Learn from other's mistakes.

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My chairman at Mercy Hospital of Pittsburgh, Ephraim Siker (president of the ASA at the time), started APSF. I remember having some worries about the potential unintended legal consequences of an ever-expanding list of "guidelines".
"An EEG-based monitor of unconsciousness (depth of an anesthesia monitor) is required to reduce the likelihood of awareness whenever total intravenous anesthesia is combined with the administration of neuromuscular blocking agents,” the APSF recommended.
So, in effect, the APSF has established a criterion for lawyers to sue and win any time a patient experiences awareness under TIVA. I don't think that awareness should ever occur with competent anesthesia, but perhaps they are correct in saying this. This is the double-edged sword of organisations like APSF.
 
Ever since BIS rolled out along with their absurd marketing practices and questionable "science", any type of processed EEG monitoring has had a bad rap right off the bat. This 1:1000 incidence of awareness statistic still keeps floating around and it's based off a questionable study many years ago. In an old issue of the ASA Monitor, there was a comment along the lines of "If your incidence of awareness is 1:1000, you probably need to work on your anesthesia skills". At that rate, my practice should be having dozens of occurrences of awareness every year. It simply doesn't, nor has it ever.
 
dannyboy1 said:
Also that the CRNA documented this fun fact in the record. Common sense not so common….
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What else were they supposed to say? Fudge the record? I think in this situation give a whopper dose of versed (although it doesn't cover retrograde amnesia). Then talk to patient afterwards, probe about awareness and hope they don't remember anything.
 
I usually won't run a TIVA unless I have remifentanil available. The potency of remi pretty much ensures adequate amnesia when paired with prop. If someone has PONV they get a block if possible, scop patch, dex, zofran, and possibly prochlorperizine near the end of the case. Although I'm pretty anal about this. Even if an inpatient comes down with a 2 day old IV, ill have the nurses put in a fresh one, or do it myself to attach the TIVA to. Having the infusion connected also helps.
 
DrOwnage said:
Even if an inpatient comes down with a 2 day old IV, ill have the nurses put in a fresh one, or do it myself to attach the TIVA to.
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I support this thought. Whenever there's a question of awareness or of an infiltrated IV causing some other issue, there are concerns about what IV was used. It's never a bad idea to place your own new IV to run essential infusions.
 
coffeebythelake said:
What else were they supposed to say? Fudge the record? I think in this situation give a whopper dose of versed (although it doesn't cover retrograde amnesia). Then talk to patient afterwards, probe about awareness and hope they don't remember anything.
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I’ve always just documented vital signs. Always left the comment section blank. Less is usually more when it comes to anesthesia documentation.
 
Please read posts 10-12

forums.studentdoctor.net

BIS monitors-- evidence and practice

Hi all-- IM/CCM here but I get a lot of good information from your threads. Every place I have worked before by current one, we have used BIS monitoring in our patients that we paralyze and prone for ARDS. Typically we would target BIS of 40 and then paralyze for 24-48 hours. My current place...
forums.studentdoctor.net forums.studentdoctor.net
 
coffeebythelake said:
What else were they supposed to say? Fudge the record? I think in this situation give a whopper dose of versed (although it doesn't cover retrograde amnesia). Then talk to patient afterwards, probe about awareness and hope they don't remember anything.
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I have had Versed several times and NOT once did it give me retrograde amnesia.
 
A human study of the propofol induction dose required to achieve a bispectral index (BIS) <60 in self-reported cannabis users showed that they required significantly higher induction doses of propofol when compared to self-reported cannabis nonusers.59 Another small study showed that administration of Sativex, a synthetic THC and CBD analogue in a 1:1 ratio, resulted in an increase in BIS even when controlling for minimum alveolar concentration of volatile anesthetics.60 It was unclear whether this represented a shallower depth of anesthesia or cannabinoid-induced increase in electroencephalogram (EEG) activity. In addition, most users utilize high-THC, minimal-CBD strains of cannabis, whereas this study utilized strains with an equal THC:CBD ratio, and it is unclear whether the CBD in this study would have a differential effect compared with THC alone. Though chronic cannabis users develop tolerance to the neurocognitive effects of the drug, it is unclear whether cross-tolerance exists between cannabis and anesthetic agents. One human study showed a lack of cross-tolerance of such effects with alcohol in heavy cannabis users.61

Thus, experimental and anecdotal data support the view that cannabis users require higher induction doses of propofol. Less is known about the maintenance phase of anesthesia. Each cannabinoid has differential effects on the body, and there are simply insufficient studies to draw firm conclusions on their individual or summated effects on anesthetic maintenance. Cannabinoid-induced elevations in EEG activity may render BIS a less reliable marker of anesthetic depth of anesthesia in this population. Further studies are needed to determine whether BIS is an effective guide in monitoring depth of anesthesia for this population. Anecdotal data would suggest that, as with induction doses, higher doses of volatile agents are required to achieve adequate maintenance.

