Autoreactive T cells targeting type II pneumocyte antigens in COVID-19 convalescent patients.

BACKGROUND: The role of autoreactive T cells on the course of Coronavirus disease-19 (COVID-19) remains elusive. Type II pneumocytes represent the main target cells of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Autoimmune responses against antigens highly expressed in type II pneumocytes may influence the severity of COVID-19 disease. OBJECTIVE: The aim of this study was to investigate autoreactive T cell responses against self-antigens highly expressed in type II pneumocytes in the blood of COVID-19 patients with severe and non-severe disease. METHODS: We collected blood samples of COVID-19 patients with varying degrees of disease severity and of pre-pandemic controls. T cell stimulation assays with peptide pools of type II pneumocyte antigens were performed in two independent cohorts to analyze the autoimmune T cell responses in patients with non-severe and severe COVID-19 disease. Target cell lysis assays were performed with lung cancer cell lines to determine the extent of cell killing by type II PAA-specific T cells. RESULTS: We identified autoreactive T cell responses against four recently described self-antigens highly expressed in type II pneumocytes, known as surfactant protein A, surfactant protein B, surfactant protein C and napsin A, in the blood of COVID-19 patients. These antigens were termed type II pneumocyte-associated antigens (type II PAAs). We found that patients with non-severe COVID-19 disease showed a significantly higher frequency of type II PAA-specific autoreactive T cells in the blood when compared to severely ill patients. The presence of high frequencies of type II PAA-specific T cells in the blood of non-severe COVID-19 patients was independent of their age. We also found that napsin A-specific T cells from convalescent COVID-19 patients could kill lung cancer cells, demonstrating the functional and cytotoxic role of these T cells. CONCLUSIONS: Our data suggest that autoreactive type II PAA-specific T cells have a protective role in SARS-CoV-2 infections and the presence of high frequencies of these autoreactive T cells indicates effective viral control in COVID-19 patients. Type II-PAA-specific T cells may therefore promote the killing of infected type II pneumocytes and viral clearance.

Enhancing European Management of Analgesia, Sedation, and Delirium: A Multinational, Prospective, Interventional Before-After Trial.

BACKGROUND: The objective of this study was to analyze the impact of a structured educational intervention on the implementation of guideline-recommended pain, agitation, and delirium (PAD) assessment. METHODS: This was a prospective, multinational, interventional before-after trial conducted at 12 intensive care units from 10 centers in Germany, Austria, Switzerland, and the UK. Intensive care units underwent a 6-week structured educational program, comprising online lectures, instructional videos, educational handouts, and bedside teaching. Patient-level PAD assessment data were collected in three 1-day point-prevalence assessments before (T1), 6 weeks after (T2), and 1 year after (T3) the educational program. RESULTS: A total of 430 patients were included. The rate of patients who received all three PAD assessments changed from 55% (107/195) at T1 to 53% (68/129) at T2, but increased to 73% (77/106) at T3 (p = 0.003). The delirium screening rate increased from 64% (124/195) at T1 to 65% (84/129) at T2 and 77% (82/106) at T3 (p = 0.041). The pain assessment rate increased from 87% (170/195) at T1 to 92% (119/129) at T2 and 98% (104/106) at T3 (p = 0.005). The rate of sedation assessment showed no signficiant change. The proportion of patients who received nonpharmacological delirium prevention measures increased from 58% (114/195) at T1 to 80% (103/129) at T2 and 91% (96/106) at T3 (p < 0.001). Multivariable regression revealed that at T3, patients were more likely to receive a delirium assessment (odds ratio [OR] 2.138, 95% confidence interval [CI] 1.206-3.790; p = 0.009), sedation assessment (OR 4.131, 95% CI 1.372-12.438; p = 0.012), or all three PAD assessments (OR 2.295, 95% CI 1.349-3.903; p = 0.002) compared with T1. CONCLUSIONS: In routine care, many patients were not assessed for PAD. Assessment rates increased significantly 1 year after the intervention. Clinical trial registration ClinicalTrials.gov: NCT03553719.

