Evaluating helicopter emergency medical missions: a reliability study of the HEMS benefit and NACA scores

Helicopter emergency medical services in Iceland between 2018 and 2022-A retrospective study

BACKGROUND

Helicopter emergency services (HEMS) are widely used to bring medical assistance to individuals that cannot be reached by other means or individuals that have time-critical medical conditions, such as chest pain, stroke or severe trauma. It is a very expensive resource whose use and importance depends on local conditions. The aim of this study was to describe flight and patient characteristics in all HEMS flights done in Iceland, a geographically isolated, mountainous and sparsely populated country, over a 5-year course.

METHODS

This retrospective study included all individuals requiring HEMS transportation in Iceland during 2018-2022. The electronic database of the Icelandic Coast Guard was used to identify the individuals and register flight data. Electronic databases from Landspitali and Akureyri hospitals were used to collect clinical variables. Descriptive statistics was applied.

RESULTS

The average number of HEMS transports was 3.5/10,000 inhabitants and the median [IQR] activation time and flight times were 30 min [20-42] and 40 min [26-62] respectively. The vast majority of patients were transported to Landspitali Hospital in Reykjavik. More than half of the transports were due to trauma, the most common medical transports were due to chest pain or cardiac arrests. Advanced medical therapy was provided for 66 (10%) of individuals during primary transports, 157 (24%) of individuals were admitted to intensive care, 188 (28%) needed surgery and 53 (7.9%) needed a coronary angiography.

CONCLUSION

In Iceland, the number of transports is lower but activation and flight times for HEMS flights are considerably longer than in other Nordic countries, likely due to geographical features and the structure of the service including utilizing helicopters both for HEMS and search and rescue operations. The transport times for some time-sensitive conditions are not within standards set by international studies and guidelines.

Severity-Driven Trends in Mortality in a Large Regionalized Critical Care Transport Service

OBJECTIVE

The epidemiology accompanying helicopter emergency medical services (HEMS) transport has evolved as agencies have matured and become integrated into regionalized health systems, as evidenced primarily by nationwide systems in Europe. System-level congruence between Europe and the United States, where HEMS is geographically fragmentary, is unclear. In this study, we provide a temporal, epidemiologic characterization of the largest standardized private, nonprofit HEMS system in the United States, STAT MedEvac.

METHODS

We obtained comprehensive timing, procedure, and vital signs data from STAT MedEvac prehospital electronic patient care records for all adult patients transported to UPMC Health System hospitals in the period of January 2012 through October 2021. We linked these data with hospital electronic health records available through June 2018 to establish length of stay and vital status at discharge.

RESULTS

We studied 90,960 transports and matched 62.8% (n = 57,128) to the electronic health record. The average patient age was 58.6 years ( 19 years), and most were male (57.9%). The majority of cases were interfacility transports (77.6%), and the most common general medical category was nontrauma (72.7%). Sixty-one percent of all patients received a prehospital intervention. Overall, hospital mortality was 15%, and the average hospital length of stay (LOS) was 8.8 days ( 10.0 days). Observed trends over time included increases in nontrauma transports, level of severity, and in-hospital mortality. In multivariable models, case severity and medical category correlated with the outcomes of mortality and LOS.

CONCLUSION

In the largest standardized nonprofit HEMS system in the United States, patient mortality and hospital LOS increased over time, whereas the proportion of trauma patients and scene runs decreased.

Prehospital tracheal intubations by anaesthetist-staffed critical care teams: a prospective observational multicentre study

BACKGROUND

Prehospital tracheal intubation is a potentially lifesaving intervention, but is associated with prolonged time on-scene. Some services strongly advocate performing the procedure outside of the ambulance or aircraft, while others also perform the procedure inside the vehicle. This study was designed as a non-inferiority trial registering the rate of successful tracheal intubation and incidence of complications performed by a critical care team either inside or outside an ambulance or helicopter.

METHODS

This observational multicentre study was performed between March 2020 and September 2021 and involved 12 anaesthetist-staffed critical care teams providing emergency medical services by helicopter in Denmark, Norway, and Sweden. The primary outcome was first-pass successful tracheal intubations.