There are no specific data regarding intraoperative analgesic use in cannabis users, but recent studies have shown that cannabis users report higher pain scores, have worse sleep, and require more rescue analgesics in the immediate postoperative phase of care.62–64 It is possible that this population may require greater analgesic use in the intraoperative phase, but there are no data to support or refute this view. Nevertheless, the use of a multimodal perioperative analgesic approach utilizing acetaminophen and a nonsteroidal anti-inflammatory drug or a cyclooxygenase-2-specific inhibitor combined with a local or regional analgesia technique, if possible, would be beneficial.65,66

A review of the anesthetic implications of marijuana use - PMC

Marijuana, derived from plants of the genus Cannabis, is the most commonly used illicit drug in the United States. Marijuana is illegal at the federal level and remains a Drug Enforcement Agency Schedule 1 substance. Nevertheless, most states have ...
www.ncbi.nlm.nih.gov www.ncbi.nlm.nih.gov
 
coffeebythelake said:
Are you saying that heavy Marijuana users need significantly more gas anesthetic as well?
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I'm saying that there is at least a greater requirement for adjuncts and if you rely on those to supplement your agent (which we do in a balanced technique) yes, more volatile agent is needed.
 
kidthor said:
I support this thought. Whenever there's a question of awareness or of an infiltrated IV causing some other issue, there are concerns about what IV was used. It's never a bad idea to place your own new IV to run essential infusions.
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Also wise not to divide paralysis and anesthesia into different iv's. Murphy's law will dictate that if one does infiltrate, it won't be the paralysis line.
 
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I rarely run full TIVA. Even in those neuromonitoring cases, I usually use a whiff of sevo…so long as they aren’t complaining about signals. If I am doing a TIVA, I will also almost always use ketamine as an adjunct. Doing TIVA to avoid nausea is dumb, in my opinion. We have tons of meds for nausea now. If I really am worried about nausea, I’ll stick on a scopolamine patch, which is very effective.
 
drmwvr said:
I'm saying that there is at least a greater requirement for adjuncts and if you rely on those to supplement your agent (which we do in a balanced technique) yes, more volatile agent is needed.
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Apsf recommendation is for minimum 0.7 MAC gas to prevent awareness under GA. Don't know of any adjustments made for Marijuana users for the purposes of preventing awareness. Maybe one of you can show me an article.
 
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BLADEMDA said:
www.webmd.com

Substance Abuse: Know the Signs

It’s not just about illegal drugs. Using pain meds, alcohol, and other legal substances the wrong way can also harm your health.
www.webmd.com www.webmd.com


Propofol Requirements Doubled
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Yeah many of the articles about Marijuana use come from GI endoscopy literature and the significantly increased propofol needs. 2x 3x more than usual doses. The fentanyl and versed dosing in the article you quote probably aren't significantly different.

Just the other day we did a TIVA for a heavy Marijuana user ran her at 175-200 mcg/kg/min for most of a 4 hour case. BIS reading 50 to 60. At end of case propofol down to 125 mcg/kg/min and she basically woke up on that dose. We turned off the propofol as we were extubating her. Not sure of you can say the same clinical significance exists with your other anesthetic drugs and Marijuana use.
 
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BLADEMDA said:
Less is known about the maintenance phase of anesthesia. Each cannabinoid has differential effects on the body, and there are simply insufficient studies to draw firm conclusions on their individual or summated effects on anesthetic maintenance. Cannabinoid-induced elevations in EEG activity may render BIS a less reliable marker of anesthetic depth of anesthesia in this population. Further studies are needed to determine whether BIS is an effective guide in monitoring depth of anesthesia for this population. Anecdotal data would suggest that, as with induction doses, higher doses of volatile agents are required to achieve adequate maintenance.
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So... maybe? Clinical significance?
I have not observed this with gas anesthetic
I do 0.7 MAC for Marijuana users just like for most anyone else. Same for red heads who are also described as requiring more anesthetic.
 
