The differences in RSI vs Gas

athomas91 · Mar 19, 2006

Mike,

as a soon to be graduate...yeah!! i will give my 2 cents...

i feel we have quite a luxury in that we often (not always) but often in the OR have a controlled environment in which we can maximize our anesthetic for the patient... ie... slow,controlled,smooth inductions.. now of course, there are trauma patients, and floor/unit emergencies where we crash em and out of neccesity it is down and dirty..

but... you will find, as we all have through this learning process, that there are a million and a half ways to skin the cat, and virtually everyone will have their own little technique that they have established through learning from others and their own trial and error...

good luck.

rn29306 · Mar 19, 2006

Hey all
In the interest of creating discussion I have a few questions.
I put people down all the time as an FN with etomidate & succs. I typically maintain sedation/paralysis with versed, fentanyl & vecc.
Besides the obvious technical differences (ie: the machines) what are the essential differences between the two?
Whould you ever use such a combo in the OR? Does that even happen?
Do you often use diprivan for induction?
In anycase, i am also opened to questions. Id love to hear for the people in my future profession!
MM

Hey Mike. Overjoyed to see that you are doing the CRNA thing.

As far as propofol as an induction agent, I would say that we use it about 70% of the time where I am at - level one trauma center. Outpatient surgery centers use it almost exclusively as an induction agent. Amidate is getting a closer look at our facilty by our docs and one trauma fellow is doing a serum cortisol study following intubation with etom. Results should be in before the year is up. Old school thought was a that a single induction shot of etom had only a very transitory inhibition of 11-betahydroxalayse and subsequent cortisol, but now more information is coming to light...we'll have to see. Anyway, sometimes use amidate for poorly compliant heart patients going for non-cardiac surgery. Some neuro guys like to rebolus amidate prior to cranial clipping. Most of our hearts get a high dose fentayl and versed induction.

Some cases do indeed call for TIVA - total intravenous anesthetic. Monitored backs and necks sometimes get TIVA. We run propofol for those cases. Actually most of our necks and backs that have nerve monitoring studies done intraop get 1/2 MAC iso (or an end-tidal of 0.6) and IV propofol for additional sedation / anesthesia at considerable rates without paralysis. So yes there are indications to run gas and IV agents at the same time.

Man as far as the gases go, there is such a difference in how they work vs not only the different variables amongst themselves (sevo, iso, des) but very different than IV agents - dude your gonna have to read a pharm book for that. Can provide some excellent reading if you need a list.

Congrats on choosing anesthesia. Good questions btw. I can see you are going to keep your pharm / physiology instructor on his or her toes.

MmacFN · Mar 19, 2006

hehe

thanks for the info!

Truly there is no one way to skin a cat!

Nitecap · Mar 20, 2006

hehe
thanks for the info!
Truly there is no one way to skin a cat!

RSI quick over view. Say you premed with versed and fent. Pt on OR table, preoxygenate for a while with 100% o2. give induction agent propofol, etomidate, thiopental, or what ever you are using so the pt goes to sleep, then give relaxant sucs, or a nondepolarizes vec, roc ect. With the RSI you do not ventilate the pt after you admin the induction agent. You push all the drugs quickly, DL and intubate. RSI will be done usually if the pt is at risk for regurge.

With a standard induction you will go a little slower and attempt to ventilate before you give the succs.

Yes etomidate and sucs are used freq and propofol probrably even more freq than etomidate.

Usually you premed with a benzo maybe and opiod and lido maybe and then induce (put them to sleep) with an induction agent such as propofol, etomidate, thiopental ect. After inducing the relaxant is given and tube placed. Once tube verified you maintain with a volatile agent or nitrous.

Inhaled inductions are done at times as well total IV anesthesia is done too.

MmacFN · Mar 20, 2006

Very different from how I do it in the field or in the hospital when im called to intubate.

My cocktail goes like this

Etomidate 20mg -> pt sedated in ~1 min -> bag if needed

-> Succs 2mg/kg or Roc-> bag to keep sat @ >95 -> tube

-> Fentanyl ~100 mcgs -> Vecc for maintained paralysis

-> versed 2-4 every 5 minutes to maintain paralysis or Diprivan

What are you giving Lido for? Avoid laryngospasm?

I dont use i for anything but that since there is no proof for it in relation to TBI.

Interesting stuff, i cant wait to get my feet wet!

