Hello! Happy New Year!

I would be really grateful  if you  could help me with tips for placing an UVC and an UAC.

We in our unit turned out to be placing it - incorrectly.We work with NG  as we don't have

Vygon catheters. How could we determine the position and depth of the catheter?

Thank you  in advance for your help.

Do you use X-ray or ultrasound to determine position of UVC/UAC? Do you use a formula to determine distance?

UVC: correct depth: tip at the level of the diaphragm on the lateral X-ray).

UAC: Mid-descending aorta, at T8 level on X-ray (range T6-T10)

We use an X-ray to control for the position of UVC and UAC and we don't have an ultrasound. We use a formula to determine the distance and are familiar with the relevant guidelines but don't have a ready protocol for these situations. Therefore, I'd be grateful for any practical insights.

 

What do you mean by placing them incorrectly?

What is interesting is that the original formulas developed in 1960's were developed to have the catheter in the right atrium, what we now know to be unsafe- recent review on methods to calculate insertion length here:

https://www.tandfonline.com/doi/full/10.1080/14767058.2020.1838478?casa_token=yLqwwr0MfEUAAAAA%3AJxsgcDBkqa3owb5sDwdIOtr-tITC-MA56taD1smV0xqhNdjOjjJX50HekBWaE-ck1FgZrDb5tZPz

I agree with @Francesco Cardona that POCUS is the way forward here, though we are not currently using it routinely either....

We currently have an app that we use but most of us tend to add 1-2cm to this calculation as it often comes out short.  

A manual calculation that often comes out closer to correct insertion length is:  UAC - weight x 3 + 9cm + cord and UVC - 1/2 of UAC length

For determining correct position on xray, T6-9 for UAC and at level of diaphragm but not in right atrium.  We often will do a lateral film (shoot through) along with an AP to determine the UVC tip is above the liver shadow.  

We occasionally will use USS to determine tip of UVC can be seen but is not in right atrium if we want to avoid another xray, however, this is not the most accurate measure.

Thank you!

We also use: (weight in kg x 3) + 9 + length of cord

 

This gives us an approximation of UAC depth. Half of UAC length approximates UVC depth. We use an AP radiograph to confirm placement. 

 

There is a method by which one can use the cardiorespiratory monitor to determine position of the UVC. Essentially you set the monitor to give an auditory beep with each heart beat. Advance the UVC until the frequency of beeps decreases (this implies the tip of the UVC is at the SA node), then pull the UVC back about 1/2 cm and it should be in a pretty good position. However, those I have seen use this technique still confirm with chest radiography. 

 

I would like to gain experience in POCUS as it might limit exposure to radiation.