Audio Doppler for Pediatric A-Lines

[HalO'Thane]

Advertisement - Members don't see this ad

Does anyone have experience with the use of the audio doppler for cannulating pediatric a-lines, particularly in the radial or dorsalis pedis arteries? I have experimented with the traditional ultrasound on kids as small as 3-5 kg but have had some challenges trying to cannulate their radial arteries, as their vessels are so small in relation to the size of the probe and it is hard to hard to properly align the needle with the cross section of the artery in the transverse view. I thought that since the audio doppler probe is so much smaller it may be easier to pinpoint these smaller vessels. If anyone has any experience and tips on this technique that would be greatly appreciated.

 

[nap$ter]

Does anyone have experience with the use of the audio doppler for cannulating pediatric a-lines, particularly in the radial or dorsalis pedis arteries? I have experimented with the traditional ultrasound on kids as small as 3-5 kg but have had some challenges trying to cannulate their radial arteries, as their vessels are so small in relation to the size of the probe and it is hard to hard to properly align the needle with the cross section of the artery in the transverse view. I thought that since the audio doppler probe is so much smaller it may be easier to pinpoint these smaller vessels. If anyone has any experience and tips on this technique that would be greatly appreciated.

audio doppler is not useful in the tiny ones, in my humble experience.

visual ultrasound may be useful. go brachial, femoral, or cutdown if you need to (personally i would need a surgeon to do the cutdown..)

i always transfix and use a wire.

 

[IlDestriero]

That's how I was trained, and we used them on the ~1 kg babies for cardiac surgery all the time. I use an ultrasound now, or do it blind.😱 Like anything, it comes down to experience and recognizing subtle changes in the doppler when you move it around and change the angle. I think most would prefer the US if given the choice. It's probably popular outside the US where $25k for an ultrasound will never be available. I'd probably be awful with it now.
I also used it in the ICU to locate the DP in patients where I couldn't canulate the radial artery.
As for the ultrasound in the little ones, use the hockey stick probe and try the transfix and wire technique.

 

[HalO'Thane]

I usually start with landmark/blind technique first for radial and DP a-lines but was inquiring about the use of audio doppler as a potential backup option vs ultrasound visualization. For femoral and axillary I usually start with ultrasound first. For neonates/preemies there have been reports of being able directly visualize the radial artery with transillumination but I have not been impressed with this technique whenever I have tried it.

 

[deleted9493]

I have only used doppler a few times in the OR--primarily in the ICU (and generally lower extremity lines, as well). I think it's helpful to scan up and down the course of the vessel with the doppler and mark several adjacent points on the skin where signal is maximal. This frees up both hands for the task but underscores the importance of needle trajectory well-approximating that of the probe.

You are likely to have much better luck with ultrasound in the small kiddos--you're right, identifying the medial/lateral position of your needle relative to the vessel can be difficult in an out-of-plane view. I don't necessarily depend on seeing my needle go through the vessel. On infants and neonates, sometimes 'all you get' is seeing the artery collapse and because it's collapsed, you regularly won't even have the benefit of seeing a satisfying flash on your way in.

I don't mean to tell you what you already know but perhaps for the benefit of others coming by...