RESULTS

Of the 422 drug-assisted tracheal intubations examined, 240 (57%) took place in the cabin of the ambulance or helicopter. The rate of first-pass success was 89.2% for intubations in-cabin vs 86.3% outside. This difference of 2.9% (confidence interval -2.4% to 8.2%) (two sided 10%, including 0, but not the non-inferiority limit Δ=-4.5) fulfils our criteria for non-inferiority, but not significant superiority. These results withstand after performing a propensity score analysis. The mean on-scene time associated with the helicopter in-cabin procedures (27 min) was significantly shorter than for outside the cabin (32 min, P=0.004).

CONCLUSIONS

Both in-cabin and outside the cabin, prehospital tracheal intubation by anaesthetists was performed with a high success rate. The mean on-scene time was shorter in the in-cabin helicopter cohort.

CLINICAL TRIAL REGISTRATION

NCT04206566.

Can video communication in the emergency medical communication centre improve dispatch precision? A before-after study in Norwegian helicopter emergency medical services

OBJECTIVES

Dispatching helicopter emergency medical services (HEMS) to the patients with the greatest medical or logistical benefit remains challenging. The introduction of video calls (VC) in the emergency medical communication centres (EMCC) could provide additional information for EMCC operators and HEMS physicians when assessing the need for HEMS dispatch. The aim of this study was to evaluate the impact from VC in the EMCC on HEMS dispatch precision.

DESIGN

An observational before-after study.

SETTING

The regional EMCC and one HEMS base in Mid-Norway.

PARTICIPANTS

EMCC operators and HEMS physicians at the EMCC and HEMS base in Trondheim, Norway.

INTERVENTION

In January 2022, VC became available in emergency calls in Trondheim EMCC. Data were collected from 2020 2021 (pre-intervention) and 2022 (post-intervention).

PRIMARY AND SECONDARY OUTCOME MEASURES

The primary outcome was the proportion of seriously ill or injured HEMS patients, defined as a National Advisory Committee for Aeronautics (NACA) score between 4 and 7. The secondary outcome was the proportion of inappropriate dispatches, defined as missions with neither provision of additional competence nor any logistical contribution based on quality indicators for physician-staffed emergency medical services.

RESULTS

811 and 402 HEMS missions with patient contact were included in the pre- and post-intervention group, respectively. The proportion of missions with NACA 4-7 was not significantly changed after the intervention (OR 1.21, 95% CI 0.92 to 1.61, p=0.17). There was no significant change in HEMS alarm times between the pre- and post-intervention groups (7.6 min vs 6.4 min, p=0.15). The proportion of missions with neither medical nor logistical benefit was significantly lower in the post-intervention group (28.4% vs 40.3%, p=0.007).

CONCLUSION

The results from this study indicate that VC is a promising, feasible and safe tool for EMCC operators in the complex HEMS dispatch process.

Acute medical missions by helicopter medical service (HEMS) to municipalities with different approach for primary care physicians

Background

The prehospital emergency system in Norway involves out-of-hours (OOH) services with on-call physicians. Helicopter emergency medical service (HEMS) are used in cases of severe illness or trauma that require rapid transport and/or an anesthesiologist’s services. In recent years, on-call primary care physicians have been less available for call-outs in Norway, and HEMS may be requested for missions that could be adequately handled by on-call physicians. Here, we investigated how different availability of an on-call physician to attend emergency patients at site (call-out) impacted requests and use of HEMS.

Methods

Our analysis included all acute medical missions in an urban and nearby rural OOH district, which had different approach regarding physician call-outs from the OOH service. For this prospective observational study, we used data from both HEMS and the OOH service from November 1^st 2017 until November 30^th 2018. Standard descriptive statistical analyses were used.

Results

The rates of acute medical missions in the urban and rural OOH districts were similar (30 and 29 per 1000 inhabitants per year, respectively). The rate of HEMS requests was significantly higher in the rural OOH district than in the urban district (2.4 vs. 1.7 per 1000 inhabitants per year, respectively). Cardiac arrest and trauma were the major symptom categories in more than one half of the HEMS-attended patients, in both districts. Chest pain was the most frequent reason for an OOH call-out in the rural OOH district (21.1%). An estimated NACA score of 5–7 was found in 47.7% of HEMS patients from the urban district, in 40.0% of HEMS patients from the rural OOH district (p = 0.44), and 12.8% of patients attended by an on-call physician in the rural OOH district (p < 0.001). Advanced interventions were provided by an anesthesiologist to one-third of the patients attended by HEMS, of whom a majority had an NACA score of ≥ 5.

