Oldsalt

To be polite - that is inaccurate...identifying conditions or states based on their presentation is something that a good educated clinician does all the time....you have to make differential diagnosis all the time to accordance with surgical conditions For example, In aggressive trauma resuc. or vascular cases - Using TEG how do you differentiate between the cause of delayed clot formation between anticoagulation or a true factor deficiency? or if the 25% rise in INR related to the blood loss or the 30ml/kg hespan that was given? or... Is the increase in BE related to volume issues or some other anion gap issue? or when consumptive coags. are refractory what is the next option? These are all basic and rhetorical questions - ...we do advance diagnosis in the process of everyday procedures...day in and day out.. OS

This question cannot be answered in this type of forum for the basic fact of origin of differing definitions. AANA's argument is based on the historic origins in the US of anesthesia providers, its rural provider percentages, and that anesthesia does not heal per se or treat an existing disease (this does not include pain patients/clinics - where anesthetist are rarely found) - it deals with management of existing states and returning the patient to the condition which they were received in. The ASA point is that anesthesia is a field of critical care and pain medicine, which does include treating existing pathologic states in addition to the end of the above sentence. But both will agree (grudgingly) that in appearance and function (& outcomes) - one private practice CRNA compared to a MDA doing a lap chole - is the same...so ...there is and there isnt a difference in function or.... as you asked does it cross the line. No I am not going to discuss the ACT. Nor will I argue the outcome studies The lines are muddied and will continue to be so- matters who you ask....the ASA has long pointed out that in addition to the above the are obvious differences in education which is expressed in level of diagnosis and treatment to augment their practice....CRNAs will tell you that the training in pure anesthesia sciences are equal. Diagnosis and treatment experience be damned - I can say that ICU experience is a varied substitution for ones ability for differential diagnosis - that CRNAs can obtain this skill but with a great degree of effort and study. So you decide..you cannot ask a CRNA or a MDA this question - we are too wired to answer in a specific fashion... thanks

I'm in agreement...I too would highly recommend to shadow both an anesthetists and anesthesiologist. Ask them point blank your concerns and questions. Then balance out the pros and cons against one path vs the other and make your choice. Do not let the comments of other determine your direction- the best choices are often those we make ourselves with good self reflection (and maybe a drink or 2). I personally see benefits to both ----so.... I also offer my Good luck ... OS

Thank you for your comment. No - no perfect formula - no such animal - but again - its foundational knowledge (the depth - no pun here intended) by which critical thinking can be based. Training - is the key - how much "foundation" are we talking about - I have been an involved researcher and educator of both residents and CRNAs - and the concern is that the "intense training" (forget the monetary gains- that is superfluous in this discussion) for many CRNA's just scratches the surface (this coming from very involved discussions with new graduates and delicate discussions with my peers)....... MAC is just not smoke and mirrors - but understanding the nuances of the multiplicity of factors that have shown to have "measurable" impact - ....that is the core of the question.......How and what degree do people take that into account? Do they use tools available to them (ie software in my first post - or if you are overseas - do you use the AGE MAC calculations?) For example....MAC and depth have direct and lasting impact even after the operation - What are your views on the studies by Monk, or Weldon, or Lennmarken? How does that change your view on how you manage your anesthetic? Do me a favor - dissect the above scenario systematically (for it is a very common situation) - I'm just interested the depth of critical thinking out there...no correct answer - but actions are revealing ...yes?

