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0:01
hi future CRNA it's jenny here coming on with a short disclaimer for today's episode i just we got pretty heavy in a pharmacology in today's episode so i wanted to come on here and just make sure everyone's well aware that while i am sharing with you what i know to be accurate it doesn't replace the responsibility of you to confirm accuracy of everything i go over today i also want to let you know that this is based on my own personal experience practicing open heart
0:26
and it doesn't necessarily mean it's going to be your experience and a lot of things that we do sometimes in anesthesia are not necessarily going by the textbook so again i some of this is opinion or preference based practice and so i encourage you to take responsibility for your own practice and to make sure you have a thorough understanding of all of these techniques and drugs and the understanding so that way when you go into your open heart rotation you truly understand why
0:52
you're doing and making these choices not just because you heard it on jenny finnell's podcast
0:58
so i hope with that you guys enjoyed today's episode and let's get into it
1:04
hi future crna welcome back to another episode of CRNA school prep academy's podcast my name is jenny finnell crna and your host today we're going to go over a special
1:15
area that i love which is cardiac pharmacology and so as some of you guys may know who have been around for a little while i do have a background in open-heart anesthesia i love open-heart anesthesia you know so again my passion for this is there and i'm happy to share with you guys some of the knowledge i have gained over the years and simply today i kind of just want to run through some down and dirty cardiac drugs with you guys i'm not going to go into the full
1:44
cardiac or not cardiac but full pharmacology lesson plan for you guys i just simply want this to be an overview so that way if you're getting ready to start your open heart rotation you kind of are familiar with some of the more common drugs that you will use in your rotation and maybe how they work on a pretty basic level so if someone were to ask you they get the gist that you know what you're what you're getting yourself into and that you understand what you're doing
2:12
i think that's kind of key when you start your specialty rotations is you know no you're not going to fly in there as an expert and you shouldn't expect yourself to but you should really have a good base and understanding of the types of drugs you're going to be using the mechanism of action and just maybe some of the key side effects to look out for or potential things that you could come up if you're using those types of drugs and also knowing how to dose them correctly so again
2:39
this is just meant to kind of give you guys a good overview of various cardiac medications also keep in mind that no matter where you do your hearts you're going to see a slightly different technique and so i can speak to what i my experience is but i also know just from my training and talking to cnas who do open heart at other hospitals that every system seems to have their own way and you know some places really routinely use nitro other places do not some places routinely
3:09
um draw up certain drugs while others do not um some places practice opioids sparing techniques even an open heart again so i'm just telling you all this ahead of time because knowing that this may not be the standard based on where you go um but i'll go ahead and jump into what i'm familiar with and share with you guys what i know all right so let's start off with some drugs i tend to when i do my my cases when i did do my cases i would like to organize things in a way that i had
3:38
my my uppers my downers my narcotics you know so i had everything kind of labeled organized i would even go to the extent if i had you know a syringe of neo and ephedrine i make sure i label them differently especially epi so if you have epi neo and ephedrine they're all purple labels you know so especially if something were to happen you need something quickly you have to make that choice what drug you want to use you want to make sure you have those labeled differently
4:05
so that's one of the first pieces of advices or advice i could give you guys
4:10
like for example epi typically was purple with a black line on it but um i would put i'd put one sideways horizontally i'd put one vert like around wrap it around the syringe so i had two purple labels on that syringe of epi and then for you know my neo maybe i i went horizontally with that one maybe for my ephedrine i went around the base uh all the way around with my ephedrine so literally all three purple syringes were labeled slightly differently so i could
4:38
easily pick them out if i were to um grab it in a pinch and this is again just one way to kind of make sure that you're being bit vigilant and safe you always still want to make sure you're reading your labels and checking things before you push anything but for me that was one more double check method that i used to make sure i was grabbing the right drug same thing goes if you have a couple
5:02
different types of narcotics or really anything that has the same color label you would you probably wouldn't be surprised because if you've experienced this you know again we kind of get label fatigue we have all these colors that we're used to and same with when you get medications out of your med drawer you're used to seeing you know the zofran with a green cap or a blue cap and that can change and so you really have to be diligent and aware of when those types of things
5:28
changes but when you have syringes with all these blue labels you could think you're giving fentanyl and you're actually getting dilaudid um you know based on how you have it diluted if they're in the same size syringe and where we did open heart we use sue fentanyl so again just making sure that you're labeling things so you can have a way to kind of double check yourself when you're before you push anything okay because once you push it you can't take it back
5:54
so we're gonna start off with drugs that are considered um i call them downers just because they're they cut they bring your blood pressure down um you know first of which it's very common is nitro a lot of patients will even come to the or who are getting ready to have a cabbage they'll come to the or on nitro at usually just like five mikes um a minute just a really low dose now a nitro bottle comes as 200 mics per ml in a bottle so typically either whether you're going
