Sterile probes

[Sonny Crocket]

I've started doing single shot blocks without any ultrasound probe cover. Gel on probe. Get a good picture. Hold probe in place. Prep site of injection with other hand. Grab needle and go. Anyone else not using a probe cover?

For catheters I use the probe sheath.

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[periopdoc]

I suspect that there is no benefit to be gained by using a cover as long as care is taken to avoid contact between the probe/gel and the needle. I suspect that keeping the gel from contacting the needle is the trickier part. A more opaque gel would be beneficial here.

-pod

 

[ASnaves]

For single shot injections, I've been doing it without a cover for years. The way I avoid the gel issue is two-fold. First, I put gel on the probe and cover it with a tegaderm to keep it clean. Second, I use a package of sterile gel so that if any does get to the injection site, it's not a problem. Many of my attendings in training did it this way and after thousands of blocks, it still remains a 0% infection rate.

 

[deleted126335]

For single shot injections, I've been doing it without a cover for years. The way I avoid the gel issue is two-fold. First, I put gel on the probe and cover it with a tegaderm to keep it clean. Second, I use a package of sterile gel so that if any does get to the injection site, it's not a problem. Many of my attendings in training did it this way and after thousands of blocks, it still remains a 0% infection rate.

+1. Use a chloraprep stick over the area to prep.

 

[RxBoy]

I've started doing single shot blocks without any ultrasound probe cover. Gel on probe. Get a good picture. Hold probe in place. Prep site of injection with other hand. Grab needle and go. Anyone else not using a probe cover?

For catheters I use the probe sheath.

This is kosher. Even Hadzik makes this point in his regional book. But like you said, catheters are a whole different issue.

He recommends:
Tegaderm on probe.
Use sterile jelly (packets)
Chloroprep the injection site

 

[Winged Scapula]

Different procedure but for my ultrasound guided core needle biopsies (8-10 gauge), I've never used a probe cover and 0% infection rate (AFAIK).

 

[Mman]

For a single shot I never put a probe cover on. Just use some sterile gel so that even if some gets dragged in with the needle it's no big deal. Sterile gloves are likely also way overrated as long as you don't touch the shaft of the needle, but I confess to using them the majority of the time out of habit.

 

[bigdan]

Our most busy regional site does not use probe covers for single shots, nor Tegaderms.

- we clean probe with skin-safe disinfectant
- Chloraprep then sterile gel
- Sterile gloves (although we'll adjust gain and depth without pause)

 

[EdPierce]

why not just use a small teggie that you dont touch the surface of. i would just be worried that repeated use skin on skin contact some bug would get into the gel from the probe itself and spread to the needle etc

 

[Mman]

why not just use a small teggie that you dont touch the surface of. i would just be worried that repeated use skin on skin contact some bug would get into the gel from the probe itself and spread to the needle etc

I'm cleaning the probe thoroughly with a Cavi-Wipe after each use to disinfect it. Not sure how much benefit a tegaderm is gonna add.

 

[climbingak]

same here. no cover no tegaderm. I do most blocks in plane so I start a good distance away from my probe so no problems of contam in my mind. Caths I use a cover.

 

[Bertelman]

For single shot injections, I've been doing it without a cover for years. The way I avoid the gel issue is two-fold. First, I put gel on the probe and cover it with a tegaderm to keep it clean. Second, I use a package of sterile gel so that if any does get to the injection site, it's not a problem. Many of my attendings in training did it this way and after thousands of blocks, it still remains a 0% infection rate.

Not sure what the point of placing gel between the Tegaderm and the probe. Just throw the tegaderm right onto the probe. Gel next.

 

[ASnaves]

My main reason for the gel under the tegaderm, quite simply, is for easier tegaderm removal afterwards. This helps prevent any of the tegaderm glue from sticking on the probe. Yeah, I know its not terribly difficult to remove all the tegaderm without the gel, but I like it and it's not like it adds anymore than 3 seconds to the actual procedure time.

 

[BLADEMDA]

Not sure what the point of placing gel between the Tegaderm and the probe. Just throw the tegaderm right onto the probe. Gel next.

Yes. I've tried it both was dozens of times and image quality doesn't see to change much between the gel techniques. But, it is easier to remove the tegaderm if there s some gel underneath it.

