King airway in obese patients...

P

paradoxicalmotion

Forum Probie
Messages
22
Reaction score
0
Points
1
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. :-)
 
Last edited by a moderator:
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.
 
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.
 
Last edited by a moderator:
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???
 
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
Click to expand...

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.
 
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.
Click to expand...

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.
 
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.
Click to expand...

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.
 
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.
Click to expand...

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

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.
 
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.
Click to expand...

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.
 
What was the unconsciousness due to? Blood gas? Respiratory effort?
 
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.
 
Did she maintain adequate oxygenation? Was ventilation monitored with ETCO2?
 
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.
 
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?
 
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?
 
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).
 
You must log in or register to reply here.
Back
Top