Help with Blockjocks

[BLADEMDA]

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Good luck with puncturing the sheath. While you may think that you have seen it all I guarantee you the more you do the more you will back off. The complications for the surgery and/or anesthesia are real and our literature shows ISBs to have the greatest incidence of these complications. Even if you just brush by the C5 and/or C6 nerve root as you pass through the sheath there is a risk of injury to the nerve. These blocks aren't worth that small but real increased risk so I avoid penetration of the sheath altogether and just get close to the nerve roots. The quality of the block is EXCELLENT with local NEAR the roots so touching C5, C6 or C7 isn't required. A common mistake is thinking you need to contact the roots or penetrate the sheath to make this block work.

The technique for placing a catheter is not without its own risks like damaging the small nerves on the way to the roots or local anesthetic for 48-72 hours increasing myotoxicity.


http://bja.oxfordjournals.org/content/111/5/840.extract


http://bja.oxfordjournals.org/content/111/5/840.full.pdf

I wanted to bump my post from 2014 to show the evidence is mounting against puncturing the sheath.

 

[Planktonmd]

American Society of Regional Anesthesia and Pain Medicine's 2015 annual meeting (abstract 282).

http://www.anesthesiologynews.com/V...a&d_id=540&i=August+2015&i_id=1212&a_id=33159

FYI, my injections are now all 1-2 mm away from the nerve roots/trunks when performing an ISB. My efficacy still remains at 99% and I firmly believe the evidence now supports this as the BEST technique in terms of risk/benefit.

How about onset time?

 

[Planktonmd]

Not every article one reads in a journal is the absolute truth and not every trial done on cadavers apply to living humans.
I always advise people to formulate their opinions based on a body of evidence over a period of time combined with their own experience, it's not a great idea to adopt every article you read and try to take credit for its findings.

 

[BLADEMDA]

Not every article one reads in a journal is the absolute truth and not every trial done on cadavers apply to living humans.
I always advise people to formulate their opinions based on a body of evidence over a period of time combined with their own experience, it's not a great idea to adopt every article you read and try to take credit for its findings.

Slim, My Group has performed well over 100 ISB's utilizing this technique of injecting the local about 0.5-1.0 mm away from the nerve/root. Success for the technique is 100/100 and onset time at 0.5 mm is 20-30 minutes. The safety of the ISB is increased utilizing this technique without sacrificing efficacy or duration of the block.

 

[BLADEMDA]

Our study indicates that needle-nerve contact is not a requirement for an effective ISB and a distance of about 8 mm between the needle tip and brachial plexus sheath produces effective and long-lasting analgesia in 50% of patients. Further, although a distance of 1.6 mm can achieve a successful block in 95% of patients, the upper limit of our CI suggests that this distance may actually be far greater. In fact, despite the large distance between the needle tip and roots of the brachial plexus in the present study, the intraoperative and postoperative opioid requirements among patients with a successful block were equivalent to recently published trials that evaluated analgesic efficacy of US-guided ISB. 29,30 Similarly, the durations of sensory blockade and motor blockade among patients with a successful block fell within previously reported ranges using similar doses of local anesthetic.


http://www.ncbi.nlm.nih.gov/pubmed/24310046

I have NEVER taken credit for the periplexus ISB technique. On the contrary, I have posted the references to the studies PROVING efficacy of the technique which I have since adopted when performing all my ISBs.

 

[Planktonmd]

Slim, My Group has performed well over 100 ISB's utilizing this technique of injecting the local about 0.5-1.0 mm away from the nerve/root. Success for the technique is 100/100 and onset time at 0.5 mm is 20-30 minutes. The safety of the ISB is increased utilizing this technique without sacrificing efficacy or duration of the block.

20-30 minutes onset means probably 45 minutes to reach surgical anesthesia... too slow slim!

 

[BLADEMDA]

Poor Technique

 

[BLADEMDA]

Good technique

 

[BLADEMDA]

Our results suggest that an equally effective sensory and motor block results from a less invasive peri-plexus interscalene block in comparison with an intra-plexus injection. This finding may help the practitioners avoid unnecessary needle-to-nerve contact and thus reduce nerve trauma.

