Hoist missions and seasonal influences on air rescue service helicopters: A descriptive study based on three German helicopters

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Of these, 10 helicopters are equipped with a rescue hoist. There is limited data on the frequency of hoist operations, tracer diagnoses, and influences such as weather and vacation periods. This study examines hoist deployment frequencies, tracer diagnostics, and the influence of vacation season at three German helicopter sites. Methods In the period from 01 Feb. 2018 to 31 Dec. 2021, a total of 1340 hoist missions were retrospectively examined descriptively for the helicopters Christoph 15 (n = 196), Christoph 1 (n = 316), and Christoph Murnau (n = 828) using their electronic mission documentation. Results 56.89% of the hoist missions were flown during the summer months, with vacation periods having a small effect on Christoph 1 only. Traumatological diagnoses clearly predominated on all three helicopters, with 75.0% on Christoph 15, 78.8% on Christoph 1, and 52.17% on Christoph Murnau. Among the traumatological indications, extremity trauma (39.29%) was the most frequent, followed by spinal injuries (10.71%), traumatic brain injuries (8.67%), and polytrauma (4.59%). Among internal medicine emergencies, collapse/syncope (5.61%) and cardiovascular arrest (3.06%) were the most common, followed by acute coronary syndromes, anaphylaxis, and hypothermia (2.55% each). Conclusions Despite the predominance of extremity injuries and syncope/collapse, where risk stratification was the primary concern and complex medical care was usually not required, there were also dynamic and complex emergency events, e.g., cardiovascular arrests, traumatic brain injuries, and anaphylaxis. Not even the Covid-19 pandemic led to a significant shift in distribution. Surprisingly, the influence of vacation periods on the frequency of operations was less pronounced even in tourism-oriented regions. For future research, other aspects need to be studied, such as the impact of severe weather on helicopter operations in the context of climate change, as well as personnel strategy (e.g., 3-person vs. 4-person crews). Helicopter Emergency Medical Service HEMS Air Rescue Hoist Alpine Rescue Mountain Medicine Figures Figure 1 Figure 2 Background Helicopter emergency medical services (HEMS), also known as air ambulance services, have evolved from the combat rescue missions during the Korean War to a modern emergency systems tool [ 1 ]. Since then, the military has established a search and rescue (SAR) system based on helicopters (with hoists) around the coastlines. In Germany, "Christoph 1" based in Munich was the first civilian rescue helicopter in 1970 [ 1 ]. Christoph 1 was also the first civilian helicopter with a hoist, which went into routine operation in 1995 [ 2 ]. For years, there has been an ongoing debate on the use and cost of HEMS versus ground-based emergency medical services (GEMS) [ 3 ]. Many articles discuss the advantages, especially in terms of "physician on scene" and "transport time to hospital" [ 4 ]. Especially in accidents involving trauma, HEMS was shown to be an effort. Nowadays, there are several additional factors [ 5 ]. On the one hand, the growth of tourism in the European Alps resulted in an increase in the number of helicopters (with hoist or longline systems). During the winter season, 16 helicopters are stationed in Tyrol [ 6 ]. On the other hand, climate change and extreme weather situations are becoming more critical. In the 2021 flood disaster in the German Ahr Valley, a hoist-equipped helicopter transferred from Munich flew more than 56 hoist missions on the first day. A narrative literature review primarily identifies gaps in the area of civilian hoist operations, outside of offshore rescues and extremely remote situations. These gaps concern, among other things, civilian mountain rescue with hoist-assisted rescue due to traumatological causes of emergency, including seasonal frequency during holidays and vacation periods. Similarly, there is no systematic data on the frequency of hoist rescue missions during weather and severe weather events. While operations in the alpine high mountains are well documented, there are gaps in touristically relevant areas such as the central mountain ranges. To discuss the benefits and advantages of hoist rescue missions for the patient (safety) and the system (efficiency), this article describes the multiple indications and uses of HEMS with hoists. The goal of this article is to provide a descriptive analysis of hoist operations in German HEMS missions using the example of three HEMS stations. In this context, we will answer two research questions (RQ). All of them relate to the observation period from 01 Feb. 2018 to 31 Dec. 2021: RQ1 Which diagnoses triggered the call for rescue helicopters for hoist missions, considering absolute and relative frequencies, divided into internal (non-traumatological) and traumatological indications? RQ2 What influence do vacation periods have on the frequency of alert for rescue helicopters for hoist missions? Methods Aim The aim is a descriptive-statistical summary of the tracer diagnoses in the period from 05 Feb. 2018 to 27 Dec. 2021 to get an overview of medical deployment priorities. In addition, the ratio of alerts to emergency medical indications, actual winch operations, and actual transports performed is presented to shed light on the proportion of technical rescues to medical indications. This knowledge is needed for strategic site planning, helicopter equipment, and the training of HEMS technical crew members (HEMS-TC), such as flight paramedics. Design The mission documentation for Christoph 15, during the period of 01 Feb. 2018 to 31 Dec. 2021, underwent a detailed retrospective analysis. Christoph 15 was chosen for the study because it had just been equipped with a hoist shortly before the survey period. To facilitate the evaluation of the evaluated data, the data of Christoph 15 are compared with the mission data of Christoph 1 and Christoph Murnau. Therefore, the scientific classification is a naturalistically observed, non-experimental design with multi-group comparison. Setting Christoph 15 is the call sign of a rescue helicopter operated by ADAC Luftrettung in the city of Straubing (Bavaria, Germany), which is located in a low mountain range. The city has a population of about 50,000 and is part of a region with high touristic resources. Christoph 1 has always been stationed in Munich, a metropolitan region in the south of Germany. Christoph Murnau is named after the town where it is stationed. The location of the small town of Murnau in the foothills of the Alps makes this dual-use helicopter ideal for alpine and high alpine operations. ADAC Luftrettung operates a fleet of rescue helicopters, staffed by trained medical personnel and equipped with specialized medical equipment to provide care to patients on scene and during transport. Christoph 15 is also equipped with a winch operated by trained hoist operators. In the context of rescue operations, a hoist may be used to lift a person from a dangerous or inaccessible location, such as a steep cliff or a collapsed building. Hoist operations require careful planning and coordination to ensure the safety of all involved parties, including the operator of the hoist, the person or object being lifted, and any other individuals in the immediate area. In Germany, all primary rescue helicopters are marked by a number (e.g., Christoph 1, Christoph 15, etc.) and all dual-use helicopters, which are mainly used for secondary flights (interhospital transfer) with the possibility of primary rescue, are marked by the station name (Christoph Murnau, Christoph Rheinland, etc.). All of the German EMS helicopters are staffed with a physician and a “flight paramedic”, the so-called HEMS technical crew member (HEMS TC). There are two different staffing strategies: First option – three persons: The HEMS TC operates the hoist (helicopter hoist operator, HHO) while the physician is alone on the ground and waits for further support, e.g., ground EMS. This is how it is done on Christoph 15. Second option – four persons: The helicopter is staffed with two HEMS TCs, one handling the ground rescue with the physician while the other one takes on the role of the HHO. This is how it is done on Christoph 1 and Christoph Murnau. Description of material Documentation of rescue and medical data is an integral part of rescue operations. In the case of Christoph 15, Christoph 1, and Christoph Murnau, this documentation is carried out digitally by the crew and transferred to a database in the so-called air rescue information and communication system (LIKS – Luftrettungsinformations- und kommunikationssystem of ADAC Luftrettung gGmbH München). Components of the documentation include, for example, geo-information data (e.g., ZIP code), information on a performed winch operation, such as rope length and winch method, but also medical information on the patient's condition as well as a short epicrisis. The files generated are used in this study as a basis for descriptive statistics. Types of statistical analysis, including a power calculation : All statistical analyses were performed with RStudio (2022.07.2, R version 4.2.2). In the