Convince me to start using BIS

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leaverus

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Almost never used it in residency and still don't in practice but see everyone else - colleagues and CRNAs - almost universally sticking them on people's foreheads and charting the numbers it spews out; but I either don't see or appreciate how the anesthetic is altered by its application. I'm not aware of any hard evidence for its utility. Does it correlate with depth? Does it "prevent" awareness? Will I get sued if a pt of mine ever has awareness and i didn't use BIS? Is it just a waste of money? I feel like proprietary algorithm = snakeoil...
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It does correlate with depth to help prevent awareness, but I don't think it needs to be used all the time. I see a lot of people reactively put it on for every case, and I guess that's fine if you're only comfortable riding a bike on training wheels.

Here are a few instances where I find the BIS monitor to be particularly helpful:
- Cardiac and trauma cases where there is a real increased risk of awareness
- Elderly or unstable patients where less anesthesia is required
- Very long cases where I usually run propofol and gas (this is mostly just to help with a quick emergence and extubation)
- Almost all TIVA cases in adult patients

Give it a try sometime, you might enjoy it.
 
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The awareness under cardiac anesthesia dogma came from the time when morphine, scopolamine and valium were among the agents of choice, cases lasted routinely many hours longer and use of halogenated agents was spotty. The agents used today, the way in which they are used and the routinely brief duration of the cases make this dogma far less valid than it used to be.
 
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thinkorswim said:
It does correlate with depth to help prevent awareness, but I don't think it needs to be used all the time. I see a lot of people reactively put it on for every case, and I guess that's fine if you're only comfortable riding a bike on training wheels.

Here are a few instances where I find the BIS monitor to be particularly helpful:
- Cardiac and trauma cases where there is a real increased risk of awareness
- Elderly or unstable patients where less anesthesia is required
- Very long cases where I usually run propofol and gas (this is mostly just to help with a quick emergence and extubation)
- Almost all TIVA cases in adult patients

Give it a try sometime, you might enjoy it.
Click to expand...
I don't get how it's going to be useful in trauma. I know my patients are at higher risk of awareness because they're on the edge of being dead. I'm going to use gas if I have room to, not because the BIS tells me.
 
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Here is a comon example: a patient on beta blockers (that would blunt the sympathetic signs of light anesthesia) undergoing surgery where the level of surgical stimulation is constantly changing like abdominal surgery.
The BIS here would be a good tool to help you determine your level of anesthesia, it's not perfect, and it's not the only way but it can certainly be helpful.
 
I find it's useful for TIVAs. It saved my ass once when the IV was partially disconnected when the RN tucked the arms. I found the growing puddle of propofol sooner because of the Bis.

I've gotten in the habit of using it for cardiac cases over the last year as a fellow, because it's part of the culture here. Every once in a while I see it trend up to the 70s and it turns out the perfusionist has the iso down to .5 for some reason, which is fine for the 70 year old but maybe not for the 23 year old IVDU ...
 
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You can watch the raw waveform for burst suppression. I use it more to limit high doses of volatile than ensure adequate volatile. Then again, culture of CRNAs here is to run a bit deeper than I normally do, and asking them to "turn down the volatile" is less wearing on me when I can point at a fancy waveform and say, "make it look like that."

It is like any of our "extra" monitors, useful at times, but not needed for majority of cases.



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leaverus said:
Almost never used it in residency and still don't in practice but see everyone else - colleagues and CRNAs - almost universally sticking them on people's foreheads and charting the numbers it spews out; but I either don't see or appreciate how the anesthetic is altered by its application. I'm not aware of any hard evidence for its utility. Does it correlate with depth? Does it "prevent" awareness? Will I get sued if a pt of mine ever has awareness and i didn't use BIS? Is it just a waste of money? I feel like proprietary algorithm = snakeoil...
Click to expand...

