Our study indicates that more than two-thirds of the European HEMS organizations provide POCUS in their helicopters and that a considerable number is planning to establish it soon. HEMS providers appreciate the increased need for POCUS integration in pre-hospital care. To our knowledge, this is the first survey regarding the pre-hospital use of POCUS in HEMS organizations across Europe.
Data suggest that POCUS is feasible and useful in HEMS. Nevertheless, the evidence regarding improving direct patient outcome is weak which needs properly designed prospective studies [10, 11, 13,14,15,16,17,18]. There are different POCUS protocols that can be used in the pre-hospital setting which include extended (e)FAST to search for intraperitoneal fluid, peri-cardiac fluid, haemothorax and pneumothorax, [19, 20], Rapid Ultrasound for Shock (RUSH) to define the cause of the shock, and Focused Assessment Transthoracic Echocardigraphy (FATE) or Focused Echocardiography in Emergency Life support (FEEL) to quickly evaluate the cardiac function [21,22,23,24,25]. Our results show, that (e)FAST is the most used protocol in HEMS. Independent of the used protocols whether (e)FAST, RUSH, FATE, FEEL or others, we think that it is important to carry out POCUS in patients in critical conditions or shock to find or exclude free fluid in the abdomen, in the thorax or in the pericardium, to detect or exclude pneumothorax, to find causes of shock and to exclude or confirm reversal causes of cardiac arrest. In this context POCUS is a physiological study, an on spot clinical decision tool, a clinical examination extension, a unique and expanding, safe and repeatable tool [1, 2].
With advancements in technology and training, the use of POCUS extended to more indications like diagnosis of eye injuries and bone fractures [26, 27]. POCUS training should be tailored towards the specific needs of the HEMS staff. The operators should be familiar with their own ultrasound machines and should be particularly knowledgeable of the sonographic artefacts that can mislead them [1, 28]. On the other hand, if the operators are familiar with their ultrasound machines they are able to make use of the record function of modern machines to record images or loops of the findings. As shown in Table 4, only minority of participants of this survey made use of the “record function” of their ultrasound machines. More than one quarter does not record the findings at all and more than 50% outline the findings in the mission protocol. Only 12% of the participants are doing both, recording as video and in the mission protocol (data not shown in Table 4). There is much potential for further improvement regarding this issue. This is very important for medicolegal issues, credentialing, closing the learning loop by reviewing the video clips, and using the clips for training and research so as to refine and advance the use of POCUS.
The participants thought that POCUS examinations of the chest, abdomen and heart are very important, vascular access are important, while POCUS for airway management and regional anesthesia is less important, (see Table 3). It is of interest to note that the needed POCUS skills for airway management and interventions are more advanced. Currently less than one-third of the participating HEMS organizations seems to have a credentialing process for using POCUS. The other two-third assumed that the HEMS crews can perform POCUS. Training must be standardized to maximize the benefit of POCUS. European HEMS organizations should agree on common POCUS curriculum with an accepted standard that suits their needs. Competency is a key factor in successful clinical applications [1, 29]. Using a Delphi methodology, Micheller et al. defined a total of five modalities (cardiac, thoracic, FAST, aorta, and procedural), with 32 measured competencies and 72 sub competencies . Consecutive quality assurance and governance is probably more challenging, as POCUS findings are interpreted in a dynamic clinical context. The availability and operator acceptance of the POCUS equipment seem to be less of a challenge, at least in Europe.
Besides the more frequent use of POCUS compared with North America, the survey underlines that HEMS in Europe is mainly physician staffed which can explain the frequent use of POCUS [9, 29]. Some participants stated that POCUS is used in more than 30% of their patients indicating proper training in a wide range of applications.
The represented study has some limitations which we would like to highlight. First, it was a voluntary online survey that carries the risk of selection bias of participants who encourage the use of POCUS. This may overestimate the value of POCUS. Second, respondents were heterogeneous, from different levels, with unequal numbers from diferent organizations. Majority were leaders in their HEMS organization, with the risk of reporting results that are preferred by them and may be different from those who use it. We decided to analyse as many answers as possible because some HEMS providers do not provide uniform POCUS approaches. Not all helicopters are equally equipped (e.g. general availability of an ultrasound machine or type of ultrasound machine), even if they are operated by the same HEMS provider. Furthermore, some points of the questionnaire were about personal opinions of the participants, which are not identical. Third, we did not get the response of all invited HEMS organizations and we are unable to make sure, that all HEMS in Europa have been reached due to constant changes in the European HEMS scenery. This carries the risk of selection bias. The survey was asked in a limited period of 30 days possibly explaining the small sample size. Fourth, female responders were few with the majority being males. Fifth, no information regarding the time required to carry out POCUS and if there were any time limiting rules when carrying out POCUS were included in the survey. Sixth, we have to acknowledge that the current study is not a hypothesis testing study trying to answer a specific research question but aimed at collecting general data on the current status of POCUS use in Europe which will help us to define more hypothesis generating questions in the future. Accoridngly, specific details on each application (like the use of local anesthesia) are missing. Finally, some of the participating countries and HEMS organizations were over represented. This was taken into consideration when reporting availability of POCUS in the organizations but could have skewed the opinion data.