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sherlock 2 question
I probably need to speak to the Bard rep, but I thought I'd ask here.  We are having problems some of the time with the sherlock 2 where the picc is seen coming down into the svc like it should then all of a sudden the tip inverts and is shown going back up.  In these cases, we go with our pre-picc measurement and finish the picc and send the pt to x-ray.  The picc tip is usually in the svc or r atrium.  What is causing sherlock to do this?  All metal is off the pt and the side rails are both down.  It seems like sometimes sherlock works well and sometimes it doesnt.  The last picc this happened on only weighed 153 lbs, so weight isnt an issue either.  Thanks
I think the Sherlock is
I think the Sherlock is accurately showing what is happening, i.e. the tip is flipping up at the distal end like  the letter J.  When this happens we will slowly pull back and re advance slowly until it drop straight down, sometimes several times.  Eventually, it will go down. sometimes withdrawing the guidewire will help. Sometimes rasing or lowering the h ead of the bed helps.  Many times it just flips on its own, which is why you are getting normal x ray readings.
Timothy L Creamer
First, I agree to contact

First, I agree to contact your Bard Access Systems rep and request a follow up from the Clinical Specialist. When you mention "all of a sudden the tip inverts and is shown going back up" I interpret this as the signal is just inverted and not indicating jugular vein involvement. Remember the microprocessors in the sensor module are only reading a signal from the magnetized tip of the stylet. Occasionally this happens and it can be frustrating because we want the signal display to always point distally. Without recalibrating it is difficult to rectify. Another variable to consider is speed of catheter advancement. Slowly advancing the catheter will allow the microprocessors in the sensor module to process/track the signal and provide a nonerratic signal display.

I hope this helps. I have used the Sherlock I & II and find the latter extremely reliable. Not sure metal in the proximity is an issue for the stated problem. 

Timothy L. Creamer, RN

PICC Team Leader, Regional Medical Center Bayonet Point

Clinical Educator, Bard Access Systems 

Timothy L. Creamer, RN

Clinical Specialist, Bard Access Systems

I have worked with both the

I have worked with both the original and the second version. What I have found is that the new version works way better than the original. What I still see, to a much less degree, if you advance too fast, you will get a unusual reading.

it is very sensitive, and I've actually seen the icon 'dance' or wiggle when the end of the sherlock wire is in a turbulent area. When I see the icon going down and all of a sudden start dancing, I pull back until it stops. Xrays have confirmed that it was now just above the RA. I suspect that the 'dancing' was the tip in the RA.

What I have had a much better success doing with the new version is confirming the reading. When I think the tip is in the proper location, but the icon suddenly jumped down or up, I do a little test -

1) confirm blood return.

2) slowly remove the sherlock wire and watch the icon track the catheter.

if that does not satisfy you, then

1) remove the sherlock wire almost all the way out. 

2) confirm the location and stability of the sherlock probe on the patient's chest.

3) Reinitialize the sherlock.

4) slowly reinsert the sherlock wire and watch it track going back in down to the lower SVC.

That usually shows me what I want to see.

Good luck!

Bud Lavin, RN, CEN

Manager - Cardaic Cath Lab / PICC Team

St. Mary's Hospital

Passaic NJ


Bud Lavin, RN, CEN

Manager - PICC Team

St. Mary's Hospital

Passaic NJ


mary ann ferrannini
 We do what Bud so
 We do what Bud so eloquently stated. I have seen this happen when I am threading the catheter too quickly (faster than 1 cm per second). We have also seen this with an azygos malposition and will attempt rethreading the catheter.I also agree that the Sherlock 2 is so much better than the the Sherlock 1.
Is anyone using the

Is anyone using the Sherlock2, or any other TLS in place of CXR for tip location?  Any studies on the topic?



Rhonda Wojtas
Since I have used the

Since I have used the Sherlock 2 I have not had any PICC lines in the IJ. If I get a confusing reading, I pull back the wire and recalibrate. I was told you need to pull back the wire past the point of where Sherlock picks up the signal, then recalibrate. Otherwise the calibration will not work. On the one or 2 occasions the Sherlock appreared to say the PICC line was going across instead of dropping, it was right and we had to adjust the PICC line. In the ICU we frequeltly get mixed signals because of all the wires they have on patients or because of paccemaker wires. If the Sherlock indicates it is going down, but we then lose the signal, we try the above. As long as Sherlock doesn't tell me it is going up I trust it and have not been wrong, with a "mixed" signal.

Hope that helps.



Rhonda Wojtas, RN PICC Team

Lowell MA

Rhonda Wojtas, RN,BSN, VA-BC

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