6:26
to run it as an infusion or whether you're going to actually dilute it you want to make sure if you're going to use it as an iv push that you're diluting this because 200 mics per ml is a lot
6:37
and so typically how i would dilute it is i would take one cc okay and again you'd want to make 20 mics per so you would dilute one cc with nine mls or a total of 10 mls to make 20 mics per so if that doesn't make sense to you what i do my head math that to me is easy is i knock off zeros like to me that's just easiest the easiest way i can simplify math is if i'm diluting something down 10 mls now you have 210 if you were to cross off two zeros now you have 20 and one meaning you
7:12
have 20 mics per one ml and so for me that's the easiest way i can kind of do that kind of math in my head and i've also seen people dilute it down to 40 mics per ml
7:26
i like it at 20 mikes per ml to me it gives me more control of how i actually give it nitro is very quick on and it's relatively short lasting the half-life is two minutes for nitro two to three minutes technically based on you know the circulation time and the patient and that type of thing but you can really burn yourself because think about you know if you really need your blood pressure down but now you have two minutes where if you overdo it now you're hypotensive and
7:56
the last thing you want to do you guys when you're pushing any kinds of vasopressors vasodilators is you don't want the yoyo effect you don't want up and then down up and then down and yes sometimes it happens you do the best you can to avoid that situation but that's not good for the patient and it's also very labor intensive for you and sometimes the more you get into that like up down
8:18
scenario the harder it's going to be to actually fix that and you know it can be very distressing not only obviously clearly for the patient but for yourself and for the whole surgical team involved because again that's just not good you don't want a up and down type of train track vitals you want train track files you want like a a steady line of vitals
8:40
so the key when you're pushing vasoactive drugs is to go slow go just little increments at a time pick one thing at a time don't mix different drugs together like don't give neo and then i'm not saying i don't ever give neo-anne ephedrine because sometimes i do but just be careful you have to know how the patient reacts to those drugs before you do that together don't just initially go for a neon ephedrine because you don't know how they're going
9:06
to react once you can gauge their reaction and trust me all patients react differently to these types of drugs then you can make that judgment call and whether you need to combine them to get the effect you want but initially start small i promise you won't be in trouble if you start small and work your way up you can always give more you cannot take it back once you give it
9:27
um so the next drug i want to bring to your attention that's very at least for me was commonly used in open heart was clevoprax this is also known as clavitipine this is a calcium channel blocker it's also mostly versus nitro and back up to nitro nitro is usually a it's mostly a vasodilator meaning it mostly affects the the venous smooth muscle where the clavicrax is mostly the arterial smooth muscle and so what's good about the club of preps
9:57
versus the nitro is you don't get the venous congestion um you can actually essentially change someone's blood pressure without really affecting their preload which if you guys understand the heart physiology which i'm not going to go into today if someone's already in heart failure um especially with the pump meaning they're they're not they're not pumping blood forward and that's the most common type of heart failure is systolic dysfunction or the pump function then
10:23
you can actually worsen someone's heart failure by increasing their preload significantly so um because think about the blood's not able to go forward so you're just going to more you're just going to pretty much dilate that ventricle even more so you really want to be careful with preload you can actually do more harm than good with it so again nitro can actually affect your preload
10:44
where clevaprex does not so we typically didn't use nitro routinely in our open heart um again some places we'll put it on five mics a minute and let it run pretty much the entire time um other places again if i was like in a tavr or something like that where i would anticipate potentially an acute increase in my blood pressure when i got the valve in place i would have nitro diluted ready
11:06
to push but for the most part in my routine open hearts i rarely ever use nitro rarely ever used it if i picked a drug of choice it would be clevoprex or clovidipine to help lower my blood pressure and again that goes on an infusion pump um i would not recommend pushing that i can't say that people have not but in my own practice it's so quick to titrate that drip that it's pretty easy to not have to draw it up as iv push you can literally start it at one or two milligrams an hour
11:38
and go up to a max of 32 milligrams an hour and again there'd be times where i would jump from two or four milligrams an hour to like eight milligrams an hour and within like 10 seconds my blood pressure was quickly adjusted because it's very quick on it's very very quick off
11:53
it's gonna look white like propofol so a lot of times i would bring my patient over on a little bit of clavoprex and you know the nurse would be like oh my gosh they're still on propofol i'm like no actually it's not propofol it's clever preps it's just they're both it's both made out of that um lipid-based kind of uh it's just a lipid-based medication so it looks white but because of that it's quickly hydrolyzed um by plasma esterases so again it's very quick on
12:22
very quick off uh the life uh half-life is approximately one minute so again within one minute half the drug is completely out of your system so it's a great drug again it can decrease your svr without affecting preload and that's cleverprx
12:37
next one i'm going to point out is nipride now this is another drug along with nitro that i didn't routinely use in my open heart but it is out there and some places will routinely string it up i think they have gotten away from that because of how expensive it is at least that's kind of my two cents on that because it is a very expensive drug
12:58
it's also very very potent you guys very potent so this affects your arterials and your veins
