A report on the experience of using ultrasound by emergency medical technicians in dealing with trauma patients in pre-hospital setting: a pilot study

Introduction Downsizing of the ultrasound devices has made it possible to make more use of it; Not only the patients no longer need to be moved to a separate room for performing ultrasonography, but also the ultrasound machine is easily brought to the patient’s bedside. This has allowed for defining more applications of ultrasound in dealing with emergency patients (1). One of its most common roles has been defined in primary surveys of trauma patients as “extended focused assessment with sonography in trauma (eFAST)”, that is performed routinely in the emergency department (ED) (2-4). Recently, Pre-hospital Trauma Life Support (PHTLS) guidelines have attempted to increase the role of pre-hospital emergency care in trauma patients, whether in terms of therapeutic interventions or diagnostic measures (5). So, the possibility of using ultrasound for performing eFAST in the pre-hospital phase has been raised and its effectiveness, advantages, and disadvantages have been challenged (3,6). It seems that pre-hospital ultrasound studies started around the year 2000 and primarily concentrated on using FAST on the aeromedical field. This has led to contradictory results in terms of feasibility, usefulness and etc (7,8). Later, more studies were designed concerning the potential benefits of its use in ground missions, on different patients, and of course, with different applications. Overall, it is believed that pre-hospital ultrasound alters the diagnosis and management of patients, but there is a paucity of evidence regarding patients’ outcomes (5). In Iran, portable ultrasound devices have not yet been deployed Brief Report Volume 6, Issue 2, 2020, p. 92-97

in ambulances; But the idea has caught the attention of administrators. Therefore, the current study was performed to provide real-time bedside ultrasonography for emergency medical technicians (EMTs) and assess the advantages and disadvantages of its application in dealing with trauma patients in pre-hospital setting from their viewpoints.

Methods
This semi-experimental study was performed from June 16, 2019 to August 25, 2019 in Tehran, Iran. Twenty EMTs were selected purposefully from those who had a bachelor's degree and at least a 2-year work experience. They underwent a training program consisting of 4 hours of theory and 4 hours of practical workshops. Then, all the EMTs performed eFAST once on a healthy person under the supervision of an emergency medicine specialist to get the required certification for performing eFAST at the scene. The selected EMTs were asked to perform eFAST using a handheld ultrasound device on trauma patients and record the images. The saved images were reviewed by an emergency medicine specialist in terms of quality and accuracy. In addition, the results of the review of the images (feedback) were communicated with the EMTs and they filled a questionnaire prepared based on the normalization process theory (NPT) in four components including coherence, cognitive participation, collective action, and reflexive monitoring. The NPT model is a conceptual tool proposed to help in understanding the factors that affect implementation processes in clinical trials and other evaluations of complex interventions. It focuses on the ways that the implementation of complex interventions is shaped by problems of workability and integration (9,10). In the end, the EMTs were free to mention their opinion regarding the advantages and disadvantages of using sonography in the pre-hospital setting. The descriptive analysis was conducted and frequency (with percentage), mean (with standard deviation, SD), median and quartile were reported as appropriate. For comparing the strengths and weaknesses of ultrasound for different domains, we calculated standard score (0-100) based on the number of questions for each domain. The standard score was the raw score divided by the number of questions multiplied by 100.

Results
All 20 participants were males and the average age was 37.8 years (SD = 4.7). In terms of work experience, 2, 5, 7 and 6 participants had a work experience of 3-5 years, 6-10 years, 11-15 years and more than 15 years, respectively. The mean score of feeling familiar with pre-hospital ultrasound was 6.42 (SD = 1.50). Also, the mean score of feeling that pre-hospital ultrasound will be a routine part of their work now and in the future was 3.11 (SD = 2.21) and 5.47 (SD = 2.14), respectively. Table 1 shows the frequency distribution of each of the questions related to awareness, attitude, as well as the practicality nature of pre-hospital ultrasound. For C1, the majority of individuals (42.1%) received a score of 9 out of a score of 4-20, and the median total score was 10.5. For C2, the majority of individuals (38.9%) received a score of 3 out of 3-15, and the median score was 6. For C3, the majority of individuals (33.3%) received a score of 18 out of a score of 6-30, and the median total score was 18. For C4, the majority of individuals (31.6%) received a score of 7 out of a score of 5-25, and the median total score was 11 ( Figure 1). Weaknesses and strengths of ultrasound regarding workload, diagnosis, management, training, practicality, patients, and early notification were studied. All areas had a combination of positive and negative questions, using a 5-point Likert scale (0-4), and a higher total score indicated more strength. The mean score for the workload with 11 questions was 17.15 (SD = 6.85) and the standardized mean score in terms of the number of questions for the workload was 31.18 (SD = 12.46). The frequency distribution of raw and standardized scores is presented in Table 2 and Figure 2. The greatest benefit of ultrasound-based on the standardized score was for patients, management, and diagnosis. Regarding the workload, the most important strength (highest score) and weakness (lowest score) were respectively, "Short time to perform the ultrasound" with the mean score of 2.4 and "Increase of responsibility without increasing of income or support" with the mean score of 0.75. Regarding the diagnosis, the most important strength (highest scores) was "It can be very helpful in diagnosing a very ill patient" and "It is effective in diagnosing pneumothorax in a noisy environment" with the mean score of 2.6, and the most important weakness (lowest score) was "It is very dangerous if it is used as a definitive diagnostic method/can easily be misinterpreted" with the mean score of 1.3. Concerning the management, the most important strength (highest score) and weakness (lowest scores) were respectively "its role in crises or cases far from the facilities is significant" with the mean score of 3.1 and "it does not make a difference for cases like fractures" with the mean score of 1.4. In terms of training, the most important strength (highest scores) and weakness (lowest scores) were respectively, "Ultrasound training motivates the staff ", with the mean score of 3.2 and "One-day training is not enough for the ultrasound" with the mean score of 0.45. Regarding the practicality, the most important strength (highest score) and weakness (lowest score) were respectively "portability" with the mean score of 3.1 and "too time-consuming to perform ultrasound" with the mean score of 1.4. With regard to the patients, the most important strength (highest scores) and weakness (lowest scores) were respectively "When The effects that pre-hospital ultrasound has on my work are important to me. I explain to patients, they realize that ultrasound is a standard of care" with the mean score of 2.8 and "patients may not want to have an ultrasound" with the mean score of 1.7. Concerning the notification, the most important strength (highest score) and weakness (lowest score) were respectively "Quick notification to the hospital ensures that appropriate and definite facilities and resources are provided to the patient faster" with the mean score of 2.6 and "There is not enough confidence in pre-hospital notification" with the mean score of 1.1.