Stability of Drugs Stored in Helicopters for Use by Emergency Medical Services: A Prospective Observational Study.

STUDY OBJECTIVE: Drugs stored in rescue helicopters may be subject to extreme environmental conditions. The aim of this study was to measure whether drugs stored under the real-life conditions of a Swiss helicopter emergency medical service (HEMS) would retain their potency over the course of 1 year. METHODS: A prospective, longitudinal study measuring the temperature exposure and concentration of drugs stored on 2 rescue helicopters in Switzerland over 1 year. The study drugs included epinephrine, norepinephrine, amiodarone, midazolam, fentanyl, naloxone, rocuronium, etomidate, and ketamine. Temperatures were measured inside the medication storage bags and the crew cabins at 10-minute intervals. Drug stability was measured on a monthly basis over the course of 12 months using high-performance liquid chromatography. The medications were considered stable at a minimum remaining drug concentration of 90% of the label claim. RESULTS: Temperatures ranged from -1.2 °C to 38.1 °C (29.84 °F to 100.58 °F) inside the drug storage bags. Of all the temperature measurements inside the drug storage bags, 37% lay outside the recommended storage conditions. All drugs maintained a concentration above 90% of the label claim. The observation periods for rocuronium and etomidate were shortened to 7 months because of a supply shortage of reference samples. CONCLUSION: Drugs stored under the real-life conditions of Swiss HEMS are subjected to temperatures outside the manufacturer's approved storage requirements. Despite this, all drugs stored under these conditions remained stable throughout our study. Real-life stability testing could be a way to extend drug exchange intervals.

Dynamics of disease characteristics and clinical management of critically ill COVID-19 patients over the time course of the pandemic: an analysis of the prospective, international, multicentre RISC-19-ICU registry.

BACKGROUND: It remains elusive how the characteristics, the course of disease, the clinical management and the outcomes of critically ill COVID-19 patients admitted to intensive care units (ICU) worldwide have changed over the course of the pandemic. METHODS: Prospective, observational registry constituted by 90 ICUs across 22 countries worldwide including patients with a laboratory-confirmed, critical presentation of COVID-19 requiring advanced organ support. Hierarchical, generalized linear mixed-effect models accounting for hospital and country variability were employed to analyse the continuous evolution of the studied variables over the pandemic. RESULTS: Four thousand forty-one patients were included from March 2020 to September 2021. Over this period, the age of the admitted patients (62 [95% CI 60-63] years vs 64 [62-66] years, p < 0.001) and the severity of organ dysfunction at ICU admission decreased (Sequential Organ Failure Assessment 8.2 [7.6-9.0] vs 5.8 [5.3-6.4], p < 0.001) and increased, while more female patients (26 [23-29]% vs 41 [35-48]%, p < 0.001) were admitted. The time span between symptom onset and hospitalization as well as ICU admission became longer later in the pandemic (6.7 [6.2-7.2| days vs 9.7 [8.9-10.5] days, p < 0.001). The PaO2/FiO2 at admission was lower (132 [123-141] mmHg vs 101 [91-113] mmHg, p < 0.001) but showed faster improvements over the initial 5 days of ICU stay in late 2021 compared to early 2020 (34 [20-48] mmHg vs 70 [41-100] mmHg, p = 0.05). The number of patients treated with steroids and tocilizumab increased, while the use of therapeutic anticoagulation presented an inverse U-shaped behaviour over the course of the pandemic. The proportion of patients treated with high-flow oxygen (5 [4-7]% vs 20 [14-29], p < 0.001) and non-invasive mechanical ventilation (14 [11-18]% vs 24 [17-33]%, p < 0.001) throughout the pandemic increased concomitant to a decrease in invasive mechanical ventilation (82 [76-86]% vs 74 [64-82]%, p < 0.001). The ICU mortality (23 [19-26]% vs 17 [12-25]%, p < 0.001) and length of stay (14 [13-16] days vs 11 [10-13] days, p < 0.001) decreased over 19 months of the pandemic. CONCLUSION: Characteristics and disease course of critically ill COVID-19 patients have continuously evolved, concomitant to the clinical management, throughout the pandemic leading to a younger, less severely ill ICU population with distinctly different clinical, pulmonary and inflammatory presentations than at the onset of the pandemic.

