Sharp or blunt needles; size matters?

[wonthurtabit1]

---

Members don't see this ad.

At an ISIS workshop, Dr. Rick Derby said that he uses blunt needles for the L-spine to decrease cutting. Do other folks use blunt needles? Also what about the propeller effect from spinning down a sharp needle with a bent tip?

He also said that those starting out should begin w/ a 22 ga then progress to a 25 ga needle for tfesi?

Also, what equipment do folks use for caudals? What about catheter choice? Arrow has been recommended.

Any other pearls on needle tecnique from the senior members would be greatly appreciated. The only benchmark I have been able to find thus far is from ISIS, no more than 8 moves to target for a tfesi, 30 secs flouro time for an uncomplicated case vs. 45s for complicated anatomy/vascular uptake.

 

[C Fiber]

I only used sharp needles in residency(because that's what I was taught) and found more intra-vascular injections with them. Also I have had more paresthesia complaints from patients with sharp needles (mostly 22 gauge). They are a whole lot cheaper though $0.75 vs. $12.00. And the thought of piercing a nerve scared me in residency.

Now in fellowship, most my attendings use blunt needles. I have not had any intravascular uptakes this year using the blunt needles. Only a few patients experienced parasthesia when the needle bumped next to the nerve. You cannot pierce the nerve with the blunt needles.

Just as a suggestion, try the 20 gauge, 10cm blunt needles first. Since the 22 gauge may be a little too flimzy for stearing, especially if you have a large pt. The 15 cm may be too long to have a good "feel". I truggled a few times before I was comfortable with the blunt needles. Another suggestion, use a 1.5" 18 gauge angiocath as your introducer and gunbarrel it before inserting your blunt needle through the angiocath. The Epimed blunt nerve block needle pack comes with an angiocath but it's a little too long.

25 gauge needles in general may be a little harder to manipulate once deep in the tissue. Also it's hard to aspirate for blood if you are intravascular. But they may do less damage?? donno.

P.S. be prepared that patients may complain about muscle spasm pain in the quadratus after a case of multiple attempts/poking with the blunt needles. Leave a little trail of local anesthetic if you had to struggle to get the needle in the right place.

Also, you may try your first few TF ESI in patients without multiple back surgeries/ scarring; and maybe do a L4/5 TF ESI instead of the L5/S1 which we all know is harder.

Good luck and stamp out pain!! 🙂

 

[member]

There is no evidence that blunt is superior to sharp needles. I know that one one of the tutors at ISIS has vested intrest in epimed which manufactures blunt needles. One cannot base decisions on single individual's clinical assumptions. I have worked with 9 attendings as a resident and as a fellow and I have not seen any difference between 22 or 25 g or sharp vs blunt needles. I think we need more clinical evidence before one can proclaim blunt needles as the standard.

 

[chinochulo]

There is no evidence that blunt is superior to sharp needles. I know that one one of the tutors at ISIS has vested intrest in epimed which manufactures blunt needles. One cannot base decisions on single individual's clinical assumptions.

And I'll bet he's making a tidy profit @ $20 bucks per needle.

 

[lobelsteve]

Actually, there is evidence showing non-superiority of either needle over the other. If PAZ doesn't chime in with the reference, I can look it up again.

The article was fairly convincing that tips don't matter.

 

[PainDr]

You cannot pierce the nerve with the blunt needles.

This isn't true. Although it's obviously harder to pierce a nerve using a blunt needle, it certainly can happen and if it does, it will cause alot more trauma than a sharp needle. I can't remember the reference off hand but I think I read this in Benzon. I'll check.

 

[paz5559]

Actually, there is evidence showing non-superiority of either needle over the other. If PAZ doesn't chime in with the reference, I can look it up again.

The article was fairly convincing that tips don't matter.

Bogduk; Sharp vs Blunt Needles; International Spine Intervention Society White Paper Interventional Spine (ie the new name for the ISIS Newsletter) Vol 5, Number 4, p07-17

Always glad to help when Dr. Lobel is to lazy to look up the reference himself (Afterall, he will be my staff here at Emory come 7/5)

 

[md2k]

And I'll bet he's making a tidy profit @ $20 bucks per needle.

Its actually 14-18$ a needle. Depending on gauge and length.

 

[md2k]

This isn't true. Although it's obviously harder to pierce a nerve using a blunt needle, it certainly can happen and if it does, it will cause alot more trauma than a sharp needle. I can't remember the reference off hand but I think I read this in Benzon. I'll check.

Yes you can but its much harder, Read the heavner study.

James E. Heavner DVM, PhD 1 1
Gabor B. Racz MD 1
Bharat Jenigiri MBBS 1
Travis Lehman 1
Miles R. Day MD


Abstract:
Background and Objectives: Complications associated with interventional pain procedures have raised questions regarding the relative safety of sharp vs. blunt needles. It has been speculated that the incidence of hemorrhage, intraneural and/or intravascular injections may be reduced by the use of blunt needles. In this study we compared penetration and bleeding associated with sharp vs. blunt needle punctures
.
Methods: Attempts were made to insert blunt and sharp needles (18-, 20-, 22-, and 25-gauge) directly or percutaneously into kidney, liver, renal artery, intestine or spinal nerve/nerve root of anesthetized dogs. Penetration and bleeding were ascertained by direct vision through a surgical wound.
Results: All attempts to directly puncture the kidney and liver with sharp needles were successful. All but one attempt to puncture a spinal nerve/nerve root with 20-, 22-, and 25-gauge sharp needles were successful but half or less attempts to puncture the intestines were successful. All attempts to puncture the renal artery with sharp needles were successful. Blunt needles never punctured the renal artery, spinal nerve/nerve root and intestines and rarely penetrated the kidney (22- and 25-gauge one time each). All attempts to puncture the liver with blunt needles were successful. Bleeding scores for kidney punctures were generally higher for larger sharp needles than for smaller ones. Bleeding scores for blunt needle punctures of the liver were generally smaller than for sharp needle puncture.

