LMAs

[buntatog]

Ok so please don't bash me, CA-1 here with 2.5 months of OR experience. About LMAs, during my first weeks I actually felt very comfortable with LMAs and general anesthesia. Nowadays, I have been shying away from LMAs and been preferring putting in an ETT for general anesthesia. Reason is lately I have been having trouble with LMA leaks and now I either have the patient too deep or too light. For my short cases (hysteroscopies, lumpectomies) I've had attendings who would maintain spontaneous respiration after IV induction with gas maintenance and narcotic dosing, and some who would put the patients on a vent with heftier IV induction doses and higher concentration volatiles, sometimes paralyzing the patient. Of course the approach is patient and type of surgery dependent, but I'm interested to know what your approaches are to LMA use, for example say a healthy 29yo for cystoscopy or hysteroscopy. Thanks again!

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[Patron]

I love LMA s because following reasons
1- smoother emergence
2- no laryngospasm , brochospasms especially smokers and asthma patients
3- no need for paralysis

I use them when ever I can except
1- full stomach
2- prone , lateral positions
3- laparascopic procedures
4- major operations on the face or neck because you dont want to loose the airway while the surgeon is operating an then screw up the surgical field.
5-I used it on obese patients <300 lbs, once I tried on a hugh patient >300 It was inadequate to oxyginate the patients even though he was spontaneously breathing.

when I insert them I partially deflate the cuff, lubricate the palate surface, induce the patient with only 50 fentanyl and good amount of propofol , I open patient mouth with my left hand with assistance of tongue depressor, i hold the LMA with right hand with my index finger at the tip and push towards the palate while inserting it, I assest ventilation and get them deep with Sevo, until they start breathing , very importing to get them deep with gas before the surgeon touch them because they might buck or even aspirate. If you want to free you hand you can put them pressure control not more than 10..

LMA are great

 

[bigeyedfish]

Part of what you need is just more cases under your belt. By this time next year you'll be moving so quick and smooth the OR nurses will be telling you to slow down.

I prefer a larger induction dose, usually just a big daddy dose of propofol. I want to make sure they are really deep while inserting the LMA because if not you can run into problems. I save narcs until after they return to breathing. I like to keep them breathing spontaneously with some pressure support if necessary. Easier to titrate the anesthetic. Then pull em deep if there no reason not to, oral airway, wake up in recovery.

 

[bigeyedfish]

when I insert them I partially deflate the cuff, lubricate the palate surface, induce the patient with only 50 fentanyl and good amount of propofol , I open patient mouth with my left hand with assistance of tongue depressor, i hold the LMA with right hand with my index finger at the tip and push towards the palate while inserting it, I assest ventilation and get them deep with Sevo, until they start breathing , very importing to get them deep with gas before the surgeon touch them because they might buck or even aspirate. If you want to free you hand you can put them pressure control not more than 10..

LMA are great

There's a couple of great points here. For me to get a good seal its key that I use the tongue blade to lift the tongue forward while inserting. I had some staff in residency who didn't like this technique and I'm not sure why.

I think most people over inflate the LMA cuff.

The other good point is that your induction dose can wear off before they get gas on board by themselves so you will have to assist them at first, either with the bag or pressure control.

 

[CrazyJake]

Patron is right on. I think it helps to have the cuff a bit inflated so it moves around the tongue/palate.

I use a tongue depressor to get the tongue out of the way and just follow the roof of the mouth...finger way down close to the cuff for control. I use a good dose of Propofol and some Fentanyl then bridge w/Sevo until Sg starts, as above.

I also put the LMA in the center of the mouth, in b/n the 2 front teeth with the wings off to the left and right - not off to the side of the mouth like an ETT. I then hook up the circut right over the forehead in b/n the eyebrows over the nose to the LMA tip.

LMA's are money.

CJ

 

[rsgillmd]

Patron is right on. I think it helps to have the cuff a bit inflated so it moves around the tongue/palate.

I use a tongue depressor to get the tongue out of the way and just follow the roof of the mouth...finger way down close to the cuff for control. I use a good dose of Propofol and some Fentanyl then bridge w/Sevo until Sg starts, as above.

