Below image is the summary of the key elements involved in establishing a POCUS program. First of all, the faculty need to be comfortable with the common POCUS applications, which comes only by repeated scanning. Performing educational scans and comparing with formal images/report is a good way to start.
While there is a lot of enthusiasm about hand-held devices because of the lower cost and enhanced portability, their image quality is not sufficient for advanced applications or comprehensive studies. It is very easy to miss findings such as a small stone, cyst or even a renal mass. On the other hand, if the main purpose of the program is to just introduce the trainees to basic applications such as evaluating extravascular lung water, these are good. Also, find the comparison of various hand held devices below courtesy of ACEP now.
We have proposed a model curriculum based on our experience and also listed the suggested number of scans for unsupervised practice by various organizations.
However, there is no universally accepted model or guideline at this time. The major hurdle is there is no clear consensus on what sonographic applications nephrologists should be learning. Some nephrologists lay emphasis on comprehensive renal ultrasound (billing analogous to radiologists), comprehensive vascular access ultrasound and procedural guidance, while others favor more focused and diagnostic applications used as an ‘adjunct to physical examination’. On the other hand, there are nephrologists who believe ultrasound is not our territory at all.
Personally, I belong to the diagnostic POCUS camp. Here is the rationale:
1. We are nephrologists and expected to know how the kidney looks like on ultrasound and the commonly encountered abnormalities. Fortunately, the kidneys are relatively easy to image and there are limited number of pathologies. Therefore, both comprehensive and limited (= used to answer a focused question) arguments make sense to me.
2. Probably, the most important thing that helps us in our day-to-day clinical practice is volume status assessment. If we really want to take ownership of this area, we NEED to know about the pump and pipes as well as the effects of leaky pipes. In other words, we should have a good understanding of the basic cardiac (including inferior vena cava assessment, venous waveforms etc.) and lung sonography.
3. Dialysis vascular access: It’s good to know how to use spectral Doppler and assess vascular abnormalities. However, this requires higher skill level (= more training) and is less helpful for a non-interventional nephrologist. One use I see is evaluation of the newly placed access for maturation in the nephrology clinic so that the patient does not need to make a trip to ultrasound department.
4. Procedural guidance: Using ultrasound guidance to place a dialysis catheter is pretty much a standard practice in the United States – so no arguments there. Kidney biopsy however is a grey area in the sense that the current training is not uniform among the nephrology fellowship programs. Interventional radiology performs these procedures at most places. If nephrology fellows are being taught how to do kidney biopsies, they should be taught how to use POCUS for marking (or real-time guidance) as well.
Will talk about other pertinent issues in future posts.
