Regional Anesthesia: A Case Example

[hokie]

JPP,

Mil does as many blocks as anyone per his posts. He seems fluent in all the Regional crap. The only block I have not heard him post much about is the Lumbar Plexus/Psoas Block. This block may look scary but it is one of the easiest blocks to technically perrform. Gurus recommend ( take this with a grain of salt as these people change their mind more than JPP at a free bar)
the nerve stimulator greater than 0.7-0.9 for this particular block. I have been using any good quadriceps twitch less than 1.0 and greater than 0.3 with excellent results and no complications.

Blade

I was alternating between LP/sciatic and fem/sciatic for total knees but I think I am going to stick with fem/sciatic for the most part now for a couple of reasons. In my experience the duration of analgesia is somewhat longer with femoral vs. LP. I think this may be in part because of epidural spread that is often seen with LP blocks (making sure the twitch disappears at <0.5mA should help with this though). The risk of epidural spread also makes femorals slightly less risky IMHO (I have had one total epidural/spinal from an LP).
Femorals are a little easier than LP blocks in general (but with experience I don't think LP's are that hard either).
I am more concerned about anticoagulation issues with LP blocks for obvious reasons... if I am putting a catheter in I will always use the femoral approach because our post-op knees get fairly aggressive anticoagulation.

My typical approach for TKR: in holding after small amt. versed/fentanyl: Femoral block with 30cc 0.5% bupi with 1:200k epi then sciatic (Labat) with 30cc 0.5% ropi with 1:200k epi. Will do the case with either IV sedation or general/LMA depending on patient, block set up time, etc.

Has anyone dealt with sciatic nerve palsy/injury after sciatic block? I haven't but I've read some discussion of omitting epi from sciatics to decrease the chance of nerve ischemia. Any thoughts (i.e. risk of unrecognized IV injection)? Also, do you routinely write for heel protection (padding,etc.) post-op?

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[VentdependenT]

For bigger-than-just-arthroscopy shoulders do you all do interscalene catheters?

Do you do general with ETT's after the block? Wha' bout LMA's in the Sitting position. Seems valid but we don't do em like that in the main OR's.

In the surgicenter its a block and mac.

 

[BLADEMDA]

I was alternating between LP/sciatic and fem/sciatic for total knees but I think I am going to stick with fem/sciatic for the most part now for a couple of reasons. In my experience the duration of analgesia is somewhat longer with femoral vs. LP. I think this may be in part because of epidural spread that is often seen with LP blocks (making sure the twitch disappears at <0.5mA should help with this though). The risk of epidural spread also makes femorals slightly less risky IMHO (I have had one total epidural/spinal from an LP).
Femorals are a little easier than LP blocks in general (but with experience I don't think LP's are that hard either).
I am more concerned about anticoagulation issues with LP blocks for obvious reasons... if I am putting a catheter in I will always use the femoral approach because our post-op knees get fairly aggressive anticoagulation.

My typical approach for TKR: in holding after small amt. versed/fentanyl: Femoral block with 30cc 0.5% bupi with 1:200k epi then sciatic (Labat) with 30cc 0.5% ropi with 1:200k epi. Will do the case with either IV sedation or general/LMA depending on patient, block set up time, etc.

Has anyone dealt with sciatic nerve palsy/injury after sciatic block? I haven't but I've read some discussion of omitting epi from sciatics to decrease the chance of nerve ischemia. Any thoughts (i.e. risk of unrecognized IV injection)? Also, do you routinely write for heel protection (padding,etc.) post-op?

I appreciate your post. I omit Epi these days from my Sciatic blocks. For TKR under blocks I prefer LP plus sciatic for tourniquet pain. Femoral plus Sciatic is excellent for post-op pain relief but I add an LMA to this technique.
As for Catheters I agree that Femoral Catheters are the safer approach and I prefer this route due to Lovenox/Coumadin issues post-operatively.

So, patients getting a pump for post-op pain the Femoral Block is my preference over LP/Psoas Approach. For those not getting a pump (single shot) I still like Psoas/LP plus Sciatic. Surgeons seem happy with either approach and we discuss single shot vs. pump for each patient. As to be expected the average Ortho Surgeon doen't care if you add an LMA to your Regional technique as long as the same post operative pain relief is obtained.

Blade

 

[BLADEMDA]

For bigger-than-just-arthroscopy shoulders do you all do interscalene catheters?

Do you do general with ETT's after the block? Wha' bout LMA's in the Sitting position. Seems valid but we don't do em like that in the main OR's.

In the surgicenter its a block and mac.