Airway management in a Helicopter Emergency Medical Service (HEMS): a retrospective observational study of 365 out-of-hospital intubations.

BACKGROUND: Airway management is a key skill in any helicopter emergency medical service (HEMS). Intubation is successful less often than in the hospital, and alternative forms of airway management are more often needed. METHODS: Retrospective observational cohort study in an anaesthesiologist-staffed HEMS in Switzerland. Patient charts were analysed for all calls to the scene (n = 9,035) taking place between June 2016 and May 2017 (12 months). The primary outcome parameter was intubation success rate. Secondary parameters included the number of alternative techniques that eventually secured the airway, and comparison of patients with and without difficulties in airway management. RESULTS: A total of 365 patients receiving invasive ventilatory support were identified. Difficulties in airway management occurred in 26 patients (7.1%). Severe traumatic brain injury was the most common indication for out-of-hospital Intubation (n = 130, 36%). Airway management was performed by 129 different Rega physicians and 47 different Rega paramedics. Paramedics were involved in out-of-hospital airway manoeuvres significantly more often than physicians: median 7 (IQR 4 to 9) versus 2 (IQR 1 to 4), p < 0.001. CONCLUSION: Despite high overall success rates for endotracheal intubation in the physician-staffed service, individual physicians get only limited real-life experience with advanced airway management in the field. This highlights the importance of solid basic competence in a discipline such as anaesthesiology.

Implications of early respiratory support strategies on disease progression in critical COVID-19: a matched subanalysis of the prospective RISC-19-ICU cohort.

BACKGROUND: Uncertainty about the optimal respiratory support strategies in critically ill COVID-19 patients is widespread. While the risks and benefits of noninvasive techniques versus early invasive mechanical ventilation (IMV) are intensely debated, actual evidence is lacking. We sought to assess the risks and benefits of different respiratory support strategies, employed in intensive care units during the first months of the COVID-19 pandemic on intubation and intensive care unit (ICU) mortality rates. METHODS: Subanalysis of a prospective, multinational registry of critically ill COVID-19 patients. Patients were subclassified into standard oxygen therapy ≥10 L/min (SOT), high-flow oxygen therapy (HFNC), noninvasive positive-pressure ventilation (NIV), and early IMV, according to the respiratory support strategy employed at the day of admission to ICU. Propensity score matching was performed to ensure comparability between groups. RESULTS: Initially, 1421 patients were assessed for possible study inclusion. Of these, 351 patients (85 SOT, 87 HFNC, 87 NIV, and 92 IMV) remained eligible for full analysis after propensity score matching. 55% of patients initially receiving noninvasive respiratory support required IMV. The intubation rate was lower in patients initially ventilated with HFNC and NIV compared to those who received SOT (SOT: 64%, HFNC: 52%, NIV: 49%, p = 0.025). Compared to the other respiratory support strategies, NIV was associated with a higher overall ICU mortality (SOT: 18%, HFNC: 20%, NIV: 37%, IMV: 25%, p = 0.016). CONCLUSION: In this cohort of critically ill patients with COVID-19, a trial of HFNC appeared to be the most balanced initial respiratory support strategy, given the reduced intubation rate and comparable ICU mortality rate. Nonetheless, considering the uncertainty and stress associated with the COVID-19 pandemic, SOT and early IMV represented safe initial respiratory support strategies. The presented findings, in agreement with classic ARDS literature, suggest that NIV should be avoided whenever possible due to the elevated ICU mortality risk.

[In-cabin rapid sequence induction : Experience from alpine air rescue on reduction of the prehospital time]. / "In cabin rapid sequence induction" : Erfahrung aus der alpinen Luftrettung zur Verkürzung der Prähospitalzeit.