I also put the LMA in the center of the mouth, in b/n the 2 front teeth with the wings off to the left and right - not off to the side of the mouth like an ETT. I then hook up the circut right over the forehead in b/n the eyebrows over the nose to the LMA tip.

LMA's are money.

CJ

They should be going towards the corners of the patient's mouth. If they are up and down or at an angle your LMA is twisted. A junior resident once put in an LMA for a hardware removal in ASU. I was still in the room because I was finishing signing off to her. It went in fine, but after she secured it she couldn't ventilate. Looking at those tips immediately clued me into the problem.

 

[jennyboo]

Nowadays, I have been shying away from LMAs and been preferring putting in an ETT for general anesthesia. Reason is lately I have been having trouble with LMA leaks and now I either have the patient too deep or too light.

Of course you will get better at managing these problems as you gain more experience. But what you're describing is not a weakness -- you are learning the major disadvantages of LMAs and learning about how LMAs can get you in trouble. We all have these problems with LMAs from time to time -- the problem isn't necessarily you, it's the disadvantages that come with the equipment. Knowing that, no matter how smooth an anesthetic you can delivery, you can still get burnt by an LMA, you now have some experience that will help you decide when to use, and when to avoid using, an LMA.

 

[Idiopathic]

They should be going towards the corners of the patient's mouth. If they are up and down or at an angle your LMA is twisted. A junior resident once put in an LMA for a hardware removal in ASU. I was still in the room because I was finishing signing off to her. It went in fine, but after she secured it she couldn't ventilate. Looking at those tips immediately clued me into the problem.

no he is referring to the stem of the lma being in the middle and not in the corner. you are right about the wings, also.

 

[Intubate]

Part of what you need is just more cases under your belt. By this time next year you'll be moving so quick and smooth the OR nurses will be telling you to slow down.

I prefer a larger induction dose, usually just a big daddy dose of propofol. I want to make sure they are really deep while inserting the LMA because if not you can run into problems. I save narcs until after they return to breathing. I like to keep them breathing spontaneously with some pressure support if necessary. Easier to titrate the anesthetic. Then pull em deep if there no reason not to, oral airway, wake up in recovery.

I used to do this too, then one day I realized it makes no sense. The LMA is basically a bigger, better oral airway anyway-- just go to pacu with the LMA and the nurses can take it out when the patient wakes up, just like they would the oral airway. Its one less step for you, and less airway obstruction for the patient.

 

[Mman]

I love LMA s because following reasons
2- no laryngospasm , brochospasms especially smokers and asthma patients


LMA are great

LMAs are a very useful tool in our tool box. They are not perfect. They can cause laryngospasm. I've watched it happen in the middle of a case with a spontaneously breathing patient. ETCO2 tracing started trailing off. I tried bagging with some positive pressure to no avail. Pulse ox dropping. Had to give succinylcholine to break it. And once it broke everything was back to normal. Until 30 minutes later when the same damn thing happened. Thankfully we were almost taking drapes down at that point so I just gave some sux and pulled it out and masked him the rest of the way.

 

[dhb]

I used to do this too, then one day I realized it makes no sense. The LMA is basically a bigger, better oral airway anyway-- just go to pacu with the LMA and the nurses can take it out when the patient wakes up, just like they would the oral airway. Its one less step for you, and less airway obstruction for the patient.

Totally agree 👍 . I exutubate everyone deep but with LMAs i relly don't care it's just an oral airway.

I never put my fingers in the mouth nor do i use a tongue depressor; i insert the LMA sideways so that the cuff doesn't drag the tongue down the turn it back into position.

 

[bigeyedfish]

I used to do this too, then one day I realized it makes no sense. The LMA is basically a bigger, better oral airway anyway-- just go to pacu with the LMA and the nurses can take it out when the patient wakes up, just like they would the oral airway. Its one less step for you, and less airway obstruction for the patient.

I hear you but my PACU nurses would crap their scrubs if you roll a patient in with any kind of tube sticking out of the mouth. Against "policy." Ohhhh academia.

 

[periopdoc]

Right now about 60% of my patients remove their LMA and hand it to me before we leave the OR. I have a lot of fun trying to get the timing perfect and I am hoping to be over 80% by the end of the year when I have had the chance to figure out my surgeons a bit better.

