# King airway in obese patients...



## paradoxicalmotion (Sep 23, 2013)

Short question: Has anyone ever had any difficulty seating a (obviously properly sized) King airway in a very obese patient?

Longer context: got called to transfer of an unconscious patient pushing about 230 kilos. When I walked into the ER they had the patients torso raised about 45 degrees and had her on a NRB. They told me over some very loud, constant snoring that she was managing her own airway. The ER doctor told me he was going to RSI her and asked my partner (also a medic) to help. After the nurse pushed the etomidate, but before she pushed the succ's, the doctor informed her he had changed his mind and didn't want to use a paralytic because he was scared they would lose her airway completely. He then spent the next half hour (without any re-dosing of the etomidate) trying to intubate her by both direct vision and video laryngoscopy, causing a decent amount of bleeding in the process because the etomidate had obviously worn off (and honestly didn't seem to be enough to sufficiently sedate her in the first place - her jaw was pretty inflexible). Once he gave up he asked me if I was comfortable maintaining her airway with nasal trumpet and BVM for the hour long trip. A few of the nurses, as well as myself and my partner tried to convince him to try a paralytic, and if he couldn't get an ET tube to pass, we could always try a King airway. He said no, and after talking a third medic from another truck into coming with, we decided to do our best maintaining the airway BLS. Long story short, it was a very harrowing trip with lots of readjusting the airway as her SpO2 trended like a rollercoaster. 

I've used King airways on obese patients before with no problems, but never on someone as large as her. I'm curious as to what other people's experiences are with it. 

Thanks.


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## TheLocalMedic (Sep 23, 2013)

Although I'm not a huge fan of the King airway in general, I suppose it's better than nothing if you have to manage an airway and can't get a tube.  Due to the difficulties I have had in placing it and getting it to seat properly without just popping out, I've resorted to using a larygoscope to open them up better and then secured it prior to inflation (adjusting it a little bit afterwards).  

I haven't ever had to use one on a super big patient, however I don't imagine that their size would make a serious difference in its efficacy.  But perhaps other people out there have actually used it on a big hoss and had a different experience.


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## Carlos Danger (Sep 23, 2013)

I have never used a King airway but I'm pretty familiar with them. All SGA's are designed for normal anatomy, which a 230 kg patient does not have. Just way too much soft tissue and resulting distortion. I am not surprised that it didn't work; in fact I would have been very impressed if it did.

Another thing to consider is how well you'd be able to provide positive pressure ventilation through an SGA, even if you could get it placed correctly. It's easy in a normal-sized patient, but a supine, morbidly obese patient has higher-than normal airway and gastric pressures and often lower ES tone, meaning they are both more difficult to deliver adequate tidal volumes to, and much more prone to vomiting. 

To take the discussion a step further, I would say this physician was 100% correct in choosing not to paralyze this patient. Patients like this are some of the most difficult airways to manage, not only because of their physical size but for numerous physiological reasons, as well. You probably will not do it more than a couple of times before running into very serious problems.

The only way I would paralyze a super-obese patient who is maintaining their own airway is if they were circling the drain and I strongly expected that loss of their airway was imminent. Otherwise the risk:benefit criteria just isn't met.


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## Carlos Danger (Sep 23, 2013)

This deals with LMA's rather than the King, but it's definitely applicable:

LMA Package Insert Key Evidence In Anesthesia Malpractice Case


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## Medic Tim (Sep 23, 2013)

I have placed numerous king airways in pts of all shapes and sizes. I have never had much luck in very obese pts. As was stated before the king is not designed for the abnormal anatomy of these pt's and it is very difficult to have a proper seal.

I would be very hesitant to add a paralytic to this situation.

op. you mentioned in your post that  "causing a decent amount of bleeding in the process because the etomidate had obviously worn off "

maybe I am a little dense this morning but are you saying that if more etomidate was given the pt's wouldn't bleed as much???


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## Christopher (Sep 23, 2013)

Halothane said:


> This deals with LMA's rather than the King, but it's definitely applicable:
> 
> LMA Package Insert Key Evidence In Anesthesia Malpractice Case



Woah. I'm certain we violate a number of package inserts as many of our treatments are not truly "on label".

Perhaps two years ago our State medical director put out a letter approving King airways for the "off label" use of emergency airway management. Of note, there is no contraindication for King LT-D or LTS-D in the obese, however, you are instructed to pad beneath the head and shoulders if you have difficulty with the device.


