basic ultrasound practical tips?

[cleansocks]

I'd like advice to improve my ability to know what the f I'm looking at with an ultrasound when i'm doing a line - especially difficult ALines.

Sometimes I see symmetric soft tissue deformity when I wiggle the needle in which case I assume the needle is in the center of that. But I rarely see the tip. So I certainly don't know if the needle's gone too far or not. Other times I don't even see the symmetrical deformity... I just see some random movement that I can't make heads or tails of.

In short axis view, I've been advised to tilt the probe so the end of it is pointing slightly towards the direction the needle's going, thus giving me a better chance of seeing more of the needle rather than just one little slice.

In long axis view for an ALine, I've been told the trick is to find as wide a lumen as possible with the probe and hold completely steady. I've seen people use this view when all else has failed so I'd like to get good at it.


But being new I still suck and it's quite frustrating. Any other tricks?

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[Narcotized]

In short axis view, I've been advised to tilt the probe so the end of it is pointing slightly towards the direction the needle's going, thus giving me a better chance of seeing more of the needle rather than just one little slice.

At least you're getting excellent advice. I cringe when I see a needle and probe practically perpendicular to each other. Who knows where that tip is and what structures it's damaging or deflating.

 

[dhb]

Get some experience while doing IJ in patients under GA: play with the probe and needle. Don't just pop the probe out for a difficult a-line and hope to get it at the first try...

 

[Mman]

At least you're getting excellent advice. I cringe when I see a needle and probe practically perpendicular to each other. Who knows where that tip is and what structures it's damaging or deflating.

A short axis view is intentionally placing the needle and probe perpendicular to each other. It is the view preferred by the majority of experienced ultrasound users for placing IJ lines.

A long axis view where the entire length of the needle is visible is preferrable for many other uses.

 

[Narcotized]

A short axis view is intentionally placing the needle and probe perpendicular to each other. It is the view preferred by the majority of experienced ultrasound users for placing IJ lines.

Well, sorry to say, if that's their technique then they are doing it like a beginner. As the original poster said, in the short axis tilt the probe so it is more parallel than perpendicular to the needle. It's just straight geometry. I'm amazed any experienced user would keep the probe perpendicular to the needle. That's a "how to" video for complications.

 

[Mman]

Well, sorry to say, if that's their technique then they are doing it like a beginner. As the original poster said, in the short axis tilt the probe so it is more parallel than perpendicular to the needle. It's just straight geometry. I'm amazed any experienced user would keep the probe perpendicular to the needle. That's a "how to" video for complications.

I'm not quite understanding. You really should maintain a perpendicular plane to the needle. That provides the best visualization. Anything less than 90 degrees and you get attenuation of the image.

Ideally when using anything in short axis, the probe itself should maintain a perpendicular plane to the needle, but be moved back and forth along the plane of needle advancement so that you can see where the tip is. In other words, as the needle is advanced, the probe is slid more distally so that it maintains it's relationship with the tip of the needle.

Tilting the probe toward or away from the needle will result in a less distinct image on the ultrasound and less ability to precisely visualize where you are.

 

[Jay K]

Narc- how do you keep an eye on ICA when cannulating IJV in plane?

My personal practice for u/s guided CVL and A-line is perpendicular cross-sectional vessel with needle out of plane. Usually same practice for difficult PIV access in high BMI people or IVDA shot vein pts.

 

[Narcotized]

Narc- how do you keep an eye on ICA when cannulating IJV in plane?

I don't do in plane. I do short axis. I adjust the probe so the carotid is side by side the IJ, never in front or behind it. I also tilt the probe back some and the needle up some (30 degrees or so) so that, while not a perfect overlap as in line, it's close enough so you won't do damage. Same for IS blocks.

 

[DrN2O]

I'm not quite understanding. You really should maintain a perpendicular plane to the needle. That provides the best visualization. Anything less than 90 degrees and you get attenuation of the image.

I agree. One should keeping the US plane and the needle axis perpendicular to each other if you want to see the needle the best. Isn't this the best way to image any tubular structure (needle or vessel)-when the US plane is perpendicular to the long axis of the structure and you get a nice cross-section? Your image of the cross-section would deteriorate if you tilt the probe. Doing a-lines under US, I need to see the artery more than the needle so I get the best picture on the artery and follow it up and down the arm. In any case, just practice all your lines in the ICU with US and it gets easier. For IJs, I do it out of plane, and switch to in plane once the wire is in to confirm it's still in the vein before I dilate.

 

[Narcotized]

I agree. One should keeping the US plane and the needle axis perpendicular to each other if you want to see the needle the best. Isn't this the best way to image any tubular structure (needle or vessel)-when the US plane is perpendicular to the long axis of the structure and you get a nice cross-section? Your image of the cross-section would deteriorate if you tilt the probe. Doing a-lines under US, I need to see the artery more than the needle so I get the best picture on the artery and follow it up and down the arm. In any case, just practice all your lines in the ICU with US and it gets easier. For IJs, I do it out of plane, and switch to in plane once the wire is in to confirm it's still in the vein before I dilate.

I could see that for an art line, but the IJ technique of a straight up probe and a perpendicular needle flat to the skin is just asking to drop a lung. I cringe when I watch that technique with the needle tip just blindly being buried down into the lower neck toward the lung. Why would you not tilt the needle up 30 degrees or so? Are there text books that advise a flat to the skin approach perpendicular to the upright plane? Even if you find it written somewhere, I still won't do that approach. I know M/M says insert the needle at a 30 degree angle, and I see no reason to go against that.

 

[fakin' the funk]

I could see that for an art line, but the IJ technique of a straight up probe and a perpendicular needle flat to the skin is just asking to drop a lung.

Isn't it really, really, REALLY difficult to cause a pneumothorax doing an U/S guided IJ? Isn't your main concern carotid artery puncture?

 

[Narcotized]

Isn't it really, really, REALLY difficult to cause a pneumothorax doing an U/S guided IJ?

Not when done with the needle at a shallow angle to the skin, and perpendicular and 3 inches past the ultrasound plane. In fact you are probably more likely with that technique than if you didn't use the ultrasound because of a false sense of security. This leaves you feeling you can keep sticking further caudal without worry because it's "really, really, REALLY difficult to cause a pneumothorax doing an U/S guided IJ." I see this technique routinely and I cringe. If the tip is well out of the ultrasound plane, you really don't know where it's heading.

 

[BobBarker]

This is how we were taught to do, for example a Right IJ central line.
1. Obtain cross-sectional view of IJ and Carotid.
2. Manipulate the probe so that the lateral side is slightly superior than the medial side, almost as if the probe is angled towards the heart.
3. Insert the needle near the lateral side of the probe, so that the needle going caudally from lateral to medial is midline with the probe. Keep the needle about 30-45 degree angle above the skin.

Doing this you should be able to see the entire length of the needle and maintain a near cross-sectional view.