I do find that I generally prefer intubation. We will see how I feel after a few thousand cases on my own though. To me, the benefits of LMA seem to be overrated and risks of ETT seem to be overblown once you become a good laryngoscopist and learn how to get smooth emergences with ETTs. Generally speaking, the cases where I absolutely must have a smooth emergence, are cases where I also need definitive airway control and thus they are not amenable to the utilization of an LMA.

Over the last five years I recall more problems with LMA's than ETTs. Mostly just minor annoyances. 2 mid-case aspirations (both were discharged from PACU a little later than planned with no sequelae), a few LMA's dislodged, and that damned annoying crowing sound that happens every once in a while. I don't recall any significant episodes of ETT related laryngospasm or bronchospasm, or laryngoscopic trauma since the first 6 months of residency.

For those of you who practiced extensively prior to the LMA era do you feel that, excluding its role as a rescue device, the LMA has been revolutionary? Personally, I find the biggest benefit being an hands free alternative to mask ventilation for short cases.

- pod

 

[periopdoc]

I hear you but my PACU nurses would crap their scrubs if you roll a patient in with any kind of tube sticking out of the mouth. Against "policy." Ohhhh academia.

You should come hang out at Harborview. We roll the patients into PACU intubated, spontaneously ventilating, with a propofol infusion running so that we can do post-op lower extremity blocks before they wake up. When we are done, we turn the propofol off and go see our next patient.

We have GREAT PACU nurses.

Or at least we did when I was there.

- pod

 

[Doctor4Life1769]

Periop,

Out of curiosity, why don't you just do pre-op blocks? That way, pt has no pain and anxiety going into the OR, and they wake with less pain? Just curious about the methodology (not questioning you).

 

[gaspasser2004]

An LMA is basically a hands free mask. If you wouldn't hypothetically do the case under mask alone, then an LMA is probably not a good choice.

Be very careful about using LMA's in already hospitalized patients. The dude who got admitted last night for kidney stones who is about to undergo a cysto/stone retrieval/stent may in fact be NPO for greater than 8 hours, but the combination of pain and the morphine PCA makes him a full stomach due to delayed gastric emptying.

I like to pull my LMA's deep and immediately insert an oral airway. Most PACU nurses don't freak out at an oral airway, even in academia.

For sitting shoulders, I prefer to use an ETT. One colleague of mine insisted on placing LMA's for these cases because if the ETT fell out, you would place an LMA anyway. To me, this is like using an intubating LMA on a difficult airway as your plan A.

LMA's are great for what they are: a mask that keeps your hands free to chart.

 

[Patron]

i totally agree with you,sick inpatient,or on narcotics should not get LMA

 

[countingdays]

Totally agree 👍 . I exutubate everyone deep but with LMAs i relly don't care it's just an oral airway.

I never put my fingers in the mouth nor do i use a tongue depressor; i insert the LMA sideways so that the cuff doesn't drag the tongue down the turn it back into position.

👍

 

[rsgillmd]

i totally agree with you,sick inpatient,or on narcotics should not get LMA

I would generalize that to anyone on more than a minimal dose of narcotics.

When I was a CA-2 I had a patient for hardware removal come in from home. She was taking Percocet with regular frequency. I was just going to place an LMA, but my attending was concerned about delayed gastric emptying despite the fact she had been NPO for approx. 14-16 hours. It was no big deal to me so we did RSI. After I placed the ETT I passed an OG tube and suctioned out about 200 ml of fluid from the stomach.

Ever since then I've had a healthy respect for the delayed gastric emptying effect of narcotics.

I am in agreement with the others -- if you would not do a case as a mask, then don't use a LMA.

 

[Idiopathic]

Periop,

Out of curiosity, why don't you just do pre-op blocks? That way, pt has no pain and anxiety going into the OR, and they wake with less pain? Just curious about the methodology (not questioning you).

others might suggest not doing blocks on asleep patients

 

[iwumd07]

How often do you guys use PSV Pro when using LMAs? I've been told to never use the vent if the patient has an LMA. I've also been told it's ok to use PSV Pro when doing so, just to give a little support and increase tidal volumes.

