To Aspirate or Not

According to Septodont, as you can see in the video, you can draw back on the plunger. Unlike the usual stainless dental syringes the plunger in the Ultra Safety Plus forms a fairly tight seal against the interior wall of the cartridge. In theory if you draw back slowly you can aspirate. I've never tried it though, I always aspirate the other way, it's easier.

 

No reason to aspirate a digital block.

Do not use Lidocaine w/ epi on digital blocks. No need to and you "may" someday wish you hadn't.

Steve

 

Ok on the first bit
Second...end arteries....thats what dont want to get into ... as you say, wish I hadnt..so I dont :drinks
Cheers
D

 

I didn't know that Craig. It's a good enough reason for me.

I was taught not to aspirate digital blocks and I don't in my clinic.

Tibial nerve block; obviously I do aspirate.
I use ordinary Scandonest (Mepivicaine) 3% Plain.
2 Cartridges/vials are drawn up in a 5ml disposable syringe (use a 21G needle for this part). If you insert the needle into the top of the glass vial, you can use the sheath of the needle to push down on the rubber-bung end of the vial, helping to empty it into the syringe.

Gives 4.4mls which is usually ample for a tibial nerve block.

Tap out any air bubbles prior to injecting. Use a 27G needle for delivery.

Job done.

 

If you use a ultra safety plus sryinge system and scandonest cartridges, there is no need to draw up the LA.
Cheers
D

 

Personally I don't aspirate for a tibial nerve block nor a digital block.

Digital block for the same reason as Craig stated above (vessels are so small). For a tibial nerve block, if you hit the artery, you get an instant flashback of blood in the syringe. In actual fact, I will often 'look' for the artery in an overweight patient where the pulse is difficult to palpate. Even where the patient is under general anaesthesia and the blood pressure has dropped to the point where the pulse is non palpable or difficult to palpate, you still see a flashback when you are in the artery. It's the same for a popliteal nerve block although strangely I do aspirate for these purely out of habit even though the vessels are pretty far away from the nerves.

I'm quite used to the horrified response from students and visitors when they come to spend a day in theatre and see very little aspirating.

Ryan

 

I haven't aspirated for any local anesthetic block in the foot or ankle now for 29 years (ever since I started my surgical residency) except, sometimes, for PT nerve blocks. I tend to keep the needle moving during injections and don't stay in one place too long so I really don't see the point for the volumes of local I inject into the foot and ankle. If one knows the anatomy of the foot and ankle well, and has learned to palpate all the nerves of the foot and ankle (John Ruch, DPM), then I see no reason to aspirate for injections other than for the PT nerve block. http://www.worldcat.org/title/regional-anesthesia-an-ankle-block-technique/oclc/022768910

Here's the handout I made to teach the students and surgical residents on how to do ankle blocks, ala Dr. Ruch, when I was in my Biomechanics Fellowship at the California College of Podiatric Medicine.

 

Hi,
thanks for this very useful thread.

Question: when you palpate the PT nerve, how do you know you havent simply 'rolled' a tendon (as they are in close proximity)?

 

When you palpate the posterior tibial (PT) nerve, the foot is held in dorsiflexion and eversion and the PT nerve can be palpated, moving your fingers from posterior-plantar to anterior-dorsal over the nerve (after lubricating the skin with isopropyl alcohol) as being the only structure that can be "plucked" like a thick and relative loose "guitar string". The PT tendon, on the other hand, is tightly held within the flexor retinaculum with dorsiflexion and eversion and is deeper and more anterior than the PT nerve. The PT nerve is more posteriorly located and has a very characteristic feel to it during this maneuver. The PT nerve is palpated posterior to the medial malleolus about 1 cm superior to the distal tip of the medial malleolus (see illustration in prior post).

 

Kevin,

thank you very much for that info. I have looked at your drawing and the area of 'insertion' is the same as the one i use, and I also tend to 'fan' and move the needle for deposition of the anaesthesia.

I should imagine palpating the nerve would add to the whereabouts of it quite significantly, however not so effective with swollen ankles or obese patients.

Thank you again, Kevin.

great stuff

 

Peter:

Yes, this technque is not very easy to perform on patients with excessively swollen or fatty medial ankles. Practice makes perfect, as with learning any new technique.