Conclusions

HEMS use did not differ between the two compared areas, but the rate of HEMS requests was significantly higher in the rural OOH district. The threshold for HEMS use seems to be independent of on-call primary care physician involvement.

Accuracy of prehospital clinicians' perceived prognostication of long-term survival in critically ill patients: a nationwide retrospective cohort study on helicopter emergency service patients

OBJECTIVES

Prehospital critical care physicians regularly attend to patients with poor prognosis and may limit the advanced therapies. The aim of this study was to evaluate the accuracy of poor prognosis given by prehospital critical care clinicians.

DESIGN

Cohort study.

SETTING

We performed a retrospective cohort study using the national helicopter emergency medical services (HEMS) quality database.

PARTICIPANTS

Patients classified by the HEMS clinician to have survived until hospital admission solely because of prehospital interventions but evaluated as having no long-term survival by prehospital clinician, were included.

PRIMARY AND SECONDARY OUTCOME

The survival of the study patients was examined at 30 days, 1 year and 3 years.

RESULTS

Of 36 715 patients encountered by the HEMS during the study period, 2053 patients were classified as having no long-term survival and included. At 30 days, 713 (35%, 95% CI 33% to 37%) were still alive and 69 were lost to follow-up. Furthermore, at 1 year 524 (26%) and at 3 years 267 (13%) of the patients were still alive. The deceased patients received more often prehospital rapid sequence intubation and vasoactives, compared with patients alive at 30 days. Patients deceased at 30 days were older and had lower initial Glasgow Coma Scores. Otherwise, no clinically relevant difference was found in the prehospital vital parameters between the survivors and non-survivors.

CONCLUSIONS

The prognostication of long-term survival for critically ill patients by a prehospital critical care clinician seems to fulfil only moderately. A prognosis based on clinical judgement must be handled with a great degree of caution and decision on limitation of advanced care should be made cautiously.

Profiling helicopter emergency medical service winch operations involving physicians in Queensland, Australia

OBJECTIVE

To analyse the mission profiles of helicopter emergency medical service (HEMS) winch operations involving LifeFlight Retrieval Medicine physicians in Queensland, Australia, specifically focusing on patients' clinical characteristics, extrication methods and scene times.

METHODS

A retrospective analysis was performed to identify all helicopter winch missions involving physicians during 2019. Demographic, clinical and non-clinical data were accessed from an electronic database used to log cases and findings presented using descriptive statistics.

RESULTS

Out of 4356 HEMS missions involving physicians, 100 (2.3%) were winch operations. Of these, 31 (31%) occurred overwater and 12 (12%) at night. In total, 106 patients were attended, and eight patient deaths occurred. Most patients were traumatically injured (66%), male (66%) and had a median (interquartile range) age of 43.5 (28-59) years. Thirteen missions (13%) involved drowning victims. This group had a higher burden of injury and comprised half of the patients treated with endotracheal intubation. Median scene time was 30 min (20-40), and the winch stretcher was the predominant patient extrication method. Physician winching occurred in 63 (63%) missions and was associated with increased scene time and increased use of the winch stretcher.

CONCLUSIONS

Winch operations involving physicians occur infrequently in Queensland HEMS, although almost a third of missions occur overwater. Drowning victims are encountered more frequently than reported elsewhere in Australian HEMS and comprised half of the patients who underwent endotracheal intubation. Patients' severity of illness and injury may contribute to the associations between winching of physicians, increased scene times and increased use of the winch stretcher.

The development of emergency medical services benefit score: a European Delphi study

Background

The helicopter emergency services (HEMS) Benefit Score (HBS) is a nine-level scoring system developed to evaluate the benefits of HEMS missions. The HBS has been in clinical use for two decades in its original form. Advances in prehospital care, however, have produced demand for a revision of the HBS. Therefore, we developed the emergency medical services (EMS) Benefit Score (EBS) based on the former HBS. As reflected by its name, the aim of the EBS is to measure the benefits produced by the whole EMS systems to patients.

Methods

This is a four-round, web-based, international Delphi consensus study with a consensus definition made by experts from seven countries. Participants reviewed items of the revised HBS on a 5-point Likert scale. A content validity index (CVI) was calculated, and agreement was defined as a 70% CVI. Study included experts from seven European countries. Of these, 18 were prehospital expert panellists and 11 were in-hospital commentary board members.

