How to have smooth wake-ups?

[DrZzZz]

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I notice a trend that people(trainees and midlevels) forego gas (all gases) especially nitrous for TIVA protocols .

Please, educate us on what TIVA stands for? You sound like some of my CRNAs. If I ask for a TIVA, I want a TIVA, not a propofol infusion with gas.

 

[OptionOffense]

No gas, no awareness if you know what you are doing.

I hope you are right!

 

[deleted875186]

Having a case of awareness is devastating to all those involved. I notice a trend that people(trainees and midlevels) forego gas (all gases) especially nitrous for TIVA protocols . I have also seen protocols that call for "no gases" in the name of ERAS. I have also witnessed us foregoing the use of gases to facilitate neuromonitoring. This is short-sighted especially how devastating a case of awareness is and how easy it is to prevent with a little bit of nitrous and or volatile agent . Part of me thinks there is a conspiracy by the precedex sales force to demonize nitrous and the volatile agents in favor of precedex infusions. Not to mention the climate freaks who say if I turn on a bit of desflurane I am the ****in' devil. Interesting times. It is only a matter of time where we see a well covered case of awareness under anesthesia amongst the many.

Desflurane and nitrous are not needed, sevo alone achieves the same effect and is more environmentally friendly and cheaper.

Not sure what precedex has to do with anything. I argued nitrous is not needed because sevo and or prop achieve the same effect, with less side effects, and less environmental impact.

 

[OptionOffense]

Please, educate us on what TIVA stands for? You sound like some of my CRNAs. If I ask for a TIVA, I want a TIVA, not a propofol infusion with gas.

huh?

 

[OptionOffense]

Desflurane and nitrous are not needed, sevo alone achieves the same effect and is more environmentally friendly and cheaper.

Not sure what precedex has to do with anything. I argued nitrous is not needed because sevo and or prop achieve the same effect, with less side effects, and less environmental impact.

Desflurane is better than sevo for maintenence. I am not a climate freak so if it is on my dial I am turning it on over sevo.
I mentioned precedex because the demonization of the gases coincided with the increase use of precedex

 

[DrZzZz]

huh?

I am not an opponent of nitrous like others here. But you said "trainees and midlevels forego all gases for TIVA" as a slight. TIVA stands for TOTAL IV anesthetic, in case you forgot. If you add in nitrous or volatile, it is not a TIVA by definition. If I ask a crna to run TIVA on a patient for whatever reason I deem it necessary, that means I don't want any gas (nitrous or volatile).

 

[DocMcCoy]

I think it is a mistake to throw nitrous oxide by the wayside. Again, it contributes significantly to MAC, and the risk of nausea is there but not significantly higher than not using nitrous in the enigma2 trial. You wont make the newspapers because your patient has nausea but you will if she has awareness. Greenhouse mehh

Agree with most of this. Nitrous with antiemetics is almost a wash concerning risk of PONV. While we should be conscientious of the environment, I’m not convinced my 15-20 min of nitrous at the end of a case has more impact than TIVA or extra prop or whatever considering plastics and medical waste. Once I see that data I’ll adjust accordingly. And I’m pretty sure nobody is going to drop a lawsuit because I was trying to save the planet.

 

[GassYous]

Agree with most of this. Nitrous with antiemetics is almost a wash concerning risk of PONV. While we should be conscientious of the environment, I’m not convinced my 15-20 min of nitrous at the end of a case has more impact than TIVA or extra prop or whatever considering plastics and medical waste. Once I see that data I’ll adjust accordingly. And I’m pretty sure nobody is going to drop a lawsuit because I was trying to save the planet.

It has been studied and the extra plastic from prop is less waste/environmental effects than gas especially if you are running the typical 2 liters per minute that everyone does for some unknown reason. Interestingly if you're blasting the oxygen you lose a lot of the benefit because it takes a lot of resources to concentrate and transport the tanks.

I don't see how you can avoid being concerned about the climate when we have all these droughts and heat waves. You think inflation is bad now? Imagine what food prices will look like when we have no water for crops and livestock.

