Inductions on the obese

[soorg]

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Anybody successful in doing slow titrated inductions on the very heavy? Someone told me he slowly titrates in propofol until they're asleep, then puts in an LMA. Does this work, or do you have to slam them with the full dose and get an airway in ASAP and pray they don't go south in the meantime?

 

[SleepIsGood]

Anybody successful in doing slow titrated inductions on the very heavy? Someone told me he slowly titrates in propofol until they're asleep, then puts in an LMA. Does this work, or do you have to slam them with the full dose and get an airway in ASAP and pray they don't go south in the meantime?

This goes for anyone, not just obese. Slowly titrate ALL meds for any case. No reason to slam anything into anyone.

 

[Arch Guillotti]

Anybody successful in doing slow titrated inductions on the very heavy? Someone told me he slowly titrates in propofol until they're asleep, then puts in an LMA. Does this work, or do you have to slam them with the full dose and get an airway in ASAP and pray they don't go south in the meantime?

Usually I do not place LMA's on the very heavy. I do not have a strict cutoff for weight because I also take into consideration the ir habitus and medical comorbidities. I think that careful preparation is the best way to avoid "going south". Good positioning, very good preoxygenation and minimization of premeds. I usually do slam in the induction drugs on these folks (!), sometimes check to see if I can ventilate first before giving muscle relaxant, sometimes just bang the sux/roc in right away after the induction - depends on if I think the are going to be easy/hard to ventilate/intubate.

 

[Bertelman]

This goes for anyone, not just obese. Slowly titrate ALL meds for any case. No reason to slam anything into anyone.

I have about a dozen attendings that would argue otherwise.

Personally, I'm happy squeezing in 150-200 of propofol over 30 seconds. Those that like to slam it in argue that any pain from injection will be less likely to be recalled if they are soon asleep. I'd rather slow the infusion and limit/prevent any pain in the first place, as well as better titrate the infusion.

Of course, my practices will surely change in the future.

 

[coprolalia]

There really aren't many good studies on the effects of obesity on the pharmacokinetics of anesthesia drugs. Likewise, "classic" assessment of airway difficulty is not always helpful.

I tend to push fast on induction agents, and go a little heavy-handed, when inserting an LMA on anyone. Remember, the offset of the effects of these drugs immediately happens by redistribution, and you're not going to paralyze. So, you need to get them deep quickly. You need to get your peak effect in the vessel rich group quickly, and it seems this would be doubly true in an obese patient who is going to have a lot more area to quickly redistribute to.

Prior proper planning is key. Ramp them to get a good sniffing position (I do this with the OR table, and not always blankets... which are hard to remove from underneath an obese patient after induction) and have back-up airway devices available. Any doubts, then go for an awake or just use the Glidescope off the bat and put a tube in. Although, I have used a lot of LMAs (including ProSeals) in obese patients without a problem.

More than one way to skin a cat.

-copro

 

[aredoubleyou]

Anybody successful in doing slow titrated inductions on the very heavy? Someone told me he slowly titrates in propofol until they're asleep, then puts in an LMA. Does this work, or do you have to slam them with the full dose and get an airway in ASAP and pray they don't go south in the meantime?

Probably doesnt make a bit of difference how you do it, important thing is to make conditions for your first attempt optimal (sufficient amount of drug, positioning, pre O2, etc) cause they're gunna desat soon eitherway. You might be more likely to need some phenyl if you slam it, but at the end of the day I highly doubt it matters.

I am also not so sure about obese people not being candidates for LMAs, if they dont have GERD, I'd put one in. As far as the massive 450 + pounders, I dont have much experience.

 

[CambieMD]

I am very conservative with the very obese. I find that an LMA is not the right airway device for everyone. My very obese tend to get an ETT. I had a very obese pt for gastric banding who I performed an awake on.

Most of my airway misadventures have invloved the very obese.

The co-morbidities make the obese a special group. They often have gerd, osa and dm.

Redundant tissue can often make DVL difficult.

The very obese get RA or ETT.

Cambie

 

[Noyac]

Inductions in the obese should be carried out just like in the normal pts. That is, you take everything into account b/4 you proceed. If a difficult intubation is on the radar then do a slow titrated induction (assuming you are not doing an awake FOI). The time from loss of consciousness till awake is shorter. If you are in a crash situation and not so much worried about the airway do a bolus induction. Remember that propofol is dosed by Ideal Body Weight for boluses. Bolus inductions will take longer to recover from.