The survival of the severely injured is dependent on the rapid and efficient prehospital treatment. Despite all efforts over the last decades and despite an improved network of rescue helicopters, the time delay between the accident event and admission to the trauma room could not be reduced. A certain proportion of the severely injured need induction of anesthesia even before arrival in hospital (typically as rapid sequence induction, RSI). Due to the medical and technical progress in video laryngoscopy as well as in the means of air rescue used in German-speaking countries, under certain conditions the possibility to carry out induction of anesthesia and airway management in the cabin of the rescue helicopter, i.e. during the transportation, seems to be a possible option to reduce the prehospital time. The aspects dealt with in this article are elementary for a safe execution. A procedure that has been tried and trusted for some time is presented as an example; however, the in-cabin RSI should only be carried out by pretrained teams using a clear standard operating procedure.

Prehospital Blood Product Transfusion in Mountain Rescue Operations.

Severely injured patients with hemorrhage present major challenges for emergency medical services, especially during mountain rescue missions in which harsh environmental conditions and long out-of-hospital times are frequent. Because uncontrolled hemorrhage is the leading cause of death within the first 48 hours after severe trauma, initiating damage control resuscitation (DCR) as early as possible after severe trauma and exporting the concept of DCR to the out-of-hospital arena is pivotal for patient survival. Appropriate bleeding control, management of coagulopathy, and transfusion of blood products are core aspects of DCR. This review summarizes the available evidence on out-of-hospital blood product transfusion and the management of coagulopathy with a special focus on mountain rescue missions. An overview of upcoming trials and possible future trends in the management of coagulopathy during rescue operations is provided.

Helicopter Emergency Medical Service Simulation Training in the Extreme: Simulation-based Training in a Mountain Weather Chamber.

Mountain rescue operations often confront crews with extreme weather conditions. Extremely cold temperatures make standard treatment sometimes difficult or even impossible. It is well-known that most manual tasks, including those involved in mountain rescue operations, are slowed by extremely cold weather. To lessen and improve the decrement in performance of emergency medical treatment caused by cold-induced manual impairment and inadequate medical equipment and supplies, simulation training in a weather chamber, which can produce wind and temperatures up to -22°C, was developed. It provides a promising tool to train the management of complex multidisciplinary settings, thus reducing the occurrence of fatal human and technical errors and increasing the safety for both the patient and the mountain emergency medical service crew.

Simulation-Based Training in Mountain Helicopter Emergency Medical Service: A Multidisciplinary Team Training Concept.

OBJECTIVE: Mountain helicopter rescue operations often confront crews with unique challenges in which even minor errors can result in dangerous situations. Simulation training provides a promising tool to train the management of complex multidisciplinary settings, thus reducing the occurrence of fatal errors and increasing the safety for both the patient and the helicopter emergency medical service (HEMS) crew. METHODS: A simulation-based training, dedicated to mountain helicopter emergency medicine service, was developed and executed. We evaluated the impact of this training by the means of a pre- and posttraining self-assessment of 40 HEMS crewmembers. RESULTS: Multidisciplinary simulation-based educational training in HEMS is feasible. There was a significant increase in self-assessed competence in safety-related items of human factors and team resource management. The highest gain of competence was demonstrated by a trend in the domain of structured decision making. CONCLUSIONS: Interprofessional simulation-based team training could have the potential to impact patient outcomes and improve rescuer safety. Simulation trainings lead to a subjective increase of self-assuredness in the management of complex situations in a difficult working environment.

Mechanical chest compressions in an avalanche victim with cardiac arrest: an option for extreme mountain rescue operations.

Mountain rescue operations often present helicopter emergency medical service crews with unique challenges. One of the most challenging problems is the prehospital care of cardiac arrest patients during evacuation and transport. In this paper we outline a case in which we successfully performed a cardiopulmonary resuscitation of an avalanche victim. A mechanical chest-compression device proved to be a good way of minimizing hands-off time and providing high-quality chest compressions while the patient was evacuated from the site of the accident.