Results

The first Delphi round resulted in 1248 intervention examples divided into ten diagnostic categories. After removing overlapping examples, 413 interventions were included in the second Delphi round, which resulted in 38 examples divided into HBS categories 3–8. In the third Delphi round, these resulted in 37 prehospital interventions, examples of which were given revised version of the score. In the fourth and final Delphi round, the expert panel was given an opportunity to accept or comment on the revised scoring system.

Conclusions

The former HBS was revised by a Delphi methodology and EBS developed to represent its structural purpose better. The EBS includes 37 exemplar prehospital interventions to guide its clinical use.

Trial registration The study permission was requested and granted by Turku University Hospital (decision number TP2/010/18).

Supplementary Information

The online version contains supplementary material available at 10.1186/s13049-021-00966-3.

Emergency physician's dispatch by a paramedic-staffed emergency medical communication centre: sensitivity, specificity and search for a reference standard

Background

Some emergency medical systems (EMS) use a dispatch centre where nurses or paramedics assess emergency calls and dispatch ambulances. Paramedics may also provide the first tier of care “in the field”, with the second tier being an Emergency Physician (EP).

In these systems, the appropriateness of the decision to dispatch an EP to the first line at the same time as the ambulance has not often been measured. The main objective of this study was to compare dispatching an EP as part of the first line emergency service with the severity of the patient’s condition. The secondary objective was to highlight the need for a recognized reference standard to compare performance analyses across EMS.

Methods

This prospective observational study included all emergency calls received in Geneva’s dispatch centre between January 1st, 2016 and June 30th, 2019. Emergency medical dispatchers (EMD) assigned a level of risk to patients at the time of the initial call. Only the highest level of risk led to the dispatch of an EP. The severity of the patient’s condition observed in the field was measured using the National Advisory Committee for Aeronautics (NACA) scale. Two reference standards were proposed by dichotomizing the NACA scale. The first compared NACA≥4 with other conditions and the second compared NACA≥5 with other conditions. The level of risk identified during the initial call was then compared to the dichotomized NACA scales.

Results

97′861 assessments were included. Overall prevalence of sending an EP as first line was 13.11, 95% CI [12.90–13.32], and second line was 2.94, 95% CI [2.84–3.05]. Including NACA≥4, prevalence was 21.41, 95% CI [21.15–21.67], sensitivity was 36.2, 95% CI [35.5–36.9] and specificity 93.2 95% CI [93–93.4]. The Area Under the Receiver-Operating Characteristics curve (AUROC) of 0.7507, 95% CI [0.74734–0.75397] was acceptable. Looking NACA≥5, prevalence was 3.09, 95% CI [2.98–3.20], sensitivity was 64.4, 95% CI [62.7–66.1] and specificity 88.5, 95% CI [88.3–88.7]. We found an excellent AUROC of 0.8229, 95% CI [0.81623–0.82950].

Conclusion

The assessment by Geneva’s EMD has good specificity but low sensitivity for sending EPs. The dichotomy between immediate life-threatening and other emergencies could be a valid reference standard for future studies to measure the EP’s dispatching performance.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13049-021-00844-y.

Evaluation of a Prehospital Rotation by Senior Residents: A Web-Based Survey

The added value of prehospital emergency medicine is usually assessed by measuring patient-centered outcomes. Prehospital rotations might however also help senior residents acquire specific skills and knowledge. To assess the perceived added value of the prehospital rotation in comparison with other rotations, we analyzed web-based questionnaires sent between September 2011 and August 2020 to senior residents who had just completed a prehospital rotation. The primary outcome was the perceived benefit of the prehospital rotation in comparison with other rotations regarding technical and non-technical skills. Secondary outcomes included resident satisfaction regarding the prehospital rotation and regarding supervision. A pre-specified subgroup analysis was performed to search for differences according to the participants’ service of origin (anesthesiology, emergency medicine, or internal medicine). The completion rate was of 71.5% (113/158), and 91 surveys were analyzed. Most senior residents found the prehospital rotation either more beneficial or much more beneficial than other rotations regarding the acquisition of technical and non-technical skills. Anesthesiology residents reported less benefits than other residents regarding pharmacological knowledge acquisition and confidence as to their ability to manage emergency situations. Simulation studies should now be carried out to confirm these findings.

Use of peripheral vascular access in the prehospital setting: is there room for improvement?

