The data presented suggest that a very limited intervention is needed to improve the technical skills of inexperienced physicians to perform FATE. The 10 supervised examinations were performed as one-on-one training in approximately three hours and resulted in significant improvement of technical image quality. Adding the three hours of supervision to the two hours of introduction sums up to a total of 5 hours training after which the novices were able to produce images suitable for interpretation in 93% of all cases. In addition, all examinations by novices contained at least one image suitable for interpretation. Not surprisingly, experts generally received higher image scores. Higher image quality is especially relevant when performing diagnostic echocardiography including advanced measurements and Doppler methods whereas images with fewer details can be sufficient in more acute situations. With POC examinations in mind, the presented data suggest that physicians with a very limited amount of training can achieve ultrasound images with great importance for evaluation of immediate cardiopulmonary status.
One of the primary obstacles to overcome during training in FATE was correct orientation of the probe, a trait that could relate to the physicians inborn visual spatial ability. Physicians with high scores in the mental rotation test indeed had superior image ratings and better probe orientation on baseline examinations. However, the issue with correct probe orientation quickly resolves, as revealed by a very high degree of correct probe orientation on evaluation. There still remained a weak, but significant correlation between abilities in the mental rotation test and image rating after the intervention, although this was less distinct than during baseline examinations. One explanation for this finding could be that we found somewhat a ceiling effect of the mental rotation test which could influence the results and it is therefore difficult to draw any significant conclusions from the current data.
When comparing novices with previous experience in ultrasound examination and novices with no previous experience, no significant difference in image rating or correct probe orientation was found. A possible explanation could be that almost all previous ultrasound experience was from vascular access and ultrasound guided nerve blocks. These procedures are done with linear probes, and adjustments are primarily done in two dimensions. This contrasts the sector probes used for FATE examinations, where correct probe orientation requires adjustment in all the four dimensions mentioned in Table .
The aspect of time consumption was not addressed in this study. Participants were allowed a total of 9 minutes for acquisition of the six standard views in the FATE protocol. Previous studies have shown that with sole focus on image acquisition experienced examiners can perform the protocol in around 70 seconds [7
Results from the current study indicate that physicians can acquire the ability to perform focused cardiac ultrasound following a very limited training. However, in order not to compromise examination quality we advocate that there be a system in place for continuing expert back-up and supervision, quality control, continuing education, and re-accreditation.
Baseline and post-intervention exanimations were performed on healthy volunteers with good image quality. This is often not the case in clinical situations, and the difference between novice and experts might be clearer in the clinical setting.
The image analysis is a subjective assessment and the scoring of subcategories has the potential for crossover when using a global score. The subjectivity was handled by using a blinded independent observer for the image analysis and possible issues concerning the global score was handled by showing results from all subcategories.
Disclosure of pathology and definition of cardiopulmonary status is the apparent objective when performing FATE. Previous studies have shown that inexperienced examiners can learn aspects of POC echocardiography with limited training [9
]. However, this study did not focus on the ability to interpret the ultrasonic images. This issue requires further attention in future studies.