Anyone using non sterile ultrasound gel for single shot blocks?

 

[powermd]

Yes. I've tried it both was dozens of times and image quality doesn't see to change much between the gel techniques. But, it is easier to remove the tegaderm if there s some gel underneath it.

Anyone using non sterile ultrasound gel for single shot blocks?

Yes. We're aware of the risk of contaminated gel and avoid touching anything with the tip of the gel squirt bottle. I alcohol and prep with benzyl chloride a wide area of skin in the region I am doing an injection and give it at least 30s to work before doing my US exam. I then re-swab the site of needle entry and avoid contact with the probe or gel. I like the idea of covering the probe with a tegaderm, but they can get quite stuck to the probe and over thousands of uses could cause early wear on the rubber coating.

 

[Oggg]

Sterile gloves but I touch non sterile stuff. It makes the nurses happy. No tegaderm or drape. Non sterile gel, just the minimum needed. Find perfect image. Wipe away excess gel with other hand. Prep needle insertion site, at least 1 full cm (usually 2cm) away from probe. Do not move probe over needle site (else reprep). Local. Needle away. In plane or out of plane.

 

[BLADEMDA]

I use sterile gloves. Good wide prep of the area. Chlorhexidine/alcohol prep (the usual stick kind).
Sterile tegaderm over probe with some gel underneath. Usually, sterile u/s gel on top of tegaderm. Usually a Braun echogenic needle.

This keeps things pretty clean and I feel good about the technique. (It's what I'd want for myself).

 

[Oggg]

Search YouTube for blockjocks to see how sterile they get for a single shot.

UltrasoundBlock.com has a "controversial issues" section with one article devoted to aseptic technique.

 

[BLADEMDA]

Search YouTube for blockjocks to see how sterile they get for a single shot.

UltrasoundBlock.com has a "controversial issues" section with one article devoted to aseptic technique.

Are you paying for the tegaderm or sterile gel? If not, then why not use them? Block Jocks work at a private ASC where they pinch every penny so the owners get the extra money.

I see no reason not to apply a tegaderm and use sterile gel along with sterile gloves.

 

[BLADEMDA]

The Food and Drug Administration is warning doctors, hospitals and clinics that contaminated ultrasound gel produced by a New Jersey company infected 16 cardiac patients and could pose serious risks to pregnant women and others who undergo ultrasound imaging and treatment.

The gel is used by radiologists, urologists, gastroenterologists, OB-GYNs, internists, nurses and ultrasound technicians for diagnostic ultrasound testing. Chiropractors and physical therapists use the gel for therapeutic ultrasound treatment of pain, inflammation and injuries.

The agency told the health professionals to stop using the gel because of contamination with two strains of bacteria. "Although Other-Sonic Generic Ultrasound Transmission Gel is not labeled as either sterile or non-sterile, it is NOT sterile," the FDA cautioned.


http://abcnews.go.com/blogs/health/...ction-risks-from-contaminated-ultrasound-gel/

 

[BLADEMDA]

European Journal of Anaesthesiology:

June 2011 - Volume 28 - Issue - p 117

Abstracts and Programme: EUROANAESTHESIA 2011: The European Anaesthesiology Congress: Local and Regional Anaesthesia

Aseptic technique during peripheral nerve blockade: A survey of attitudes and practice in the Wessex region: 8AP4‐1


Golding, J. A.; Burmeister, L.



Free Access





Article Outline



Author Information




Poole Hospital NHS Foundation Trust, Department of Anaesthesiology, Poole, United Kingdom


Background and Goal of Study: Infectious complications associated with peripheral nerve blockade (PNB) are a potentially devastating complication of regional anaesthesia. There is little evidence regarding the frequency of infection associated with PNB. There is however, at least one reported fatality1 attributed to infection as a direct consequence of PNB.As the use of PNB increases there is concern that the infectious complication rate may also increase. ASRA recommendations suggest that PNB should be approached in the same manner as any invasive procedure and that aseptic protocols are followed2.We designed a survey to assess attitudes and practice amongst anaesthetists in Wessex.

Methods: An online survey was sent via email to all grades of anaesthetists in all acute trusts within the Wessex area.