RSI quick over view. Say you premed with versed and fent. Pt on OR table, preoxygenate for a while with 100% o2. give induction agent propofol, etomidate, thiopental, or what ever you are using so the pt goes to sleep, then give relaxant sucs, or a nondepolarizes vec, roc ect. With the RSI you do not ventilate the pt after you admin the induction agent. You push all the drugs quickly, DL and intubate. RSI will be done usually if the pt is at risk for regurge.
With a standard induction you will go a little slower and attempt to ventilate before you give the succs.
Yes etomidate and sucs are used freq and propofol probrably even more freq than etomidate.
Usually you premed with a benzo maybe and opiod and lido maybe and then induce (put them to sleep) with an induction agent such as propofol, etomidate, thiopental ect. After inducing the relaxant is given and tube placed. Once tube verified you maintain with a volatile agent or nitrous.
Inhaled inductions are done at times as well total IV anesthesia is done too.

rn29306 · Mar 20, 2006

What are you giving Lido for? Avoid laryngospasm?
I dont use i for anything but that since there is no proof for it in relation to TBI.

Reasons for lidocaine: 1. to take the sting out of induction doses of propofol, esp in a hand or worse, wrist vein.

2. blunt the ANS response to cold steel in da' mouf and shoving a garden hose thru cords.

There are also proponents of using what we call a LTA. Do a DL and stick this white narrow stick thru the cords, watch a black line go thru, then inject the 2% lido at the other end. It sprays lido ALL OVER THE PLACE, basically anesthetizing the skin where the cuff will be inflated.

Mike you are going to be amazed at the compliance of an anesthesia circuit compared to an ambu. We use a single tube (really a tube within a tube) and have the soft green bags to ventilate with. You can tell so much about what is going on rather than the damned ambu. Some institutions I have been to have a true double circuit attached to a bag that is rather stiff and I hate those systems.

MmacFN · Mar 20, 2006

Thanks! Im very excited to be moving on! I cant wait to start!

Trying to decide where to go now is the big thing!

Hey Mike. Overjoyed to see that you are doing the CRNA thing.
As far as propofol as an induction agent, I would say that we use it about 70% of the time where I am at - level one trauma center. Outpatient surgery centers use it almost exclusively as an induction agent. Amidate is getting a closer look at our facilty by our docs and one trauma fellow is doing a serum cortisol study following intubation with etom. Results should be in before the year is up. Old school thought was a that a single induction shot of etom had only a very transitory inhibition of 11-betahydroxalayse and subsequent cortisol, but now more information is coming to light...we'll have to see. Anyway, sometimes use amidate for poorly compliant heart patients going for non-cardiac surgery. Some neuro guys like to rebolus amidate prior to cranial clipping. Most of our hearts get a high dose fentayl and versed induction.
Some cases do indeed call for TIVA - total intravenous anesthetic. Monitored backs and necks sometimes get TIVA. We run propofol for those cases. Actually most of our necks and backs that have nerve monitoring studies done intraop get 1/2 MAC iso (or an end-tidal of 0.6) and IV propofol for additional sedation / anesthesia at considerable rates without paralysis. So yes there are indications to run gas and IV agents at the same time.
Man as far as the gases go, there is such a difference in how they work vs not only the different variables amongst themselves (sevo, iso, des) but very different than IV agents - dude your gonna have to read a pharm book for that. Can provide some excellent reading if you need a list.
Congrats on choosing anesthesia. Good questions btw. I can see you are going to keep your pharm / physiology instructor on his or her toes.

MmacFN · Mar 20, 2006

heheh

I forget about the comfort issues when your not crashing the airway

Now the lido makes sense

That compliance is an interesting thing. As you know, we use bags all the time to see where we are sitting with compliance, especially in the trauma pt with a suspected pneumo, i dont trust the vent when i cannot hear the alarms

Do i know you from flightweb?

Reasons for lidocaine: 1. to take the sting out of induction doses of propofol, esp in a hand or worse, wrist vein.
2. blunt the ANS response to cold steel in da' mouf and shoving a garden hose thru cords.
There are also proponents of using what we call a LTA. Do a DL and stick this white narrow stick thru the cords, watch a black line go thru, then inject the 2% lido at the other end. It sprays lido ALL OVER THE PLACE, basically anesthetizing the skin where the cuff will be inflated.
Mike you are going to be amazed at the compliance of an anesthesia circuit compared to an ambu. We use a single tube (really a tube within a tube) and have the soft green bags to ventilate with. You can tell so much about what is going on rather than the damned ambu. Some institutions I have been to have a true double circuit attached to a bag that is rather stiff and I hate those systems.

Nitecap · Mar 20, 2006

Very different from how I do it in the field or in the hospital when im called to intubate.
My cocktail goes like this
Etomidate 20mg -> pt sedated in ~1 min -> bag if needed
-> Succs 2mg/kg or Roc-> bag to keep sat @ >95 -> tube
-> Fentanyl ~100 mcgs -> Vecc for maintained paralysis
-> versed 2-4 every 5 minutes to maintain paralysis or Diprivan
What are you giving Lido for? Avoid laryngospasm?
I dont use i for anything but that since there is no proof for it in relation to TBI.

Interesting stuff, i cant wait to get my feet wet!