Thanks for your post. Absolutely - In terms of those fundamentals - how do you adjust for age variations, temp, and MAC multiples? Example: Say youre doing a LE Vasc. Case (Fem-Pop - something to that nature) - on a 86 yo, 68KG, - good EF (>50%) cardiopulm checks out - HTN on Betas, Ok METs level >4, using a 50:50 o2/n20 - your ET of ISO is .3 , On Vecur. 1/4TOF, Soft BP w/ high pulse pressure variability (>13%) ranging low 80's systolic (represents of over 50% reduction from resting state), HR in low 90's, temp is 34.8. Gases come back with HB at 9.7, ICA - 3.76 (temp adjusted) Exchange is Ok, BE trending downward, Electrol K 3.1, MG 1.5 - UOP @ .3cc/kg/hr - (creat @ 1.4) , 4 hours now into the case with 3 more to go..... Very common scenario right? 20 ways to Sunday in approaching this - Is this an appropriate level for this patient? - what's the min. MAC - What makes you nervous - or not? How would you personally proceed (skin this cat) - from a fundamental prospective? No right answer - just exchanging knowledge.... thank for your attention OS

Thanks for your question. MAC is defined as minimum alveolar concentration to achieve specific end points (Awake levels, Movement, BAR) - first described by Eger over 40 years ago - it was initially used as a point that defined movement but as more research was done - further applications on the range of various concentrations help identify specific levels in which the clinicans could utilize PIAs. The common method is to used specific published ET % (MAC), which has specific application for an average age of around 40 (n20 104, D - 6, S- 2.05, I - 1.15, E - 1.68, H -0.74- note Enfl and Hal are not commonly used in the US anymore) - Generally used to describe the possibility of movement in a patient - Using the number one as the constant - a MAC of 1 describes about 50% of the patients moving to a surgical stim - Furthermore, Surgical MAC is defined as 1.3 (Hence the above numbers would change increase by the above number X 1.3 - simple yes?) There are other "levels' that can apply to MAC so... if you are shooting for MAC awake - where the constant is .34 - .37 for PIA but .55 for n20...it would be also applied to the above numbers... Ok Hang in there...there is more...Variability applies to many things in medical science - but it is how to adjust for them is the key - hence there has been specific research to this end - starting in 1997...basic log regression calculations - as per my previous posts... GA requires we always keep ET% monitored and appropriate - hence the use of MAC - but folks will decide what MAC numbers to use ..or not to use Dont get me wrong - calculating a specific number will burn you - but understanding how to do it and when it can apply, how to use, and further adjust...- that is the key to understanding what one is doing.. It is not often in the clinical realm we can adjust be calculating at least a "reasonable" adjustment - hence the theoretical..... My questions is how much are people actually doing these days in terms of the recent application of newer theoretical thought to the practical - are they using more recent research or not. In the US we dont have monitors that do this for us - we only have one software for PALM (see previous post) that can do it... That alls - I could go on - but it requires that you attend one of my classes Did that help? Thanks for your post OS

Let me apologize - since my original post was a bit overstated and over the top... The question that I wanted to ask - is how much application of fundamental understanding should we demand of ourselves and our partners? For the rest is superfluous if it doesn't matter - Right? It boils down to the process of the individual's ability to find the "enough" level - as you rightly put.. for example - is the movement voluntary or involuntary (latter being part of the NRM - nociceptive reflex arch or mechanism) - what if your ET% of ISO is at 3% and this happens ? ???hmmm??? Do you then give more? This is rhetorical - yes - but you get the picture... Are our actions based on feelings/generalizations or science or both - hence are we able to quantify and validate our actions? It is the process in how we get to the final action is the core of my question.... How important are the published MAC numbers/calculations in your everyday practice and how do you adjust for age and temp variations? I do thank you for your time and comments. And again apologize to all on this post if I seem more on the attack rather than wanting a discussion. OS

Yes - but it is not those I was referring too - there were 3 other attributes (inference to clinical judgment - yes?). I have met very poor clinicians and very excellent intelligent clinicians - ---the former is the obvious choice...The jeopardy contestant(s) can stay in the classroom... OS

Thanks your your reply. What numbers and research are you basing 50%? If you are using age old MAC numbers - do you know that they apply to an average age of 40 (meta analysis research - but you know that right?) - hence the spread.. Additionally - if you apply your 50% application ....if that is your feeling..... how do you clinically safely quantify depth in your paralyzed patients? The question is actually clear - its not aggression - its frustration at the lack of understanding on some very base fundamental research/science that many either don't know or dismiss out of hand- hence cannot have a clear and concise discussion. The question stands - thanks for your insight .. OS