13:05
so it's a vasodilator very potent essentially how it works is it actually produces nitric oxide and nitric oxide in itself as is the dilator okay another thing you have to be in keep in mind with nitride and this usually only plays into patients in icu because it's the longer you're on it the more risk you have with this or at high doses is cyanide toxicity so because of the metabolite um you know again it can produces cyanide and so if you're on it for a
13:35
longer period of time um i believe it's over like 72 hours like a couple like several days um you can actually have the cyanide toxicity or it can be shorter than 72 days if you're on high doses of it and again patients with hepatic and renal impairment can actually have more significant complications from this because they're not able to adequately remove the metabolites from the nitride drip so when you're using nitride if you're using in your open heart again it's usually
14:03
going to be temporary just for the case itself and may or may not go with the patient over to the icu
14:09
um but you start low uh so point i would potentially start i look really low like .25 mics per kilo per minute okay the max is 10 mics per kilo per minute i have never ever seen that get close on a patient i can't even imagine having that kind of a dose on the patient they'd have to have some severe uncontrolled hypertension to be on that kind of a dose
14:31
but again an open heart less is more you always want to go really really low when you're titrating your drips and just always work your way to what you need so again i would start it very low
14:43
um so that kind of covers the three most common drugs that i saw routinely in my open heart to decrease someone's blood pressure quickly the other thing that we i'm just going to throw it out there and again not all places will do this some places will actually probably frown on this so please don't go into your open heart rotation if you're like well jenny fennell told me that this this is what she did um make sure you're always chatting with your attendant attending your crna
15:08
making sure you're coming up with a good game plan on how you like to do things um and also especially if it's like your first day or first week in open heart take just try to be more you should always be observant but really try to pay attention to what you're attending is doing what your cna is doing and really pick up on those cues because that's really going to help guide you into how they like to do things um but i would use gas so typically open heart you put on you put
15:34
them on iso and you let them coast at point six uh end tidal of iso that's uh typically how you would run an open heart case but um and don't get me wrong i did like them there most the time you know and depending on the you have to obviously use your best judgment as a patient how old is the patient are they a young person going through an open heart or versus someone who's in their mid to
15:55
late 80s so as you guys know you know your demand your metabolic demand is going to be different based on your age are also are you cooling the patient versus and having to warm them back up well when you warm up a patient you increase their metabolic need so again you're going to have to adjust your gas accordingly but we use we use an adjunct midazzolam burstsad so again the risk of recall is very low especially if you have 0.6 iso on and you're
16:24
using sue fentanyl and you're using midazolam it's very very low and keep in mind mac awake is 0.3
16:31
so you still have more you still have amnesia on board and if you think about what you're doing in open heart you don't really want to you want to use enough gas to cause amnesia but you want to control their vital signs with other drugs that's why we use vasopressors you know opioids anxiolytics that you know amnestic drugs so again we're kind of combining all these different drugs together to kind of create a perfect little picture for the patient
16:57
because gas can be a big vasodilator which is again why sometimes i used it so if we were in a pinch and i didn't have clevoprax stringed and ready to go i didn't have nitro drawn up and diluted i would use my gas um and now the i want to caution you guys with this because if you you have to be very careful with this this can burn you if you um and don't get me wrong you have to learn the technique but you know remember flows up you know the gas is up flows up flows down
17:25
you're not going to get you're not going to get the gas on as fast so your flows kind of control the speed of which you get the gas on and the gas off meaning you can slam you can get the gas on pretty quickly and then you get the gas off pretty quickly but you have to keep your flows up if you're going to get the gas off quickly so you know i would typically increase my flows increase my gas until i saw somewhat of a change in the blood pressure and then based on how quickly
17:49
they were dropping i would either leave my flows up turn the gas down or if they weren't dropping very quickly i would turn my flows down and turn the gas down but i let them hold on to that gas a little bit longer as they gradually coasted down and i would also be cognizant of it the entire time and be adjusting my flows as needed to either dilute the gas or go back up with the gas and so
18:12
that technique worked beautifully um but again it's it's something that you kind of have to learn how to do i don't suggest you go in there and just try to do it on your first day um and also if you don't see them doing that i also don't suggest you doing that if you see them doing it well then embrace it and try to learn how to use your gas to control the blood pressure because it's definitely
18:31
can come in handy if you're in a pinch okay so let's go ahead and get into some vasopressors okay as well as some inotropes some positive ionotropes so um ionotropy is the contractility of the heart if that is not a term that you're familiar with so a positive inotrope is increasing the contractility of the heart um and then if you have a negative ion trope it does the opposite and so one of the most common drugs you're going to use in open heart are is epi so epi affects
19:05
both alpha and beta receptors and um you know at higher doses it affects more alpha than beta so the beta is where you get the contractility and the alpha is where you get the squeeze where you actually get the um basal contraction so again based on what you're using it for you can actually change the dosing and at lower doses it actually can be a vasodilator and a bronchiodilator because it affects mostly beta-2 receptors and so typically unless we we rarely ever used epi for a