Discussion
The present study, after a short experience of using ultrasound in the pre-hospital phase, evaluated its pros and cons in various aspects. Overall, it seems that EMTs welcomed its use, even though they thought that it might somewhat lead to an increase in their workload. Moreover, they believed that sufficient training was not provided for them. The interviewees were uncertain about the viewpoints of the patients as well as the how it could affect the patients' outcome. But they considered it practical, and were aware of the support and desire of the management system to use ultrasound in the ambulances. This may be due to the lack of a classification of trauma centers in some areas, as well as the limited number of appropriate hospitals in case the technician detects positive FAST. Also, in some cases, because of the short time of transfer (especially in air medical transport), there is not enough time to use the ultrasound. Therefore, the pre-hospital ultrasound is recommended in cases of far distance to the hospital and there is also the possibility of triage to select the appropriate hospital. In a study conducted by Walcher et al, it was reported that the accuracy of FAST performed in the pre-hospital phase was about 99% and the results ultimately led to a change in the management of about 30% of patients. However, it took only about 2-3 minutes to complete the FAST (11). It should be mentioned that in Walcher and colleagues' study, physicians or paramedics who underwent proper training courses performed the FAST. But, in Iran, there is no physician or paramedic in EMS ambulances, and all EMTs have the same degree with various work experiences. It  seems that the managers should consider this point before the establishment of the ultrasound devices in ambulances or at least before running a project and provide adequate training courses. One of the points raised by the participants in the present study was that how pre-hospital ultrasonography could affect patients' outcome. There are several case reports that indicate the usefulness of pre-hospital ultrasonography in detecting tamponade in patients with penetrating chest trauma which result in either pericardiocentesis or improved triage process of the patients (12,13). Its usefulness was introduced not only in terms of performing advanced procedures but also in avoiding unnecessary procedures (14). Although pre-hospital ultrasound may not change the pre-hospital management of the most common conditions, it could be life-saving in some instances. Therefore, it is better to define and determine its uses prior to its general application in the system. By reviewing current literature, we found a pilot study conducted by Chin et al. in which 20 EMT-paramedics with no prior ultrasonography training underwent a brief course (a 2-hour training session) and thereafter were tested on image acquisition skills as well as image interpretation for several life-threatening conditions such as pneumothorax, pericardial effusion, and cardiac activity. They reported that the enrolled EMT-paramedics were able to perform the Prehospital Assessment with UltraSound for Emergencies (PAUSE) protocol (15). There are some other published papers, which reported that EMS physicians and paramedics without prior ultrasonography training can be trained effectively after a short course (16)(17)(18)(19).
Overall, it seems that ultrasound in Iran, like many developed countries, is going to be widely used in the prehospital emergency system (20). But the structure of this organization in our country is very different from that of the rest of the world, and naturally, different planning needs to be designed in order to make the best use of this tool in the pre-hospital setting.

Limitations
In the current study, we did not assess the learning curve of the participated EMTs. Also, the results of the performed eFAST did not alter the patients' outcome, so we cannot discuss it in this regard.

Conclusion
The EMTs participated in the current study, generally, welcomed using ultrasonography in pre-hospital setting for dealing with trauma patients; but they thought that sufficient training is required before its general establishment in ambulances. They also had concern about its effect on patients' management and outcome.

Authors' contributions
The conception and design of the work by PHK, PS and PHS; Data acquisition by FD, SB and EA; Analysis and interpretation of data by PS, PHS and SB; Drafting the work by FD, SB and EA; Revising it critically for important intellectual content by PHK, PS, and PHS; All the authors approved the final version to be published; and agree to be accountable for all aspects of the work in ensuring that questions related to the accuracy or integrity of any part of the work.

Ethical issues
The study proposal was approved by the ethics committee of Tehran University of Medical Sciences (code: IR.TUMS. VCR.REC.1397.1065) and the investigators fully adhered to the Declaration of Helsinki Principles throughout the study.