 

[DocMcCoy]

It has been studied and the extra plastic from prop is less waste/environmental effects than gas especially if you are running the typical 2 liters per minute that everyone does for some unknown reason. Interestingly if you're blasting the oxygen you lose a lot of the benefit because it takes a lot of resources to concentrate and transport the tanks.

I don't see how you can avoid being concerned about the climate when we have all these droughts and heat waves. You think inflation is bad now? Imagine what food prices will look like when we have no water for crops and livestock.

Didn’t say I wasn’t concerned. Just not sure how much of an issue 10 minutes of nitrous is. There are a lot of ways to reduce our environmental impact.

 

[woopedazz]

The most environmentally friendly anaesthetic has been described recently. Can't remember the paper, but basically it's:

Propofol TIVA (including palstic waste/electricity/etc)
Lowest flow of supplemental O2 into the circuit to maintain FiO2 (as above, to reduce concentrating/transport cost/pollution).
Total fresh gas flow (mainly medical air) at ~5-6L/min to extend the life of the CO2 absorber when compared to low-flow anaesthetics.

I don't actually do the above very frequently, but the data is out there.

 

[2Fast2Des]

Desflurane is better than sevo for maintenence. I am not a climate freak so if it is on my dial I am turning it on over sevo.
I mentioned precedex because the demonization of the gases coincided with the increase use of precedex

Lol wut? Why is Des better than sevo...? Even if you have a long case, it doesn't take much magic to emerge a patient appropriately... There a few infographics and data to show the greenhouse gas effects of 1 Mac hour of each volatile compared to the output of a car for each. Des and Nitrous are by far much more damaging, there's no 2 ways around it, especially when there are simple alternatives

 

[GassYous]

Lol wut? Why is Des better than sevo...? Even if you have a long case, it doesn't take much magic to emerge a patient appropriately... There a few infographics and data to show the greenhouse gas effects of 1 Mac hour of each volatile compared to the output of a car for each. Des and Nitrous are by far much more damaging, there's no 2 ways around it, especially when there are simple alternatives

Des is worse as it is irritating and causes sympathetic activation. Numbers drop really quickly though

 

[OptionOffense]

Des is worse as it is irritating and causes sympathetic activation. Numbers drop really quickly though

It is metabolized by the body the least tho. Sevo the most.

 

[deleted875186]

It is metabolized by the body the least tho. Sevo the most.

So what. Metabolites never been shown to cause injury except for enflurane.

 

[abolt18]

Lol wut? Why is Des better than sevo...? Even if you have a long case, it doesn't take much magic to emerge a patient appropriately... There a few infographics and data to show the greenhouse gas effects of 1 Mac hour of each volatile compared to the output of a car for each. Des and Nitrous are by far much more damaging, there's no 2 ways around it, especially when there are simple alternatives

Is this still true if I'm running my FG flow at 0.2L/min? I'll take my low flow des over your 2L/min sevo every day. No way it has a greater greenhouse effect at those levels.

 

[NVO]

Is this still true if I'm running my FG flow at 0.2L/min? I'll take my low flow des over your 2L/min sevo every day. No way it has a greater greenhouse effect at those levels.

Isn't des something like >20x worse than Sevo in regards to greenhouse effect? so with those flows Sevo would still be better right. And you are also consuming more volatile with des regardless of flows since youre giving a higher concentration (sevo being the more potent gas).

 

[deleted875186]

Isn't des something like >20x worse than Sevo in regards to greenhouse effect? so with those flows Sevo would still be better right. And you are also consuming more volatile with des regardless of flows since youre giving a higher concentration (sevo being the more potent gas).

This is correct, under lower FGF des is still worse for the environment. Nitrous doesn’t degrade in the atmosphere for an incredibly long time which is why it’s particularly bad as well. I’ve seen some people do the old half nitrous half des at 2L/min FGF, which is probably the worst environmental anesthetic you could do.

 

[Dantrolene FC]

You must also account for lower solubility of des, the one factor in its favor.

 

[abolt18]

Isn't des something like >20x worse than Sevo in regards to greenhouse effect? so with those flows Sevo would still be better right. And you are also consuming more volatile with des regardless of flows since youre giving a higher concentration (sevo being the more potent gas).