first step, the data was prepared and missing values were analyzed. To answer RQ 1 & RQ 2, frequency, dispersion- and position parameters were used. To allow for comparison, the data from Christoph 1, Christoph 15, and Christoph Murnau were compared for the same period. The dataset was analyzed to distinguish between traumatological and (non-traumatological, s.o.) procedures and to verify hoist operations. Two additional variables were created to allow a nominally scaled allocation. As the diagnoses were documented by the doctors and paramedics in free text without any standardization, there were abbreviations and descriptions that had to be analyzed manually. For example: A tibia fracture was abbreviated as “Tib#”, and in some cases ICD codes were entered. The document analysis was carried out in the style of a simplified qualitative content analysis with MAXQDA 2020 [Version 20.4.2]. The result was a mapping of history and diagnosis to tracer diagnoses. To answer RQ 2 , vacation periods were compared to non-vacation periods. All legal holidays in Bavaria were also counted as vacation periods. Table 1 shows these in terms of absolute and relative frequencies. During the study period, all data sets on the winch operations of the three helicopters were evaluated; i.e., this study represents a complete survey. We quote Walters [ 7 ], who elaborates on the subject: “[…] Significance tests are not necessary—and, in fact, are inappropriate—if data are available for the entire population.” Quality of measurements Interrater agreement was determined for both the generated variables and the tracer diagnoses based on document analysis. As these are dichotomous assessments, deviations after processing are not acceptable. For this purpose, tracer diagnoses were made first, anamnesis and diagnosis were then analyzed in parallel by CE and PD, and finally interrater agreement was tested. Results Missing Data There was no missing data for the frequency of the hoist missions analyzed. Descriptive statistics A total of 196 hoist operations were carried out by Christoph 15 during the survey period. Christoph 1 flew 316 hoist missions and Christoph Murnau 828 during the same period. The detailed results are presented below in the order of the research questions. RQ1 – Frequency and tracer diagnoses The frequency of hoist missions differed greatly between the three helicopters. The alpine helicopter Christoph Murnau leads the frequency statistics, followed by the metropolitan helicopter Christoph 1 and then Christoph 15, which is located at the edge of the Bavarian Forest. For all helicopters, there was a gradual increase in hoist missions over the years. Table 1 shows the absolute and relative frequencies by month and year. Table 1: Hoist mission frequencies of Christoph 15 compared with Christoph 1 and Christoph Murnau Christoph 15 Christoph 1 Christoph Murnau Absolute frequency Relative frequency (%) Absolute frequency Relative frequency (%) Absolute frequency Relative frequency (%) Total Missions by month January February March April May June July August September October November December Missions by year 2018 2019 2020 2021 196 13 18 11 11 20 23 24 30 19 19 5 3 33 37 61 65 100 6.63 9.18 5.61 5.61 10.20 11.73 12.24 15.31 9.69 9.69 2.55 1.53 16.83 18.88 31.12 33.16 316 10 21 19 19 20 39 42 45 53 26 14 8 58 81 91 86 100 3.16 6.65 6.01 6.01 6.33 12.34 13.29 14.24 16.77 8.23 4.43 2.53 18.35 25.63 28.80 27.21 828 11 46 45 41 79 96 104 162 127 75 21 21 179 200 204 245 100 1.33 5.56 5.43 4.95 9.54 11.59 12.56 19.57 15.34 9.06 2.54 2.54 21.62 24.15 24.64 29.59 The data presented in Table 1 shows that 96 missions (48.97%) were flown by Christoph 15 during the summer and late summer months (June - September), 179 missions (56.64%) by Christoph 1, and 489 missions (59.06%) by Christoph Murnau. This shows that a total of 764 hoist missions (56.89%) were flown during the summer months. Figures 1 show the mission frequencies of Christoph 15, Christoph 1, and Christoph Murnau per year and month as stacked bar charts. Figure 2 visualizes the absolute and relative mission frequencies that are detailed in Table 1. While Table 1 only shows the absolute and relative deployments, an evaluation of the tracer diagnoses is necessary to answer RQ 1. Table 2 shows that for Christoph 15, the traumatological indications clearly predominate with a factor of 3.13. The other two helicopters show similar patterns. Table 2: Mission frequency of Christoph 15, Christoph 1, and Christop Murnau in the years 2018 - 2021 Christoph 15 Christoph 1 Christoph Murnau Absolute frequency Relative frequency (%) Absolute frequency Relative frequency (%) Absolute frequency Relative frequency (%) Total Internal Trauma Hoist No hoist Missions by year 2018 Trauma Internal Hoist No hoist 2019 Trauma Internal Hoist No hoist 2020 Trauma Internal Hoist No hoist 2021 Trauma Internal Hoist No hoist 47 147 194 1 23 10 33 0 29 8 63 1 48 13 60 1 47 16 65 0 23.98 75.00 98.98 0.51 11.73 5.1 16.84 0 14.80 4.08 18.37 0.51 24.47 6.63 30.61 0.51 23.98 8.16 33.16 0 249 67 290 26 45 13 58 0 69 12 76 5 75 16 86 5 26 60 70 16 21.20 78.80 91.77 8.23 14.24 4.11 29.59 0 21.84 3.80 38.78 2.55 23.73 5.06 38.78 2.55 8.23 18.99 35.71 8.16 212 432 761 1 92 56 168 1 111 58 194 0 104 50 188 0 125 48 211 0 25.60 52.17 91.91 0.12 11.11 6.76 20.29 0.12 13.41 7.00 23.43 0 12.56 6.04 22.71 0 15.10 5.80 25.48 0 An analysis of the most common tracer diagnoses of Christoph 15 (Table 3) showed that extremity trauma clearly dominated the surgical indications, while collapse and syncope led the internal medicine indications. RQ 2 : Table 4 shows the vacation days in the study area . Not only the weekdays were counted, but also the weekends in between and the weekends immediately before and after. Example: In 2018, the winter holidays in Bavaria began on Monday, 12 Feb. and ended on Friday, 16 Feb. The dates 10 Feb. (Saturday), 11 Feb. (Sunday), 17 Feb. (Saturday), and 18 Feb. (Sunday) were counted as holidays. Table 4: Vacation days in study area Year / Vacation Days Absolute frequency Relative frequency (%) Total Vacation periods No vacation days 2018 Vacation days No vacation days 2019 Vacation days No vacation days 2020 Vacation days No vacation days 2021 Vacation days No vacation days 1429 446 983 334 105 229 365 112 253 365 115 250 365 114 251 100.00 31.21 68.79 100.00 31.44 68.56 100.00 30.68 69.32 100.00 31.51 68.49 100.00 31.23 68.77 Table 5 shows the frequency of rescue operations with hoist , in each case during vacation and holiday periods in Bavaria, compared to non-vacation periods. Table 5: Comparison of operation frequency during vacation periods and non-vacation periods Absolute frequency Relative frequency (%) Total (n = 1340) Vacation periods No vacation periods Christop 15 Vacation periods No vacation periods Christoph 1 Vacation periods No vacation periods Christoph Murnau Vacation periods No vacation periods 452 888 79 117 94 222 279 549 33.73 66.27 40.31 59.69 29.75 70.25 33.70 66.30 Discussion In this retrospective study, 1340 rescue helicopter missions were examined at the locations of Christoph 15 (Straubing), Christoph 1 (Munich), and Christoph Murnau (Murnau) in the period from 01 Feb. 2018 to 31 Dec. 2021. In all cases, an indication for the use of the rescue hoist was given by the managing control center. The reason was the introduction of the rescue hoist on Christoph 15. Interpretation With regard to RQ 1 , if we look at the question of which diagnoses (or reports) triggered the deployment of the three German air rescue helicopters, it immediately becomes apparent that, in terms of frequency, injuries to the extremities were the most frequent, both in trauma emergencies and overall. Trauma to the extremities can usually be managed well with appropriate restraint, immobilization, and anesthesia. Complex emergency medical interventions are usually not necessary and were not found in any of the cases analyzed in the study. Collapse and syncope were the most common internal medicine emergencies. Here, too, the focus should not be on complex interventions, but rather on risk stratification in the sense of early detection of high-risk syncopal episodes [ 8 ]. A different picture is seen for diagnoses of traumatic brain injuries, polytrauma, acute coronary syndrome, spinal injuries, and cardiovascular arrest, which can result in complex action situations. Overall, for all hoist missions in all months analyzed, trauma events were clearly the most frequent. It is also clear from the data that the vast majority of hoist operations were due to an objectifiable medical problem. Overall, it is surprising that almost all calls for hoist rescue were actually answered with a hoist. This is surprising in that such accurate call retrieval and situation assessment by dispatchers is often not possible. In this context, the appropriateness of the use of a hoist must be discussed critically, and the question must be raised as to whether a cognitive fixation bias in the sense of a self-fulfilling prophecy may have been the driving force behind some of the hoist applications carried out. It is also interesting to note that the frequency of lift missions increased rapidly after the first year (2018) of implementation on Christoph 15, and then remained at a nearly constant level, analogous to Christoph Murnau