Benefit of mechanical chest compression devices in mountain HEMS: lessons learned from 1 year of experience and evaluation.

INTRODUCTION: Pre-hospital care of cardiac arrest patients in the mountain environment is one of the most challenging problems for helicopter medical emergency services (HEMS) teams. To provide high-quality chest compression with minimal hand s-off-time is very demanding in the alpine area. METHODS: We used and evaluated mechanical chest compression devices (Lucas and AutoPulse) and investigated if these are good and useful tools in the alpine HEMS. Over a period of 12 months we performed 7 CPRs in remote alpine terrain. CONCLUSION: On the strength of our past experience, CPR under special circumstances like deep hypothermia, in which a prolonged CPR is essential, the use of the Lucas and/or AutoPulse was an easy and sufficient tool even in difficult alpine terrain which requires special rescue missions like winch or MERS evacuation.

Enhancing patient safety: detection of in-hospital hazards and effect of training on detection (by training in a low-fidelity simulation Room of Improvement based on hospital-specific CIRS cases).

IMPORTANCE: Adequate situational awareness in patient care increases patient safety and quality of care. To improve situational awareness, an innovative, low-fidelity simulation method referred to as Room of Improvement, has proven effective in various clinical settings. OBJECTIVE: To investigate the impact after 3 months of Room of Improvement training on the ability to detect patient safety hazards during an intensive care unit shift handover, based on critical incident reporting system (CIRS) cases reported in the same hospital. METHODS: In this educational intervention, 130 healthcare professionals observed safety hazards in a Room of Improvement in a 2 (time 1 vs time 2)×2 (alone vs in a team) factorial design. The hazards were divided into immediately critical and non-critical. RESULTS: The results of 130 participants were included in the analysis. At time 1, no statistically significant differences were found between individuals and teams, either overall or for non-critical errors. At time 2, there was an increase in the detection rate of all implemented errors for teams compared with time 1, but not for individuals. The detection rate for critical errors was higher than for non-critical errors at both time points, with individual and group results at time 2 not significantly different from those at time 1. An increase in the perception of safety culture was found in the pre-post test for the questions whether the handling of errors is open and professional and whether errors are discussed in the team. DISCUSSION: Our results indicate a sustained learning effect after 12 weeks, with collaboration in teams leading to a significantly better outcome. The training improved the actual error detection rates, and participants reported improved handling and discussion of errors in their daily work. This indicates a subjectively improved safety culture among healthcare workers as a result of the situational awareness training in the Room of Improvement. As this method promotes a culture of safety, it is a promising tool for a well-functioning CIRS that closes the loop.

Accuracy between prehospital and hospital diagnosis in helicopter emergency medical services and its consequences for trauma care.

PURPOSE: For optimal prehospital trauma care, it is essential to adequately recognize potential life-threatening injuries in order to correctly triage patients and to initiate life-saving measures. The aim of the present study was to determine the accuracy of prehospital diagnoses suspected by helicopter emergency medical services (HEMS). METHODS: This retrospective multicenter study included patients from the Swiss Trauma Registry with ISS ≥ 16 or AIS head ≥ 3 transported by Switzerland's largest HEMS and subsequently admitted to one of twelve Swiss trauma centers from 01/2020 to 12/2020. The primary outcome was the comparison of injuries suspected prehospital with the final diagnoses obtained at the hospital using the abbreviated injury scale (AIS) per body region. As secondary outcomes, prehospital interventions were compared to corresponding relevant diagnoses. RESULTS: Relevant head trauma was the most commonly injured body region and was identified in 96.3% (95% CI: 92.1%; 98.6%) of the cases prehospital. Relevant injuries to the chest, abdomen, and pelvis were also common but less often identified prehospital [62.7% (95% CI: 54.2%; 70.6%), 45.5% (95% CI: 30.4%; 61.2%), and 61.5% (95% CI: 44.6%; 76.6%)]. Overall, 7 of 95 (7.4%) patients with pneumothorax received a chest decompression and in 22 of 39 (56.4%) patients with an instable pelvic fracture a pelvic binder was applied prehospital. CONCLUSION: Approximately half of severe chest, abdominal, and pelvic diagnoses made in hospital went undetected in the challenging prehospital environment. This underlines the difficult circumstances faced by the rescue teams. Potentially life-saving interventions such as prehospital chest decompression and increased use of a pelvic binder were identified as potential improvements to prehospital care.