I like it pure TIVA only.
Otherwise...I don't use it. I like these studies
- one of the biggest studies to evaluate BIS, showed no advantage over ET Anesthetic monitoring: NEJM BAG-RECALL STUDY
- one of the coolest studies to evaluate it when only muscle relaxant is given: Response of bispectral index to neuromuscular block in awake volunteers† | BJA: British Journal of Anaesthesia | Oxford Academic
 
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I've never used it and never will.
 
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drmwvr said:
The awareness under cardiac anesthesia dogma came from the time when morphine, scopolamine and valium were among the agents of choice, cases lasted routinely many hours longer and use of halogenated agents was spotty. The agents used today, the way in which they are used and the routinely brief duration of the cases make this dogma far less valid than it used to be.
Click to expand...

It's not at all a dogma of the past. Fast-track cardiac surgery and extubating in the OR these days necessitates less narcotic and benzodiazepine administration, but we still fully paralyze the patient on induction and during bypass. In addition, while placing lines prior to incision, we still routinely run the gas below 0.3 MAC.
 
thinkorswim said:
It does correlate with depth to help prevent awareness, but I don't think it needs to be used all the time. I see a lot of people reactively put it on for every case, and I guess that's fine if you're only comfortable riding a bike on training wheels.

Here are a few instances where I find the BIS monitor to be particularly helpful:
- Cardiac and trauma cases where there is a real increased risk of awareness
- Elderly or unstable patients where less anesthesia is required
- Very long cases where I usually run propofol and gas (this is mostly just to help with a quick emergence and extubation)
- Almost all TIVA cases in adult patients

Give it a try sometime, you might enjoy it.
Click to expand...


this is the only time I BIS patients
 
thinkorswim said:
It's not at all a dogma of the past. Fast-track cardiac surgery and extubating in the OR these days necessitates less narcotic and benzodiazepine administration, but we still fully paralyze the patient on induction and during bypass. In addition, while placing lines prior to incision, we still routinely run the gas below 0.3 MAC.
Click to expand...

This is why during my arterial line placement (especially if there's vague or no history of "social drugs") i give a little versed and see what happens. If they're snoozing after 2 mg then I'm pretty sure the amount of anesthetic I typically use will be enough. If I give 5-10 and they're still talking coherent then I know they'll need a heavy amount plus gas.....this applies to my CV cases
 
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thinkorswim said:
It's not at all a dogma of the past. Fast-track cardiac surgery and extubating in the OR these days necessitates less narcotic and benzodiazepine administration, but we still fully paralyze the patient on induction and during bypass. In addition, while placing lines prior to incision, we still routinely run the gas below 0.3 MAC.
Click to expand...

Well, it's old dogma that isn't valid today and reflects archaic anesthesia and surgical practice. It doesn't die because it is constantly repeated. Elective cardiac cases today, at least in PP, are as short or shorter than involved general surgery cases which receive similar anesthetic equivalent as a garden variety "fast track" cardiac anesthetic. There has been no demonstrable spike in the incidence of awareness/recall since the advent of the fast track paradigm, to the contrary, it has fallen. And fast track doesn't mean being stingy with the anesthetics, either. It means use the agents at our disposal in the context the procedure to the extent of the advantages that they bring. Just like any other case.
 
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I use it if the patient has a history of Intra-Op recall. If patient uses illicit drugs
If patient is on pain medications.

The problem with BIS is that it needs a lot of TLC. I have to press the monitor on the forehead and also put some tape over it so that there is good contact. When I was practicing in northern suburb of Los Angeles every patient and every anesthesiologist was using it. May be CYA anesthesia.

May be it decreases the amount of anesthesia that is needed. I try to titrate the anesthetic gas to 40-50 in healthy and 50-60 in those with compromised.
May be it decreases the incidence of postoperative delirium?

It does not replace our skill or judgement and the BIS becomes artificially high when muscle relaxation is inadequate
 
leaverus said:
Almost never used it in residency and still don't in practice but see everyone else - colleagues and CRNAs - almost universally sticking them on people's foreheads and charting the numbers it spews out; but I either don't see or appreciate how the anesthetic is altered by its application. I'm not aware of any hard evidence for its utility. Does it correlate with depth? Does it "prevent" awareness? Will I get sued if a pt of mine ever has awareness and i didn't use BIS? Is it just a waste of money? I feel like proprietary algorithm = snakeoil...
Click to expand...