and Christoph 1. In RQ 2, we examined the influence of regional vacation periods on the frequency of hoist missions. As expected, the absolute number of hoist missions outside the vacation period (887 days) was greater than during the vacation period (425 days). On the basis of the distribution of missions during vacation periods, it can be concluded that the influence of vacation periods on mission frequency is less pronounced, even in tourism-oriented regions. The Covid-19 pandemic did not lead to any significant shift in the distribution either. Only in the case of Christoph 15 can a higher proportion be observed during the vacation period. This is contrary to the availability of rescue helicopters in Austria, especially in the winter months. The number of rescue helicopters is being deliberately increased in order to be able to handle an increased volume of operations, especially during holiday periods. Finally, it should be emphasized that the analysis of when and which deployment took place is extremely important. This is particularly the case when planning to provide a rescue winch and cover the costs for it. Limitations This study represents three helicopter sites. In Germany, there are currently 67 rescue helicopters and 12 dual use helicopters, of which 10 have a hoist. Due to geographic, structural, and organizational differences, generalization is not always possible or useful. The quality of the study also depends on the quality of the documentation provided by the helicopter crews. If information was incomplete or incorrect, this may have affected the results of the study. This also applies to the tracer diagnoses listed. If this information is missing or if the leading problem is not correctly documented, misinterpretations may occur. This not only underscores the importance of thorough documentation, but also of human-centered documentation systems that are easy to use, interoperate with other IT components, and can be viewed as a time saver with good user acceptance. Future research For future research, other aspects need to be investigated, such as the impact of severe weather events on helicopter operations in the context of climate change. The 2021 flood disaster in the Ahr Valley in Germany showed that helicopter stations without a hoist can very quickly receive an urgent alert to rescue people from life-threatening situations. The question also arises as to whether, in addition to the dispatch center, which provides a very good indication, any further indication by the crew itself is necessary as part of the reconnaissance of the landing site. Increasing development and density also raises the question of whether the unattended intervals could be shortened by having the physician depart by hoist [ 9 ]. Furthermore, fundamental strategies of the hoist concept should be examined: What are the advantages of a four-person crew (as on Christoph 1 and Christoph Murnau) over a three-person crew (as on Christoph 15)? Conclusions In this retrospective study based on the mission documentation of the hoist missions of three EMS helicopters, the overall leading incidence was found to be extremity injuries without the subsequent need for complex medical intervention. Collapse and syncope were the leading causes of non-traumatological emergencies, although here as well, there was usually no need for complex medical care and the focus was on risk stratification. However, this should not mask the fact that a small but not insignificant proportion of tracer diagnoses point to injuries and diseases that can lead to complex, time-critical, and dynamic situations, such as traumatic brain injury, acute coronary syndrome, spinal injuries, and cardiac arrest. It is also noteworthy that almost all hoist mission alerts were actually answered with a hoist rescue. Surprisingly, the influence of vacation periods on the frequency of operations was less pronounced even in tourism-oriented regions. Minor effects were only observed for one helicopter (Christoph 1). Also, the Covid-19 pandemic did not lead to any significant shift in distribution. After the introduction of the hoist on Christoph 15 (Straubing, Bavaria), a rapid stabilization of hoist deployment frequency can be observed, which indicates a corresponding acceptance of and need for it. In future research, other aspects need to be studied, such as the impact of severe weather on helicopter operations in the context of climate change, as well as personnel strategy (e.g., 3-person vs. 4-person crews). Declarations Ethics approval: Ethikkommision bei der LMU München, Projekt Nr.: 23-0936 KB: According to an assessment by the LMU Ethicscommittee, there is no need for advice. Consent for publication: Not Applicable Data availability: The datasets used and/or analyzed during the current study are available from the corresponding author on reasonable request. Competing interest: PD and CE do not declare any conflicts. DW is the medical director of ADAC Luftrettung GmbH for the South Germany region. Funding: No grant or funding was received. Authors´ contributions: DW was responsible for coordinating the working group. CE was responsible for formatting the manuscript, submission, and data preparation and analysis. DW and PD contributed their expertise in air rescue mainly in the presentation of the current situation in Germany and the discussion of the results. PD and DW were also involved in the internal quality management of the study, e.g., crosschecking of results and data transmission. JS contributed extensively to the discussion. All authors revised the text. Acknowledgments: „Many thanks to Prof. Dr. Bernhard Zwißler, [Hospital of the Ludwig-Maximilians-University Munich (LMU), Department of Anesthesiology, Munich, Germany] and Dr. David Häske [Universitätsklinikum Tübingen, Center for Public Health and Health Services Research], for scientific advice as well as Mrs Sonnhild Naminga, Fraunhofer IESE, for the linguistic proofreading.“ References Andruszkow H, Hildebrand F, Lefering R, Pape H-C, Hoffmann R, Schweigkofler U. Ten years of helicopter emergency medical services in Germany: do we still need the helicopter rescue in multiple traumatised patients? Injury 2014; 45 Suppl 3:S53-8. doi: 10.1016/j.injury.2014.08.018. Ruppert M, van Boemmel T, Lefering R, Fiala W, Gäßler M. Einsatzspektrum in der Hoistenrettung. Notfall Rettungsmed 2017; 20(6):486–94. doi: 10.1007/s10049-017-0314-6. Tsuchiya A, Tsutsumi Y, Yasunaga H. 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Intended for physicians and other advanced life support personnel. Scand J Trauma Resusc Emerg Med 2020; 28(1):117. doi: 10.1186/s13049-020-00790-1. Walters WH. Survey design, sampling, and significance testing: Key issues. The Journal of Academic Librarianship 2021; 47(3):102344. doi: 10.1016/j.acalib.2021.102344. Sutton R, Ricci F, Fedorowski A. Risk stratification of syncope: Current syncope guidelines and beyond. Auton Neurosci 2021; 238:102929. doi: 10.1016/j.autneu.2021.102929. Pietsch U, Knapp J, Mann M, Meuli L, Lischke V, Tissi M et al. Incidence and challenges of helicopter emergency medical service (HEMS) rescue missions with helicopter hoist operations: analysis of 11,228 daytime and nighttime missions in Switzerland. Scand J Trauma Resusc Emerg Med 2021; 29(1):92. doi: 10.1186/s13049-021-00898-y. Additional Declarations Competing interest reported. PD and CE do not declare any conflicts. DW is the medical director of ADAC Luftrettung GmbH for the South Germany region. 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PD and CE do not declare any conflicts. DW is the medical director of ADAC Luftrettung GmbH for the South Germany region.","formattedTitle":"Hoist missions and seasonal influences on air rescue service helicopters: A descriptive study based on three German helicopters","fulltext":[{"header":"Background","content":"\u003cp\u003eHelicopter emergency medical services (HEMS), also known as air ambulance services, have evolved from the combat rescue missions during the Korean War to a modern emergency systems tool [\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e]. Since then, the military has established a search and rescue (SAR) system based on helicopters (with hoists) around the coastlines. In Germany, \"Christoph 1\" based in Munich was the first civilian rescue helicopter in 1970 [\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e]. Christoph 1 was also the first civilian helicopter with a hoist, which went into routine operation in 1995 [\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e]. For years, there has been an ongoing debate on the use and cost of HEMS versus ground-based emergency medical services (GEMS) [\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e]. Many articles discuss the advantages, especially in terms of \"physician on scene\" and \"transport time to hospital\" [\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e]. Especially in accidents involving trauma, HEMS was shown to be an effort. Nowadays, there are several additional factors [\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eOn the one hand, the growth of tourism in the European Alps resulted in an increase in the number of helicopters (with hoist or longline systems). During the winter season, 16 helicopters are stationed in Tyrol [\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e]. On the other hand, climate change and extreme weather situations are becoming more critical. In the 2021 flood disaster in the German Ahr Valley, a hoist-equipped helicopter transferred from Munich flew more than 56 hoist missions on the first day.