Early sevoflurane sedation in severe COVID-19-related lung injury patients. A pilot randomized controlled trial.

BACKGROUND: This study aimed to assess a potential organ protective effect of volatile sedation in a scenario of severe inflammation with an early cytokine storm (in particular IL-6 elevation) in patients suffering from COVID-19-related lung injury with invasive mechanical ventilation and sedation. METHODS: This is a small-scale pilot multicenter randomized controlled trial from four tertiary hospitals in Switzerland, conducted between April 2020 and May 2021. 60 patients requiring mechanical ventilation due to severe COVID-19-related lung injury were included and randomized to 48-hour sedation with sevoflurane vs. continuous intravenous sedation (= control) within 24 h after intubation. The primary composite outcome was determined as mortality or persistent organ dysfunction (POD), defined as the need for mechanical ventilation, vasopressors, or renal replacement therapy at day 28. Secondary outcomes were the length of ICU and hospital stay, adverse events, routine laboratory parameters (creatinine, urea), and plasma inflammatory mediators. RESULTS: 28 patients were randomized to sevoflurane, 32 to the control arm. The intention-to-treat analysis revealed no difference in the primary endpoint with 11 (39%) sevoflurane and 13 (41%) control patients (p = 0.916) reaching the primary outcome. Five patients died within 28 days in each group (16% vs. 18%, p = 0.817). Of the 28-day survivors, 6 (26%) and 8 (30%) presented with POD (p = 0.781). There was a significant difference regarding the need for vasopressors (1 (4%) patient in the sevoflurane arm, 7 (26%) in the control one (p = 0.028)). Length of ICU stay, hospital stay, and registered adverse events within 28 days were comparable, except for acute kidney injury (AKI), with 11 (39%) sevoflurane vs. 2 (6%) control patients (p = 0.001). The blood levels of IL-6 in the first few days after the onset of the lung injury were less distinctly elevated than expected. CONCLUSIONS: No evident benefits were observed with short sevoflurane sedation on mortality and POD. Unexpectedly low blood levels of IL-6 might indicate a moderate injury with therefore limited improvement options of sevoflurane. Acute renal issues suggest caution in using sevoflurane for sedation in COVID-19. TRIAL REGISTRATION: The trial was registered on ClinicalTrials.gov (NCT04355962) on 2020/04/21.

The forgotten cohort-lessons learned from prehospital trauma death: a retrospective cohort study.

BACKGROUND: Trauma related deaths remain a relevant public health problem, in particular in the younger male population. A significant number of these deaths occur prehospitally without transfer to a hospital. These patients, sometimes termed "the forgotten cohort", are usually not included in clinical registries, resulting in a lack of information about prehospitally trauma deaths. The aim of the present study was to compare patients who died prehospital with those who sustained life-threatening injuries in order to analyze and potentially improve prehospital strategies. METHODS: This cohort study included all primary operations carried out by Switzerland's largest helicopter emergency medical service (HEMS) between January 1, 2011, and December 31, 2021. We included all adult trauma patients with life-threatening or fatal conditions. The outcome of this study is the vital status of the patient at the end of mission, i.e. fatal or life-threatening. Injury, rescue characteristics, and interventions of the forgotten trauma cohort, defined as patients with a fatal injury (NACA score of VII), were compared with life-threatening injuries (NACA score V and VI). RESULTS: Of 110,331 HEMS missions, 5534 primary operations were finally analyzed, including 5191 (93.8%) life-threatening and 343 (6.2%) fatal injuries. More than two-thirds of patients (n = 3772, 68.2%) had a traumatic brain injury without a significant difference between the two groups (p > 0.05). Thoracic trauma (44.6% vs. 28.7%, p < 0.001) and abdominal trauma (22.2% vs. 16.1%, p = 0.004) were more frequent in fatal missions whereas pelvic trauma was similar between the two groups (13.4% vs. 12.9%, p = 0.788). Pneumothorax decompression rate (17.2% vs. 3.7%, p < 0.001) was higher in the forgotten cohort group and measures for bleeding control (15.2% vs. 42.7%, p < 0.001) and pelvic belt application (2.9% vs. 13.1% p < 0.001) were more common in the life-threating injury group. CONCLUSION: Chest decompression rates and measures for early hemorrhage control are areas for potential improvement in prehospital care.