19:38
vasopressor in open heart i routinely would use it as a cardiac dose which would be .03 mics per kilo per minute we really didn't titrate that unless unless the based on the cardiac index we saw they needed we needed more um but even then we would go up by very very little 0.04 you know i rarely ever saw anyone get to 0.06 and that's usually if things were not going well that they would end up on a 0.06 dose and that's even still very low um you know if
20:09
they were ended up you know really not doing well obviously we could take them up to the max dose but again on a routine uh open heart someone who had really low cardiac output who needed that um
20:23
just a little bit of uh support you know we kind of teetered them on the line of beta 2 beta beta 1 stimulation and so it was still probably enough to give them a little bit of vasodilatory a little bit of bronchodilatory effect but also just a little bit of beta 1 to help with contractility the other issue with things like epi is it will increase your heart rate and because of that you're going to increase your o2 demand and so that's not that's that's not necessarily good
20:50
right you don't want someone who already has a poor heart function to have increased o2 demand so you have to be really careful with epi because it actually can worsen someone who already is
21:03
you know not getting enough you know not meeting their metabolic demand with the blood flow and oxygen and things like that so again we would use it a very small dose if we used it and you also want to remember someone who has a physiology like aortic stenosis you really don't want to whip the heart essentially is what we would always say and it's because you know they have a very concentric hypertrophied ventricle and they don't
21:31
have a lot of filling space so if you're giving putting something like that on epi you're again they don't have they can't fill very well because usually they're very hypertrophy their chambers smaller uh for having to overcome uh the increased pressure they need to eject out of the stenosed aortic valve so again epi is really not a good drug of choice for those patients
21:52
so just keep that in mind um a better drug of choice is levofed so the reason why you know again uh leave a fed will give you a little bit of alpha a little bit of beta it's a little more um forgiving with the heart rate with the heart rate increase you can still see a significant heart increase with increase with levo but not that much considering the low doses that we use and um when i say low dose you know 0.02 0.03 mics per kilo per minute we rarely ever went
22:23
up above 0.08 if you're at 0.08 of levo after an open heart case you need to be starting to think what's what's going on you know did potentially um did their one of their bypasses go down because that has happened um i've seen a patient get moved over to from the operating room table to their bed and they have noticeable svt or st elevation and turns out one of their graphs went down so that can happen but if you're ever again at a 0.08 0.08 mics per kilo per minute dose of leave
22:57
a fed after an open heart you really have to be thinking you know especially look at their svr are you over squeezing them you really want to be evaluating their svr before you just put them on a high dose of levofen okay if you're really vasoplegic and you need at squeeze that's okay but make sure you're evaluating that you don't want someone who has extremely high svr and you're at a high dose of levofed and you know you're just squeezing and squeezing what they really need is
23:21
an inotrope so um you know and their their pump is actually failing so you want to make sure you're being cognizant of that because maybe they need some background epi with it okay and a lower dose of level so again my suggestion to you is to start leave a fed off at a 0.02 to 0.06 mic per kilo per minute i typically would start at a 0.03 that's typically where i would start or 0.02 and work my
23:46
way way up to 0.06 but that was usually the range i stayed in you guys it was very very small range
23:52
of levo that we ended up needing and again assessing do they need fluid you know assessing is it because they're dry you don't want to just keep squeezing someone who needs fluid so always assess what's causing the hypotension don't just start treating it and not knowing why it's it's what's causing it um because you can actually do more harm than good
24:12
all right so that is levo next we're gonna go into vaso um and let me back up for just a moment because i forgot to mention how you mix levofed and i also forgot to mention how you mix epi i figured i'd throw this in there i actually think it would be really cool if i actually went through like a anesthesia math with you guys um i have a full course of anesthesia and math inside steroids
24:35
prep academy um a couple hours worth but i think if i did like a down and dirty anesthesia math mental math i should say with you guys i think it'll really help some of you because i promise you math anesthesia is not hard and it's very routine you do it all the time so it becomes very simple and i love simple so um when you're mixing up epi and livo i promise you it's not as scary as it sounds typically how we did it is for like epi we would put four milligrams in 250 mls
25:05
and whenever you put any drug into 250 mls the math is super easy and i'm super excited to share this with you because it'll blow your mind um you know instead of using some kind of you know the fancy way of doing math if you put let's say 4 milligrams and 250 4 times 4 is 16 so now you have 16 mics per ml it's that simple you times all the milligrams whatever you put in 250 you times it
25:30
by four of the milligrams and that's what you get in mics so if you're putting eight milligrams of levofed into a 250 bag then you're going to get 32 mics per cc it's really that simple so i that'll always work that's only what for a 250 bag keep in mind but again kind of nice easy math for you guys
25:52
so um back on to vaso so vaso is a potent vasoconstrictor so it increases your arterial blood pressure it increases and essentially how it works it's actually a hormone okay it's which is found in the hypothalamus and it's sent to the posterior pituitary which is where it's released into the blood and um essentially it kind of can work in your kidneys to help reabsorb fluids but it's very potent it's an acls drug so you definitely should be familiar with it and