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## Carlos Danger (Sep 23, 2013)

Christopher said:


> Woah. I'm certain we violate a number of package inserts as many of our treatments are not truly "on label".
> 
> Perhaps two years ago our State medical director put out a letter approving King airways for the "off label" use of emergency airway management. *Of note, there is no contraindication for King LT-D or LTS-D in the obese,* however, you are instructed to pad beneath the head and shoulders if you have difficulty with the device.



That's interesting. I wouldn't think using Kings as backup devices is considered "off label", since they are actively marketed to EMS agencies. I actually would have assumed that they are approved as a primary airway for emergencies, just given their marketing. 

For LMA's, I know for sure that use as a back-up airway is "on label", but as a primary, first-line airway they are only intended to be used in certain patients and situations. The morbidly obese are definitely not one of them. What complicates it is that there are many different types of LMA's now, and they are each a little different in their intended use.

It's kind of interesting, since from what I understand LMA's are used in Europe far more often than ETT's for all types of surgeries in all types of patients. Here though, they are used pretty sparingly.


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## chaz90 (Sep 23, 2013)

Halothane said:


> It's kind of interesting, since from what I understand LMA's are used in Europe far more often than ETT's for all types of surgeries in all types of patients. Here though, they are used pretty sparingly.



I obviously don't have nearly as much experience in the OR as you do, but how much do you think that varies by hospital and area? Several different hospitals I've seen have used LMAs quite frequently. CRNAs and anesthesiologists I've spoken to have mentioned they prefer LMAs over Kings or Combi Tubes as their SGA of choice and use them almost exclusively when the patient isn't intubated.


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## Medic Tim (Sep 23, 2013)

chaz90 said:


> I obviously don't have nearly as much experience in the OR as you do, but how much do you think that varies by hospital and area? Several different hospitals I've seen have used LMAs quite frequently. CRNAs and anesthesiologists I've spoken to have mentioned they prefer LMAs over Kings or Combi Tubes as their SGA of choice and use them almost exclusively when the patient isn't intubated.



It is getting harder for students to get tubes(where I went to school) as the LMA is used in a majority of cases.


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## paradoxicalmotion (Sep 23, 2013)

Medic Tim, you're not dense, I just could have been clearer. After the initial dose of etomidate, the ER doc dinked around for a couple minutes before taking his first look via direct laryngoscopy. He spent about 15 minutes attempting (in between periods of bagging her) via DL, and then spent another 15 with the video laryngoscope. She was never in that time period given further doses of etomidate or any other sedative. The entire time he had to use a significant amount of force to get past the fact that she was fairly clamped down and fighting the blade. After his attempts there was considerable bleeding from her gums (her and her family shared about six teeth between the three of them - she was mostly gums). I have seen facilitated intubations before, and in them the etomidate seemed to be much more effective and the patients jaw was much more compliant.


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## Carlos Danger (Sep 23, 2013)

chaz90 said:


> I obviously don't have nearly as much experience in the OR as you do, but *how much do you think that varies by hospital and area? Several different hospitals I've seen have used LMAs quite frequently. *CRNAs and anesthesiologists I've spoken to have mentioned they prefer LMAs over Kings or Combi Tubes as their SGA of choice and use them almost exclusively when the patient isn't intubated.



It does vary quite a bit. Some places do use them much more than others. Where I am now, we use them on maybe 10% or less of general cases, and never on obese or sick or emergent patients, or those having any kind of big surgery done. One of the issues is that so many general surgeries are being done laparoscopically now, which is a relative (or absolute, depending on who you ask) contraindication to SGA use because of the higher airway pressures needed to ventilate those patients.

When I worked in the northeast as a paramedic, we also had issues getting our tubes in the OR because LMA's were so frequently used.

If the hospital I'm at now allowed paramedics in the OR (they only allow the crew from their own HEMS program), you'd have no problems getting a handful in a morning, easily. I'm really hoping that when I'm done with school I'll end up in a place that lets me have prehospital providers in my OR as much as I want to. 

Most anesthesia providers I've known or worked with are familiar with only 2 invasive airways: the ETT and LMA. Of course VL is a big thing now, and fiberoptics are in some places. Kings and other SGA's haven't made much inroads into the anesthesia world, at least from what I've seen so far in my brief career.


