Cervical SNRB - how high?

[epidural man]

---

Members do not see this ad.

This isn't a question for y'all who are going to chastise me for performing selective nerve root blocks in the cervical region....yea I know, I'm ******ed, you're an amazing physician who only makes the right choice everytime, you are way better than me, etc.

Now, for those of you who wallow in the mud and stoop to the miserable and evil level of performing them...how high would you go?

I got a request for a C3. Vert is way protected at this level, should I do it? I've never gone that high that I recall....

 

[lobelsteve]

C zero baby. I snrb foramen magnum.

Level unimportant. Review MRI and note VA for aberrant anatomy. Use contrast. Use 0.5cc of lidocaine at target. Cannot do anything bad unless you dissect a V A. See the mri comment.

My question is what you gonna do with the info?

 

[101N]

This isn't a question for y'all who are going to chastise me for performing selective nerve root blocks in the cervical region....ya I know, I'm ******ed, you're an amazing physician who only makes the right choice everytime, you are way better than me, etc.

Now, for those of you who wallow in the mud and stoop to the miserable and evil level of performing them...how high would you go?

I got a request for a C3. Vert is way protected at this level, should I do it? I've never gone that high that I recall....

I've been doing spinal procedures for about 15yrs, most of that time in a department with orthopedic spine surgeons or neurosurgeons. While C3 and C4 radics are rare, if you work with spine surgeons you will see them and they may ask you to perform these injections. As you gain experience with both the image reading and procedure, you may eventually opt to perform them yourself as a part of your work up.

No magic to the procedure, use dex and be very judicious on your anesthetic volume and concentration as a high spinal is a real possibility. If you are uncomfortable, dont' do it. FWIW: I find C1/2 arthrograms to be a MUCH scarier procedure than any CTFESI.

 

[lobelsteve]

.....repost

 

[clubdeac]

Agree..go as high as you like. Risk doesn't increase as you go cephalad. 101N, why is a C1/2 arthrogram scarier? Are you doing them lateral or from AP?

 

[knoxdoc]

No magic to the procedure, use dex and be very judicious on your anesthetic volume and concentration as a high spinal is a real possibility.

Are you talking about a risk of high spinal as a result of injecting LA into the nerve root sleeve (and thus intrathecal) or as a result of injecting intra-vascularly?

 

[101N]

Are you talking about a risk of high spinal as a result of injecting LA into the nerve root sleeve (and thus intrathecal) or as a result of injecting intra-vascularly?

TF epidural flow will do it. During fellowship - or shortly after - I proved this by using 2cc's of 4% on 2 patients. Damn good motor block, then sleepy, then obtunded, then intubated for 1. Both fine, me and my nurse, not so much.

Now I use 1-2cc's of 2%.

 

[SSdoc33]

TF epidural flow will do it. During fellowship - or shortly after - I proved this by using 2cc's of 4% on 2 patients. Damn good motor block, then sleepy, then obtunded, then intubated for 1. Both fine, me and my nurse, not so much.

Now I use 1-2cc's of 2%.

you do realize that with 2 cc LA and presumably 1 cc of dex, your medication is going literally all over the place. up to the foramen magnum and down to the cervicothoracic junction. there is ZERO selectivity in this injection, yet a relatively high risk. you seem to be a reasonably thoughtful individual. explain again how this makes sense?

if you are looking for selectivity, just put in 0.5 cc local.

if you are looking for a theraupeutic response, just use steroid.

IMHO, neither option is a good one.

 

[101N]

you do realize that with 2 cc LA and presumably 1 cc of dex, your medication is going literally all over the place. up to the foramen magnum and down to the cervicothoracic junction. there is ZERO selectivity in this injection, yet a relatively high risk. you seem to be a reasonably thoughtful individual. explain again how this makes sense?

if you are looking for selectivity, just put in 0.5 cc local.

if you are looking for a theraupeutic response, just use steroid.

IMHO, neither option is a good one.