26:25
typically how we would use it now you can either put it on a drip or you can do iv push we would occasionally put on a drip you don't typically titrate it once it's on a drip you usually let it kind of just stay as at its baseline rate but if you were to use it as iv push you typically dilute 20 units into 19 so you take one ml which is one ml of the vasopressin and you dilute it into 19 ccs of saline which makes 20 mls total which dilutes it down to 20 or one unit per
26:55
for a total of 20 units in that entire syringe and you would then push either a half to one unit at a time again always start small push that little half see how they react because it's very potent so some patients react very well to vasopressin some don't um vasopressin is kind of the drug of choice if you have a patient who is vasoplegic from um lisinopril or any of the prills any of the pril drugs um it's a great drug for that so even if you're not an open heart case
27:25
even if you're in a case and someone's on on a ace inhibitor uh vasopressin's a great drug of choice if they're not reacting to the neo that you're giving so keep that in the back of your mind but just be very very careful with it again you want to make sure you're looting it correctly because it is very very potent you never ever want to not dilute that drug i mean you have to dilute that drug so just be very careful with it if you're putting it in a 50cc bag
27:50
just match you know you want to make sure you're putting 50 units and 50 cc's so it's you know obviously it's 20 units per so you have to make sure one of the vials you're only taking a half cc from that to get 50 units to put in 50 cc's so that's typically how we would um dilute vasopressin when we're putting it on a drip okay so we're going to go into milrinone milrinone is a phosphodiesterase inhibitor okay so it actually um modulates uh cyclic adenosine
28:25
monophosphate or camp okay and it it's a positive inotrope but it also decreases your afterload and so it's kind of a unique thing about melrone again that you can kind of have both decrease in afterload and a positive inotrope and typically why it's selected is for the positive ionotrope not that the afterload is not desirable but what i will say at least in an open heart situation
28:52
not a lot sometimes patients won't tolerate milrone even though it is a good drug of choice for them they don't typically tolerate it if they can't tolerate the decrease in afterload so it can be kind of a iffy drug whether it's going to tank their blood pressure or not so you again have to go very slow with this we would never ever bolus it if you look it up you know any kind of textbook it'll say to give
29:15
a loading dose we would never do that because that typically almost always would cause hypotension so again we would skip the loading dose and we would start it at .375 mics per kilo per minute and that's where we would leave it again we didn't really titrate it we just kind of left it there um and if the patient tolerated it great if they didn't then we would we would have to stop it
29:36
so um that's milrinone okay um a drug that i want to touch on that's also very common other than the next most common drug which i'll get into last um is ephedrine and so ephedrine comes in 50 milligram vials okay the dose per kilo is 0.2 milligrams per kilo however i still think that's kind of a high dose like especially now that i do a lot of pediatric cases you always want to go low like i said before you want to see how people are going to react ephedrine is
30:09
one of those drugs where you never know what you're going to get when you give it you could give 5 milligrams to a good size adult and have a heart rate over 100 but from 70. you know so you know or you could give five milligrams and you could see nothing or you give 10 milligrams you could see nothing um ephedra is one of those drugs where you can actually kind of kind of get quickly acclimated to it or i'm trying to think of a better word for that there's a word
30:35
and i can't think of it right now but it kind of um over a period of time you kind of get sensitized to it so you don't react the same way i have seen that happen where initially it works really well and then you get halfway through your stick and it's like you're giving water so again ephedra is one of those drugs it's a indirectly acting vasopressor
30:55
and it works on alpha and beta but it ultimately works by inhibiting a norepinephrine reuptake which essentially allows more norepinephrine to circulate in the body meaning it increases your blood pressure norepinephrine is a natural catecholamine in your body that increases your blood pressure so um that's how ephedrine works it helps by decreasing reuptake of that catecholamine
31:20
and um so again that's what i can say about ephedrine again it's kind of could be somewhat unpredictable and how it can react in in patients so i would start off maybe just try like .1 milligrams per kilo to start and then you can always give more again say that a couple different times you can always give more once you give it you can't take it back and just make sure that you're diluting it appropriately and again it comes as 50 milligrams
31:43
and you want to dose it um you know and a good size adult five milligrams 2.5 milligrams button a kid you really want to make sure you're being very cognizant of the weight-based dosing the 0.1 per kilo and i'd even go less than that sometimes just until you know how they're gonna react um okay so that's ephedrine now we're gonna go into the most common vasopressor that you guys are gonna use like it's it's gonna be glued to your hand essentially in anesthesia
32:12
and that's neo okay everyone loves neo neo is like just you have neo it's always ready to go and um it's ivy push you know you can do a drip that's fine but i'm gonna go over the iv push um because that's nine times out of ten how you're gonna use it in anesthesia now a lot of hospitals now are doing these pre-filled syringes which is really nice it's kind of spoils you but i also think because of that i think sometimes students get into
32:38
the or and they don't realize how to dilute it appropriately because now again they're kind of spoiling you with pre-diluting things and putting it in your med drawer so and you should always know how to dilute neo because it is an emergency drug if you need it you need to know how to use it and use it safely it comes in a 10 milligram vial that is not safe okay um you know this is just me
33:00