Results and Discussion: A total 463 questionnaires were sent, the response rate was 54%. Only 21% were aware of departmental guidelines for aseptic precautions for single shot PNB and 5% for catheter techniques(CT). 28% do not use gowns or face mask for single shot PNB, whereas 45% use glove, gown and mask for catheter insertion.61% of respondents use the recommended 2% chlorhexidine skin preparation, with the rest using less concentrated solutions. Only 13% report using a sterile drape for single shot PNB whereas 93% do use a drape for CT. 62% do not use sterile ultrasound gel. Probe sterility was maintained by a full cover sheath by 23%, “op‐site” by 72%, and not at all by 5%.

Conclusion(s): Given the paucity of evidence it is perhaps unsurprising that a wide variety of practice is found. Despite the lack of robust data available clear guidance exists from expert opinion.The use of ultrasound should not result in any reduction in aseptic standards, as our data shows sterility has been compromised with the advent of ultrasound guided regional anaesthesia. Use of “regional anaesthesia packs” which contain preprepared sterile equipment may help routine adherence to sterile technique.In the absence of absolute data it seems reasonable to follow sensible precautions in order to avoid an entirely avoidable complication.

 

[BLADEMDA]

http://books.google.com/books?id=gM...erile ultrasound gel for nerve blocks&f=false

 

[BLADEMDA]

Sterile gloves but I touch non sterile stuff. It makes the nurses happy. No tegaderm or drape. Non sterile gel, just the minimum needed. Find perfect image. Wipe away excess gel with other hand. Prep needle insertion site, at least 1 full cm (usually 2cm) away from probe. Do not move probe over needle site (else reprep). Local. Needle away. In plane or out of plane.

No Tegaderm- The probe isn't sterle so extra care is needed to avoid touching the injection site prior to block needle placement. The use of a tegaderm avoids this concern.

Non sterile gel- Minimum needed is a vague statement. What if you need a little more?
Also, you are wiping away excess gel "with the other hand" so what are you wiping away the excess gel with? I assume a non sterile 4X4. Sterile Gel avoids this concern.

Prep- I assume you prep the area after the probe is in position so the "clean area" is near the probe but not touching it. Since the entry site is 1-2 cm from the probe this area is sterile. If you move the probe over the skin entry site then a new prep stick is needed for a reprep of area. Tegaderm and sterile Gel avoids this concern.

Sterile Gloves- Glad to read you use them.

I see no reason not to use a tegaderm, sterile gloves and sterile gel doing these blocks. I have more room for needle positioning and probe movement without stopping to reprep the area. I also have less concern if a small, tiny amount of gel touches the needle.
I like the option of moving my probe and/or needle anywhere in the sterile area without stopping my procedure.

If in your career just one infection is avoided or prevented by using sterile gel, tegaderm and sterile gloves then why not use them?

 

[Mman]

The concern with ultrasound gel contacting the needle isn't just the sterility or lack thereof, there is a reasonable concern that we don't know the safety of perineural ultrasound gel and you should probably avoid dragging it in through the puncture site as much as you can anyway.

I wipe away my excess gel before I stick the needle in with the chloraprep stick. It's sterile and does a pretty damn good job at getting the gel wiped out of the way. Of course I usually just make sure the gel is nowhere near where the needle is going to be in the first place. It's only if imaging is a struggle and I've got the probe moving around a lot that I need to wipe the gel off.

 

[BLADEMDA]

The concern with ultrasound gel contacting the needle isn't just the sterility or lack thereof, there is a reasonable concern that we don't know the safety of perineural ultrasound gel and you should probably avoid dragging it in through the puncture site as much as you can anyway.

I wipe away my excess gel before I stick the needle in with the chloraprep stick. It's sterile and does a pretty damn good job at getting the gel wiped out of the way. Of course I usually just make sure the gel is nowhere near where the needle is going to be in the first place. It's only if imaging is a struggle and I've got the probe moving around a lot that I need to wipe the gel off.

Of course you should avoid dragging u/s gel through the insertion site. I agree that wiping away the excess with a sterile 4x4 or a new chlorhexedine stick is a good idea (remember that chlorhexedine itself is potentially neurotoxic).

Clinically, I doubt that 0.1-0.2 mls of sterile u/s gel has a real negative impact on our patients getting a nerve block. Perhaps, multiple injections of the same nerve or plexus would have more potential for the u/s gel, chlorhexedine, etc to injury the nerve/nerves.
(look at the study below).