\u003c/p\u003e \u003cp\u003eA narrative literature review primarily identifies gaps in the area of civilian hoist operations, outside of offshore rescues and extremely remote situations. These gaps concern, among other things, civilian mountain rescue with hoist-assisted rescue due to traumatological causes of emergency, including seasonal frequency during holidays and vacation periods. Similarly, there is no systematic data on the frequency of hoist rescue missions during weather and severe weather events. While operations in the alpine high mountains are well documented, there are gaps in touristically relevant areas such as the central mountain ranges.\u003c/p\u003e \u003cp\u003eTo discuss the benefits and advantages of hoist rescue missions for the patient (safety) and the system (efficiency), this article describes the multiple indications and uses of HEMS with hoists. The goal of this article is to provide a descriptive analysis of hoist operations in German HEMS missions using the example of three HEMS stations. In this context, we will answer two research questions (RQ). All of them relate to the observation period from 01 Feb. 2018 to 31 Dec. 2021:\u003c/p\u003e \u003cp\u003e \u003cstrong\u003eRQ1\u003c/strong\u003e \u003c/p\u003e\u003cp\u003eWhich diagnoses triggered the call for rescue helicopters for hoist missions, considering absolute and relative frequencies, divided into internal (non-traumatological) and traumatological indications?\u003c/p\u003e \u003cp\u003e\u003c/p\u003e \u003cp\u003e \u003cstrong\u003eRQ2\u003c/strong\u003e \u003c/p\u003e\u003cp\u003eWhat influence do vacation periods have on the frequency of alert for rescue helicopters for hoist missions?\u003c/p\u003e"},{"header":"Methods","content":"\u003cp\u003e \u003cstrong\u003eAim\u003c/strong\u003e \u003c/p\u003e\u003cp\u003eThe aim is a descriptive-statistical summary of the tracer diagnoses in the period from 05 Feb. 2018 to 27 Dec. 2021 to get an overview of medical deployment priorities. In addition, the ratio of alerts to emergency medical indications, actual winch operations, and actual transports performed is presented to shed light on the proportion of technical rescues to medical indications. This knowledge is needed for strategic site planning, helicopter equipment, and the training of HEMS technical crew members (HEMS-TC), such as flight paramedics.\u003c/p\u003e\u003cp\u003e \u003cstrong\u003eDesign\u003c/strong\u003e \u003c/p\u003e\u003cp\u003eThe mission documentation for Christoph 15, during the period of 01 Feb. 2018 to 31 Dec. 2021, underwent a detailed retrospective analysis. Christoph 15 was chosen for the study because it had just been equipped with a hoist shortly before the survey period. To facilitate the evaluation of the evaluated data, the data of Christoph 15 are compared with the mission data of Christoph 1 and Christoph Murnau. Therefore, the scientific classification is a naturalistically observed, non-experimental design with multi-group comparison.\u003c/p\u003e\u003cp\u003e \u003cstrong\u003eSetting\u003c/strong\u003e \u003c/p\u003e\u003cp\u003eChristoph 15 is the call sign of a rescue helicopter operated by ADAC Luftrettung in the city of Straubing (Bavaria, Germany), which is located in a low mountain range. The city has a population of about 50,000 and is part of a region with high touristic resources. Christoph 1 has always been stationed in Munich, a metropolitan region in the south of Germany. Christoph Murnau is named after the town where it is stationed. The location of the small town of Murnau in the foothills of the Alps makes this dual-use helicopter ideal for alpine and high alpine operations.\u003c/p\u003e\u003cp\u003eADAC Luftrettung operates a fleet of rescue helicopters, staffed by trained medical personnel and equipped with specialized medical equipment to provide care to patients on scene and during transport. Christoph 15 is also equipped with a winch operated by trained hoist operators. In the context of rescue operations, a hoist may be used to lift a person from a dangerous or inaccessible location, such as a steep cliff or a collapsed building. Hoist operations require careful planning and coordination to ensure the safety of all involved parties, including the operator of the hoist, the person or object being lifted, and any other individuals in the immediate area.\u003c/p\u003e\u003cp\u003eIn Germany, all primary rescue helicopters are marked by a number (e.g., Christoph 1, Christoph 15, etc.) and all dual-use helicopters, which are mainly used for secondary flights (interhospital transfer) with the possibility of primary rescue, are marked by the station name (Christoph Murnau, Christoph Rheinland, etc.). All of the German EMS helicopters are staffed with a physician and a “flight paramedic”, the so-called HEMS technical crew member (HEMS TC). There are two different staffing strategies: First option – three persons: The HEMS TC operates the hoist (helicopter hoist operator, HHO) while the physician is alone on the ground and waits for further support, e.g., ground EMS. This is how it is done on Christoph 15. Second option – four persons: The helicopter is staffed with two HEMS TCs, one handling the ground rescue with the physician while the other one takes on the role of the HHO. This is how it is done on Christoph 1 and Christoph Murnau.\u003c/p\u003e\u003cp\u003e \u003cstrong\u003eDescription of material\u003c/strong\u003e \u003c/p\u003e\u003cp\u003eDocumentation of rescue and medical data is an integral part of rescue operations. In the case of Christoph 15, Christoph 1, and Christoph Murnau, this documentation is carried out digitally by the crew and transferred to a database in the so-called air rescue information and communication system (LIKS – Luftrettungsinformations- und kommunikationssystem of ADAC Luftrettung gGmbH München). Components of the documentation include, for example, geo-information data (e.g., ZIP code), information on a performed winch operation, such as rope length and winch method, but also medical information on the patient's condition as well as a short epicrisis. The files generated are used in this study as a basis for descriptive statistics.\u003c/p\u003e\u003cp\u003e \u003cb\u003eTypes of statistical analysis, including a power calculation\u003c/b\u003e: All statistical analyses were performed with RStudio (2022.07.2, R version 4.2.2). In the first step, the data was prepared and missing values were analyzed. To answer RQ 1 \u0026amp; RQ 2, frequency, dispersion- and position parameters were used. To allow for comparison, the data from Christoph 1, Christoph 15, and Christoph Murnau were compared for the same period. The dataset was analyzed to distinguish between traumatological and (non-traumatological, s.o.) procedures and to verify hoist operations. Two additional variables were created to allow a nominally scaled allocation. As the diagnoses were documented by the doctors and paramedics in free text without any standardization, there were abbreviations and descriptions that had to be analyzed manually. For example: A tibia fracture was abbreviated as “Tib#”, and in some cases ICD codes were entered. The document analysis was carried out in the style of a simplified qualitative content analysis with MAXQDA 2020 [Version 20.4.2]. The result was a mapping of history and diagnosis to tracer diagnoses. To answer \u003cb\u003eRQ 2\u003c/b\u003e, vacation periods were compared to non-vacation periods. All legal holidays in Bavaria were also counted as vacation periods. Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e shows these in terms of absolute and relative frequencies.\u003c/p\u003e\u003cp\u003eDuring the study period, all data sets on the winch operations of the three helicopters were evaluated; i.e., this study represents a complete survey. We quote Walters [\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e], who elaborates on the subject: “[…] Significance tests are not necessary—and, in fact, are inappropriate—if data are available for the entire population.”\u003c/p\u003e\u003cp\u003e \u003cstrong\u003eQuality of measurements\u003c/strong\u003e \u003c/p\u003e\u003cp\u003eInterrater agreement was determined for both the generated variables and the tracer diagnoses based on document analysis. As these are dichotomous assessments, deviations after processing are not acceptable. For this purpose, tracer diagnoses were made first, anamnesis and diagnosis were then analyzed in parallel by CE and PD, and finally interrater agreement was tested.\u003c/p\u003e"},{"header":"Results","content":"\u003cp\u003e\u003cstrong\u003eMissing Data\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThere was no missing data for the frequency of the hoist missions analyzed.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eDescriptive statistics\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eA total of 196 hoist operations were carried out by Christoph 15 during the survey period. Christoph 1 flew 316 hoist missions and Christoph Murnau 828 during the same period. The detailed results are presented below in the order of the research questions.