Background

Previous studies have shown that prehospital insertion of peripheral vascular access is highly variable. The aim of this study is to establish the proportion of peripheral vascular access placement and its use with regard to both the severity of cases and the main problem suspected by the paramedics involved. Over-triage was considered to have taken place where peripheral vascular access was placed but unused and these cases were specifically analysed in order to evaluate the possibility of improving current practice.

Methods

This is a one-year (2017) retrospective study conducted throughout one State of Switzerland. Data were extracted from the state’s public health service database, collected electronically by paramedics on RescueNet® from Siemens. The following data were collected and analyzed: sex, age, main diagnosis suspected by paramedics and the National Advisory Committee for Aeronautics score (NACA) to classify the severity of cases.

Results

A total of 33,055 missions were included, 29,309 (88.7%) with a low severity. A peripheral vascular access was placed in 8603 (26.0%) cases. Among those, 3948 (45.9%) were unused and 2626 (66.5%) of these patients had a low severity score. Opiates represent 48.3% of all medications given. The most frequent diagnosis among unused peripheral vascular access were: respiratory distress (12.7%), neurological deficit without coma or trauma (9.6%), cardiac condition with thoracic pain and without trauma or loss of consciousness (9.6%) and decreased general condition of the patient (8.5%).

Conclusions

Peripheral vascular access was set in 26% of patients, nearly half of which were unused. To reduce over-triage, special attention should be dedicated to cases defined by EMS on site as low severity, as they do not require placement of a peripheral vascular access as a precautionary measure. Alternative routes, such as the intra-nasal route, should be promoted, particularly for analgesia, whose efficiency is well documented. Emergency medical services medical directors may also consider modifying protocols of acute clinical situations when data show that mandatory peripheral vascular access, in stroke cases for example, is almost never used.

Reliability of prehospital patient classification in helicopter emergency medical service missions

Background

Several scores and codes are used in prehospital clinical quality registries but little is known of their reliability. The aim of this study is to evaluate the inter-rater reliability of the American Society of Anesthesiologists physical status (ASA-PS) classification system, HEMS benefit score (HBS), International Classification of Primary Care, second edition (ICPC-2) and Eastern Cooperative Oncology Group (ECOG) performance status in a helicopter emergency medical service (HEMS) clinical quality registry (CQR).

Methods

All physicians and paramedics working in HEMS in Finland and responsible for patient registration were asked to participate in this study. The participants entered data of six written fictional missions in the national CQR. The inter-rater reliability of the ASA-PS, HBS, ICPC-2 and ECOG were evaluated using an overall agreement and free-marginal multi-rater kappa (Κ_free).

Results

All 59 Finnish HEMS physicians and paramedics were invited to participate in this study, of which 43 responded and 16 did not answer. One participant was excluded due to unfinished data entering. ASA-PS had an overall agreement of 40.2% and Κ_free of 0.28 in this study. HBS had an overall agreement of 44.7% and Κ_free of 0.39. ICPC-2 coding had an overall agreement of 51.5% and Κ_free of 0.47. ECOG had an overall agreement of 49.6% and Κ_free of 0.40.

Conclusion

This study suggests a marked inter-rater unreliability in prehospital patient scoring and coding even in a relatively uniform group of practitioners working in a highly focused environment. This indicates that the scores and codes should be specifically designed or adapted for prehospital use, and the users should be provided with clear and thorough instructions on how to use them.

Evaluation of the discriminative performance of the prehospital National Advisory Committee for Aeronautics score regarding 48-h mortality

OBJECTIVE

The National Advisory Committee for Aeronautics (NACA) score is used by many emergency medical services to assess the severity of prehospital patients. Little is known about its discriminative performance regarding short-term mortality.

PARTICIPANTS AND METHODS

We retrospectively included adult missions between 2008 and 2014 in a Swiss ground and air-based emergency medical services. We excluded uninjured or dead-on-scene patients. Primary outcome was assessment of the discriminative performance of the NACA score to classify the 48-h vital status of patients. Overall discrimination was quantified using the area under receiver operating characteristic curve (AUC). We also explored the influence of epidemiological characteristics (age and sex), mechanism (trauma or nontrauma) and clinical parameters (respiratory rate, oxygen saturation, heart rate, systolic blood pressure, capillary refill time, and Glasgow Coma Scale) on its discriminative performance. We then assessed the incremental value of these variables in the classification accuracy of a rule based on these variables in addition to the NACA score.