At my institutions we have done several thousand shoulder scopes/open rotator cuff repairs in the sitting position with LMA plus Interscalene block.
This is a great technique as airway patency is preserved but the option for Propofol drip instead of Sevo/Des is maintained. Only one minor complication where the patient had to have the LMA exchanged for E.T. tube in the middle of the case.

Blade

 

[jetproppilot]

At my institutions we have done several thousand shoulder scopes/open rotator cuff repairs in the sitting position with LMA plus Interscalene block.
This is a great technique as airway patency is preserved but the option for Propofol drip instead of Sevo/Des is maintained. Only one minor complication where the patient had to have the LMA exchanged for E.T. tube in the middle of the case.

Blade

I concur.

Did a total shoulder yesterday on a big dude...6 foot, 230 pounder.

Right sided interscalene block....went with the advice I got on this forum about bupivicaine (my standard) vs. ropivicaine (which was suggested).

30 mL .5% ropiv in holding. Twenty minutes later the dude went to scratch his nose and was cracking up...da arm was dead.

Into the room, Propofol 250 mg (upped the dose since no opiods were used), LMA #4.

Sevo maintained at .5% or so.

Long case...about 2.5 hours.

Guy woke up crisp, talking on the way to recovery, with no pain, no nausea.

 

[swpm]

I use it for sedation in ortho cases with a good block that are going to run looooooong.

I'm a young'un in residency, only used dexmedetomidine a few times.

The problem I have with it in ortho cases is that the noise from the power tools and jolting from the hammering keeps waking up the patients, and they get squirrelly. Maybe I've just been lucky enough to get crazy patients (WHAT ARE THEY DOING WITH THE BUZZ SAW MY GOD DID THEY CUT OFF MY LEG?), or maybe I'm just not using enough dex.

How high do you guys usually go on the dex infusions, assuming you have a good block? That .2-.7 mcg/kg/h "ICU sedation" range people kick around seems to be inadequate more often than not. But I've heard some people say they've used doses 10x that in the OR without problems.

 

[jetproppilot]

(WHAT ARE THEY DOING WITH THE BUZZ SAW MY GOD DID THEY CUT OFF MY LEG?), or maybe I'm just not using enough dex.

.

Its titratable, as you know.

I think sometimes we get too caught up in recommended doses.

The correct dose is what works for that specific patient.

The doses we learn are starting points. Sometimes its enough. Sometimes its too much.

If they're worried that their leg is being cut off, they're way too awake, IMHO.

I would've increased the dose by about 50%....too much? Back it down 25%. Too little? Increase by 25%.

You can generally find the sweet-spot on most pts in 10-15 minutes.

But theres always those that are either apneic or moving, which makes you wanna go be a Taco Bell manager.

 

[VentdependenT]

I'm a young'un in residency, only used dexmedetomidine a few times.

The problem I have with it in ortho cases is that the noise from the power tools and jolting from the hammering keeps waking up the patients, and they get squirrelly. Maybe I've just been lucky enough to get crazy patients (WHAT ARE THEY DOING WITH THE BUZZ SAW MY GOD DID THEY CUT OFF MY LEG?), or maybe I'm just not using enough dex.

How high do you guys usually go on the dex infusions, assuming you have a good block? That .2-.7 mcg/kg/h "ICU sedation" range people kick around seems to be inadequate more often than not. But I've heard some people say they've used doses 10x that in the OR without problems.

You may need to go as high as 5-10 ucg/kg/h to get the desired effect. Is it safe? I dunno, but those doses have been used before for precedex as a primary anesthetic.

I think the .2-.7 dose just doesn't cut it for the non geriatrics. In the unit we go up to 1.5ucg/kg/hr.

However considering that monster bolus'/infusions of the stuff have been given accidentally because of decimal point and MINUTES vs HOURS errors without devastating side effects I'm pretty sure its safe. Biggest side effects were oversedation (without apnea) and 20% drop in pressure/hr which resolved in 20-30 min

Just watch out in hypovolemics (they'll bottom out big time) & folks with 2nd degree heart blocks as the stuff can cause bradyrythmias and even asystole.

The bolus can be left out and you can just start the infusion in the holding area and keep cranking it up until your desired effect....what Jet said.

 

[Unconscious]

For bigger-than-just-arthroscopy shoulders do you all do interscalene catheters?

Do you do general with ETT's after the block? Wha' bout LMA's in the Sitting position. Seems valid but we don't do em like that in the main OR's.

In the surgicenter its a block and mac.

The only Catheter for UE/shoulder surgeries that we do is posterior cervical cath. We still do GETA on shoulders b/c most ortho guys hate having pts awake, plus, it takes some of them longer then expected, now these cath we only put for total shoulders not for arthroscopies or RC repair, for those we use interscalenes.