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## Christopher (Sep 23, 2013)

Halothane said:


> That's interesting. I wouldn't think using Kings as backup devices is considered "off label", since they are actively marketed to EMS agencies. I actually would have assumed that they are approved as a primary airway for emergencies, just given their marketing.



The King was originally only approved for short duration sedative procedures where the patient was considered to be at "low risk" for aspiration. The FDA called them to the carpet for marketing it as an emergency airway tool in 2009.


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## truetiger (Sep 23, 2013)

What was the unconsciousness due to? Blood gas? Respiratory effort?


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## paradoxicalmotion (Sep 23, 2013)

Not entirely sure. She was brought in by another crew. No family, she'd just moved to the area. Only history they could get from a friend was she had a history of alcoholism and cirrhosis. Sugar was good. Tox screen negative. She had a high ammonia level so the ER doc thought it might be hepatic encephalopathy.

My supervisor and I are waiting to hear back from the hospital we transferred her to for follow-up.


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## truetiger (Sep 23, 2013)

Did she maintain adequate oxygenation? Was ventilation monitored with ETCO2?


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## paradoxicalmotion (Sep 23, 2013)

When I got there she was maintaining around 92% SpO2 and 50 mmHg ETCO2. After the attempted intubations, she was no longer able to maintain oxygenation (left to her own devices she was sitting around 70%). With a nasal trumpet and a BVM we were able to maintain her between 85% and 90%, with a whole lot of suctioning.


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## truetiger (Sep 23, 2013)

This patient should been intubated prior to your transfer. The ED physician should of either RSI'd or not at all. I understand he wasn't comfortable with his own skills but he did not help himself by administering the Etomidate. He gave a sedative to a patient that was already unconscious. It did nothing to improve his intubating conditions while increasing risk of aspiration. So after screwing around in her airway causing trauma, he then created suboptimal airway/ventilation\oxygenation conditions for you. An hour is a long way to be bagging a patient like that. What were you suctioning from her airway?


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## paradoxicalmotion (Sep 23, 2013)

Bloody saliva.


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## Akulahawk (Sep 23, 2013)

I'm kind of surprised that retrograde wire-guided intubation wasn't attempted... Perhaps it's unusual enough that it's just not thought of?


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## paradoxicalmotion (Sep 23, 2013)

I don't know a whole lot about retrograde intubation but my best guess is it wouldn't have been an option here because of the total lack of neck on this patient (think Jabba the Hutt).


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## Akulahawk (Sep 23, 2013)

paradoxicalmotion said:


> I don't know a whole lot about retrograde intubation but my best guess is it wouldn't have been an option here because of the total lack of neck on this patient (think Jabba the Hutt).


That makes sense... In that situation, it makes sense that there's just a LOT of tissue to go through just to find the cricothyroid membrane, and if you can't find that, I sense much :censored::censored: coming from somewhere or someone.


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## paradoxicalmotion (Sep 23, 2013)

Given the experiences I've had with this particular ER and their airway management capabilities in the past, I'd seriously doubt they would even have the necessary equipment (granted, like I said, I'm not super familiar with the procedure and I don't know what it requires) or even the know-how to do it.


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## triemal04 (Sep 23, 2013)

Of of curiosity, what would you have done during your 1 hour transport if you stopped being able to effectively ventilate the patient with a BVM?

Would you have attempted to intubate the patient?  With or without paralytics (if you have that option?)

Would you have then placed a King airway?

Something else?

I'm sure you had a plan in place, I'd just like to know what it was.

I don't know what the capabilities of that hospital are, but personally I would have refused to leave until the airway was secured with SOMETHING.  King, LMA, igel, ET tube, something would be in place before I left.  If that meant that the ER doctor admitted defeat and called anesthesia, a RT, ICU doctor or someone else then so be it.  But if he felt that her airway was unstable enough that it needed to be secured in the ER with all their available resources, then it damn sure needed to be done before you left that setting.


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## paradoxicalmotion (Sep 23, 2013)

The capabilities of the hospital are minimal. He was the only physician there at the time. They do not have any RTs on staff, and I believe their anesthesiologist is shared between a few of the area hospitals - I did ask the nurse if anyone knew how to page/get ahold of him, and no one knew. 

Like I said before, my service has had issues in the past with this hospital and their airway management - if it had been any other hospital I would have refused to transport until the airway was secure. In this case had I been any less comfortable with managing the airway BLS, I would have insisted. 