 

[BLADEMDA]

Anesth Analg. 2011 Sep;113(3):657-9. Epub 2011 Jun 16.

Ultrasound gel-nerve contact: an experimental animal histologic study.

El-Dawlatly A, Kathiry K, Al Rikabi A, Hajjar W, Al Obaid O, Alzahrani T.


Source

Department of Anesthesia, College of Medicine, King Saud University, PO Box 2925, Riyadh 11461, Saudi Arabia. [email protected]


Abstract

BACKGROUND:

Ultrasound (US) regional nerve block requires the use of gel applied over the skin. With subsequent needle insertion, some of the gel may adhere either on the shaft or within the needle lumen and may be carried to the perineural structures or intraneurally. We performed this experimental animal study to investigate the effects of US gel contact on the nerve histologic structure.

METHODS:

Nine male beagle dogs were studied. Dogs 1 to 3 were the control group and dogs 4 to 9 were the study group. Bilateral posterior tibial nerves were dissected and exposed for the control group. Nerve specimens were obtained for histologic examination immediately for the first dog, at 24 hours for the second dog, and at 48 hours for the third dog followed by wound closure. For the study group, bilateral posterior tibial nerves were exposed, and 2 mL US gel was applied locally directly on the nerve, followed by wound closure. Nerve specimens were excised at 24 hours from one side and at 48 hours from the other side. Nerve specimens were examined by a neuropathologist for evidence of nerve inflammation.

RESULTS:

The control nerve specimens showed no significant pathology. Nerve specimens of the study group at the end of 24 hours of gel-nerve contact showed mild focal perineural inflammatory changes with clusters of polymorph leukocytes. At 48 hours, perineural moderate inflammatory changes with clusters of lymphocytes and macrophages were demonstrated in 2 animals. Long-term neurologic deficit in the form of limping was observed for all dogs.

CONCLUSION:

Histologic features after perineural exposure to US gel are rather nonspecific and likely of no clinical significance. However, further studies are needed to determine the effect of US gel injection on intraneural tissues.

 

[BLADEMDA]

DISCUSSION

The results demonstrate that the lumen of regional anesthesia needles can carry macroscopic quantities of ultrasound gel. This ultrasound gel can potentially be injected around nerves. The use of a smaller needle or a stylet reduces, but does not prevent, the penetration of gel into tissues.

The composition of ultrasound gels is often proprietary information and not available to end-users. Ultrasound gels, including some available as sterile preparations, may contain propylene glycol.1,2 Propylene glycol is widely used in oral and parenteral drugs. Intramuscular injection of drugs, such as diazepam, that use organic solvents like propylene glycol are associated with myotoxicity.3 Propylene glycol also causes effective neurolysis and a pure preparation has been suggested as an alternative to phenol.4 In the 1950s, a formulation of procaine called Efocaine was promoted because of its long duration of action. It contained, among other things, 78% propylene glycol. The extended duration of action was attributed to "coagulation necrosis" of nerves by the vehicle.5

The literature on clinical toxicity attributed to ultrasound gel has been limited to contact dermatitis.1,2,6–10 There are no data demonstrating clinical problems related to the use of ultrasound gel for invasive procedures. A consideration may be that biopsy procedures typically involve aspiration through the needle and regional anesthesia involves injection. Clinical toxicity will not necessarily result from the injection of gel because any toxicity is likely to be dose related. The amount of gel carried by needles is small and will be rapidly diluted by the injectate. Ultrasound gels also have lower concentrations of propylene glycol than those in the studies assessing neurotoxicity described above.


http://www.ncbi.nlm.nih.gov/pubmed/20508136

 

[Oggg]

Once the needle goes in, my probe doesn't move. It's useless to move the probe over your needle insertion site anyways.

Nice find on the dog article. I wish they had done more experimenting. Poor dogs though.