Side note: How often do you extubating patients deep? Is this an academia vs. PP thing? Keeping PACU nurses happy vs. patient safety? I can understand extubating most kids deep and any patients undergoing supra or infraglottic surgeries or those involving the thyroid. Here at home (PP), a lot of CRNAs extubate deep and the reason they gave me was "the patients dont buck and cough in the PACU and it keeps the nurses happy". At my away, most patient were extubated awake and I was told this was to ensure airway safety, regardless of what the PACU nurses felt was best. Comments?

 

[periopdoc]

Out of curiosity, why don't you just do pre-op blocks?

Excellent question. I spent three years trying to figure that one out and change the practice. One of the reasons that I was given was that we were doing the blocks for post-operative pain control and wanted to maximize the post-op duration. Another was space and privacy issues in pre-op and staffing issues that didn't allow us to move patients to another room for placing the blocks pre-op. Ultimately I just learned to accept it. They may have changed to doing more preop blocks with the significantly larger new preop area that went into operation a little over a year ago.

others might suggest not doing blocks on asleep patients

I think we have had this discussion before on SDN, but show me evidence that doing lower extremity blocks on anesthetized patients confers any increased risk. Our ever growing experience with regional anesthesia in anesthetized pediatric patients is making the unsafe practice argument even weaker than it already was.

- pod

 

[Hamhock]

I think we have had this discussion before on SDN, but show me evidence that doing lower extremity blocks on anesthetized patients confers any increased risk. Our ever growing experience with regional anesthesia in anesthetized pediatric patients is making the unsafe practice argument even weaker than it already was.

- pod

If the "discussion" was 'heated' or 'ugly', no worries; but if not, I am curious what the "unsafe practice arguement" is. [I am not sure how to search for that]

Thanks, HH

 

[periopdoc]

Pediatric Regional Anesthesia: Beyond the Caudal - Allison Kinder Ross, MD, John B. Eck, MD and Joseph D. Tobias, MD

A common misconception is that performing blocks on anesthetized patients, particularly in children, is not safe. The anesthesia literature that has provided safety data on pediatric regional anesthesia has concluded that, overall, these techniques have extremely small complication rates (5&#8211;11). The limitation to these reports is that they typically only include information on the central neuraxis blocks. An exception to this limitation was demonstrated by the report from the French-Language Society of Pediatric Anesthesiologists (5). This one-year study of 24,409 regional blocks in children revealed a complication rate of 1.5 per 1000 in the 60% of children receiving central blocks, and 0 per 1000 in the 38% of children who received peripheral nerve blocks.

The French Study that they quote

Epidemiology and morbidity of regional anesthesia in children: a one-year prospective survey of the French-Language Society of Pediatric Anesthesiologists - E Giaufré, B Dalens and A Gombert

Unfortunately Kinder-Ross et al overstate the safety data from the original paper as not all 24,409 blocks were performed under general anesthesia.

89% (21,724) of these 24,409 neuraxial and peripheral nerve blocks were performed under "light general anesthesia."

There were a total of 23 complications, all in the central block group. Unfortunately, the authors do not report the distribution of complications between the anesthetized and the non-anesthetized groups.

1,464 of these blocks were extremity blocks. It is not possible to tell from the paper what percent of the extremity blocks were performed under general anesthesia and it is very possible that it was significantly less than the 89% quoted for all regional blocks. The older age ranges are over-represented in the total number of extremity blocks making it likely that the percentage of extremity blocks performed under general anesthetic was quite a bit lower than the overall 89% rate reported. Therefore, the conclusions may not be applicable to a primarily extremity block based system.

We are left to wonder if there was any difference in complication rates between the GA and the non-GA groups. It is unlikely that GA was a significant risk factor when you consider the types of complications reported, but not impossible. Still, the total risk was quite minimal and it does argue that regional anesthesia under general anesthesia is quite safe.

- pod

 

[Intensivist]

What is your magic number when it comes to DLs? What is No. is considered sufficient to make you a laryngoscopist to say the day?

 

[dhb]

After I placed the ETT I passed an OG tube and suctioned out about 200 ml of fluid from the stomach.

Gastric volume does not correlate with aspiration risk..

 

[sevoflurane]

If I were to do a post-op block while the patient is still asleep, I'd prolly just do it in the OR vs. PACU. Just cuz of simplicity....