Oral transmucosal fentanyl citrate analgesia in prehospital trauma care: an observational cohort study.

BACKGROUND: Pain is one of the major prehospital symptoms in trauma patients and requires prompt management. Recent studies have reported insufficient analgesia after prehospital treatment in up to 43% of trauma patients, leaving significant room for improvement. Good evidence exists for prehospital use of oral transmucosal fentanyl citrate (OTFC) in the military setting. We hypothesized that the use of OTFC for trauma patients in remote and challenging environment is feasible, efficient, safe, and might be an alternative to nasal and intravenous applications. METHODS: This observational cohort study examined 177 patients who were treated with oral transmucosal fentanyl citrate by EMS providers in three ski and bike resorts in Switzerland. All EMS providers had previously been trained in administration of the drug and handling of potential adverse events. RESULTS: OTFC caused a statistically significant and clinically relevant decrease in the level of pain by a median of 3 (IQR 2 to 4) in NRS units (P < 0.0001). Multiple linear regression analysis showed a significant absolute reduction in pain, with no differences in all age groups and between genders. No major adverse events were observed. CONCLUSIONS: Prehospital administration of OTFC is safe, easy, and efficient for extrication and transport across all age groups, gender, and types of injuries in alpine environments. Side effects were few and mild. This could provide a valuable alternative in trauma patients with severe pain, without the delay of inserting an intravenous line, especially in remote areas, where fast action and easy administration are important.

Factors influencing on-scene time in a physician-staffed helicopter emergency medical service (HEMS): a retrospective observational study.

BACKGROUND: For helicopter emergency service systems (HEMS), the prehospital time consists of response time, on-scene time and transport time. Little is known about the factors that influence on-scene time or about differences between adult and paediatric missions in a physician-staffed HEMS. METHODS: We analysed the HEMS electronic database of Swiss Air-Rescue from 01-01-2011 to 31-12-2021 (N = 110,331). We included primary missions and excluded missions with National Advisory Committee for Aeronautics score (NACA) score 0 or 7, resulting in 68,333 missions for analysis. The primary endpoint 'on-scene time' was defined as first physical contact with the patient until take-off to the hospital. A multivariable linear regression model was computed to examine the association of diagnosis, type and number of interventions and monitoring, and patient's characteristics with the primary endpoint. RESULTS: The prehospital time and on-scene time of the missions studied were, respectively, 50.6 [IQR: 41.0-62.0] minutes and 21.0 [IQR: 15.0-28.6] minutes. Helicopter hoist operations, resuscitation, airway management, critical interventions, remote location, night-time, and paediatric patients were associated with longer on-scene times. CONCLUSIONS: Compared to adult patients, the adjusted on-scene time for paediatric patients was longer. Besides the strong impact of a helicopter hoist operation on on-scene time, the dominant factors contributing to on-scene time are the type and number of interventions and monitoring: improving individual interventions or performing them in parallel may offer great potential for reducing on-scene time. However, multiple clinical interventions and monitoring interact and are not single interventions. Compared to the impact of interventions, non-modifiable factors, such as NACA score, type of diagnosis and age, make only a minor contribution to overall on-scene time.