RESULTS

We included 11 567 patients out of 11 639 (72 exclusions for missing data). Overall AUC was 0.86. The score was more discriminant for trauma (AUC = 0.95 vs. 0.83), and for younger patients (AUC = 0.91 for 16-59 vs. 0.78 for 84-104 years). Adding age, sex, mechanism, and clinical parameters resulted in a classification rule with higher discriminative performance than NACA score alone (AUC of 0.92 vs. 0.86; P < 0.001).

CONCLUSION

The NACA score is an efficient way to discriminate victims regarding short-term mortality. Its performance can be enhanced by also integrating epidemiological and clinical parameters into an extended classification rule.

Neonatal Transport in the Practice of the Crews of the Polish Medical Air Rescue: A Retrospective Analysis

The aim of the study was to present characteristics of patients transported in incubators by crews of Helicopter Emergency Medical Service (HEMS) and Emergency Medical Service (EMS) of the Polish Medical Air Rescue as well as the character of their missions. The study was based on the method of retrospective analysis of neonatal transports with the use of transport incubators by the crews of HEMS and EMS of the Polish Medical Air Rescue. The study covered 436 medical and rescue transports of premature babies and full-term newborns in the period between January 2012 and December 2018. The study group consisted mainly of male patients (55.05%) who, on the basis of the date of delivery, were qualified as full-term newborns (54.59%). During the transport their average age was 37.53 (standard deviation, SD 43.53) days, and their average body weight was 3121.18 (SD 802.64) grams. A vast majority of neonatal transports were provided with the use of a plane (84.63%), and these were medical transports (79.36%). The average transport time was 49.92 (SD 27.70) minutes with the average distance of 304.27 km (SD 93.05). Significant differences between premature babies and full-term newborns were noticed in terms of age and body weight at the moment of transport, diagnosis based on the International Statistical Classification of Diseases and Related Health Problems (ICD-10), the most commonly used medications (prostaglandin E1, glucose, furosemide, vitamins), National Advisory Committee for Aeronautics (NACA) scale rate as well as the mission type and the presence of an accompanying person.

Checklists in pre-hospital advanced airway management

BACKGROUND

In pre-hospital care, pre-intubation checklists (PICL) are widely implemented as a safety measure and guidelines support their use. However, the true value of PICL among experienced airway providers is unknown. This study aims to explore possible benefits and disadvantages of PICL in the pre-hospital setting.

METHODS

We performed a subgroup analysis of a prospective, observational, multicentre study on pre-hospital advanced airway management in the Nordic countries between May 2015 and November 2016. The original trial was designed to investigate the success rates of pre-hospital tracheal intubations and the incidence of complications. Our study limited inclusion to drug assisted intubations performed by anaesthesiologists. Intubation success rates and complication rates were plotted against checklist use.

RESULTS

We analyzed 588 pre-hospital intubations for medical and traumatic emergencies. Overall, checklists were used in 60.5% of instances. Applying checklists was associated with increased success at first and second intubation attempts. There was no significant difference in the overall success rates (99.4% and 99.1%). Oesophageal misplacement was more common in the No-PICL group (2.2% vs 0.3%) but otherwise the incidence of airway related complications did not differ between the groups. Scene time was significantly shorter in the No-PICL group (23.6 vs 27.5 minutes).

CONCLUSION

In this retrospective study, checklist use correlated with fewer attempts at intubation when securing the airway. Despite this, we found no association between checklist use and the overall TI success rate or the incidence of serious adverse events. Scene times were shorter without PICL.

The NACA score as a predictor of ventricular cardiac arrhythmias - A retrospective six-year study

BACKGROUND

Helicopter Emergency Medical Service (HEMS) conducts the evaluation of a patient's condition using NACA score before transporting the patient to hospital. The conditions inside the rescue helicopter limit or even make it impossible to conduct some medical procedures. An appropriate classification of the patient may lead to a lower possibility of occurrence of adverse events during the flight. The aim of the research was to evaluate the correlation of NACA score with the cardiac arrhythmia that may be life threatening.

METHODS

A retrospective observational study included a group of 47,131 patients, who were transported by HEMS services between 2012 and 2017. The research was conducted using the analysis of variance ANOVA running a post hoc test. In order to calculate the correlation of variables, Kruskal-Wallis and r-Pearson tests were carried out, interpreting the results according to J. Gilville's scale. The significance level was set at α = 0,05.