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eRQ1 \u0026ndash; Frequency and tracer diagnoses\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe frequency of hoist missions differed greatly between the three helicopters. The alpine helicopter Christoph Murnau leads the frequency statistics, followed by the metropolitan helicopter Christoph 1 and then Christoph 15, which is located at the edge of the Bavarian Forest. For all helicopters, there was a gradual increase in hoist missions over the years. Table \u003cspan\u003e1\u003c/span\u003e shows the absolute and relative frequencies by month and year.\u003c/p\u003e\n\u003cp\u003eTable 1: Hoist mission frequencies of Christoph 15 compared with Christoph 1 and Christoph Murnau\u003c/p\u003e\n\u003cdiv\u003e\n \u003ctable border=\"1\" cellspacing=\"0\" cellpadding=\"0\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd width=\"20.330578512396695%\" rowspan=\"2\" valign=\"top\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd width=\"24.462809917355372%\" colspan=\"2\" valign=\"top\"\u003e\n \u003cp\u003eChristoph 15\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"27.272727272727273%\" colspan=\"2\" valign=\"top\"\u003e\n \u003cp\u003eChristoph 1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"27.93388429752066%\" colspan=\"2\" valign=\"top\"\u003e\n \u003cp\u003eChristoph Murnau\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"13.900414937759336%\" valign=\"top\"\u003e\n \u003cp\u003eAbsolute frequency\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.804979253112034%\" valign=\"top\"\u003e\n \u003cp\u003eRelative frequency (%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.804979253112034%\" valign=\"top\"\u003e\n \u003cp\u003eAbsolute frequency\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"17.42738589211618%\" valign=\"top\"\u003e\n \u003cp\u003eRelative frequency (%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"18.87966804979253%\" valign=\"top\"\u003e\n \u003cp\u003eAbsolute frequency\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.182572614107883%\" valign=\"top\"\u003e\n \u003cp\u003eRelative frequency (%)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"20.330578512396695%\" valign=\"top\"\u003e\n \u003cp\u003eTotal\u003c/p\u003e\n \u003cp\u003eMissions by month\u003c/p\u003e\n \u003cp\u003eJanuary\u003c/p\u003e\n \u003cp\u003eFebruary\u003c/p\u003e\n \u003cp\u003eMarch\u003c/p\u003e\n \u003cp\u003eApril\u003c/p\u003e\n \u003cp\u003eMay\u003c/p\u003e\n \u003cp\u003eJune\u003c/p\u003e\n \u003cp\u003eJuly\u003c/p\u003e\n \u003cp\u003eAugust\u003c/p\u003e\n \u003cp\u003eSeptember\u003c/p\u003e\n \u003cp\u003eOctober\u003c/p\u003e\n \u003cp\u003eNovember\u003c/p\u003e\n \u003cp\u003eDecember\u003c/p\u003e\n \u003cp\u003eMissions by year\u003c/p\u003e\n \u003cp\u003e2018\u003c/p\u003e\n \u003cp\u003e2019\u003c/p\u003e\n \u003cp\u003e2020\u003c/p\u003e\n \u003cp\u003e2021\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"11.074380165289256%\" valign=\"top\"\u003e\n \u003cp\u003e196\u003c/p\u003e\n \u003cp\u003e13\u003c/p\u003e\n \u003cp\u003e18\u003c/p\u003e\n \u003cp\u003e11\u003c/p\u003e\n \u003cp\u003e11\u003c/p\u003e\n \u003cp\u003e20\u003c/p\u003e\n \u003cp\u003e23\u003c/p\u003e\n \u003cp\u003e24\u003c/p\u003e\n \u003cp\u003e30\u003c/p\u003e\n \u003cp\u003e19\u003c/p\u003e\n \u003cp\u003e19\u003c/p\u003e\n \u003cp\u003e5\u003c/p\u003e\n \u003cp\u003e3\u003c/p\u003e\n \u003cp\u003e33\u003c/p\u003e\n \u003cp\u003e37\u003c/p\u003e\n \u003cp\u003e61\u003c/p\u003e\n \u003cp\u003e65\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"13.388429752066116%\" valign=\"top\"\u003e\n \u003cp\u003e100\u003c/p\u003e\n \u003cp\u003e6.63\u003c/p\u003e\n \u003cp\u003e9.18\u003c/p\u003e\n \u003cp\u003e5.61\u003c/p\u003e\n \u003cp\u003e5.61\u003c/p\u003e\n \u003cp\u003e10.20\u003c/p\u003e\n \u003cp\u003e11.73\u003c/p\u003e\n \u003cp\u003e12.24\u003c/p\u003e\n \u003cp\u003e15.31\u003c/p\u003e\n \u003cp\u003e9.69\u003c/p\u003e\n \u003cp\u003e9.69\u003c/p\u003e\n \u003cp\u003e2.55\u003c/p\u003e\n \u003cp\u003e1.53\u003c/p\u003e\n \u003cp\u003e16.83\u003c/p\u003e\n \u003cp\u003e18.88\u003c/p\u003e\n \u003cp\u003e31.12\u003c/p\u003e\n \u003cp\u003e33.16\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"13.388429752066116%\" valign=\"top\"\u003e\n \u003cp\u003e316\u003c/p\u003e\n \u003cp\u003e10\u003c/p\u003e\n \u003cp\u003e21\u003c/p\u003e\n \u003cp\u003e19\u003c/p\u003e\n \u003cp\u003e19\u003c/p\u003e\n \u003cp\u003e20\u003c/p\u003e\n \u003cp\u003e39\u003c/p\u003e\n \u003cp\u003e42\u003c/p\u003e\n \u003cp\u003e45\u003c/p\u003e\n \u003cp\u003e53\u003c/p\u003e\n \u003cp\u003e26\u003c/p\u003e\n \u003cp\u003e14\u003c/p\u003e\n \u003cp\u003e8\u003c/p\u003e\n \u003cp\u003e58\u003c/p\u003e\n \u003cp\u003e81\u003c/p\u003e\n \u003cp\u003e91\u003c/p\u003e\n \u003cp\u003e86\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"13.884297520661157%\" valign=\"top\"\u003e\n \u003cp\u003e100\u003c/p\u003e\n \u003cp\u003e3.16\u003c/p\u003e\n \u003cp\u003e6.65\u003c/p\u003e\n \u003cp\u003e6.01\u003c/p\u003e\n \u003cp\u003e6.01\u003c/p\u003e\n \u003cp\u003e6.33\u003c/p\u003e\n \u003cp\u003e12.34\u003c/p\u003e\n \u003cp\u003e13.29\u003c/p\u003e\n \u003cp\u003e14.24\u003c/p\u003e\n \u003cp\u003e16.77\u003c/p\u003e\n \u003cp\u003e8.23\u003c/p\u003e\n \u003cp\u003e4.43\u003c/p\u003e\n \u003cp\u003e2.53\u003c/p\u003e\n \u003cp\u003e18.35\u003c/p\u003e\n \u003cp\u003e25.63\u003c/p\u003e\n \u003cp\u003e28.80\u003c/p\u003e\n \u003cp\u003e27.21\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.041322314049587%\" valign=\"top\"\u003e\n \u003cp\u003e828\u003c/p\u003e\n \u003cp\u003e11\u003c/p\u003e\n \u003cp\u003e46\u003c/p\u003e\n \u003cp\u003e45\u003c/p\u003e\n \u003cp\u003e41\u003c/p\u003e\n \u003cp\u003e79\u003c/p\u003e\n \u003cp\u003e96\u003c/p\u003e\n \u003cp\u003e104\u003c/p\u003e\n \u003cp\u003e162\u003c/p\u003e\n \u003cp\u003e127\u003c/p\u003e\n \u003cp\u003e75\u003c/p\u003e\n \u003cp\u003e21\u003c/p\u003e\n \u003cp\u003e21\u003c/p\u003e\n \u003cp\u003e179\u003c/p\u003e\n \u003cp\u003e200\u003c/p\u003e\n \u003cp\u003e204\u003c/p\u003e\n \u003cp\u003e245\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"12.892561983471074%\" valign=\"top\"\u003e\n \u003cp\u003e100\u003c/p\u003e\n \u003cp\u003e1.33\u003c/p\u003e\n \u003cp\u003e5.56\u003c/p\u003e\n \u003cp\u003e5.43\u003c/p\u003e\n \u003cp\u003e4.95\u003c/p\u003e\n \u003cp\u003e9.54\u003c/p\u003e\n \u003cp\u003e11.59\u003c/p\u003e\n \u003cp\u003e12.56\u003c/p\u003e\n \u003cp\u003e19.57\u003c/p\u003e\n \u003cp\u003e15.34\u003c/p\u003e\n \u003cp\u003e9.06\u003c/p\u003e\n \u003cp\u003e2.54\u003c/p\u003e\n \u003cp\u003e2.54\u003c/p\u003e\n \u003cp\u003e21.62\u003c/p\u003e\n \u003cp\u003e24.15\u003c/p\u003e\n \u003cp\u003e24.64\u003c/p\u003e\n \u003cp\u003e29.59\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n \u003c/table\u003e\n \u003cdiv align=\"left\"\u003eThe data presented in Table 1 shows that 96 missions (48.97%) were flown by Christoph 15 during the summer and late summer months (June - September), 179 missions (56.64%) by Christoph 1, and 489 missions (59.06%) by Christoph Murnau. This shows that a total of 764 hoist missions (56.89%) were flown during the summer months. Figures 1 show the mission frequencies of Christoph 15, Christoph 1, and Christoph Murnau per year and month as stacked bar charts. Figure 2 visualizes the absolute and relative mission frequencies that are detailed in Table 1.\u003c/div\u003e\n \u003cdiv align=\"left\"\u003eWhile Table 1 only shows the absolute and relative deployments, an evaluation of the tracer diagnoses is necessary to answer RQ 1. Table 2 shows that for Christoph 15, the traumatological indications clearly predominate with a factor of 3.13. The other two helicopters show similar patterns.\u003c/div\u003e\n \u003cdiv align=\"left\"\u003eTable 2: Mission frequency of Christoph 15, Christoph 1, and Christop Murnau in the years 2018 - 2021\u003c/div\u003e\n \u003ctable border=\"1\" cellspacing=\"0\" cellpadding=\"0\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd width=\"19.205298013245034%\" rowspan=\"2\" valign=\"top\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd width=\"27.483443708609272%\" colspan=\"2\" valign=\"top\"\u003e\n \u003cp\u003eChristoph 15\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"27.483443708609272%\" colspan=\"2\" valign=\"top\"\u003e\n \u003cp\u003eChristoph 1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"25.827814569536425%\" colspan=\"2\" valign=\"top\"\u003e\n \u003cp\u003eChristoph Murnau\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"17.21311475409836%\" valign=\"top\"\u003e\n \u003cp\u003eAbsolute frequency\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.80327868852459%\" valign=\"top\"\u003e\n \u003cp\u003eRelative frequency (%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"17.21311475409836%\" valign=\"top\"\u003e\n \u003cp\u003eAbsolute frequency\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.80327868852459%\" valign=\"top\"\u003e\n \u003cp\u003eRelative frequency (%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.98360655737705%\" valign=\"top\"\u003e\n \u003cp\u003eAbsolute frequency\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.98360655737705%\" valign=\"top\"\u003e\n \u003cp\u003eRelative frequency (%)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"19.205298013245034%\" valign=\"top\"\u003e\n \u003cp\u003eTotal\u003c/p\u003e\n \u003cp\u003eInternal\u003c/p\u003e\n \u003cp\u003eTrauma\u003c/p\u003e\n \u003cp\u003eHoist\u003c/p\u003e\n \u003cp\u003eNo hoist\u003c/p\u003e\n \u003cp\u003eMissions by year\u003c/p\u003e\n \u003cp\u003e2018\u003c/p\u003e\n \u003cp\u003eTrauma\u003c/p\u003e\n \u003cp\u003eInternal\u003c/p\u003e\n \u003cp\u003eHoist\u003c/p\u003e\n \u003cp\u003eNo hoist\u003c/p\u003e\n \u003cp\u003e2019\u003c/p\u003e\n \u003cp\u003eTrauma\u003c/p\u003e\n \u003cp\u003eInternal\u003c/p\u003e\n \u003cp\u003eHoist\u003c/p\u003e\n \u003cp\u003eNo hoist\u003c/p\u003e\n \u003cp\u003e2020\u003c/p\u003e\n \u003cp\u003eTrauma\u003c/p\u003e\n \u003cp\u003eInternal\u003c/p\u003e\n \u003cp\u003eHoist\u003c/p\u003e\n \u003cp\u003eNo hoist\u003c/p\u003e\n \u003cp\u003e2021\u003c/p\u003e\n \u003cp\u003eTrauma\u003c/p\u003e\n \u003cp\u003eInternal\u003c/p\u003e\n \u003cp\u003eHoist\u003c/p\u003e\n \u003cp\u003eNo hoist\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"13.907284768211921%\" valign=\"top\"\u003e\n \u003cp\u003e47\u003c/p\u003e\n \u003cp\u003e147\u003c/p\u003e\n \u003cp\u003e194\u003c/p\u003e\n \u003cp\u003e1\u003c/p\u003e\n \u003cp\u003e23\u003c/p\u003e\n \u003cp\u003e10\u003c/p\u003e\n \u003cp\u003e33\u003c/p\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003cp\u003e29\u003c/p\u003e\n \u003cp\u003e8\u003c/p\u003e\n \u003cp\u003e63\u003c/p\u003e\n \u003cp\u003e1\u003c/p\u003e\n \u003cp\u003e48\u003c/p\u003e\n \u003cp\u003e13\u003c/p\u003e\n \u003cp\u003e60\u003c/p\u003e\n \u003cp\u003e1\u003c/p\u003e\n \u003cp\u003e47\u003c/p\u003e\n \u003cp\u003e16\u003c/p\u003e\n \u003cp\u003e65\u003c/p\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"13.57615894039735%\" valign=\"top\"\u003e\n \u003cp\u003e23.98\u003c/p\u003e\n \u003cp\u003e75.00\u003c/p\u003e\n \u003cp\u003e98.98\u003c/p\u003e\n \u003cp\u003e0.51\u003c/p\u003e\n \u003cp\u003e11.73\u003c/p\u003e\n \u003cp\u003e5.1\u003c/p\u003e\n \u003cp\u003e16.84\u003c/p\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003cp\u003e14.80\u003c/p\u003e\n \u003cp\u003e4.08\u003c/p\u003e\n \u003cp\u003e18.37\u003c/p\u003e\n \u003cp\u003e0.51\u003c/p\u003e\n \u003cp\u003e24.47\u003c/p\u003e\n \u003cp\u003e6.63\u003c/p\u003e\n \u003cp\u003e30.61\u003c/p\u003e\n \u003cp\u003e0.51\u003c/p\u003e\n \u003cp\u003e23.98\u003c/p\u003e\n \u003cp\u003e8.16\u003c/p\u003e\n \u003cp\u003e33.16\u003c/p\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"13.907284768211921%\" valign=\"top\"\u003e\n \u003cp\u003e249\u003c/p\u003e\n \u003cp\u003e67\u003c/p\u003e\n \u003cp\u003e290\u003c/p\u003e\n \u003cp\u003e26\u003c/p\u003e\n \u003cp\u003e45\u003c/p\u003e\n \u003cp\u003e13\u003c/p\u003e\n \u003cp\u003e58\u003c/p\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003cp\u003e69\u003c/p\u003e\n \u003cp\u003e12\u003c/p\u003e\n \u003cp\u003e76\u003c/p\u003e\n \u003cp\u003e5\u003c/p\u003e\n \u003cp\u003e75\u003c/p\u003e\n \u003cp\u003e16\u003c/p\u003e\n \u003cp\u003e86\u003c/p\u003e\n \u003cp\u003e5\u003c/p\u003e\n \u003cp\u003e26\u003c/p\u003e\n \u003cp\u003e60\u003c/p\u003e\n \u003cp\u003e70\u003c/p\u003e\n \u003cp\u003e16\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"13.57615894039735%\" valign=\"top\"\u003e\n \u003cp\u003e21.20\u003c/p\u003e\n \u003cp\u003e78.80\u003c/p\u003e\n \u003cp\u003e91.77\u003c/p\u003e\n \u003cp\u003e8.23\u003c/p\u003e\n \u003cp\u003e14.24\u003c/p\u003e\n \u003cp\u003e4.11\u003c/p\u003e\n \u003cp\u003e29.59\u003c/p\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003cp\u003e21.84\u003c/p\u003e\n \u003cp\u003e3.80\u003c/p\u003e\n \u003cp\u003e38.78\u003c/p\u003e\n \u003cp\u003e2.55\u003c/p\u003e\n \u003cp\u003e23.73\u003c/p\u003e\n \u003cp\u003e5.06\u003c/p\u003e\n \u003cp\u003e38.78\u003c/p\u003e\n \u003cp\u003e2.55\u003c/p\u003e\n \u003cp\u003e8.23\u003c/p\u003e\n \u003cp\u003e18.99\u003c/p\u003e\n \u003cp\u003e35.71\u003c/p\u003e\n \u003cp\u003e8.16\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"12.913907284768213%\" valign=\"top\"\u003e\n \u003cp\u003e212\u003c/p\u003e\n \u003cp\u003e432\u003c/p\u003e\n \u003cp\u003e761\u003c/p\u003e\n \u003cp\u003e1\u003c/p\u003e\n \u003cp\u003e92\u003c/p\u003e\n \u003cp\u003e56\u003c/p\u003e\n \u003cp\u003e168\u003c/p\u003e\n \u003cp\u003e1\u003c/p\u003e\n \u003cp\u003e111\u003c/p\u003e\n \u003cp\u003e58\u003c/p\u003e\n \u003cp\u003e194\u003c/p\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003cp\u003e104\u003c/p\u003e\n \u003cp\u003e50\u003c/p\u003e\n \u003cp\u003e188\u003c/p\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003cp\u003e125\u003c/p\u003e\n \u003cp\u003e48\u003c/p\u003e\n \u003cp\u003e211\u003c/p\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"12.913907284768213%\" valign=\"top\"\u003e\n \u003cp\u003e25.60\u003c/p\u003e\n \u003cp\u003e52.17\u003c/p\u003e\n \u003cp\u003e91.91\u003c/p\u003e\n \u003cp\u003e0.12\u003c/p\u003e\n \u003cp\u003e11.11\u003c/p\u003e\n \u003cp\u003e6.76\u003c/p\u003e\n \u003cp\u003e20.29\u003c/p\u003e\n \u003cp\u003e0.12\u003c/p\u003e\n \u003cp\u003e13.41\u003c/p\u003e\n \u003cp\u003e7.00\u003c/p\u003e\n \u003cp\u003e23.43\u003c/p\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003cp\u003e12.56\u003c/p\u003e\n \u003cp\u003e6.04\u003c/p\u003e\n \u003cp\u003e22.71\u003c/p\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003cp\u003e15.10\u003c/p\u003e\n \u003cp\u003e5.80\u003c/p\u003e\n \u003cp\u003e25.48\u003c/p\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n \u003c/table\u003e\n\u003c/div\u003e\n\u003cp\u003eAn analysis of the most common tracer diagnoses of Christoph 15 (Table 3) showed that extremity trauma clearly dominated the surgical indications, while collapse and syncope led the internal medicine indications.\u003c/p\u003e\n\u003cdiv\u003e\n \u003cdiv align=\"left\"\u003e\u003cbr\u003e\u003cimg src=\"https://myfiles.space/user_files/122228_c8a1650c59388082/122228_custom_files/img1708942216.png\"\u003e\u003c/div\u003e\n\u003c/div\u003e\n\u003cp\u003e\u003cstrong\u003eRQ 2\u003c/strong\u003e: Table \u003cspan\u003e4\u003c/span\u003e shows the \u003cstrong\u003evacation days in the study area\u003c/strong\u003e. Not only the weekdays were counted, but also the weekends in between and the weekends immediately before and after. Example: In 2018, the winter holidays in Bavaria began on Monday, 12 Feb. and ended on Friday, 16 Feb. The dates 10 Feb. (Saturday), 11 Feb. (Sunday), 17 Feb. (Saturday), and 18 Feb. (Sunday) were counted as holidays.\u003c/p\u003e\n\u003cdiv\u003e\n \u003cdiv align=\"left\"\u003eTable 4: Vacation days in study area\u003c/div\u003e\n\u003c/div\u003e\n\u003ctable border=\"1\" cellspacing=\"0\" cellpadding=\"0\" title=\"Table 4:\" width=\"612\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd width=\"35.51554828150573%\" valign=\"top\"\u003e\n \u003cp\u003eYear / Vacation Days\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"32.40589198036007%\" valign=\"top\"\u003e\n \u003cp\u003eAbsolute frequency\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"32.0785597381342%\" valign=\"top\"\u003e\n \u003cp\u003eRelative frequency (%)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"35.51554828150573%\" valign=\"top\"\u003e\n \u003cp\u003eTotal\u0026nbsp;\u003c/p\u003e\n \u003cp\u003e\u0026nbsp; \u0026nbsp; \u0026nbsp; Vacation periods\u003c/p\u003e\n \u003cp\u003e\u0026nbsp; \u0026nbsp; \u0026nbsp; No vacation days\u003c/p\u003e\n \u003cp\u003e2018\u003c/p\u003e\n \u003cp\u003e\u0026nbsp; \u0026nbsp; \u0026nbsp; Vacation days\u003c/p\u003e\n \u003cp\u003e\u0026nbsp; \u0026nbsp; \u0026nbsp; No vacation days\u003c/p\u003e\n \u003cp\u003e2019\u003c/p\u003e\n \u003cp\u003e\u0026nbsp; \u0026nbsp; \u0026nbsp;Vacation days\u003c/p\u003e\n \u003cp\u003e\u0026nbsp; \u0026nbsp; \u0026nbsp;No vacation days\u003c/p\u003e\n \u003cp\u003e2020\u003c/p\u003e\n \u003cp\u003e\u0026nbsp; \u0026nbsp; \u0026nbsp;Vacation days\u003c/p\u003e\n \u003cp\u003e\u0026nbsp; \u0026nbsp; \u0026nbsp;No vacation days\u003c/p\u003e\n \u003cp\u003e2021\u003c/p\u003e\n \u003cp\u003e\u0026nbsp; \u0026nbsp; \u0026nbsp;Vacation days\u003c/p\u003e\n \u003cp\u003e\u0026nbsp; \u0026nbsp; \u0026nbsp;No vacation days\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"32.40589198036007%\" valign=\"top\"\u003e\n \u003cp\u003e1429\u003c/p\u003e\n \u003cp\u003e446\u003c/p\u003e\n \u003cp\u003e983\u003c/p\u003e\n \u003cp\u003e334\u003c/p\u003e\n \u003cp\u003e105\u003c/p\u003e\n \u003cp\u003e229\u003c/p\u003e\n \u003cp\u003e365\u003c/p\u003e\n \u003cp\u003e112\u003c/p\u003e\n \u003cp\u003e253\u003c/p\u003e\n \u003cp\u003e365\u003c/p\u003e\n \u003cp\u003e115\u003c/p\u003e\n \u003cp\u003e250\u003c/p\u003e\n \u003cp\u003e365\u003c/p\u003e\n \u003cp\u003e114\u003c/p\u003e\n \u003cp\u003e251\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"32.0785597381342%\" valign=\"top\"\u003e\n \u003cp\u003e100.00\u003c/p\u003e\n \u003cp\u003e31.21\u003c/p\u003e\n \u003cp\u003e68.79\u003c/p\u003e\n \u003cp\u003e100.00\u003c/p\u003e\n \u003cp\u003e31.44\u003c/p\u003e\n \u003cp\u003e68.56\u003c/p\u003e\n \u003cp\u003e100.00\u003c/p\u003e\n \u003cp\u003e30.68\u003c/p\u003e\n \u003cp\u003e69.32\u003c/p\u003e\n \u003cp\u003e100.00\u003c/p\u003e\n \u003cp\u003e31.51\u003c/p\u003e\n \u003cp\u003e68.49\u003c/p\u003e\n \u003cp\u003e100.00\u003c/p\u003e\n \u003cp\u003e31.23\u003c/p\u003e\n \u003cp\u003e68.77\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003eTable \u003cspan\u003e5\u003c/span\u003e shows the frequency of \u003cstrong\u003erescue operations with hoist\u003c/strong\u003e, in each case during vacation and holiday periods in Bavaria, compared to non-vacation periods.