Tegaderm just seemed to cause more problems and slow me down. If you put gel then tegaderm, sometimes the tegaderm moves around on you, or it becomes slippery and hard to hold. The tegaderm can crease up, or catch air bubbles. It's hard to put on sterilely with sterile gloves and remain sterile. The opaque paper backing is hard to take off once it's on the probe, and often tears, meaning I have to use my fingernails to peel up the next piece. If you leave the backing on, you're not holding the smooth probe anymore and it feels different. If you put the tegaderm on non sterilely, then you've already made a compromise. At my place, I don't have an assistant to put on a teg for me. My hospital is in the red, so I don't see the need to waste tegs. My private ASC doesn't track our waste, but over there I need every second I can get to speed up my blocks. I use the prep stick(s) to wipe my non sterile gel away from the 1-2cm around my needle insertion site. If you used way too much gel, you can use non sterile gauze to wipe away your non sterile gel, but then follow it with your sterile prep. If you get your perfect picture before you insert your needle, you don't need gel anywhere except underneath the probe at the perfect spot. I think there was a recent RAPM article that said chlorhex prep for SAB was totally safe. Avoid touching the needle shaft at all times, even when using a long needle that might bow on you a little before penetrating skin.

 

[blockman958]

Reviving this thread because we recently had this debate at my institution. I have always questioned the sanity of draping the patient with 10 blue towels, placing a sheath on the probe, and employing sterile gloves for a single shot. How is a single shot nerve block any different than an intramuscular flu shot? Is there really any greater risk of infection from a needle that targets the saphenous nerve versus a deltoid injection?

Regarding catheters, I have probably done 3-5 catheters a day for the past four years and I've never had an infection (and I follow my catheters in the hospital). My technique: I double glove. I don't use a sheath for the ultrasound. I use non-sterile gel for the probe. I don't use blue towels. I chloraprep the insertion site. Once the needle is in the correct position, I remove the injection tubing from the needle. Then I ask my assistant to pull off my outer gloves so that my hands are sterile. Now I thread the catheter (which has been kept sterile) directly through the needle. What are your concerns regarding this technique? We place indwelling catheters in peripheral veins all the time with a simple alcohol swipe. If you feel like my technique is less than adequate, should we be wearing sterile gloves and wide sterile preps for peripheral IV insertions?

 

[Consigliere]

Reviving this thread because we recently had this debate at my institution. I have always questioned the sanity of draping the patient with 10 blue towels, placing a sheath on the probe, and employing sterile gloves for a single shot. How is a single shot nerve block any different than an intramuscular flu shot? Is there really any greater risk of infection from a needle that targets the saphenous nerve versus a deltoid injection?

Regarding catheters, I have probably done 3-5 catheters a day for the past four years and I've never had an infection (and I follow my catheters in the hospital). My technique: I double glove. I don't use a sheath for the ultrasound. I use non-sterile gel for the probe. I don't use blue towels. I chloraprep the insertion site. Once the needle is in the correct position, I remove the injection tubing from the needle. Then I ask my assistant to pull off my outer gloves so that my hands are sterile. Now I thread the catheter (which has been kept sterile) directly through the needle. What are your concerns regarding this technique? We place indwelling catheters in peripheral veins all the time with a simple alcohol swipe. If you feel like my technique is less than adequate, should we be wearing sterile gloves and wide sterile preps for peripheral IV insertions?

I do the same thing but I've been doing a higher volume and for at least twice as long and I've NEVER had an infection.

 

[deleted162650]

I do the same thing but I've been doing a higher volume and for at least twice as long and I've NEVER had an infection.

Ok Blade

 

[GravelRider]

Wait until the Clipboard Army watches you do a block. It will be wide prep, full body drape, scrub in, full surgical gown and gloves. It doesn't matter that it doesn't make sense.

 

[Consigliere]

Ok Blade

There is currently no available instrumentation to detect how little I care whether or not you believe me.

 

[Consigliere]

Check that.....apparently there is:

 

[deleted162650]

There is currently no available instrumentation to detect how little I care whether or not you believe me.

I actually thought you were being sarcastic. You really place >5 PNB catheters every single day, and have been doing so for the last 8 years??? Do you work at the International Center for Orthopds who Love Regional? I completely believe that you have never had an infection. I think PNB's (both SS and caths) are very low risk for infection.

 

[Consigliere]

I actually thought you were being sarcastic. You really place >5 PNB catheters every single day, and have been doing so for the last 8 years??? Do you work at the International Center for Orthopds who Love Regional? I completely believe that you have never had an infection. I think PNB's (both SS and caths) are very low risk for infection.

No. I average 5 a WEEK and have been doing that for over 8 years. Sorry for the confusion.

