) casos, estando 16 pacientes vivos no 30º (6,0 por cento) dia, 10 tendo recebido alta hospitalar (3,9 por cento), sendo que 6 (2,3 por cento) com escore CPC I-II. A PCR no domicílio associou-se inversamente com a sobrevida no 30º dia (p = 0,001) e na alta hospitalar (p = 0,02). Um ritmo inicial "chocável" (p = 0,008) associou-se à sobrevida aos 30 dias. O intervalo tempo-resposta e tempo colapso até início da RCP foram significativamente menores em sobreviventes aos 30 dias. Em análise multivariada, foram preditores independentes de mortalidade aos 30 dias um ritmo inicial chocável (razão de chance [RC] = 0,28 e intervalo de confiança [IC] de 95,0 por cento = 0,10 - 0,81; p = 0,02) e PCR no domicílio (RC = 3,0 e IC 95,0 por cento = 1,04 - 8,7; p = 0,04). CONCLUSÃO: O atendimento pré-hospitalar da PCR em Porto Alegre tem resultados limitados, porém equiparáveis a outras localidades internacionais. É necessário o reforço de cada elo da corrente da sobrevivência para aperfeiçoar o atendimento pré-hospitalar, visando melhora de resultados clinicamente relevantes.

BACKGROUND: Little is known about the immediate outcomes of the Mobile Emergency Medical Services (SAMU) in Brazil. OBJECTIVE: To evaluate clinical predictors of survival of patients in cardiorespiratory arrest (CRA) in the nonhospital environment treated by the SAMU in the city of Porto Alegre. METHODS: The present study has a prospective and observational design. The evaluated outcomes were 30-day survival and hospital discharge, in addition to the Cerebral Performance Category (CPC) score I-II. RESULTS: From January to October 2008, a total of 593 patients in nontraumatic CRA were treated and 260 cardiopulmonary resuscitation (CPR) attempts were made. There was an initial successful outcome in 52 (20.0 percent) cases, with 16 patients (6.0 percent) alive on the 30th day and 10 being discharged from the hospital (3.9 percent), of which 6 (2.3 percent) presented CPC I-II score. The CPR at home was inversely associated with 30-day survival (p = 0.001) and hospital discharge survival (p = 0.02). An initial "shockable" rhythm (p = 0.008) was associated with 30-day survival. The response-time and collapse-time intervals until CPR start were significantly shorter in 30-day survivors. At multivariate analysis, independent 30-day mortality predictors were an initial shockable rhythm (odds ratio [OR] = 0.28 and 95 percent confidence interval [95 percentCI] = 0.10 - 0.81; p = 0.02) and CPR at home (OR = 3.0 and 95CI percent = 1.04 - 8.7; p = 0.04). CONCLUSION: The pre-hospital care of CRA in the city of Porto Alegre has limited results; however, they are comparable to the results from other international locations. It is necessary to reinforce each link of the survival chain to improve pre-hospital care, aiming at improving clinically relevant outcomes.

FUNDAMENTO: Los Servicios de Atención Móvil de Urgencia (SAMU) en el Brasil han resultados inmediatos poco conocidos. OBJETIVO: Evaluar los predictores clínicos de sobrevida de los pacientes en parada cardiorrespiratoria (PCR) en el ambiente no hospitalario atendidos por el SAMU de Porto Alegre. MÉTODOS: Estudio observacional y prospectivo. Los desenlaces evaluados fueron sobrevida en 30 días y hasta el alta hospitalaria, además de escore del Cerebral Performance Category (CPC) I-II. RESULTADOS: De enero a octubre de 2008, fueron atendidos 593 pacientes en PCR no traumática y fueron realizadas 260 tentativas de resucitación cardiopulmonar (RCP). Hubo éxito inicial en 52 (20,0 por ciento) casos, estando 16 pacientes vivos en el 30º (6,0 por ciento) día, 10 teniendo recibido alta hospitalaria (3,9 por ciento), siendo que 6 (2,3 por ciento) con escore CPC I-II. La PCR en el domicilio se asoció inversamente con la sobrevida en el 30º día (p = 0,001) y en el alta hospitalaria (p = 0,02). Un ritmo inicial pasible de "shockeable" (p = 0,008) se asoció a la sobrevida a los 30 días. El intervalo tiempo-respuesta y tiempo colapso hasta comienzo de la RCP fueron significativamente menores en supervivientes a los 30 días. En análisis multivariado, fueron predictores independientes de mortalidad a los 30 días un ritmo inicial "shockeable" (razón de posibilidad [RC] = 0,28 y intervalo de confianza [IC] de 95,0 por ciento = 0,10 - 0,81; p = 0,02) y PCR en el domicilio (RC = 3,0 y IC 95,0 por ciento = 1,04 - 8,7; p = 0,04). CONCLUSIÓN: La atención prehospitalaria de la PCR en Porto Alegre tiene resultados limitados, sin embargo equiparables a otras localidades internacionales. Es necesario el refuerzo de cada eslabón de la cadena de supervivencia para perfeccionar la atención prehospitalaria, buscando mejora de resultados clínicamente relevantes.

Aerotransporte: aspectos básicos y clínicos / Air transport: basic and clinical aspects

El transporte aéreo de pacientes es una realidad cada vez más frecuente. Las condiciones y el ambiente presentado durante un vuelo, así como los cambios fisiológicos que ahí ocurren en los pacientes y en la tripulación son parámetros que el equipo médico debe conocer antes de enfrentarse a esta actividad. En este artículo se revisarán elementos propios de la aviación y de cómo estos influyen en el organismo humano; también se analizarán algunas recomendaciones a considerar.

Air transport of patients is an increasingly common reality. The conditions and the environment presented during a flight, as well as the physiological changes that occur in patients there and the crew are parameters that the medical team should know before taking on this activity. This article will review elements of aviation and how they affect the human organism also discusses some recommendations to consider.