The “F” in FAST does not mean “fast”; it stands for “focused”. The good thing is that everyone agrees to that, but we so often forget. This week has turned into the right upper quadrant (RUQ) view of the FAST week! I actually don’t mind that at all and I love it – as too many incomplete FAST scans are done (and accepted). It’s tragic, actually. I get it, and I’ve been there – you feel rushed because you either have too many patients to see, others need the ultrasound machine, or your consultants or surgeons are yelling at you to hurry up because they want to roll the patient or get that life-saving chest radiograph (don’t get me started!). It needs to be a complete, deliberate, and dedicated study. You should know when and how to do the FAST, especially the RUQ as it is one of the most accurate, and how to do it well. After having shown you several cases and images of real patients, some (including me) still have a hard time getting the perfect views of each of the sections of the RUQ (yes, there are “sections” of the RUQ) even though everything is done the right way. Well, thankfully, there are some little tricks to improve your image quality - so that you feel confident about telling that consultant the FAST results with your voice confident, back straight, chest out and shoulders back. You may even want to add a “booya” at the end of it.
Recall that it does have limitations (I do keep saying that because it’s amazing how soon people forget, especially those who become great at it and think it’s the best thing since sliced bread - where did that saying come from anyways?). It is a screening tool for free intraperitoneal fluid. It is NOT a diagnostic tool for injury.
General tips: once you place the probe in the midaxillary line, lower rib cage, at the level of the xiphoid process, you’ll see the region of interest (at least you’ll see the liver). Be dedicated in how you evaluate the RUQ -
1. Patient position – Keep them supine, or place in trendelenberg if you can, for as long as you can – this will allow the fluid to accumulate in the RUQ
2. Technique – Start high - from diaphragm views down to the paracolic gutter -
3. Stop, Stay, and Fan – Stop at each intercostal space, stay there, and slowly and widely fan through that region (anterior to posterior) – then slide down to the next rib space, stop, stay, and slowly & widely fan again (don’t slide and fan at the same time – even if you’re in a hurry – because you’ll miss something). As an example, when viewing the liver-kidney interface, the kidney should be out of view, come into view fanning from anterior to posterior kidney, and then go out of view completely when finishing posteriorly.
Each Section of the RUQ view has its difficulty and there are some tricks to get that perfect image of that section as well (you will not be able to see everything in one rib space):
1. Above the diaphragm trick: first, increase your depth (from 13cm to 16cm, or 16cm to 19cm - depending on the size of the liver and the image on your screen) to see above the diaphragm well. If the rib shadows get in your way (and I know they can be annoying) but sliding up a rib space causes air scatter on your image so that you cannot see the diaphragm well – here’s a tip — > stay in the lower space where you have a good view below the diaphragm and have the patient take a deep breath. The diaphragm lowers and moves away from under that rib shadow to being in your view! It’s great! Don’t forget, once you have it there, slowly fan in that region. The video below shows the effect of breathing in to help the view:
2. Below the dipahragm trick: keep that increased depth, have the patient take a deep breath if needed, and focus on the area between the diaphragm and the liver but also its lower edge where the liver curves up into morrison’s pouch – the little area will hide fluid, but you’ll find it as long as you look there. The below iage shows the the area where the liver curves shows more fluid with fanning.
3. Morrison’s pouch section trick: This is the area between the liver and around the superior pole of kidney. It commonly misses the inferior pole of the kidney and the paracolic gutter (where free fluid will be seen first and better) which is why I separate the two sections out. First, decrease your depth to center this region on the screen – by doing this you’ll lose your diaphragm views, but who cares?! You’ve seen that part already. If having the patient take a breath does not help get the rib shadows out of your way, then you can oblique your probe to be in line with the ribs. Your kidney will be in a more oblique or transverse view but it is a good alternative. The below video illustrates that this view should be centered ont he screen, and does miss the inferior pole of the kidney and left liver edge – requiring another view at a lower rib space to be complete.
4. Between left liver edge and inferior pole of kidney (includes paracolic gutter) trick – The best trick is to decrease your depth even more (ie. 16cm to 13cm) in order to visualize this area well while you slowly fan through it. If it is behind a rib shadow, you can have the patient breathe in or oblique your probe to help. The below video illustrates that free fluid will be seen only in this section but may not be around superior pole of kidney.
5. Paracolic gutter view trick – If the above view does not include the very left liver edge (but does include the inferior pole of the kidney), then you will need to slide down one more rib spaces to see the left liver edge and paracolic gutter section. The below video illustrates that even though you see the liver-inferior pole of kidney interface, you are still missing the paracolic gutter – so you’re not done!
The below videos show that the paracolic gutter may not be where the inferior pole of kidney is, but can and will show free fluid well, and therefore, most be evaluated. (ignore the “LUQ” in image)