I neither feel threatened nor upset by your post - but would like to take the time to thank you for it. It has provided a degree of insight that many have found uncomfortable. Many have questioned your intent & truthfulness. I do not. For there is a clear difference. I am not too sure about the intelligence bend on your post - In my mind it is in terms of preparation rather than intelligence. We are not schooled well (or in some cases ....not at all) in the art of differential diagnosis or actual medical management of pathologic states - from diagnostic, treatment, to resolution .....of which helps peri-operatively in management and recognition. Nor is our training in regional blocks (of which I have the training post grad - axill, scalene variations, fem, fa. iliacs, peribulbar, pop, etc..) up to par or even existing....Nor in chronic pain management, - the list goes on....Are many CRNAs really the "same"? No.... New grads, nor many in practice, actually get to do any of this - so when I hear someone in training or in practice say they are "as well trained as MDA" - upon questioning - they are far from it. Doing GA and central axis blocks is such a small component of practice.....Pushing drugs and flipping switches - I dare say...- my 10 year old can do that. But being able to elaborate and extrapolate on a multiplicity of areas and levels - that shows thinking, training, and education. This is not to say that the education is not available - it is - but only if one actively seeks it post graduation. Preparation not intelligence - but thanks for your time and our post...

Seriously, If it were my mother, father, son or daughter - give me the top 1% every time - I want the guy that knows everything, that is cool, calm, collected, and intelligent. I certainly hope that the schools should be very fastidious about who is accepted and who is not. OS

What is the general understanding and use of the information that folks are getting about MAC these days? What I mean is ......what type of education about patient specific adjustments are students being educated on about MAC? i.e. For it has been established that Inhibitory actions on movement with GA occur on multiples planes - vol. mvt loss at lower concentrations and actual response abolishing at the dorsal and ventral root ... hence the supposed role of central control of somatic reflexes under GA is a biasness , and has remained the sine qua non for years. Since the understanding/acceptance of unconsciousness is a central mechanism than surely central motor depression also goes hand in hand. Right? - No....on the contrary, as per Rampil (2003) numerous attempts have been made to find a correlation with LOC and movement - ..none has been reliably identified. But we persist in using these correlates...Why? Furthermore.....we persist in over overpressuring patients - many times to hemodynamic instability, in chasing a specific MAC number. It certainly cannot be in an attempt to gain/maintain unconsciousness .... esp. when amnesia has been repeatedly found to occur at significantly lower concentrations ( Eger - see Mawake studies) and on top of that Mawake is AGE adjusted - in which the most direct and simple log regression calculation being MAC40 AGENT * 10-.00269(age-40) - sorry can't write exponentials here but you know the calc (or should)... So for many elderly - this equates to over anesthetizing - This cal can easily help any clinician to see an approximate level to achieve. But I see daily the misuse of non age adjusted MAC monitors - with ET PIA levels being titrated based on that .... in many case without regard to hemodynamics (again in disregards of the principles of Snow, Guedel, and Woodbridge) - requiring pressor drips to maintain that MAC number. In light of the possible mortality and depth issues (Weldon, Lenmarken, and Monks) this seems ridiculous. If low ET readings are the issue - bispectral analysis can assist in maintaining an appropriate level of amnesia. I am not a fan of BIS - but is does have its uses. The use of AGE specific ET MAC monitors are in use in the UK but in the none are in use in the US and there is only one software that will actually calculate various Age adjusted MAC multiples (I think at http://www.gasshead.com or something like that). Strange for these concepts have been around for several years but still remain "fringe" to many CRNAs In speaking with new grads and older practitioners - I have yet to find one that can speak in depth about agents that are used daily - at least locally- My posting is to see if this is actually the case in other institutions and what students are being educated on. My concern is simple....... These are not esoteric concepts... if CRNAs are to call themselves experts -should they not be incredibly well versed on the most basic and commonly used agents at their disposal? Hence my question.....So what exactly is being taught at the master level these days?