but i've seen people draw up on a tv syringe that makes me i i mean i've seen it done obviously if you do it safely and appropriately that's totally fine but i that makes me i don't like that i really don't like that um i always dilute it um you know in 100cc bag or you can take two 10cc vials and double dilute it that's okay too but just make sure that you're getting 100 mics per ml that's what you ultimately want is 100 mics per ml okay and so again when you're giving neo um
33:31
it's an alpha one okay and so it causes arterial vasoconstriction all right so it's very potent and again it comes as a 10 milligram file um you'd never ever ever want to push 10 milligrams at once and typically again you could put 10 milligrams and 100 mls and back to like kind of like some basic easy math for you guys i like knocking off zeros like that's my favorite thing to do it's
33:56
like so rewarding to knock off zeros when you're doing math so you know if you have 10 milligrams 100 mls if you knock off both those zeros now you're left with you know your or that's if you're diluting it further down now you're left with 1 and then 10 which makes 1 or 10 mics per ml that might have gotten a little confusing but ultimately you start off with 10 milligrams
34:19
okay and you're putting it in 100 ml okay so again you're essentially diluting it down to make 100 mics per and you can also make it into 40 mics per i've seen that also be the dose of choice and the dose per kilo is two milligrams or two mics per kilo is the dose per kilo if you want to know that um it's very again it's a very common drug to use it's a very great drug you just have to be very careful with it and always back to like you want to make sure
34:50
you're going slow with it and making sure you know people how people are going to react okay
34:57
all right so now we're going to go on to narcotics and
35:03
benzos but i'm not going to really go into all the different types of narcotics and benzos um so now we're going to go into fentanyl so fentanyl one to two mics per kilo is the loading dose uh i like to kind of do the one per kilo i think for intubation if it's not going to be a stimulating case and especially if you want to get them back breathing early on i like the one like per kilo loading dose
35:27
but you're not wrong to give two just keep in mind how stimulating is the case going to be you know how long are you going to have to wait before you have stimulation because you could then deal with some hypotension because of it so um so fentanyl is a mu opioid receptor it binds to the mu opioid
35:46
everything is compared back to morphine when you're looking at narcotics that's kind of how you can kind of judge how potent it is and so fentanyl is 100 times more potent than morphine so keep that in mind um and typically back to the open heart scenario um we didn't routinely use fentanyl for our open hearts every now and then we did based on you know
36:10
preference um but uh typically you would give one gram of fentanyl prior to sternotomy so that's a lot of fentanyl so um but it just goes to show that again it's not nearly as potent as the drug that i was used to using and liked using which was sue fentanyl
36:27
typically what we would do when i would use fentanyl in my open hearts is again a gram prior to sternotomy and then i would start after intubation and all that um you would actually and after going on pump you would start your your mics per kilo per hour drip and typically that's about two mics per kilo per hour of fentanyl is typically what we would use in our open hearts as a continuous drip so we would actually do nimbax fentanyl
36:54
and and again fentanyl would be left to the two mics per kilo per hour and we wouldn't titrate it we would still give the gram of fentanyl prior to sternotomy and that's typically how we would do those cases and we would leave that on up until the very end of the case same with the nimbex
37:10
so duration of action of fentanyl is 30 to 60 minutes
37:14
and so that's kind of what you know that's probably all i'm going to share with you today on fentanyl again you may or may not see fentanyl use an open heart i will say it's probably the most common drug or narcotic to use in open heart i found it to be more labor-intensive okay um
37:32
i saw a lot more ups and downs with with my blood pressure with fentanyl versus using to sue fentanyl and so we're going to go to the sue fentanyl next so sue fentanyl the duration of action is 30 minutes so it's more potent but it actually is shorter acting
37:48
for its peak effect and things like so i just it was it just seemed to be a little more forgiving um and again less swings you you could i feel like you could control it better essentially and control the patient's um reaction to pain better with sue fentanyl
38:05
and typically all you need to blunt intubation stimulation is .3 mics per kilo very low dose to blunt the sympathetic surge you get with intubation so again typically for open heart we would give anywhere from 25 to 50 mics for induction
38:24
they would it comes in a 250 mic vial or a 50 mic vial if i was doing a carotid for example um i could use suppenal for carotid and obviously i wouldn't do 250 mics for carotid but i would get my 50 mic vial i would dilute it down to 5 mics per ml and then you would maybe give 20 mics for induction and then maybe like another five to 15 more mics throughout the rest of the case so on average you're giving anywhere from 35 to 40 mics for the entire carotid and it blunts the
38:54
cough you know so they don't wake up coughing and bucking they're usually very comfortable
38:59
so it's a great drug for carotids i don't think a lot of people think about that because they're they're you have to be careful with it because you can get a lot of apnea um but as long as you're dosing it appropriately and not giving it right before the end of the case you're going to be fine and again just giving someone five mics is not gonna be so much that they're gonna go apnik okay but if you're slamming them with 15 20 mics yeah you're gonna get some
39:21
app yeah so just be cognizant of how to dose it and you'll be just fine but it's a really really great drug it can cause bradycardia um which typically you know if you're in a heart you know you don't want them to have a fast heart rate and it'll increase your cardiac demand so we welcomed some bradycardia now sometimes people got a little too bradycardia bradycardic like in the 30s you
39:43
know so sometimes we would actually have to give a little bit of robinol or we would use ephedrine if they needed a blood pressure support medication but again really great drug for pain control