With my cervical selective injections I try to get a SNRB pattern on purpose. Typically I will advance the bevel to the pillar and stop. This usually leads to lateral flow along the root with little or now flow up to the axilla of the root. I am gun shy of epidural flow given those two TFESIs that caused obtundation. IMO .5cc local isn't sufficient anesthetic to give reliable diagnostic information.

 

[SSdoc33]

With my cervical selective injections I try to get a SNRB pattern on purpose. Typically I will advance the bevel to the pillar and stop. This usually leads to lateral flow along the root with little or now flow up to the axilla of the root. I am gun shy of epidural flow given those two TFESIs that caused obtundation. IMO .5cc local isn't sufficient anesthetic to give reliable diagnostic information.

ahh, i see. apparently, fluid is less viscous in Oregon than it is in York, PA.

you are fooling yourself. too smart for your own (or the patient's own) good.

no such thing as a SNRB. especially in the C-spine

 

[knoxdoc]

TF epidural flow will do it. During fellowship - or shortly after - I proved this by using 2cc's of 4% on 2 patients. Damn good motor block, then sleepy, then obtunded, then intubated for 1. Both fine, me and my nurse, not so much.

Now I use 1-2cc's of 2%.

Wow. That's scary as hell. Thanks for sharing this.

 

[bedrock]

2cc is WAY too much. I assume the York reference was to Furmans' paper.....?

I agree there is no such thing as a complete SNRB, but they do have value in limited situations with vague imaging, a sane patient, and a non-diagnostic EMG.

I use .4ml of 4% in c-spine and .6ml of 4% in L-spine. More selective with small volume and concentrated medication. I've never needed more volume than this to get an answer.

Agree with staying far lateral for cervical SNRB to avoid high spinal.

 

[clubdeac]

Would like to clarify, I thought 101N was talking about a c2/3 facet, not c1/2. Totally different... my bad

 

[epidural man]

no such thing as a SNRB. especially in the C-spine

AGreed

I no longer document as a "selective NRB" - I use the term "targeted NRB"

 

[ampaphb]

They are not targeted, selective, or incompletely selective, in the neck or the back.

Furman showed that, "Diagnostic LS-TFESI or SNRB blocks limiting injectate to a single, ipsilateral segmental level cannot reliably be considered diagnostically selective with volumes exceeding 0.5mL. Injectate volumes greater than 0.5mL are consistently non-selective and cannot be used reliably for diagnostic block procedures in the epidural space."

Pain Physician. 2008 Nov-Dec;11(6):855-61.​

 

[101N]

Ok, I'm going to change from 1mL 2% to 0.6mL of 4% if the goal is a diagnostic SNRB. (I also use a Stimuplex needle in an effort to produce a concordant paresthesia prior to injecting.)

Eur Spine J. 2006 Oct;15(10):1465-71. Epub 2005 Dec 8.
Distribution patterns of transforaminal injections in the cervical spine evaluated by multi-slice computed tomography.
Anderberg L, Säveland H, Annertz M.
Source
Department of Neurosurgery, University Hospital, Lund, Sweden. [email protected]
Abstract
Transforaminal injections are sometimes used for the diagnosis and treatment of painful conditions in the lumbar and to a lesser degree in the cervical spine. The technique is most often used when investigating/treating radiculopathy caused by degenerative disease. But how selective are the nerve root blocks? What possible structures other than the intended nerve root are affected from such injections? This study was undertaken in order to try to answer these questions, as no study focusing on the possible spread from the transforaminal selective nerve root blocks in the cervical spine has been performed earlier. In three groups of patients, each group including three patients, we injected three different volumes (0.6, 1.1 and 1.7 ml) with a transforaminal technique in the cervical spine. In all the injections, a small amount of contrast media was added. The spread of the injections were then investigated using multi-slice computed tomography with reconstructions. The imaging revealed a possible effect on other nerve roots than the intended ones when a larger volume was used for the root blocks. The spread was related to the injected volume as well as to local anatomy (size of foraminal area). In this study, only 0.6-ml injections could be accepted for being selective enough for diagnostic investigations.