 

[fakin' the funk]

Regarding catheters, I have probably done 3-5 catheters a day for the past four years and I've never had an infection (and I follow my catheters in the hospital). My technique: I double glove. I don't use a sheath for the ultrasound. I use non-sterile gel for the probe. I don't use blue towels. I chloraprep the insertion site. Once the needle is in the correct position, I remove the injection tubing from the needle. Then I ask my assistant to pull off my outer gloves so that my hands are sterile. Now I thread the catheter (which has been kept sterile) directly through the needle. What are your concerns regarding this technique?

Nice technique. Seems like nothing wrong with it in principle. In practice, maybe a bit finicky -- but probably no more finicky than using a sterile ultrasound sheath.

 

[fakin' the funk]

Reviving this thread because we recently had this debate at my institution. I have always questioned the sanity of draping the patient with 10 blue towels, placing a sheath on the probe, and employing sterile gloves for a single shot. How is a single shot nerve block any different than an intramuscular flu shot? Is there really any greater risk of infection from a needle that targets the saphenous nerve versus a deltoid injection?

As I said in another thread, to my knowledge there has NEVER been a reported case of a local or soft tissue infection following a single shot nerve block. The last time I scoured Pubmed was 2013, though.

There are multiple reports of soft tissue infection with PNB catheters, usually in patients with systemic or local infections or a glaring immune deficiency like a HgbA1C of 12

 

[BLADEMDA]

I do a lot of blocks. I have nurses, crnas, etc. assist me often. Hence, I try to display professional technique to those around me which includes sterile gel (when possible), tegaderm over the probe and sterile gloves. Do I think all of this is necessary? No. Do I think the nurses and staff believe it is necessary? Yes. I'd rather take ownership of the process myself than have them tell me how I must be doing the block. As it is, the whole time out thing is a pain in the arse and now they want a second time out for each additional block?

Most likely, a quick second wipe with the chloraprep right before the injection is probably sufficient to wipe away the gel and prevent infection.

 

[blockman958]

As I said in another thread, to my knowledge there has NEVER been a reported case of a local or soft tissue infection following a single shot nerve block. The last time I scoured Pubmed was 2013, though.

There are multiple reports of soft tissue infection with PNB catheters, usually in patients with systemic or local infections or a glaring immune deficiency like a HgbA1C of 12

Thank you all for the good info. Obviously, the patients in these reports aren't the greatest catheter candidates and shouldn't have received the catheter in the first place. I'm sure this is the same patient population that develops infections from peripheral IV's.

I appreciate gravelrider and blade's perspectives and I absolutely respect need to keep our nurses happy.

 

[Ronin2258]

I plan to start offering pre-op iPACKs/adductor canal blocks to our knees here. Most of the surgeons here like them post-op for neural assessment after surgery (a few will change if they see results.) Since we are not starting catheters yet (our floor nurses still panic at the idea,) they have to be single shot.

My plan was to do them aseptically with drape/cover for the first few since they are also paranoid of infection. Political? Maybe. But it shows that we are also concerned with infections to go to that extreme. Also, it allows us to get the drapes in stock so when we do give the floor nurses training/tranquilizers (so they don't freak out,) for catheters, they are in our system.

This is what we as a department have to do to overcome inertia and tyranny of logistics/support.

 

[vector2]

I plan to start offering pre-op iPACKs/adductor canal blocks to our knees here. Most of the surgeons here like them post-op for neural assessment after surgery (a few will change if they see results.) Since we are not starting catheters yet (our floor nurses still panic at the idea,) they have to be single shot.

My plan was to do them aseptically with drape/cover for the first few since they are also paranoid of infection. Political? Maybe. But it shows that we are also concerned with infections to go to that extreme. Also, it allows us to get the drapes in stock so when we do give the floor nurses training/tranquilizers (so they don't freak out,) for catheters, they are in our system.

This is what we as a department have to do to overcome inertia and tyranny of logistics/support.

For adductor catheters, one of our staff scans first and marks out the position of the probe where the best picture can be seen. After that, preps as usual and places a clear drape with the hole over the insertion site. Since your ultrasound position is relatively far away from the insertion site, he just has someone slide the probe under the drape and grasps it through the drape to get a picture. Saves you from having to use a probe cover every time.