Let me attempt to answer your questions:

1. Hard evidence for utility- limited data to none

2. Does it correlate with depth- yes, to some degree especially with BIS readings less than 20; so, if you typically overdose your vapor it may be helpful. In addition, minimizing the use of volatile agents in sick and/or elderly patients is likely the most beneficial use of the BIS device.

3. Does it prevent awareness- yes and no. When using vapor as the main anesthetic agent BIS is inferior to ET Vapor concentration. An ET vapor MAC of 0.7 is superior to a BIS value of 40 in terms of preventing recall. That said for a pure TIVA the BIS device is the best method we have for preventing recall.

4. Lawsuits- BIS is inferior to an ET MAC of 0.7 so no you won't get sued for not using a BIS if you typically run at least 0.7 MAC of volatile agent. For TIVA cases and other cases where you MAC is less than 0.5 MAC of volatile agent I recommend the BIS device.

5. Waste of money- probably the way most people use or don't use the BIS it is a waste of money.

Finally, BIS is not "snake oil" but it has its limitations. I selectively use the BIS for my cases which means i I typically use it 10% of the time.

Examples of cases I use BIS:

1. TIVA with any muscle relaxant

2. Elderly or ASA 4 (limit the volatile agent to the minimum)

3. History of recall ( BIS plus an ET vapor concentration of at least 0.7 or higher)

4. History of Chronic Pain or taking Benzos daily
 
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BLADEMDA said:
Examples of cases I use BIS:

1. TIVA with any muscle relaxant

2. Elderly or ASA 4 (limit the volatile agent to the minimum)

3. History of recall ( BIS plus an ET vapor concentration of at least 0.7 or higher)

4. History of Chronic Pain or taking Benzos daily
Click to expand...

Examples of cases I use BIS:

None
 
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I think the device is flawed and it's use is primarily cya or as an additional monitor used in context understanding its flaws. As a cya I think you'd be held to it if most of your peers use it.

With that said, it's pretty hard to argue that it is completely worthless or shouldn't be used in TIVA cases however.
 
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thinkorswim said:
It's not at all a dogma of the past. Fast-track cardiac surgery and extubating in the OR these days necessitates less narcotic and benzodiazepine administration, but we still fully paralyze the patient on induction and during bypass. In addition, while placing lines prior to incision, we still routinely run the gas below 0.3 MAC.
Click to expand...

Need the cardiac surgeons to buy into the fast track thing. When they want to watch the chest tubes for 3-4 hours every single case it hardly matters. I lost count of how many cases the last year I probably could've extubated in the OR, if only the surgeons were game.


Someday Bis will have a viable competitor. The concept of a processed EEG to gauge anesthetic depth is good but I hate their device (expensive crappy stickers and all), I hate their marketing, and I have little faith that the number means what they say it means most of the time.
 
dhb said:
How do you justify it working in one context and not in another?
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The argument is that it's the best we have in the TIVA scenario. The reality is that it's a random number generator and just because it's the best we have doesn't make it useful. IE: See CVP.
 
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Every time somebody writes BIS, I read BS. ;)
 
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dhb said:
How do you justify it working in one context and not in another?
Click to expand...
Im not sure this really answers the question but we're neally 100% sure that Sevo with the dial on 2 will keep everyone asleep without awareness, therefore, in just about every case a BIS is useless. Whereas propofol at 125 mcg/kg/min may zonk one person but is just a bender at the bar for another, therefore, you have to (theoretically) put a BIS on the head of the TIVA patient to make sure the dose you're using is working.

This is why they're saying BIS is a waste for inhaled anesthetics unless you're dialing the gas down to less that a MAC if the patient is old or CV compromised.