I did have a backup plan: At my request the nurse drew up induction doses of etomidate and succ's (my service does have RSI capability but we don't carry nearly enough of either for an induction dose of a patient that size), which I had sitting on the counter, right next to a King airway out of the package, next to an open tube of lube, next to a laryngoscope and blade. If I lost her airway enroute my plan was to RSI her, try the King, and if necessary, use the laryngoscope to help seat it properly. I know some will probably argue I should at least try for an ET intubation before going to a King, but with her SpO2 rollercoastering on me, I figured the less playing around and looking for cords the better at this point.


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## triemal04 (Sep 23, 2013)

Well done.  Sounds like you did what you could before leaving and had a well thought through plan and had it as prepared and ready to go as possible.  Can't ask for more than that.  And if anyone complains about you not wanting to attempt ETI in this situation...I wouldn't listen.

I would think about a couple of things, and if this type of situation really is an ongoing issue, then it really needs to be looked into, and resolved ASAP at a higher level than you.

What if the King didn't work?  I'm guessing you would have tried ETI at that point, but if that also failed, you are now in a "can't intubate can't ventilate" scenario where your backup airway has also failed.  You've allready recognized that this isn't someone who's neck you want to be cutting...so...what would you do?  I would rather be faced with that situation in the ER before leaving while the patient is still under the care of the MD, or at least know before leaving that the BVM is the only option.

Keep in mind that this is a 500+lb patient who has just had multiple traumatic attempts at securing an airway.  What if her tissue starts to swell?  What may have been an airway that could be ventilated by BVM (with difficulty), is now something very different.

What I'm getting at is insisting that the king at least be attempted before leaving or another practitioner be brought in, especially with that long of a transport.  It sounds like this is not a hospital that would stand behind you if something went wrong after you left, so ensuring that things were as stable as possible before leaving, beyond being best for the patient, is best for YOU.

I don't know what resources are available, but it is also worth considering if bringing in another outside resource would be viable.  In this particular case with the limited info you shared the patient doesn't sound extremely time sensitive, so waiting for more hands could be worth it.

Really, the head of your department and medical director need to be involved, if they aren't allready.  If this really is a recurring problem then you and your service are heading for a disaster.  Even if the hospital or physician group refuses to change things, having a documented attempt at change when something goes badly will be extremely beneficial.  

And it is "when," not "if."


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## truetiger (Sep 24, 2013)

RSI'ing this patient once she starts crashing is going to be a disaster. You noted that you were having to work to keep her in the high 80's, low 90's. Once a patient's pulse ox drops below 90, its going to start dropping exponentially faster. You have think, she has no residual volume due to her size. Now you take a sick, obese patient  and you have a real problem if she goes apneic on you. You'll be playing catch up on the side of the road with no support.


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## Handsome Robb (Sep 24, 2013)

So this might be completely impossible and I only have a basic knowledge of retrograde intubations and with what you've described about he facility I highly doubt it even was a thought but could it be done under ultrasound guidance?

Again, I have a limited knowledge of retrograde intubations and ultrasound capabilities.

I'm with others I'd have been real upset about taking this patient without an airway in place. Sounds like they're gonna be too big for a tracheostomy. I know that's jumping way down the algorithm but if you can't protect her airway or she dies from aspiration acquired pneumonia who cares about here hepatic encephalopathy?

Also, too add to the LMA vs ETI in ORs during my paramedic clinicals almost every single procedure was done with an LMA. Pretty disappointing for me from a student standpoint. I still learned a ton about airway management but we don't use LMAs.


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## Carlos Danger (Sep 24, 2013)

RSI is not the answer in a patient like this, unless she was truly in extremis. I do not blame the doctor for not wanting to use NMB's. This is a patient who needs to be intubated by anesthesia or ENT, quite possibly using an awake fiberoptic technique. 

If the doc absolutely could not secure the airway and really had no one to call, then the patient should have stayed in the ED - on CPAP or BIPAP if needed - until someone came in the next morning who could do it. Both the transporting crew and the patient were put in a really bad situation because of "this patient needs to get out of here-itis".

Someone mentioned retrograde. That may have been a good option IF you could easily palpate the CTM, but in a 500+ patient I imagine they may not have been able to, which means they also couldn't do a cric, which is another reason why NMB's were a bad idea.