RESULTS

The average number of points using NACA score for the studied group was 4,06 (SD ± 1,38). Twelve heart rhythms were selected while evaluating correlations using NACA score. There was a significant relation between the ECG variable and NACA score (p = 0,003). There was a very strong correlation between NACA score and the following: VF/pVT (r-Pearson = 0,856; p = 0,006), PEA (r-Pearson = 0,810; p = 0,015) and Asystole (r-Pearson = 0,728; p = 0,026).

CONCLUSIONS

NACA score allows to predict the risk of occurrence of ventricular arrhythmia of the myocardium as well as cardiac arrest. The possibility of occurrence of a life-threatening rhythm is significantly higher in patients classified as NACA IV or higher.

Helicopter Emergency Medical Service (HEMS) Response in Rural Areas in Poland: Retrospective Study

The aim of the study was to identify the characteristics of missions performed by HEMS (Helicopter Emergency Medical Service) crews and the analysis of health problems, which are the most common cause of intervention in rural areas in Poland. The study was conducted using a retrospective analysis based on the medical records of patients provided by the HEMS crew, who were present for the emergencies in rural areas in the period from January 2011 to December 2018. The final analysis included 37,085 cases of intervention by HEMS crews, which accounted for 54.91% of all the missions carried out in the study period. The majority (67.4%) of patients rescued were male, and just under a quarter of those rescued were aged between 50-64 years. Injuries (51.04%) and cardiovascular diseases (36.49%) were the main diagnoses found in the study group. Whereas injuries were significantly higher in the male group and patients below 64 years of age, cardiovascular diseases were higher in women and elderly patients (p < 0.001). Moreover, in the group of women myocardial infarction was significantly more frequent (30.95%) than men, while in the group of men head injuries (27.10%), multiple and multi-organ injuries (25.93%), sudden cardiac arrest (14.52%), stroke (12.19%), and epilepsy (4.95%) was significantly higher. Factors that are associated with the most common health problems of rural patients are: gender and age, as well as the seasons of the year and the values of the Glasgow Coma Scale (GCS), Revised Trauma Score (RTS), and National Advisory Committee for Aeronautics (NACA) used to assess the clinical status of patients.

Comparison of two prehospital predictive models for mortality and impaired consciousness after severe traumatic brain injury

BACKGROUND

The primary aim was to investigate the performance of a National Advisory Committee for Aeronautics based predictive model (NACA-BM) for mortality at 14 days and a reference model using motor GCS (GCS-RM). The secondary aim was to compare the models for impaired consciousness of survivors at 14 days (IC-14; GCS ≤ 13).

METHODS

Patients ≥16 years having sustained TBI with an abbreviated injury scale score of head region (HAIS) of >3 were included. Multivariate logistic regression models were used to test models for death and IC-14. The discrimination was assessed using area under the receiver-operating curves (AUROCs); noninferiority margin was -5% between the AUROCs. Calibration was assessed using the Hosmer Lemeshow goodness-of-fit test.

RESULTS

Six hundred and seventy seven patients were included. The median age was 54 (IQR 32-71). The mortality rate was 31.6%; 99 of 438 surviving patients (22.6%) had an IC-14. Discrimination of mortality was 0.835 (95%CI 0.803-0.867) for the NACA-BM and 0.839 (0.807-0.872) for the GCS-RM; the difference of the discriminative ability was -0.4% (-2.3% to +1.7%). Calibration was appropriate for the NACA-BM (χ² 8.42; P = 0. 393) and for the GCS-RM (χ² 3.90; P = 0. 866). Discrimination of IC-14 was 0.757 (0.706-0.808) for the NACA-BM and 0.784 (0.734-0.835) for the GCS-RM; the difference of the discriminative ability was -2.5% (-7.8% to +2.6%). Calibration was appropriate for the NACA-BM (χ² 10.61; P = 0.225) and for the GCS-RM (χ² 6.26; P = 0.618).

CONCLUSIONS

Prehospital prediction of mortality after TBI was good with both models, and the NACA-BM was not inferior to the GCS-RM. Prediction of IC-14 was moderate in both models.

The mission characteristics of a newly implemented rural helicopter emergency medical service

Background

Physician-staffed helicopter emergency services (HEMS) can provide benefit through the delivery of specialist competence and equipment to the prehospital scene and through expedient transport of critically ill patients to specialist care. This paper describes the integration of such a system in a rural Swedish county.

