you don't even know what power means. once again, in another thread, i'm afraid i will have to ask you politely to just stop talking lest you look like a bigger dummy.i'm just a dumb D.O. though. do whatever you want, Dr. M.D.
Cocaine
- Thread starter Noyac
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you don't even know what power means. once again, in another thread, i'm afraid i will have to ask you politely to just stop talking lest you look like a bigger dummy.i'm just a dumb D.O. though. do whatever you want, Dr. M.D.
Originally Posted by Surfer
that study only had 40 patients in each group. not nearly enough power.
I was under the impression that
Power = the probability that a study will find a statistically significant difference when one truly exists.
AND
Power directly relates to the number of subjects. And so the way to increase the power of a study is to increase the number of subjects recruited for a study.
The authors themselves admit that the study has low power (although they only extend this claim to the most extreme adverse event):
I expect they also had p-values >0.05 and wide Confidence Intervals.
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Power = n = ((t-tab @DF and alpha/2) +(t-tab @ DF and (1 - beta)) + (s^2/ delta)
As EC said, power is the probability of detect a true positive in the face of a true positive being present. Hence power is equal to 1 - beta (beta = the chance you will commit a type two error, which is to say you will accept the null hypothesis when you should reject it.).
You can manipulate this formula a number of way, general a priori studies (using an estimate of variance, desired alpha, beta and delta (where delta = smallest detectable difference between groups)) give an estimate of the necessary n. Often though, preliminary experiments turn out to give a different variance than the rest of the studies, so n can be adjusted on the fly.
IIRC. - Can't emphasize this enough, I had a few cursory lectures on this during my ANOVA course and I've done a smidge of reading, but not enough to be an expert by any chance. I hope I haven't confused anyone or posted inaccurate info. If I have, please feel free to point it out to me.
Usually, post hocs power determinations are done to see if you could even detect a given difference amongst groups or what the true power is in the fact of the detected difference. The answer to improving both is increasing n. That said, n = 40 seems small, but we've all got to start somewhere.
As EC said, power is the probability of detect a true positive in the face of a true positive being present. Hence power is equal to 1 - beta (beta = the chance you will commit a type two error, which is to say you will accept the null hypothesis when you should reject it.).
You can manipulate this formula a number of way, general a priori studies (using an estimate of variance, desired alpha, beta and delta (where delta = smallest detectable difference between groups)) give an estimate of the necessary n. Often though, preliminary experiments turn out to give a different variance than the rest of the studies, so n can be adjusted on the fly.
IIRC. - Can't emphasize this enough, I had a few cursory lectures on this during my ANOVA course and I've done a smidge of reading, but not enough to be an expert by any chance. I hope I haven't confused anyone or posted inaccurate info. If I have, please feel free to point it out to me.
Usually, post hocs power determinations are done to see if you could even detect a given difference amongst groups or what the true power is in the fact of the detected difference. The answer to improving both is increasing n. That said, n = 40 seems small, but we've all got to start somewhere.
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Here's hypothetically what may happen if this case fell my way.
Medicare/medicaid--case cancelled by me 100%
fee for service/private ins--if surgeon doesn't cancel I would make sure I get exact time of last coke dose and depending on that I explain risks to pt. If the pt is without a cardiac history I proceed.
We do gamble in this field. But the payoff needs to be worth the risk😉
Medicare/medicaid--case cancelled by me 100%
fee for service/private ins--if surgeon doesn't cancel I would make sure I get exact time of last coke dose and depending on that I explain risks to pt. If the pt is without a cardiac history I proceed.
We do gamble in this field. But the payoff needs to be worth the risk😉
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Uh ok. go take a statistics course and get back to me. In the meantime, if you think a n=40 proves positive utox for cocaine is safe for elective surgery then by all means, go ahead. like i have said repeatedly, there is no reason to do this case. no surgeon will want do it anyway. and in a patient who is most likely medicare/medicaid, why bother? risk/benefit. i'm not going to ask him "when did you last use?" either. i have a positive utox. if i was into asking the patient, i'd have asked, and not spent the money on a lab test. cancel. move on.
i'm just a dumb D.O. though. do whatever you want, Dr. M.D.
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So you treat pts differently based on their insurance?
I've followed the thread.
Initially I said to myself cancel....but then remembered, even before Noy subsequently posted, how cocaine is used in some ENT procedures,
WHICH MADE ME GO HMMMMMMMMMM....
I remained undecided.
Until now.
I'd cancel the case.
I know what the studies say. I'm also in the class of anesthesiologists thats decided to push cases forward when the fine line exists.
Not this one.
Dudes, the patient has a drug addiction to COCAINE.
People that do cocaine do not, stereotypically, imbibe casually.
This isnt a Friday Nite Out With The Boys
situation.
And we wanna put the dude to sleep for an invasive procedure thats gonna require him to comply with post operative directions so his wounds will get better?