\u003c/p\u003e\n\u003cp\u003eTable 5: Comparison of operation frequency during vacation periods and non-vacation periods\u003c/p\u003e\n\u003cdiv\u003e\n \u003ctable border=\"1\" cellspacing=\"0\" cellpadding=\"0\" title=\"Table 4:\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd width=\"33.333333333333336%\" valign=\"top\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd width=\"33.333333333333336%\" valign=\"top\"\u003e\n \u003cp\u003eAbsolute frequency\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"33.333333333333336%\" valign=\"top\"\u003e\n \u003cp\u003eRelative frequency (%)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"33.333333333333336%\" valign=\"top\"\u003e\n \u003cp\u003eTotal (n = 1340)\u003c/p\u003e\n \u003cp\u003e\u0026nbsp; \u0026nbsp; \u0026nbsp; Vacation periods\u003c/p\u003e\n \u003cp\u003e\u0026nbsp; \u0026nbsp; \u0026nbsp; No vacation periods\u003c/p\u003e\n \u003cp\u003eChristop 15\u003c/p\u003e\n \u003cp\u003e\u0026nbsp; \u0026nbsp; \u0026nbsp; Vacation periods\u003c/p\u003e\n \u003cp\u003e\u0026nbsp; \u0026nbsp; \u0026nbsp; No vacation periods\u003c/p\u003e\n \u003cp\u003eChristoph 1\u003c/p\u003e\n \u003cp\u003e\u0026nbsp; \u0026nbsp; \u0026nbsp;Vacation periods\u003c/p\u003e\n \u003cp\u003e\u0026nbsp; \u0026nbsp; \u0026nbsp;No vacation periods\u003c/p\u003e\n \u003cp\u003eChristoph Murnau\u003c/p\u003e\n \u003cp\u003e\u0026nbsp; \u0026nbsp; \u0026nbsp;Vacation periods\u003c/p\u003e\n \u003cp\u003e\u0026nbsp; \u0026nbsp; \u0026nbsp;No vacation periods\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"33.333333333333336%\" valign=\"top\"\u003e\n \u003cp\u003e452\u003c/p\u003e\n \u003cp\u003e888\u003c/p\u003e\n \u003cp\u003e79\u003c/p\u003e\n \u003cp\u003e117\u003c/p\u003e\n \u003cp\u003e94\u003c/p\u003e\n \u003cp\u003e222\u003c/p\u003e\n \u003cp\u003e279\u003c/p\u003e\n \u003cp\u003e549\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"33.333333333333336%\" valign=\"top\"\u003e\n \u003cp\u003e33.73\u003c/p\u003e\n \u003cp\u003e66.27\u003c/p\u003e\n \u003cp\u003e40.31\u003c/p\u003e\n \u003cp\u003e59.69\u003c/p\u003e\n \u003cp\u003e29.75\u003c/p\u003e\n \u003cp\u003e70.25\u003c/p\u003e\n \u003cp\u003e33.70\u003c/p\u003e\n \u003cp\u003e66.30\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n \u003c/table\u003e\n\u003c/div\u003e"},{"header":"Discussion","content":"\u003cp\u003eIn this retrospective study, 1340 rescue helicopter missions were examined at the locations of Christoph 15 (Straubing), Christoph 1 (Munich), and Christoph Murnau (Murnau) in the period from 01 Feb. 2018 to 31 Dec. 2021. In all cases, an indication for the use of the rescue hoist was given by the managing control center. The reason was the introduction of the rescue hoist on Christoph 15.\u003c/p\u003e\n\u003ch3\u003eInterpretation\u003c/h3\u003e\n\u003cp\u003eWith regard to \u003cb\u003eRQ 1\u003c/b\u003e, if we look at the question of which diagnoses (or reports) triggered the deployment of the three German air rescue helicopters, it immediately becomes apparent that, in terms of frequency, injuries to the extremities were the most frequent, both in trauma emergencies and overall. Trauma to the extremities can usually be managed well with appropriate restraint, immobilization, and anesthesia. Complex emergency medical interventions are usually not necessary and were not found in any of the cases analyzed in the study. Collapse and syncope were the most common internal medicine emergencies. Here, too, the focus should not be on complex interventions, but rather on risk stratification in the sense of early detection of high-risk syncopal episodes [\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e]. A different picture is seen for diagnoses of traumatic brain injuries, polytrauma, acute coronary syndrome, spinal injuries, and cardiovascular arrest, which can result in complex action situations. Overall, for all hoist missions in all months analyzed, trauma events were clearly the most frequent. It is also clear from the data that the vast majority of hoist operations were due to an objectifiable medical problem.\u003c/p\u003e \u003cp\u003eOverall, it is surprising that almost all calls for hoist rescue were actually answered with a hoist. This is surprising in that such accurate call retrieval and situation assessment by dispatchers is often not possible. In this context, the appropriateness of the use of a hoist must be discussed critically, and the question must be raised as to whether a cognitive fixation bias in the sense of a self-fulfilling prophecy may have been the driving force behind some of the hoist applications carried out.\u003c/p\u003e \u003cp\u003eIt is also interesting to note that the frequency of lift missions increased rapidly after the first year (2018) of implementation on Christoph 15, and then remained at a nearly constant level, analogous to Christoph Murnau and Christoph 1.\u003c/p\u003e \u003cp\u003eIn RQ 2, we examined the influence of regional vacation periods on the frequency of hoist missions. As expected, the absolute number of hoist missions outside the vacation period (887 days) was greater than during the vacation period (425 days). On the basis of the distribution of missions during vacation periods, it can be concluded that the influence of vacation periods on mission frequency is less pronounced, even in tourism-oriented regions. The Covid-19 pandemic did not lead to any significant shift in the distribution either. Only in the case of Christoph 15 can a higher proportion be observed during the vacation period. This is contrary to the availability of rescue helicopters in Austria, especially in the winter months. The number of rescue helicopters is being deliberately increased in order to be able to handle an increased volume of operations, especially during holiday periods. Finally, it should be emphasized that the analysis of when and which deployment took place is extremely important. This is particularly the case when planning to provide a rescue winch and cover the costs for it.\u003c/p\u003e\n\u003ch3\u003eLimitations\u003c/h3\u003e\n\u003cp\u003eThis study represents three helicopter sites. In Germany, there are currently 67 rescue helicopters and 12 dual use helicopters, of which 10 have a hoist. Due to geographic, structural, and organizational differences, generalization is not always possible or useful.\u003c/p\u003e \u003cp\u003eThe quality of the study also depends on the quality of the documentation provided by the helicopter crews. If information was incomplete or incorrect, this may have affected the results of the study. This also applies to the tracer diagnoses listed. If this information is missing or if the leading problem is not correctly documented, misinterpretations may occur. This not only underscores the importance of thorough documentation, but also of human-centered documentation systems that are easy to use, interoperate with other IT components, and can be viewed as a time saver with good user acceptance.\u003c/p\u003e\n\u003ch3\u003eFuture research\u003c/h3\u003e\n\u003cp\u003eFor future research, other aspects need to be investigated, such as the impact of severe weather events on helicopter operations in the context of climate change. The 2021 flood disaster in the Ahr Valley in Germany showed that helicopter stations without a hoist can very quickly receive an urgent alert to rescue people from life-threatening situations. The question also arises as to whether, in addition to the dispatch center, which provides a very good indication, any further indication by the crew itself is necessary as part of the reconnaissance of the landing site. Increasing development and density also raises the question of whether the unattended intervals could be shortened by having the physician depart by hoist [\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e]. Furthermore, fundamental strategies of the hoist concept should be examined: What are the advantages of a four-person crew (as on Christoph 1 and Christoph Murnau) over a three-person crew (as on Christoph 15)?\u003c/p\u003e"},{"header":"Conclusions","content":"\u003cp\u003eIn this retrospective study based on the mission documentation of the hoist missions of three EMS helicopters, the overall leading incidence was found to be extremity injuries without the subsequent need for complex medical intervention. Collapse and syncope were the leading causes of non-traumatological emergencies, although here as well, there was usually no need for complex medical care and the focus was on risk stratification. However, this should not mask the fact that a small but not insignificant proportion of tracer diagnoses point to injuries and diseases that can lead to complex, time-critical, and dynamic situations, such as traumatic brain injury, acute coronary syndrome, spinal injuries, and cardiac arrest. It is also noteworthy that almost all hoist mission alerts were actually answered with a hoist rescue. Surprisingly, the influence of vacation periods on the frequency of operations was less pronounced even in tourism-oriented regions. Minor effects were only observed for one helicopter (Christoph 1). Also, the Covid-19 pandemic did not lead to any significant shift in distribution. After the introduction of the hoist on Christoph 15 (Straubing, Bavaria), a rapid stabilization of hoist deployment frequency can be observed, which indicates a corresponding acceptance of and need for it. In future research, other aspects need to be studied, such as the impact of severe weather on helicopter operations in the context of climate change, as well as personnel strategy (e.g., 3-person vs. 4-person crews).