Conclusion: Blunt needles are less likely than sharp ones to enter vital structures and/or produce hemorrhage. Thus, blunt needles may be preferable to sharp ones for performing interventional pain procedures.

 

[Doctodd]

If you insert slow enough with a sharp needle, and the patient is awake which they should be, then you will get a paresthesia before you "harpoon" any nerve. Unless you are inserting the needle at 20mph or the patient isnt awake to tell you they had a paresthesia, i dont see any SIGNIFICANT difference for doing basic patients and basic procedures. At L3 i go ALOT slower for TFESI's if at all. For LFBSS patients, i think the trauma from a blunt needle into all the scar tissue they have would take a long time which causes increased risks anyway.

T

 

[Aether2000]

Once you get a paresthesia, you have already harpooned the nerve with a sharp needle. Blunt needles can also cause nerve trauma through impaling the nerve against a bony backdrop...

 

[Medprd]

Its actually 14-18$ a needle. Depending on gauge and length.

Epimed's blunt needles range from a low of $9.50 to a max of $16.25 depending on order qty, gauge size, curved or straight, and included introducer.

Epimed sells standard nerve block needles too, not just blunts.

As far as catheters go, Epimed has 14 different catheters to let you choose what's best. They run from $12 all the way up to $76 depending on whether you use a soft catheter for an ESI or need a steerable one for a site specific injection. Arrow only has 2 catheters and they are both more expensive than the equivalent Epimed catheter.

Accusations that an ISIS instructor has a vested interest in pushing blunt needles are reckless and irresponsible. Blunt needles may reduce your chances of complications and further studies need to be done to confirm. Ultimately, it's your choice. Epimed will sell you both.

 

[drrinoo]

The debate over blunt vs. sharp is an oversimplification of the debate.
This is also a debate over a long beveled needle vs. a short beveled needle.
This is also a debate over whether the injectate exits at the tip of the needle or more proximally (Whitacre).
This is also a debate about reducing the risk of a direct intraneural injection (see below)
This is also a debate about other complications related to sharp needles...Wilkinson had an unacceptable pneumothorax rate with thoracic sympathetic RF and sharp needles....Vaisman developed a massive pelvic hematoma following an ilioinguinal nerve block...one colleague that I know perforated bowel after doing an ilioinguinal nerve block...

Unfortunately, the sharp vs. blunt needle debate won't be solved due to the sheer numbers of patients required to study this problem...hence, we have to rely on surrogate information in the literature or (cringe) common sense...you can start with A Hadzic, a highly respected regional anesthesiologist:

1. Reg Anesth Pain Med. 2004 May-Jun;29(3):201-5. Related Articles, Links


Injection pressures by anesthesiologists during simulated peripheral nerve block.

Claudio R, Hadzic A, Shih H, Vloka JD, Castro J, Koscielniak-Nielsen Z, Thys DM, Santos AC.

2. Hadzic A, Dilberovic F, Shah S, Kulenovic A, Kapur E, Zaciragic A, Cosovic E, Vuckovic I, Divanovic KA, Mornjakovic Z, Thys DM, Santos AC. Related Articles, Links
Combination of intraneural injection and high injection pressure leads to fascicular injury and neurologic deficits in dogs.
Reg Anesth Pain Med. 2004 Sep-Oct;29(5):417-23.


The reality is that several societies are teaching practitioners these techniques in workshops....what is the point of teaching physicians, if you don't believe they can acquire competency?...if one believes that you do not have to go through a rigorous neurosurgical training program (remember some of the earliest papers on cervical transforaminals, i.e., snrbs were published by neurosurgeons at Hopkins), then it is shameful/hypocritical for physicians to blame other physicians for causing complications because of technical failures...

rather, we have to devise methods to improve the safety of the technique, abandon the procedure or have only a core group of practitioners perform the procedure

but, telling people to not bend a sharp needle, to not use a blunt needle and to not be technically incompetent to avoid complications is ludicrous.

 

[Aether2000]

I could not agree more....the debate is far from over and we just don't have enough data to make completely informed decisions.
I know of no ISIS instructors that have any vested interest in selling Epimed needles. To the contrary, in the recent Bogduk white paper, I was astonished to find such a condemnation of bending sharp needles and the rationale for not doing so, and the ISIS paper on blunt needles. I have used bent sharp needles for many many years to very successfully navigate to areas that would otherwise be impossible to approach with straight needles. My introduction to bent needles came from Gabor who had the guts and verve to berate me for teaching using only straight needles. After returning to my clinic, I decided to prove Gabor wrong by comparing bent vs straight needles....but he was completely correct as I demonstrated to myself with comparative needle techniques. I now only rarely use completely straight needles, and usually fashion the appropriate bend angle and length of the bend dependent on the anatomy of the patient, the depth to the target, and based on my experience with the angle of bend required for a specific procedure. There are some cases in which a bend of 5 degrees is sufficient, but some may require 50 degree bend over 1 cm.
I have used blunt needles since the mid 1990s when the only blunt injection needles available were Radionics RF needles. Based on the safety I have seen after performance of over 1000 lateral recess blocks at L4-5 and L5-S1 using a caudal approach with a blunt needle, I can attest to the fact that with blunt needles one may definitely achieve far greater choice in accurate needle placement than one can with a sharp needle. But there are times when sharp needles are more appropriate...
So it indeed is not a black or white issue only....it is yet another shade of grey in pain medicine.