These results are interesting as they show that there is no benefit from the more aggressive needle placement compared with the peri-plexus technique in terms of block-onset. It is likely that once the surrounding nerve sheath is contacted, it is the properties of the local anaesthetic (concentration, lipid solubility and pKa) and not the exact needle placement that determines the block onset.

http://onlinelibrary.wiley.com/enhanced/doi/10.1111/j.1365-2044.2011.06712.x/

 

[BLADEMDA]

http://www.researchgate.net/publica...uided_Interscalene_Block_An_Exploratory_Study


In summary, our results suggest that it is not necessary to position the needle tip as close as possible to the nerve roots to achieve effective and long-lasting analgesia after US-guided ISB for ambulatory shoulder surgery.

 

[Planktonmd]

Our results suggest that an equally effective sensory and motor block results from a less invasive peri-plexus interscalene block in comparison with an intra-plexus injection. This finding may help the practitioners avoid unnecessary needle-to-nerve contact and thus reduce nerve trauma.

These results are interesting as they show that there is no benefit from the more aggressive needle placement compared with the peri-plexus technique in terms of block-onset. It is likely that once the surrounding nerve sheath is contacted, it is the properties of the local anaesthetic (concentration, lipid solubility and pKa) and not the exact needle placement that determines the block onset.

http://onlinelibrary.wiley.com/enhanced/doi/10.1111/j.1365-2044.2011.06712.x/

No they are wrong! The onset is significantly quicker if you go through the sheath regardless of the anesthetic you use.
If you are doing your blocks for post-op pain, as I suspect you are, then that 45 minutes to achieve a good block is not a problem but if the block is your anesthetic then 45 minutes is way too long.

 

[BLADEMDA]

No they are wrong! The onset is significantly quicker if you go through the sheath regardless of the anesthetic you use.
If you are doing your blocks for post-op pain, as I suspect you are, then that 45 minutes to achieve a good block is not a problem but if the block is your anesthetic then 45 minutes is way too long.

Even if you achieve a faster onset time by 10 minutes the possibility of nerve injury is higher with the intraplexus vs periplexus ISB. For patient safety the better technique is periplexus utilizing U/S with or without Nerve stimulation. If the needle tip is 0.5 mm or less from the nerve root/trunk the block will work 99% of the time.

This technique can not be extrapolated to the other blocks we routinely perform except perhaps Femoral and Axillary blocks where close is good enough.

 

[BLADEMDA]

My Technique for placing an ISB catheter out of plane. I usually advance the catheter 3-4 cm farther than the picture shows for the needle tip. Perhaps, the safest technique?

Ultrasound image of the interscalene groove with arrow showing the ideal position of the needle tip or interscalene catheter, using an out-of-plane (OOP) technique, just lateral to the medial border of scalenus medius. N = nerve root.

 

[BLADEMDA]

My Technique for placing an ISB catheter out of plane. I usually advance the catheter 3-4 cm farther than the picture shows for the needle tip. Perhaps, the safest technique?

Ultrasound image of the interscalene groove with arrow showing the ideal position of the needle tip or interscalene catheter, using an out-of-plane (OOP) technique, just lateral to the medial border of scalenus medius. N = nerve root.

The brachial plexus is imaged in the conventional way and the medial border of scalenus medius is identified at a point where the nerve roots are most closely related. The needle can then be placed just lateral to this border using an out-of-plane technique until the tip lies just lateral to the plexus but just within the body of the scalenus medius muscle. The catheter can then be inserted and threaded 3–4 cm beyond the needle, in an inferior direction away from the neuraxis, thus providing a degree of protection from misplacement. Scalenus muscle tissue and fascia therefore provide another physical barrier, increasing the safety of the catheter and reducing the likelihood of intravascular placement.

http://onlinelibrary.wiley.com/enhanced/doi/10.1111/anae.12124

 

[sevoflurane]

Yeah.. I never do a single end point as described above. Seems silly to deposit it all in one place if you are looking for quick onset and good distribution.

I usually hit it above C5 and hydrodissect from lateral to medial. Then do the same below the bottom trunk. My onset is always ninja fast as most can't touch their nose before induction. This is what it always looks like with this technique: I call it the Brachial Plexus Encarceration. Simple, safe and effective.

 

[sevoflurane]

Always try and land my catheter around C5. If there is a nice big gap between trunks, I have no issues landing the catheter between them- just like sciatic catheters: I now put the catheter between the tibial and peroneal nerves= more surface area to get all the fassicles bupivicainized .

 

[sevoflurane]