This study demonstrates that a modular US curriculum with didactic lectures and hands on training may be helpful in teaching US use for anesthesiologists, as trainees had significant improvement in their theoretical knowledge and in the time needed to perform psychomotor skills; however, an improvement in needle visualization in a visuomotor skill and in identification of correct anatomical structures in a visuospatial skill could not be achieved.
Sonographic techniques are challenging to learn. Learning US requires the integration of multiple skill sets including identification of appropriate patients, image acquisition, image interpretation, and integration of findings into the clinical management of patients [
18]. To perform medical sonographic examinations, the use of psychomotor skills is crucial. Central components of medical US imaging are visuomotor and visuospatial psychomotor skills [
20]. These skills are best acquired in stages using a sequenced and stepped teaching approach. Therefore, critical care US programs include didactic teaching, direct supervision and maintenance of a logbook [
9]. Unlike other programs, the German AFS sonography curriculum includes a combination of both didactic lectures and hands-on training. An attendance confirmation is provided but without proof of clinical practical training. For this reason, we tried to show whether or not an US course without subsequent retraining in daily clinical practice improves participants’ knowledge and psychomotor skills. We were able to show that these skills can only partially be improved by the given US courses. The trainees improved significantly in the time needed to perform the tasks, but not in puncture quality and in correctly identifying anatomical structures. In contrast, theoretical knowledge improved significantly. Consequently, we do not feel that completion of this course is sufficient to perform independently US for regional anesthesia or for diagnostic purposes.
In this study, psychomotor skills were practiced by the trainee immediately after lecture demonstration. The instructors followed a traditional two-step model to teach psychomotor skills. After a short demonstration of the skill the instructor acted mainly as a coach, following instructional strategies relevant for teaching complex skills in US [
18,
21]. Despite frequent hands-on training during the course, it seems likely that an improvement in psychomotor skills can only be achieved through everyday clinical practice. Indeed, a longitudinal US curriculum, compared to a single stand-alone workshop, improved the ability of internal medical residents to correctly identify static US images at 6 months [
15]. In addition, after 1 year of training point of care sonography anesthesiology residents can successfully acquire images of acceptable quality [
24]. Interestingly, the greatest improvements in quality and acquisition time were for vascular access and pulmonary US. In an emergency medicine study, physicians acquired the ability to interpret focused assessment with sonography in trauma (FAST) images earlier than the technical skills required to actually perform the examination. The incidence of specific technical errors improved with hands-on experience [
12]. From this study it was concluded that more than 60 examinations are needed to reduce the incidence of technical errors below 5%. In contrast, for focused TTE, other studies have demonstrated that it can be performed by novice practitioners with minimal training only [
13,
23]. As in our course, the goals were achieved using a combination of both didactic lectures and small group skills training, which were practiced by the learner immediately after the initial lecture demonstration to facilitate the clinical expertise and skill reinforcement [
23]. In addition, an only 60-min didactic presentation on TTE for intensive care unit (ICU) trainees may be useful in teaching basic TTE skills and encouraging the use of bedside TTE in the ICU [
17]. Such a short didactic presentation was chosen, because the authors proposed that one of the most common barriers to implementing TTE education is the lack of time. The barriers to delivering a high-quality training program are often the lack of trainers and no spare time for further medical training [
9]. The major challenge in the posttest was to perform better in describing anatomical structures correctly and in better needle visualization in our puncture model. Although all participants have entered the noodles without continuous needle visualization thereby saving time, advancing the needle without observing the needle tip is not recommended due to a higher complication rate during vascular access procedures and also during regional anesthesia [
26]. To improve these practical skills it seems mandatory, that clinical experience must be supported by a trainer and supervised by an expert and, thus, constantly mentored after an US course. Effectiveness of the educational modality used in sonographic training merits further investigation. Delivery of didactic teaching varies between face to face courses and online teaching modules, and differs in the duration and structure. Model simulation education strategies may improve training more than standardized didactic lectures. Videoclip-based pathology lectures may improve content retention [
24]. These two education strategies are also used for the AFS curriculum. They could perhaps be extended by exercises on real patients in order to improve practical skills. It has been shown that education taught on non-ideal, real-world patients and not healthy volunteers can increase the efficacy of learning [
17]. In addition, novices’ sonographic skills showed greater improvement when feedback was combined with validated metrics [
1]. Systematic reviews have shown that simulation-based training in health care is significantly more effective than alternative teaching methods or no intervention [
7]. Simulation-based medical education training was effective in improving short and long-term competency in, and knowledge of central venous catheter insertion [
5]. Most likely for lack of time, the AFS curriculum does not incorporate this teaching methodology; however, the new PFE curriculum includes US simulators as an optional tool and it could be an additional methodology in the context of clinically practical training also in the other AFS modules. As an alternative to the two-step model used during the hands-on training, other step-by-step instructional models could perhaps improve the training modules. The efficacy of using different step-by-step instructional models to teach psychomotor skills is subject of ongoing debate. When using the five-step George and Doto model or the Walker and Peyton four-step model, simple skill acquisition was significantly enhanced in studies [
30,
31]. In contrast, other studies comparing different skill teaching models identified no significant differences in cases of complex skill acquisition [
2,
10,
16,
22]. Because of this paucity of evidence it does not seem necessary to change the use of the two-step model.