 

[sevoflurane]

I rarely do this as I like the benifit of decrease N/V, constipation, itching, urinary retention etc.. associated with intra-op narcotics. I also think the case runs a hell of a lot smoother with blocks on board + ketafol/mag + .4 MAC. Some would say this is overkill, but I don't think my patients think so.

 

[Doctor4Life1769]

Excellent question. I spent three years trying to figure that one out and change the practice. One of the reasons that I was given was that we were doing the blocks for post-operative pain control and wanted to maximize the post-op duration. Another was space and privacy issues in pre-op and staffing issues that didn't allow us to move patients to another room for placing the blocks pre-op. Ultimately I just learned to accept it. They may have changed to doing more preop blocks with the significantly larger new preop area that went into operation a little over a year ago.



I think we have had this discussion before on SDN, but show me evidence that doing lower extremity blocks on anesthetized patients confers any increased risk. Our ever growing experience with regional anesthesia in anesthetized pediatric patients is making the unsafe practice argument even weaker than it already was.

- pod

Thanks for the replies. Greatly appreciated!

 

[IlDestriero]

My practice is essentially 100% peds, with some late teens and older previously operated on patients. Nearly 100% of our blocks and catheters are placed under GA, including spinals and epidurals. They all do fine.

I always use pressure support with my LMAs as well. If I need high pressures (over 18) I pull the LMA and intubate.

WRT pulling the tube deep, I think it's fine if they have a normal airway and didn't obstruct significantly on induction. I don't ever do it with T&As though, or any airway surgery.

 

[michigangirl]

My practice is essentially 100% peds, with some late teens and older previously operated on patients. Nearly 100% of our blocks and catheters are placed under GA, including spinals and epidurals. They all do fine.

I always use pressure support with my LMAs as well. If I need high pressures (over 18) I pull the LMA and intubate.

WRT pulling the tube deep, I think it's fine if they have a normal airway and didn't obstruct significantly on induction. I don't ever do it with T&As though, or any airway surgery.

Ditto on the above. Regarding LMA's, in kids they can be even more of a pain in the ass "Lose My Airway=LMA" as kids tend to laryngospasm more easily and just a simple small change in LMA position or getting a tad light can precipitate scary laryngospasm- which always seems to be in a room with a CA-1 on their first day of peds ;-) I argue that LMA's in kids are much more challenging to learn to manage than ETTs. A simple port-a-cath placement can quickly turn into a hypoxic bradycardic arrest. no fun.

 

[rsgillmd]

Gastric volume does not correlate with aspiration risk..

Maybe not with aspiration risk, but I believe it does with risk of aspiration pneumonia if aspiration occurs.

I believe the study that is usually quoted is the one that suggested risk of aspiration pneumonia is greatest if pH is <2.5 or aspirated volume >0.4 ml/kg (25 ml for typical adult).

Obviously pH is more important than volume considering we give 30 ml of Bicitra to a typical adult. Also particulate vs non-particulate content.

It's not aspiration that worries most of us, but aspiration pneumonia.

 

[Idiopathic]

Ditto on the above. Regarding LMA's, in kids they can be even more of a pain in the ass "Lose My Airway=LMA" as kids tend to laryngospasm more easily and just a simple small change in LMA position or getting a tad light can precipitate scary laryngospasm- which always seems to be in a room with a CA-1 on their first day of peds ;-) I argue that LMA's in kids are much more challenging to learn to manage than ETTs. A simple port-a-cath placement can quickly turn into a hypoxic bradycardic arrest. no fun.

Not my experience at all, did probably 100 peds LMA case, pulled every one deep and had one spasm and no issues with oxygenation or ventilation.

 

[IlDestriero]

Not my experience at all, did probably 100 peds LMA case, pulled every one deep and had one spasm and no issues with oxygenation or ventilation.

I use LMAs all the time in kids without problems either. Maybe the CA1 doesn't know the age adjusted MAC of sevo?

 

[doctadre]

I used to do this too, then one day I realized it makes no sense. The LMA is basically a bigger, better oral airway anyway-- just go to pacu with the LMA and the nurses can take it out when the patient wakes up, just like they would the oral airway. Its one less step for you, and less airway obstruction for the patient.

do you transport your patients to PACU with supplemental oxygen? if so, do you use a mapleson? or do you just throw a mask over the end of the LMA?