Cambie, I follow your reasoning but I also wanted to point out that LMA's have been used with much success in the obese population and many will argue that the LMA, when appropriate, can lead to fewer post-op complications in the obese. Pulmonary complications have been identified as the most frequent post-operative complications, which occurred in 29% to 40% of obese patients. Even with the dedicated, experienced anesthesia team, in patients undergoing gastric bypass, the rate of post-operative respiratory complications is 8% in the group of BMI of 43 or less and 14% in the group of BMI of more than 43. The average annual incidence of postoperative complications in the USA is 4%. Interestingly, recent study on anesthesia-related death in labor identified that black mothers were nearly 34 times more likely to suffer an anesthesia-related death than were whites. Eight of the 10 women who died were obese. No deaths linked to failed intubation during induction of general anesthesia. All deaths occurred during emergence, transport or recovery period.

Source: Peri-operative Anesthesia Management of Obese Patients and the Current Practice in USA
Pei-Shan Zhao, MD, PhD.
Dept. of Anesthesia, Brockton Hospital, Brockton, MA, USA

I typically have no problem using an LMA in an obese pt if they fit the criteria. You avoid muscle relaxants and their respiratory dynamics can be maintained. There are reports of less post-op complications in these pts when LMA's are used.

 

[dfk]

There really aren't many good studies on the effects of obesity on the pharmacokinetics of anesthesia drugs. Likewise, "classic" assessment of airway difficulty is not always helpful.

I tend to push fast on induction agents, and go a little heavy-handed, when inserting an LMA on anyone. Remember, the offset of the effects of these drugs immediately happens by redistribution, and you're not going to paralyze. So, you need to get them deep quickly. You need to get your peak effect in the vessel rich group quickly, and it seems this would be doubly true in an obese patient who is going to have a lot more area to quickly redistribute to.

Prior proper planning is key. Ramp them to get a good sniffing position (I do this with the OR table, and not always blankets... which are hard to remove from underneath an obese patient after induction) and have back-up airway devices available. Any doubts, then go for an awake or just use the Glidescope off the bat and put a tube in. Although, I have used a lot of LMAs (including ProSeals) in obese patients without a problem.

More than one way to skin a cat.

-copro

hey copro,
any specific way of doing this without the blankets, etc...? i'm assuming you're just manipulating the table adjustments to get the desired position? and also, i'm assuming you use blankets or the like when using tables that you cannot manipulate to your desire? thanks-

 

[Noyac]

hey copro,
any specific way of doing this without the blankets, etc...? i'm assuming you're just manipulating the table adjustments to get the desired position? and also, i'm assuming you use blankets or the like when using tables that you cannot manipulate to your desire? thanks-

Welcome back.

WE have a firm foam wedge that some of my partners use.

I just put them in rev t-berg as much as I need. This is usually all thats necessary.

 

[Monty Python]

..... Interestingly, recent study on anesthesia-related death in labor identified that black mothers were nearly 34 times more likely to suffer an anesthesia-related death than were whites. Eight of the 10 women who died were obese. No deaths linked to failed intubation during induction of general anesthesia. All deaths occurred during emergence, transport or recovery period.

.

Did the study speculate about the causes of such a wide difference between ethnic groups? Was the incidence rate of black obesity markedly higher than the incidence rate of white obesity in the study groups? Did something subjective skew the results?

 

[Noyac]

Did the study speculate about the causes of such a wide difference between ethnic groups? Was the incidence rate of black obesity markedly higher than the incidence rate of white obesity in the study groups? Did something subjective skew the results?

Yeah, they were treated by crna's. Just kidding really.

I read this study awhile back and there was a good explanation for the differences but I can't recall what it was. I seem to remember the higher rate of poor or lack of prenatal care as a factor. but I'm totally going off recall which isn't as good these days.

If I can find the reason I'll let you know.

 

[Noyac]

Here's the article:

: Myhre JM, Riesner MN, Polley LS, Naughton IN: A series of anesthesia-related maternal deaths in Michigan, 1985–2003. ANESTHESIOLOGY 2007; 106:1096–104


Here's an editorial on it:

http://www.alrf.asso.fr/site/obstetrique/neuf_2007/edito.pdf

 

[dfk]

Welcome back.

WE have a firm foam wedge that some of my partners use.

I just put them in rev t-berg as much as I need. This is usually all thats necessary.

thanks. 😉
i've used a wedge of type at another facility. where i'm at now, well, let's just say it costs money to have those. they do work well. practically put the patient in a great sniffing position of sorts. in my mind, they must be practically inexpensive in comparison to extra laundry.