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## paradoxicalmotion (Sep 24, 2013)

Halothane, quick question about using fiberoptics - The only times I've seen it performed have been in very busy, metro ED's and it was the EM residents performing it, rather than anesthesia. I myself don't know very much about it. Is this a procedure I can expect a rural ER physician to be trained in, and beyond that will they even have the equipment necessary?


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## Av8or007 (Sep 25, 2013)

This is a tough one. If they weren't unconscious I would have said to do them awake with topical anesthesia +/- moderate ketamine sedation.

Since the pt is unconscious, this presents an issue since an awake intubation is no longer possible. I would say (not that i know anything about this so take with a mole of salt) that you would first want to try preoxygenation to get the spo2 up to a safe level.

It may be possible to preoxygenate on BiPap if you are at the bedside at all times but use caution.


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## Av8or007 (Sep 25, 2013)

It may be possible to preoxygenate on BiPap if you are at the bedside at all times but use caution re the risk of aspiration and recognition of apnea.

If the patient requires manual/mechanical ventilation then use a peep valve - failure to oxygenate at high fio2's is often due to shunt. 

If/when spo2 is at a safe level, apply an nc @15 for ApOx. Position the patient, ramping as required.

As for intubation im not sure of the best approach, but you do need first pass success in these obese pts.

One could use etomidate or even ketamine (can we get some vitals to help select meds?). Ketamine will preserve whatever little airway reflexes the patient has and they will keep breathing. 

One suggestion would be to attempt placement of a king/lma after ONE attempt at ETI. 
If this SGA can be successfully placed, then either ventilate through that or use a bougie to exchange the SGA for an et tube once the patient has been reoxygenated. (this can be done on lma, not sure about king).


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## Handsome Robb (Sep 25, 2013)

I have another thought. While she isn't awake she's still spontaneously breathing, no? Is a NTI reasonable. I'm guessing no with the atypical anatomy but I still argue that something needs to be done.

Also, av8 brings up a HUGE point. I think a bougie and video laryngoscopy or fiber optics would be a good solution for an airway attempt. I also agree with a bougie exchange which I believe av8 mentioned as well. If you can get the king seated well enough and get we bougie in that's a definite possibility with laryngoscopy assistance.


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## Carlos Danger (Sep 25, 2013)

In the real world, the best option is probably VL done with ketamine or dexmedetomidine and aerosolized lidocaine, and a bougie close at hand. Positioning is KEY with very large patients. If that doesn't work, then you can hopefully use CPAP (if needed) to bring their sats back up maintain until you figure out a retrograde or fiberoptic approach. Anything you do is very risky in a patient this large, though, especially when they are already sick and therefore working on what little reserve they have. You'd really have to be prepared for rapid decompensation and be prepared to cric quickly (assuming you can locate the CTM, of course).  



paradoxicalmotion said:


> Halothane, quick question about using fiberoptics - The only times I've seen it performed have been in very busy, metro ED's and it was the EM residents performing it, rather than anesthesia. I myself don't know very much about it.



You don't see these done much in the ED in general, because it isn't really an emergency procedure. 

When it is, I've never seen or heard of it being done by anyone other than anesthesia, ENT, or pulmonology. In the ED it is most commonly anesthesia, IME, but I'm sure there are places where it is different. I don't know if it is something that most EM residents are trained in.  

A big part of an awake fiberoptic intubation isn't just using the fiberoptic scope to place the tube; it's the anesthesia that goes along with it. The patient needs to stay breathing and cooperative, yet be able accept an ET tube. Or they need their airway reflexes blocked with local nerve blocks. So for that reason probably more than any other, these generally end up being anesthesia's thing.



paradoxicalmotion said:


> Is this a procedure I can expect a rural ER physician to be trained in, and beyond that will they even have the equipment necessary?



Most likely not. I'm sure there are some out there somewhere who are, but they'd probably be a small minority.

It's important to keep in mind that it's a relatively small percentage of patients in whom fiberoptic intubation is indicated. Again, it's not really an emergency procedure, though it could be if the operator is really good at it.


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## paradoxicalmotion (Sep 25, 2013)

At one point during his laryngosocopy attempts I did suggest ketamine, to which he replied that he didn't believe they have it. I offered ketamine out of my narc pouch and he refused, stating the etomidate was enough. 

As far as positioning goes, while he was off dealing with another patient I was directing set up for everything, and with the help of a second crew, the x-ray tech, and the lab tech, we were able to ramp up the patient so the ear was in line with the sternum.


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