First thing this dudes gonna do post op, stereotypically, is a
BIG FAT LINE.
And thats all I got right now. Stereotypes. I don't know this dude. What I'm gonna do is in the best interest of him, from my physician perspective.
Too much potential predictable, deleterious outcome for
1)The patient
2)The surgeon
3)Me
This is an elective case.
I don't routinely cancel cases.
I'm cancelling this one.
Initially I said to myself cancel....but then remembered, even before Noy subsequently posted, how cocaine is used in some ENT procedures,
WHICH MADE ME GO HMMMMMMMMMM....
I remained undecided.
Until now.
I'd cancel the case.
I know what the studies say. I'm also in the class of anesthesiologists thats decided to push cases forward when the fine line exists.
Not this one.
Dudes, the patient has a drug addiction to COCAINE.
People that do cocaine do not, stereotypically, imbibe casually.
This isnt a Friday Nite Out With The Boys
situation.
And we wanna put the dude to sleep for an invasive procedure thats gonna require him to comply with post operative directions so his wounds will get better?
First thing this dudes gonna do post op, stereotypically, is a
BIG FAT LINE.
And thats all I got right now. Stereotypes. I don't know this dude. What I'm gonna do is in the best interest of him, from my physician perspective.
Too much potential predictable, deleterious outcome for
1)The patient
2)The surgeon
3)Me
This is an elective case.
I don't routinely cancel cases.
I'm cancelling this one.
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I would like to contribute BUT this is a public thread.
Noy- I think your question is a trap.....
I am with Jet, Surfer...
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Cancel
And I'm not into cancelling cases either, but someone had enough suspicion to check his utox (which suggests that he's probably shady), and now he has a documented positive utox. This is a totally elective case. Even if the rarest of the rare complication associated with cocaine abuse occurred in this guy 1- you do not have the resources at your ASC to take care of him appropriately and 2- you'll be paying for his nightly eightballs for the rest of his life after his lawyer get through with you. Yes, we probably do these cases all the time, but today, with this patient, it has been documented. Do it another day.
And I'm not into cancelling cases either, but someone had enough suspicion to check his utox (which suggests that he's probably shady), and now he has a documented positive utox. This is a totally elective case. Even if the rarest of the rare complication associated with cocaine abuse occurred in this guy 1- you do not have the resources at your ASC to take care of him appropriately and 2- you'll be paying for his nightly eightballs for the rest of his life after his lawyer get through with you. Yes, we probably do these cases all the time, but today, with this patient, it has been documented. Do it another day.
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I would rather treat this hernia electively now than deal with it when the patient comes with an incarcerated hernia, vomiting, dehydrated and acutely intoxicated.
So, I would just do the case now.
The only reason we are even having this discussion is because some one ordered an unnecessary urine Tox screen. Normally this patient would have gone to the OR without any hesitation which happens to all the drug addicts that never tell us about their addiction.
The moral values of the patient and his character should not be a factor in our decision.
As for the concern about liability you can say that there is no literature showing that surgery is contraindicated on patients with positive cocaine in the urine, so since the patient is not showing clinical signs of acute cocaine intoxication you are not violating a standard of care if you proceed with surgery.
So, I would just do the case now.
The only reason we are even having this discussion is because some one ordered an unnecessary urine Tox screen. Normally this patient would have gone to the OR without any hesitation which happens to all the drug addicts that never tell us about their addiction.
The moral values of the patient and his character should not be a factor in our decision.
As for the concern about liability you can say that there is no literature showing that surgery is contraindicated on patients with positive cocaine in the urine, so since the patient is not showing clinical signs of acute cocaine intoxication you are not violating a standard of care if you proceed with surgery.
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Living in Baltimore, treating an addict is routine and vast majority admit to use. We don't get tox screens unless the patient appears acutely intoxicated. It's a no brainer that acute ingestion would get delayed. Doing screens on all addicts would probably cut our volume by 20%.
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I think that's a bit too concrete there: you easily see vasospasm in a cath lab (non-sustained) without seeing ST changes. But, sure, sustained vasospasm can indeed lead to ST changes....
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Playa, playa...hehehe
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Not every spasm causes ST changes but if you see ST elevation especially in more than one location (lateral and inferior for example),
in a patient that fits the profile you should think spasm and treat accordingly.
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Fair enough
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For the record, I'd do this case if he is not acutely high. I'm sure most of you knew this already.
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I concur...
If every positive cocaine utox got canceled, then I could be sitting around a whole lot more...
just out of curiosity-> do you guys cancel for other drugs? heroin, PCP, MJ?
drccw
this is too big of a generalization. a signficant portion of cocaine is used by people in a casual binge fashion on the weekends. it is ABSOLUTELY a friday night drug. (think wealthy, young, work hard, play hard wall street types, lawyers, etc.) this has been true since the 80s.