Giving the fentanyl before intubation would def. help to blunt the sympathetic response to DL. As the lido does as well. Also if you give a RSI dose of Roc (1.2mg) depending on how long your flight is and how long you need the pt down the Vec may not be necessary though it depends on again how long how need relaxation for. Also as for the versed I guess you are using for centrally mediated relaxation ? as well sedation and anxiolysis if you really need then down long ativan may not be a bad choice since it will last long requiring less freq larger boluses of versed causing more freq changes in hemodynamics. Also propofol is not really know for its muscle relaxant properties.

You seem to have a pretty good head start on your knowledge of some of these drugs. When you enter school and really learn on a molecular, receptor, enzymatic and ion level how these drugs work to cause their effects you will be freaking and amazed. Really if I knew half of what I know now while working in the ICU as a nurse about the drugs that I administered nearly everyday I would have provided way better care for my patients no doubt and been able to make more thought out judegements.

As a nurse you know what. For example you know versed will cause sedation, anxiolysis, amnesia and may decrease my DP, resp drive ect. As a CRNA you understand not only what but how and why. You understand that Versed binds to a benzo site on a GABAa ionotropic receptor causing a conformational change keeping Cl- channels open or opening more ect allowing more Cl- to enter the cell leading to a more negative membrane potential (hyperpolarized)that requires a stronger stimulus to depolarize the neuron to cause its effect.

Sounds like you will do fine though. Good luck and dont loose that desire to learn and succeed.

MmacFN · Mar 20, 2006

Hye Nitecap

Yes im very excited. Many of the drugs I currently use I learned alot about in an advanced pharmacology class i took a few years ago. I was getting sick of not knowing why it worked.

I really do enjoy learning new stuff. I am so excited to get into school again i cannot even explain it. Once im there its awesome. Ill be glad when the waiting and the decisions are made and i have an acceptance in my hand.

What sortof doses are your using pre intubation of fentanyl. My understanding is it can be up to 50 mcgs per kg. Im sortof limited there as i typically only carry 400 mcg at any given time.

I have also had some hypotension issues with versed but i only ever use it now for continious sedation. Sometimes i go with droperidol 1.25 - 2 and that also does a nice job. Often i slam them with fentanyl since the drug works so well. At times ill use morphine and counter the hypotensive effects with benedryl 12.5 - 25 IV. Turns out the hypotension MS causes is histamine mediated. Other than that i have valiume but i dont find that does a great job. We dont carry ativan currently due to the difficulty in maintaining it prehospital.

My goal with all my intubations is to make sure they dont feel/remember it and stay that way until the wean in the ICU. Ive actually had pts who ive intubated when working flight then in the ICU as they are being weaned. Its sortof unusual. :)

truthfully, i cant wait to goto those pharm classes. I have recently retaken inorganic chem I & II and really enjoyed them. Also really liked biochem. Now just have to find a school and get in

Giving the fentanyl before intubation would def. help to blunt the sympathetic response to DL. As the lido does as well. Also if you give a RSI dose of Roc (1.2mg) depending on how long your flight is and how long you need the pt down the Vec may not be necessary though it depends on again how long how need relaxation for. Also as for the versed I guess you are using for centrally mediated relaxation ? as well sedation and anxiolysis if you really need then down long ativan may not be a bad choice since it will last long requiring less freq larger boluses of versed causing more freq changes in hemodynamics. Also propofol is not really know for its muscle relaxant properties.
You seem to have a pretty good head start on your knowledge of some of these drugs. When you enter school and really learn on a molecular, receptor, enzymatic and ion level how these drugs work to cause their effects you will be freaking and amazed. Really if I knew half of what I know now while working in the ICU as a nurse about the drugs that I administered nearly everyday I would have provided way better care for my patients no doubt and been able to make more thought out judegements.
As a nurse you know what. For example you know versed will cause sedation, anxiolysis, amnesia and may decrease my DP, resp drive ect. As a CRNA you understand not only what but how and why. You understand that Versed binds to a benzo site on a GABAa ionotropic receptor causing a conformational change keeping Cl- channels open or opening more ect allowing more Cl- to enter the cell leading to a more negative membrane potential (hyperpolarized)that requires a stronger stimulus to depolarize the neuron to cause its effect.
Sounds like you will do fine though. Good luck and dont loose that desire to learn and succeed.

yoga crna · Mar 20, 2006

Don't forget that fentanyl can cause a rigid chest, While it happens infrequently, it can get your attention. It happened last Friday to a patient who I was anesthetizing for a facelift. Oxygen sat dropped quickly, but I was able to ventilate her after the muscle relaxant started to work.

Mike,

You are asking good questions. Try to spend some time in the operating room with a good CRNA. It will be invaluable for you and get a good perspective of the level of knowledge need to be a CRNA. Also, pick up a basic anesthesia text on Amazon and read, read, read.

Yoga