\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eEthics approval:\u0026nbsp;\u003c/strong\u003eEthikkommision bei der LMU M\u0026uuml;nchen, Projekt Nr.: 23-0936 KB:\u0026nbsp;According to an assessment by the LMU Ethicscommittee, there is no need for advice.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConsent for publication:\u0026nbsp;\u003c/strong\u003eNot Applicable\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eData availability:\u003c/strong\u003e The datasets used and/or analyzed during the current study are available from the corresponding author on reasonable request.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCompeting interest:\u0026nbsp;\u003c/strong\u003ePD and CE do not declare any conflicts. DW is the medical director of ADAC Luftrettung GmbH for the South Germany region.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFunding:\u0026nbsp;\u003c/strong\u003eNo grant or funding was received.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthors\u0026acute; contributions:\u0026nbsp;\u003c/strong\u003eDW was responsible for coordinating the working group. CE was responsible for formatting the manuscript, submission, and data preparation and analysis. DW and PD contributed their expertise in air rescue mainly in the presentation of the current situation in Germany and the discussion of the results. PD and DW were also involved in the internal quality management of the study, e.g., crosschecking of results and data transmission.\u003cstrong\u003e\u0026nbsp;\u003c/strong\u003eJS contributed extensively to the discussion. All authors revised the text.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u0026nbsp;\u003c/strong\u003e\u003cstrong\u003eAcknowledgments:\u0026nbsp;\u003c/strong\u003e\u0026bdquo;Many thanks to Prof. Dr. Bernhard Zwi\u0026szlig;ler, [Hospital of the Ludwig-Maximilians-University Munich (LMU), Department of Anesthesiology, Munich, Germany] and Dr. David H\u0026auml;ske [Universit\u0026auml;tsklinikum T\u0026uuml;bingen, Center for Public Health and Health Services Research], for scientific advice as well as Mrs Sonnhild Naminga, Fraunhofer IESE, for the linguistic proofreading.\u0026ldquo;\u0026nbsp;\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\n\u003cli\u003eAndruszkow H, Hildebrand F, Lefering R, Pape H-C, Hoffmann R, Schweigkofler U. Ten years of helicopter emergency medical services in Germany: do we still need the helicopter rescue in multiple traumatised patients? Injury 2014; 45 Suppl 3:S53-8. doi: 10.1016/j.injury.2014.08.018.\u003c/li\u003e\n\u003cli\u003eRuppert M, van Boemmel T, Lefering R, Fiala W, G\u0026auml;\u0026szlig;ler M. Einsatzspektrum in der Hoistenrettung. Notfall Rettungsmed 2017; 20(6):486\u0026ndash;94. doi: 10.1007/s10049-017-0314-6.\u003c/li\u003e\n\u003cli\u003eTsuchiya A, Tsutsumi Y, Yasunaga H. Outcomes after helicopter versus ground emergency medical services for major trauma--propensity score and instrumental variable analyses: a retrospective nationwide cohort study. Scand J Trauma Resusc Emerg Med 2016; 24(1):140. doi: 10.1186/s13049-016-0335-z.\u003c/li\u003e\n\u003cli\u003eWake K, Noguchi T, Hishinuma H, Zaitsu M, Kikuchi J, Uchida M et al. Characteristics of patients who received helicopter emergency medical services in Japan from 2012 to 2019: a retrospective analysis of data from Tochigi Prefecture. Scand J Trauma Resusc Emerg Med 2022; 30(1):25. doi: 10.1186/s13049-022-01012-6.\u003c/li\u003e\n\u003cli\u003eLechleuthner A. Architecture of emergency medical services in Germany. Notfall Rettungsmed 2021; 24(S1):1\u0026ndash;8. doi: 10.1007/s10049-019-0597-x.\u003c/li\u003e\n\u003cli\u003eSumann G, Moens D, Brink B, Brodmann Maeder M, Greene M, Jacob M et al. Multiple trauma management in mountain environments - a scoping review : Evidence based guidelines of the International Commission for Mountain Emergency Medicine (ICAR MedCom). Intended for physicians and other advanced life support personnel. Scand J Trauma Resusc Emerg Med 2020; 28(1):117. doi: 10.1186/s13049-020-00790-1.\u003c/li\u003e\n\u003cli\u003eWalters WH. Survey design, sampling, and significance testing: Key issues. The Journal of Academic Librarianship 2021; 47(3):102344. doi: 10.1016/j.acalib.2021.102344.\u003c/li\u003e\n\u003cli\u003eSutton R, Ricci F, Fedorowski A. Risk stratification of syncope: Current syncope guidelines and beyond. Auton Neurosci 2021; 238:102929. doi: 10.1016/j.autneu.2021.102929.\u003c/li\u003e\n\u003cli\u003ePietsch U, Knapp J, Mann M, Meuli L, Lischke V, Tissi M et al. Incidence and challenges of helicopter emergency medical service (HEMS) rescue missions with helicopter hoist operations: analysis of 11,228 daytime and nighttime missions in Switzerland. Scand J Trauma Resusc Emerg Med 2021; 29(1):92. doi: 10.1186/s13049-021-00898-y.\u003c/li\u003e\n\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":true,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true},"keywords":"Helicopter Emergency Medical Service, HEMS, Air Rescue, Hoist, Alpine Rescue, Mountain Medicine","lastPublishedDoi":"10.21203/rs.3.rs-3900486/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-3900486/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003ch2\u003eBackground\u003c/h2\u003e \u003cp\u003eIn the German emergency medical services, 67 rescue helicopters and 12 helicopters for rescue and intensive care transport missions provide their services mostly under visual flight conditions. Of these, 10 helicopters are equipped with a rescue hoist. There is limited data on the frequency of hoist operations, tracer diagnoses, and influences such as weather and vacation periods. This study examines hoist deployment frequencies, tracer diagnostics, and the influence of vacation season at three German helicopter sites.\u003c/p\u003e\u003ch2\u003eMethods\u003c/h2\u003e \u003cp\u003eIn the period from 01 Feb. 2018 to 31 Dec. 2021, a total of 1340 hoist missions were retrospectively examined descriptively for the helicopters Christoph 15 (n\u0026thinsp;=\u0026thinsp;196), Christoph 1 (n\u0026thinsp;=\u0026thinsp;316), and Christoph Murnau (n\u0026thinsp;=\u0026thinsp;828) using their electronic mission documentation.\u003c/p\u003e\u003ch2\u003eResults\u003c/h2\u003e \u003cp\u003e56.89% of the hoist missions were flown during the summer months, with vacation periods having a small effect on Christoph 1 only. Traumatological diagnoses clearly predominated on all three helicopters, with 75.0% on Christoph 15, 78.8% on Christoph 1, and 52.17% on Christoph Murnau. Among the traumatological indications, extremity trauma (39.29%) was the most frequent, followed by spinal injuries (10.71%), traumatic brain injuries (8.67%), and polytrauma (4.59%). Among internal medicine emergencies, collapse/syncope (5.61%) and cardiovascular arrest (3.06%) were the most common, followed by acute coronary syndromes, anaphylaxis, and hypothermia (2.55% each).\u003c/p\u003e\u003ch2\u003eConclusions\u003c/h2\u003e \u003cp\u003eDespite the predominance of extremity injuries and syncope/collapse, where risk stratification was the primary concern and complex medical care was usually not required, there were also dynamic and complex emergency events, e.g., cardiovascular arrests, traumatic brain injuries, and anaphylaxis. Not even the Covid-19 pandemic led to a significant shift in distribution. Surprisingly, the influence of vacation periods on the frequency of operations was less pronounced even in tourism-oriented regions. For future research, other aspects need to be studied, such as the impact of severe weather on helicopter operations in the context of climate change, as well as personnel strategy (e.g., 3-person vs. 4-person crews).\u003c/p\u003e","manuscriptTitle":"Hoist missions and seasonal influences on air rescue service helicopters: A descriptive study based on three German helicopters","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2024-02-26 20:23:30","doi":"10.21203/rs.3.rs-3900486/v1","editorialEvents":[{"type":"communityComments","content":0}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"414ae006-2719-4e9d-8346-2764677c0c58","owner":[],"postedDate":"February 26th, 2024","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[],"tags":[],"updatedAt":"2025-01-03T09:53:42+00:00","versionOfRecord":[],"versionCreatedAt":"2024-02-26 20:23:30","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-3900486","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-3900486","identity":"rs-3900486","version":["v1"]},"buildId":"qtupq5eGEP_6zYnWcrvyt","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}