39:55
um so sue fentanyl is about um 500 to a thousand times more potent than morphine i know that's kind of a big range but again i think it probably just depends on the patient and uh you know how they react to it but it gave me the range of 500 to 1 000 times more potent than morphine so it's uh very potent and that's all i have to share with you about sue fentanyl
40:25
um all right so let's go on to midazolam verse said the most common ves benzo you're going to use anesthesia so um typically in an open heart we give anywhere from 5 to 10 milligrams we typically gave five i know a lot of institutions give 10. i think that's a lot um because think about it a lot of these patients are older maybe have some kind of renal insufficiency and 10 milligrams could you know put grandma off her rocker for well over a week or more afterwards
40:54
so i try to think about these patients even though i know they spent some time in the icu afterwards they are typically still going home you know within that week so you know are they going to go home and fall and and then have maybe and then i always worry about falls and bleeds because a lot of these patients go home on blood thinners you know so i i get nervous using versailles and a lot of versailles especially in older people because the last thing you want
41:19
to do is cause them to go home and fall and hit their head and have something else bad happen so be aware of that it's it's not it's a great drug don't get me wrong i like it but you got to be cognizant of who you're giving it to and what the renal function is and just do you really need that much you know because again you're going to have gas um you know typically what we did is we would give two or three for induction and we would give two or three during uh the wake up
41:45
you know so when they're getting ready to come off bypass we would give the other two or three okay or during bypass we would give i would typically wait till they kind of came off that way i'd make sure it didn't go into the circulating to the pump um because sometimes some of your drugs get stuck in in the on the side of the tubing and from the pump the cardiopulmonary bypass machine so that's typically why i would wait um and so again and also again so if you're cooling someone
42:12
for an open heart and you're warming them back up you're going to increase your metabolic demand so being cognizant of that and getting more reverse said for a case like that we typically didn't cool all of our open hearts okay don't we'd only do that if we did like a circle rest case and even then we'd only cool we'd only do the circle rest for max 10 minutes and so we would use brevitol decadron ice the head or instead of brevitol we would give a dose of propofol
42:37
essentially all you're trying to do is cause the iso isoelectric activity in the brain so decreasing someone's metabolic need to like zero you know they don't have any they don't have any thoughts going on in that brain um so yeah it's just be aware of how you're using it and why you're using it don't just slam someone with tenniver said and think that that's fine
42:59
if you have a whole 10 milligrams you don't have to use it all so again we would give five typically but every place does it a little bit different and so midazolam affects the gaba receptor and the duration of action is one to six hours that's a big range as i just said one to six hours so six hours versus one hour what kind of person are you how much alcohol do you drink on a on a daily basis you know what's your um you know this is broken down you know the
43:28
cytochrome p450 you're going to hear that a lot in in your pharmacology courses and anesthesia it's how you metabolize a lot of drugs and you know patients who drink a lot of alcohol or take a lot of different types of drugs anyways at baseline tend to have more of this enzyme that breaks down our anesthetic drugs and so some patients are very sensitive to it and it will like one milligram will make them like amnestic other people you give three milligrams they're like
43:57
when are you gonna start sedating me and they're crawling out of their skin so but that being said even patients who are acting like that who are crawling out of their skin i know i know i i'm pretty quickly to give them more as well but at the same time they may not remember being like that even though they're awake and interacting they may be amnestic so keep that in mind it's kind of like being drunk but not but not acting like but like being awake and and and
44:27
in the moment aware of what you're doing but then like the next day you're like i don't remember any of that so that's kind of how versaid works a little bit it's probably the best uh relationship i can kind of give you because sometimes patients again will be you know asking when are you gonna sedate me for you know a very minor procedure but you have to realize they may they even though they're acting like they're not sedated chances are they're not gonna remember that okay
44:51
all right so let's get into um briefly because i'm not going to go into this a lot this lecture's already been relatively long but opioid sparing again is kind of an up and coming technique it's very widely accepted and used and it's great i think it has a lot of benefits for the patient so just real quickly if you're doing an open heart with an opioid sparing technique some of the things they do they usually do a regional block one of the most pride common ones um and again
45:19
this can vary based on where you do your rotation but is the sap serratus interior plane block okay to help block the sternotomy incision pain they can also do a pectoralis nerve block
45:35
but they follow what they call eraz which is not just an open heart it's for a lot of different types of procedures but essentially what that stands for is enhanced recovery after surgery and they're looking for ways to cut down on narcotic use because narcotics are not benign they come with side effects you know constipation ileus um you know just it's just overall and now obviously the addicting factor to it too it's just overall not good um for patients
46:02
so they do things like lidocaine infusions uh lidocaine infusions are good for neuropathic pain um and essentially lidocaine is a sodium channel blocker okay so and by blocking your sodium channels it essentially leads to pain um decreased pain generation you know to put it in simplified terms um it pretty much weakens your peripheral and osteoceptors to pain and decreases your central excitability that's essentially how lidocaine infusions work now i will say it has to