.... The possession of knowledge does not kill the sense of wonder and mystery. There is always more mystery.....Anais Nin Oh most certain - that there are no absolutes (other than the proverbial two) but my emphasis is on broad foundational knowledge tempered with clinical application. Yes - one cant avoid the uncertainties when Murphy raises his head - but one can certainly mitigate the shinnanagins that take place. I can read all the sports illustrated swim suit model editions ever written but it wont ever get me a date with one - just maybe be able to pick one out of a crowd:)

Thanks for the response. Let me be the devils advocate.... I agree on some levels - but the argument was similar when anaesthetists were practicing at diploma levels when the transition to Masters was proposed..do you remember that? ...the other thing is this.... whereas I have found a sage and undeniable truth in practice ..... "once bitten...twice shy" ..... in which one or a few cases determine future action - usually due to poor outcomes and being completely at wits end - where one is reactive rather than proactive. I have found that merely functioning at a technical level is not enough when practicing privately. And that is a farce to imply otherwise. An old partner of mine said this most directly, in an all CRNA practice, ...... "It's not the anesthesia that is difficult, but the medicine" Administering the anesthesia is highly technical but - in order to get to that point of deciding "it is safe to proceed or should I not" can be daunting esp if these preoperative issues directly lead to intra-operative events. For example, new graduates I have met can do an enormous number of varying cases - but are severely lacking in areas that I have mentioned in my above post. It is not the large number of mind numbing and unchallenging cases that define us (they will establish routine/complacency- if anything -for sure) - but rather those cases that completely taken us by surprise, are challenging, have painted us in a corner, where tunnel vision has set in and we are at wits end - for some ...your .5% is more common than not ...and is also the base of morbidity and mortality numbers the ASA love to quote when speaking about anaesthetist (yes another mud fling) Take away point: Don't misread this - I am enormously proud of my peers - I just think d/t generalized and accepted constraints we are limited in the quality and amount of training. The ASA wants this difference - for that is what separates them from the rest of us "technicians" ....Do I support a PHd??? Heavens - no - But what do I support is a more and enriching education with less constraints on us...(Note to self - add this to Christmas list for next year)

A Colleague and long friend of mine is on the task force researching the feasibility of all CRNA's programs to require a doctorate degree for entrance to CRNA practice. Though I am all for being well educated, I must pause to think on the rationale of this route. First of all, I know that there are limitations placed on CRNA's. From the public view of who provides care (oh so your an anesthesiologist?) to the incredible skill variability of the clinicians I know (most can provide a decent general anesthetic and some degrees of regional (central axis) - but are severely limited on peripheral nerve blocks and chronic pain management, to myopic understanding of some of the basic tasks of the ability to process varying differential diagnosis of cardiopulmonary issues (ie. be able to identify / substantiate rational for cancellation and verbalize the importance/interpretation and clinical relevance of required test(s) for risk stratification)...well I can go on - but most experienced CRNAs know what I am talking about....You dont leave school with these very critical and important skills - only maybe the ability to quote Morgan, Miller, or Barash...... Almost the majority of these experiences have come post graduation for myself .... at the expense of learning on the job & at the potential detriment of my patients ( the old adage "I dont know what I dont know - so damn the torpedoes and full speed ahead" - please pass me some clean scrub bottoms also). Only a constant recognition that learning never stops has kept me in the loop. So yes...by all means.... Doctorate all the way - if this helps to bring all clinicians to a standard & elevated level of practice in these aforementioned areas ( list not all inclusive) ....but - that brings me to the core question...... If this does become policy..CRNA PHD.( I am not sure about the time-line to implementation) ..would most people decide to go the MDA route? I know that I would have thought long and hard at that crossroad... AND....is this an attempt to assuage and lessen the gap that separates CRNAs from MDs? (Insert picture of sharks at a feeding frenzy here) Let the mud fly.... Oldsalt