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coffeebythelake said:
So... maybe? Clinical significance?
I have not observed this with gas anesthetic
I do 0.7 MAC for Marijuana users just like for most anyone else. Same for red heads who are also described as requiring more anesthetic.
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For me it's far less about recall (tho I have my own anecdote about a heavy dope smoker and that) than it is about movement. Sugammadex aside, paralyzing when you don't have to or profound paralysis when you don't have to, IMO, isn't clean, especially when, as you pointed out, these people wake up crisply when someone else would still be asleep. There's more to a successful anesthetic than 'was there recall?'
 
drmwvr said:
For me it's far less about recall (tho I have my own anecdote about a heavy dope smoker and that) than it is about movement. Sugammadex aside, paralyzing when you don't have to or profound paralysis when you don't have to, IMO, isn't clean, especially when, as you pointed out, these people wake up crisply when someone else would still be asleep. There's more to a successful anesthetic than 'was there recall?'
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With inhaled agents I consider their responses within the realm of normal population variability. So while some people may claim that all anesthesia requirements of Marijuana users is higher, which may or may not be true (even the articles posted by blade say that much), the only situation where I find a significant clinical difference (and hence change my practice routinely) is with heavy Marijuana users and propofol.

Personally I like to keep patients reasonably muscle relaxed until near case end (from 0 to 2 twitches on TOF) because I use less anesthetic to keep them still. That and judicious use of opioids. You call muscle relaxant use not clean, I actually think jt is a more elegant balanced anesthetic.

And yes it really depends on how you define a "successful anesthetic". Lack of awareness under general anesthesia score big points in my mind.
 
coffeebythelake said:
With inhaled agents I consider their responses within the realm of normal population variability. So while some people may claim that all anesthesia requirements of Marijuana users is higher, which may or may not be true (even the articles posted by blade say that much), the only situation where I find a significant clinical difference (and hence change my practice routinely) is with heavy Marijuana users and propofol.

Personally I like to keep patients reasonably muscle relaxed until near case end (from 0 to 2 twitches on TOF) because I use less anesthetic to keep them still. That and judicious use of opioids. You call muscle relaxant use not clean, I actually think jt is a more elegant balanced anesthetic.

And yes it really depends on how you define a "successful anesthetic". Lack of awareness under general anesthesia score big points in my mind.
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So, how do I define a successful anesthetic?

1. No recall
2. Good hemodynamics and vitals (e.g. HR, BP, Sat, etc)
3. Smooth induction, airway placement and wake-up
4. No N/V and minimal pain in PACU

Naturally, number 1 comes first for a good reason but the other 3 do matter.
 
More reason to use volatiles, they are easier, inexpensive, environmentally safe if you do low flows, and super reliable. When prop won’t put someone down, sevo always works. Agree about PONV, lots of meds to prevent it, doesn’t mean I necessarily need to do a TIVA.
 
BLADEMDA said:
So, how do I define a successful anesthetic?

1. No recall
2. Good hemodynamics and vitals (e.g. HR, BP, Sat, etc)
3. Smooth induction, airway placement and wake-up
4. No N/V and minimal pain in PACU

Naturally, number 1 comes first for a good reason but the other 3 do matter.
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5. Patient doesn’t move during surgery. (Can be very important for some procedures.)
 
dipriMAN said:
More reason to use volatiles, they are easier, inexpensive, environmentally safe if you do low flows, and super reliable. When prop won’t put someone down, sevo always works. Agree about PONV, lots of meds to prevent it, doesn’t mean I necessarily need to do a TIVA.
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when people run the mask on high flows it basically negates the environmental benefits of using prop. I try to keep them around 2.
 
dipriMAN said:
More reason to use volatiles, they are easier, inexpensive, environmentally safe if you do low flows, and super reliable. When prop won’t put someone down, sevo always works. Agree about PONV, lots of meds to prevent it, doesn’t mean I necessarily need to do a TIVA.
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Name doesn't check out.
 
coffeebythelake said:
Well thats the same thing..
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no it's not....can't say the number of times that I'm reasonably sure the patient is aware, but I'm doing everything in my power to make certain they don't remember it...working in CT/vascular exclusively, this is not an infrequent concern...they either die on the table, on the ventilator in the ICU or the high school kid wheels them to their daughter-in-laws mini van days or weeks later.
 