46:34
be an infusion a one-time bolus of lidocaine even though it does have some of those properties it's not going to give you the same effect as an actual infusion where you're keeping your
46:45
concentration over a period of time the same so then fusion is really what works the best for that
46:51
then you have your gabapentin which is also an anti-convulsant so again neuropathic pain it decreases excitability of posterior of the posterior horn essentially of neurons which are responsible for the stimulation of pain and modulation of pain so that's how gabapentin works then you have something like carb loading which is not even a medication at all it's just carb loading why do they do that because it decreases um you know patients who
47:20
who fast you know they typically have uh insulin resistance then when they start eating again and um it kind of just messes with their whole metabolic system
47:30
the like a true diabetic needs to be careful with carb loading i you know i know that there's limitations to it but essentially by carb loading and by not putting your body under that starvation stress you're reducing your overall stress hormone response generation so that in itself can decrease pain and so that's why they do it for patients who again are not brittle diabetics
47:54
then of course you have your tylenol and nsaids keep in mind tylenol is not an nsaid tylenol is an antipyretic and an anti-analgesic but it's not an anti-inflammatory medication um it only it only affects your cox-2 receptor where you have your true nsaids like toradol which is a non-selective cox-1 cox-2 inhibitor that is an anti-inflammatory medication um another quick little tidbit you know you got to be very when you're giving toward all especially
48:26
if you're giving 30 milligrams and let's just say your patient's 60 years old be aware that you know turtle is very hard on your kidneys you can put someone into a into
48:36
renal insufficiency with toradol especially if they're older so just decrease the dose if you're going to give it give 15 milligrams you really can't do a lot of harm with a big whopping dose toward all like 30 milligrams so um in a pediatric population we do a 0.3 milligram per kilo dose so that's how we dose it um but again the adult i think sometimes we get so used just giving standard doses we don't think about it so just be aware of that and also
49:03
be aware that if you're over 50 years old you should be starting to starting to think about should i be decreasing the dose even though they can handle 30 maybe it should only get 15
49:13
because it's not a benign drug in that sense so then you have ketamine which is an mda antagonist okay um so again that can especially if you're giving ketamine like in small doses if you're i would say a good dose like a preventative dose for pain is anywhere from like i don't know maybe 50 milligrams to start uh and then maybe you work another 10 or 10 or 30 milligrams throughout the case to wake up that seems to be a pretty good you know you know even if it's not 50
49:45
maybe you started with 30 milligrams and then um titrated in 10 more milligrams throughout the case and for a total of 50 or 60. i think that's a kind of a good small still a small enough dose where you know you shouldn't get you know crazy nystagmus or anything crazy when you wake up i still caution you and using versailles i think that's a good idea to still use a little bit of her said if you're giving ketamine because there can be
50:09
hallucinogenic effects with ketamine and who wants to wake up crawling on the ceiling i don't please don't do that to me i don't want to itch my skin off because there's ants crawling all over me um so it can't have those potential side effects so just be aware that you typically get that more with like an induction dose of ketamine but it still can't happen with low doses so just be aware
50:30
then you also have precydex which is an alpha 2 agonist okay it essentially reduces substance p which is a neurotransmitter that modulates pain substance p is pain um and so i guess kind of it works by decreasing your norepi circulation too so it actually can cause not only can it cause bradycardia but it can actually cause hypotension um and it's also very interesting you can have have kind of like a transient hypertension
50:59
with precedence especially if you're giving a bolus of it and i recently saw that it does happen i think it's extremely rare to be quite honest because i don't and no one that i was even with that day had ever seen it before including myself but that actually can happen too um so just be aware that you know prosthetics is not a benign drug you got to make sure you're giving it slowly when you are giving a bowless load of it but that's kind of the gist of how it works so i
51:26
know i threw a lot at you guys i tried to cut it condense it into little quick little tidbits not not to overwhelm you with everything um i hope i covered everything is in good enough uh form um one thing obviously i'm tend to be the kind of person who kind of goes back to things sometimes and i'm like oh did i say that right you know because i'm speaking really quickly and i don't know but one thing i want to go back to real quick i'm not sure if i said this correctly
51:53
and the last thing i want to do is confuse anyone here um as i'm going to go back to my neo and the 10 milligrams and 100 mls so 10 milligrams is 10 000 mics and so whenever you're figuring out head mass you want to think about how many mics am i am i giving um so 10 milligrams 10 000 mics and so back to the whole deletion of zeros if you write down 10 000 and then if you write down 100 and if you cross off two zeros and two zeros on both ends on the 100 and the 10 000 now you're
52:27
left with 101 so again that's 1 cc is 100 mics and so again i don't know if i thoroughly explained that or if i got anyone confused that's the last thing i want to do so i want to back back up and make sure i went over that of course i'm always here if you have questions reach out to me and i can put my email in the show notes if you have any questions about this lecture i know it was heavy but i hope you guys enjoyed i hope it helped some somewhat um kind of clear clarify
52:55
things and what you're in store for if you're getting ready to start your open heart rotation that's super exciting and yeah so hope you guys enjoyed and i hope you have a fabulous day
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