But to back up Consigliere, for the most part, if you run Prop at 150 or more with a narc drip of some sort, ie Remi or Fentanyl, most normal patients won't be aware and if they're drunks or druggies, turned that stuff up to 250 - 300 with some versed.
 
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Please help me clarify this article: Prevention of Intraoperative Awareness with Explicit Recall in an Unselected Surgical Population: A Randomized Comparative Effectiveness Trial . When they say "anesthetic concentration" do they mean end-tidal anesthetic concentration or merely the anesthetic concentration on the dial. Here at my institution we don't have ETAG analyzers but the legend says everyone uses it in the USA. Is that true?

Other articles about this mention end-tidal ETAG especifically. I read the protocol too and it is still not clear what the authors meant.
 
parcus said:
Here at my institution we don't have ETAG analyzers but the legend says everyone uses it in the USA. Is that true?
Click to expand...

Yes, I've had it for every single case I've ever done with volatile.


What country are you in??
 
facted said:
The argument is that it's the best we have in the TIVA scenario. The reality is that it's a random number generator and just because it's the best we have doesn't make it useful. IE: See CVP.
Click to expand...

On a side note, why are so many people doing PURE TIVA ? Doesnt it make you feel better to have 0.4-0.8 of sevo on, to ensure that even if something happens with the IV, you have something on board. Whats the downside of adding a small dose of agent to the TIVA? Id recommend it
 
Hoya11 said:
On a side note, why are so many people doing PURE TIVA ? Doesnt it make you feel better to have 0.4-0.8 of sevo on, to ensure that even if something happens with the IV, you have something on board. Whats the downside of adding a small dose of agent to the TIVA? Id recommend it
Click to expand...

Don't forget to wear a rubber every time. After all, wouldn't it be much safer? What if she's 'infiltrated'? :eek::laugh:
 
Hoya11 said:
On a side note, why are so many people doing PURE TIVA ? Doesnt it make you feel better to have 0.4-0.8 of sevo on, to ensure that even if something happens with the IV, you have something on board. Whats the downside of adding a small dose of agent to the TIVA? Id recommend it
Click to expand...
MH
 
parcus said:
Please help me clarify this article: Prevention of Intraoperative Awareness with Explicit Recall in an Unselected Surgical Population: A Randomized Comparative Effectiveness Trial . When they say "anesthetic concentration" do they mean end-tidal anesthetic concentration or merely the anesthetic concentration on the dial. Here at my institution we don't have ETAG analyzers but the legend says everyone uses it in the USA. Is that true?

Other articles about this mention end-tidal ETAG especifically. I read the protocol too and it is still not clear what the authors meant.
Click to expand...
From the paper:
Operating rooms were randomized every 3 months based on even- or odd-numbered operating rooms to either (1) electronic alerts in the event of median BIS values >60, or (2) electronic alerts for median age-adjusted MAC level of <0.5.
Click to expand...
It's the end-tidal concentration. I haven't seen an electronic record that reads the setting on the dial yet. We can see both inspiratory and expiratory concentrations for all of our gases.
 
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It's utterly useless. Tells you yesterdays news. Medico legally I use it in tiva only
A good dose of roc without any hypnosis drops it to 40
 
Hoya11 said:
On a side note, why are so many people doing PURE TIVA ? Doesnt it make you feel better to have 0.4-0.8 of sevo on, to ensure that even if something happens with the IV, you have something on board. Whats the downside of adding a small dose of agent to the TIVA? Id recommend it
Click to expand...

because then you can't call it TIVA? I've never had anything "happen" to my IV and for nearly every case I've ever done a TIVA on, I've also had at least one other IV anyway.
 
leaverus said:
because then you can't call it TIVA? I've never had anything "happen" to my IV and for nearly every case I've ever done a TIVA on, I've also had at least one other IV anyway.
Click to expand...

Besides anything happening to your IV, running a little gas lets you run less prop, therefore you are changing the stick/pump less, and also a little of 2 agents is better than a lot of 1 agent. multimodal anesthesia
 
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