NOT crack.
cocaine.
however, the subtle hint Noy gave us (which surfer and others correctly picked up on, and that i initially missed/minimized) is that this guy had a utox sent. why was that sent? what information about this guy prompted the surgeon to send this lab test?
perhaps the surgeon knows something about the guy that we don't. perhaps this guy IS tyrone biggums.
in that case, all of the issues we know about acute cocaine intoxication and the subsequent risk of anesthesia may apply, and we should think long and hard before putting this dude to sleep.
however, i still maintain that it DOES matter what the patient looks like, and what his history is. although there may be some lab values that would lead me to cancel a case just based on a number, this is not one of them.
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Had a case this past weekend with a similar dilemma. Pt was early 40s, had head of femur fx, utox positive for heroin and THC. Pt endorsed using heroin on a regular basis. Healthy pt otherwise. My plan, pent, sux tube and 10mg of morphine. Case finished in 1.5 hrs. No issues. I know it was not cocaine but point is that a positive utox would not deter me from putting anyone to sleep unless other concerning issues were present.
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Counterpoint is that a femur fracture is not an elective case. Could be delayed for a short period but not the same as a hernia repair. Either way, as long as the patient isn't acutely high or drunk a positive tox screen is not a contraindication to being operated on (and should be the surgeon's call).
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Interesting thing happened to me today: patient under GA for removal of a prolactinoma (trans-sphenoidal) starting BP 110/70 HR 70 no history of HTN
Surgeon puts cocaine in the nostrils surgery hasn't started yet etDES is around 4.5 i look up at the monitor and the BP is 200/110 HR 90 😱
I could find no other explanation than the cocaine how would you treat this?
Surgeon puts cocaine in the nostrils surgery hasn't started yet etDES is around 4.5 i look up at the monitor and the BP is 200/110 HR 90 😱
I could find no other explanation than the cocaine how would you treat this?
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Short acting drugs that aren't beta blockers - NTG or more gas are what I'd reach for first. Look at the ECG, etCO2/vent. Don't let the surgeon start until you've figured it out.
Light anesthesia is also a possibility even though they haven't really started the surgery yet. 3/4 MAC of gas leaves some room for a response to DL and the ETT. Was she in pins or just a headrest?
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Pain doc, non-Anes trained. So grain of salt.
How do you consent this guy?
I think things will likely go smoothly and it's an easy case and you guys just deal with the additional hemodynamic issues if they arise.
But when the poop hits the fan.......
1. UDS + cocaine
2. Who did an MMSE or documented mental status on the chart and that he was of sound mind and body and was able to give an adequate informed consent? If you can prove he was not intoxicated by cocaine and add the added risks to the informed consent with the addition of cocaine, that might help.
3. When the douche dies from an MI, or strokes out, or gets an infection 2 months later from unrelated IVDA: and the lawsuit arises..... "so you knew my client's brother was high on cocaine and you insisted on performing an elective surgery in an ASC, leading to his MI and subsequent death".
Not like it would ever happen, but then you'd be biting the pillow. Cancel for informed consent, I'm sure medically you've all seen worse.
How do you consent this guy?
I think things will likely go smoothly and it's an easy case and you guys just deal with the additional hemodynamic issues if they arise.
But when the poop hits the fan.......
1. UDS + cocaine
2. Who did an MMSE or documented mental status on the chart and that he was of sound mind and body and was able to give an adequate informed consent? If you can prove he was not intoxicated by cocaine and add the added risks to the informed consent with the addition of cocaine, that might help.
3. When the douche dies from an MI, or strokes out, or gets an infection 2 months later from unrelated IVDA: and the lawsuit arises..... "so you knew my client's brother was high on cocaine and you insisted on performing an elective surgery in an ASC, leading to his MI and subsequent death".
Not like it would ever happen, but then you'd be biting the pillow. Cancel for informed consent, I'm sure medically you've all seen worse.
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Cocaine high only lasts about 60 minutes. Do you think he did the cocaine on the way to the ASC?
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Based on someone suspicious enough to order a UDS, I'm sure a jury might.
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Cancel the case...
One of my attendings, who is a big name in anesthesia, expert witness type told us a story recently.
Young guy, elective case, anesthesiologist unaware of social history. Patient arrests on induction, they code him for a while and he comes back. Patient sues everybody because he now has trouble concentrating.
I can't remember the exact details, but long story short, it was overlooked that the patient used cocaine in the previous few days. Therefore, recent cocaine use in an elective case = trouble.
One of my attendings, who is a big name in anesthesia, expert witness type told us a story recently.
Young guy, elective case, anesthesiologist unaware of social history. Patient arrests on induction, they code him for a while and he comes back. Patient sues everybody because he now has trouble concentrating.
I can't remember the exact details, but long story short, it was overlooked that the patient used cocaine in the previous few days. Therefore, recent cocaine use in an elective case = trouble.