Except that when I'm running flows that low, I theoretically should be running a closed circuit and be blowing zero volatile into the environment. Adding to the circuit only to replace that which has been absorbed/metabolized (I know, it's barely metabolized, but still not zero)?

 

[deleted875186]

Except that when I'm running flows that low, I theoretically should be running a closed circuit and be blowing zero volatile into the environment. Adding to the circuit only to replace that which has been absorbed/metabolized (I know, it's barely metabolized, but still not zero)?

The only thing that matters environmentally is how much liquid sevo versus how much liquid des is used, which depends on FGF, percent dialed in, and duration.

 

[OptionOffense]

Isn't des something like >20x worse than Sevo in regards to greenhouse effect? so with those flows Sevo would still be better right. And you are also consuming more volatile with des regardless of flows since youre giving a higher concentration (sevo being the more potent gas).

are you treating a patient or the environment?

 

[NVO]

are you treating a patient or the environment?

I dont think they're mutually exclusive choices

 

[OptionOffense]

I dont think they're mutually exclusive choices

Why dont you give NO anesthesia, which is best for the environment.

 

[GassYous]

Is this still true if I'm running my FG flow at 0.2L/min? I'll take my low flow des over your 2L/min sevo every day. No way it has a greater greenhouse effect at those levels.

2L/min sevo?

 

[<(^_^)>]

Took a look into this and came away surprised by the data:

Running desflurane at 6% with flows of 2l/min is 134 kg co2 per hour.

Sevo 2.2% at 2l is 2.8 kg co2 per hour.

Iso is 5.2 kg co2 per hour

nitrous is about 30 kg per hour for 50%.

conversely plastic tubing etc is on the order of 4x the weight of plastic as co2 (assuming it’s all combusted as medical waste - no recycling here). So for 134 kg co2 = 33.5 kg plastic tubing/syringes/glide scopes or 74lb…every hour.

A 20ml syringe is 15 grams or 0.015kg, 0.060 kg co2. So per hour of des that’s 558 20 ml syringes. Or per hour of sevo that’s still 46 20 ml syringes worth per hour.


So take home message for me was:

Plastic waste in anesthesia is small potatoes unless you’re already doing TIVA.

Desflurane really is that bad.

Nitrous is probably best used judiciously, but also not that bad if used just at the end of the case.

An old post of mine. Additional point of reference a gallon of gasoline is about 10 kg co2 factoring in processing etc. If you turn on nitrous for last 15 minutes that's not even a gallon of gas. On the flip side if you have nitrous on for 10 hours a day that's ~30 gallons of gas a day, not trivial. Desflurane for 10 hours is 130 gallons of gas a day. Worth not using (to me). Obviously lower flows will lead to lower emissions.

If we had a carbon tax of 100 a ton a nitrous wakeup would cost 70 cents more, and a gallon of gas would be a dollar more...and a ton of coal (currently 100-125) would be ~400 a ton. Most scientists say carbon should cost at least 50 a ton, possibly 100, few say over 200. So at the high end of a carbon tax (200) your nitrous wakeup would cost an extra 1.40 USD...but your des would cost an extra ~26 dollars an hour (at 2L/min that is).

 

[GassYous]

An old post of mine. Additional point of reference a gallon of gasoline is about 10 kg co2 factoring in processing etc. If you turn on nitrous for last 15 minutes that's not even a gallon of gas. On the flip side if you have nitrous on for 10 hours a day that's ~30 gallons of gas a day, not trivial. Desflurane for 10 hours is 130 gallons of gas a day. Worth not using (to me). Obviously lower flows will lead to lower emissions.

If we had a carbon tax of 100 a ton a nitrous wakeup would cost 70 cents more, and a gallon of gas would be a dollar more...and a ton of coal (currently 100-125) would be ~400 a ton. Most scientists say carbon should cost at least 50 a ton, possibly 100, few say over 200. So at the high end of a carbon tax (200) your nitrous wakeup would cost an extra 1.40 USD...but your des would cost an extra ~26 dollars an hour (at 2L/min that is).

Very interesting. I try to keep my flows below half a liter and don't use any extra tubing that I don't need. I use prop gtt from my induction syringe and try to hook it up direct to the line instead of using extra tubing.