drmwvr said:
no it's not....can't say the number of times that I'm reasonably sure the patient is aware, but I'm doing everything in my power to make certain they don't remember it...working in CT/vascular exclusively, this is not an infrequent concern...they either die on the table, on the ventilator in the ICU or the high school kid wheels them to their daughter-in-laws mini van days or weeks later.
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I think we are going down a rabbit hole by trying to knit-pick the terms.
The outcome we are trying to prevent with general anesthesia is intraoperative recall.
We do this by providing a general anesthetic at a dose meant to prevent awareness.
Hence we use terms such as MAC-aware (level at which 50% population aware) and MAC-awake (level at which 50% population awake) , with the former being a lower gas concentration than the latter. in other words a patient can be awake and not be aware. The important point to make is that we are applying population studies which presume a normal distribution of responses, while at the same time interested in the individual outcome. When we provide 0.7 MAC of gas, that is meant to encompass 99.9% (or similar number meant to be multiple standard deviations) of the population so they will not be aware during the procedure. And this is also a concentration where the overwhelmingly vast majority of patients are also unconscious.
 
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intraoperative recall encompasses a range. the ones that make the news are often due to serious errors or omissions in delivering the anesthetic leading to explicit recall where the patient "was wide awake, felt the pain, tried to move but couldn't, remembered conversations". Like the example provided by the OP. Like that case from WashU that made the news not long ago. But at sub-hypnotic sub-amnestic anesthetic levels the patient may have some degree of awareness and recall feelings of unease or hazy fleeting recollections of intraoperative events.
 
linkin06 said:
I wonder how long this went unrecognized. Probably the crna put the tube in and then opened up their bejeweled, oblivious to screaming vitals. Supervising is the worst
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It really is. I'm frequently checking in on charts and the rooms to make sure everything is going smoothly. The worst is if you have crnas that do not call and get in over their heads and you find out by chart checking or walking in in on a situation. Basically making a urgent situation into an emergency.
 
Anybody else feel like this new wave of CRNAs are in love with TIVA? I frankly don't find it worth the hassle, but most CRNAs love it.
 
Ronin786 said:
Anybody else feel like this new wave of CRNAs are in love with TIVA? I frankly don't find it worth the hassle, but most CRNAs love it.
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Nah. Tivas require too much prep work. Set up the pump, put on a bis, etc. They want set and forget. Most crnas i work with including the new ones go for default mid fent prop roc tube sevo. Same reason why they always seem to blast the sevo at 1.2 MAC because they can't even ve bothered to check twitches every 15 to 30 min.
 
Stop this TIVA madness. I rarely run TIVA unless for an MH protocol patient. Remember the zofran shortage??? I run GAS and propofol. Get the GAS off early and have your patients emerge from the propofol not the inhalation agent. You want to know what causes PONV high end tidal agent emergences. Just…. Plain…. Stupid….. To run TIVA. Dont get me started about TIVAS for cancer surgery……
 
Ronin786 said:
Anybody else feel like this new wave of CRNAs are in love with TIVA? I frankly don't find it worth the hassle, but most CRNAs love it.
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Must be a regional thing. People do the stuff they were told to do in training so I bet they came from a program where TIVAs were trendy.

I remember being right out of residency and I did some moonlighting work at this place where one guy did TIVAs for everyone. I met him one day and he asks, all excited, if I knew how to do TIVAs! I think I kind of blinked, and said "know how ... uh, sure" ... and then he went on about how great they are. Kind of weird like TIVAs were some amazing advanced technique that only a few people knew how to do.

coffeebythelake said:
Nah. Tivas require too much prep work. Set up the pump, put on a bis, etc. They want set and forget. Most crnas i work with including the new ones go for default mid fent prop roc tube sevo. Same reason why they always seem to blast the sevo at 1.2 MAC because they can't even ve bothered to check twitches every 15 to 30 min.
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I sometimes get resistance when I tell CRNAs to start a phenylephrine infusion to meet my MAP goals, what with the bolus syringe being right there and all. Never once have I had anyone ask to do a TIVA ... though a few believe in low dose propofol voodoo infusions for antiemetic purposes, run simultaneously with a MAC of gas.
 
I use tiva <5% of my GAs. Probably <2%. Pt with hx of bad PONV? Check. Aside from ponv concerns, I think there are some aspects of tiva that are nicer than gas anesthetic. I think patients wake up a lot smoother on propofol and recovery seems to be faster with less persistent grogginess.
 
Anesthesia resident CA1 here . I have a question based on my experience in OR for last year. , in this scenario , when she wasn’t receiving any propofol her vitals should be reflecting that. Does it mean the CRNA / whoever was in this case was really negligent not paying attention to vitals ?
 
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