Methods

This is a retrospective database study recording the outcomes of every emergency call centre dispatch request as well as the clinical and operational data from all completed missions during this service’s first year in operation.

Results

During the study period, HEMS completed 478 missions out of which 405 (84,7%) were primary missions to prehospital settings and 73 (15,3%) were inter-hospital critical care transfers. A majority (55,3%) of primary missions occurred in the regions furthest from our hospitals, in municipalities housing only 15,6% of the county’s population. The NACA (IQR) score on primary and secondary missions was 4 (2) and 5 (1), respectively.

Conclusions

This study describes the successful integration of a physician-based air ambulance service in a Scandinavian rural region. Municipalities distant from our hospitals benefitted as they now have access to early specialist intervention and expedient transport to critical hospital care. Our hospitals and most populated areas benefitted from HEMS secondary mission capability as they gained a dedicated ICU transport service that could provide specialist intensive care during rapid inter-hospital transfer.

The impact of the patient's initial NACA score on subjective and physiological indicators of workload during pre-hospital emergency care

BACKGROUND

Excessive workload may impair patient safety. However, little is known about emergency care providers' workload during the treatment of life-threatening cases including cardiopulmonary resuscitation (CPR). Therefore, we tested the hypothesis that subjective and physiological indicators of workload are associated with the patient's initial NACA score and that workload is particularly high during CPR.

METHODS

NASA task load index (NASA-tlx) and alarm codes were obtained for 216 sorties of pre-hospital emergency medical care. Furthermore, initial NACA scores of 140 patients were extracted from the physicians' protocols. The physiological workload indicators mean heart rate (HR) and permutation entropy (PeEn) were calculated for 51 sorties of primary care. General linear mixed models were used to analyze the association of NACA scores with subjective (NASA-tlx) and physiological (mean HR, PeEn) measures of workload.

RESULTS

In contrast to the physiological variables PeEn (p = 0.10) and HR (p = 0.19), the mental (p<0.001) and temporal demands (p<0.001) as well as the effort (p<0.001) and frustration (p = 0.04) subscale of the NASA-tlx were significantly associated with initial NACA scores. Compared to NACA = I, an initial NACA score of VI (representing CPR) increased workload by a mean of 389.5% (p = 0.001) in the mental and 345.9% (p<0.001) in the temporal demands, effort by a mean of 446,8% (p = 0.002) and frustration by 190.0% (p = 0.03). In line with the increase in NASA-tlx, PeEn increased by 20.6% (p = 0.01) and HR by 6.4% (p = 0.57).

CONCLUSIONS

Patients' initial NACA scores are associated with subjective workload. Workload was highest during CPR.

Inter-disciplinary cooperation in a physician-staffed emergency medical system

BACKGROUND

On-scene management of pre-hospital emergencies is often inter-disciplinary, involving ground-emergency medical services (EMS), police- and fire services, and in Norway general practitioners on-call. This can also be supplemented by physician-staffed EMS (P-EMS), utilizing helicopters or rapid response vehicles. We hypothesized that P-EMS cooperates extensively with other emergency services, and therefore the primary aim of this study was to investigate the fraction of inter-disciplinary cooperation between P-EMS and other emergency services.

METHODS

Retrospective, observational study of primary pre-hospital missions with patient contact performed at a Norwegian P-EMS base from 01.01.06 to 31.12.15. Descriptive statistics, comparisons using Student`s t-test, and chi-squared test for trend were applied.

RESULTS

Inter-disciplinary cooperation occurred in 94.3% of the 8580 missions, of which physician-staffed EMS cooperated with ground EMS in 92.4%, general practitioner 32.9%, police service 11.6% and fire service 11.8%. Trauma constituted 34.4 and cardiac arrest 14.1% of missions. The mean National Advisory Committee for Aeronautics score was 4.21 (95% Confidence Interval 4.18-4.24). There was an overall decrease in cooperation with general practitioners and the police service (P < 0.001). During helicopter missions, we reported a decrease in general practitioner cooperation compared to an increase during rapid response car missions (P < 0.001). In cardiac arrest cases, cooperation with both general practitioners and the fire service increased (P < 0.001).

CONCLUSION

Physician-staffed EMS cooperates extensively with other professional emergency services, especially ground-EMS. On-scene cooperation with general practitioners decreased, whereas there was an increased cooperation with the fire service in a "first-responder" role during cardiac arrest missions.