i have been working on smoother wakeups. the technique i have been employing is using either morphine or fentanyl and titrating in 2mg per cc of mso4 or 10 mcg of fent to keep respirations about 12- 18 per minute. (obviously in patients that are spont vent.) while doing this i cut back on the gas in increments. when it comes time to extubate they usually will open their eyes to command, wont buck as much and seem more comfortable. i try this in patients that i am not worried about resp depress and airway issues. adn the morphine keeps em more comfortable into postop for obvious reasons.
the question is, do many of you do this? i have worked with some ppl that almost refuse to use narcs near the end of the case on anyone. i dont know if they have been burned in the past or what. this also is adults, not peds where i currently am.
Never had a rigid chest that Sux won't cure. Obviously I would never push all those narcs without wanting to secure the airway. Never had rigid chest with Fentanyl but Sufenta/Alfenta on the other hand will cause a rigid chest in large doses.
I use the actual weight for narcotic boluses. Fat is a great reservoir for Fentanyl. Again, every situation and patient is different. I use these large amounts on ASA 1-2 without COPD, Hx of severe sleep apnea etc.. ..
I always thought the 'Rigid Chest' was from rapid Fentanyl bolus, not necessarily the amount. That said, in almost 10 years of critical care, I don't think I have ever seen the rigid chest phenomena from Fentanyl....I have only read about it. I also hope I do not see it any time soon! :)
Never had a rigid chest that Sux won't cure. Obviously I would never push all those narcs without wanting to secure the airway. Never had rigid chest with Fentanyl but Sufenta/Alfenta on the other hand will cause a rigid chest in large doses.
I use the actual weight for narcotic boluses. Fat is a great reservoir for Fentanyl. Again, every situation and patient is different. I use these large amounts on ASA 1-2 without COPD, Hx of severe sleep apnea etc.. ..
Snakebitten - you are exactly 100% dead-on-the-money correct in how you are dosing your Fentanyl. One of the attendings that I work with on an almost daily basis did much of the early animal studies on the pharmacokinetics of Fentanyl and wrote the Opiod chapter in Barash when I was a student in 1990. He taught me that dosing Fentanyl 8-12 mcg/kg at induction provided very predictable results and stable hemodynamics. I only dose in this manner if I'm fairly confidant that the case will last 1 hour or more although I have always been able to wake up patients when I have misjudged. Like you, I can't remember the time that I had to resort to Narcan. My typical regimen for TAH as an example is 500 - 700 mcg Fent on induction followed in about 30 min by 10mg MSO4. As the Fentanyl levels start to tail off during the second half hour of the case, the MSO4 is reaching peak efficacy. The end result is a great preemptive analgesia anesthetic with the patient waking up very quickly and absolutely pain free. PACU time is paradoxically decreased with this technique because the nurses are not having to give pain meds to keep the patient comfortable. I have been using this technique for many years and constantly get the question - "what is it that you are doing different??" because my patients wake up so smoothly and quickly and are easy to recover.
Pre-emptive analgesia is the key to a truely elegant anesthetic. Dose your narcotic preemptively instead of reactively (BP and HR changes) and you will get a consistently smooth anesthetic course and a really great wakeup.
I have read that low does of ketamine (5-20mg iv) provide profound analgesia and may act to decrease narcotic requirements. Does anyone out there do this?
I always thought the 'Rigid Chest' was from rapid Fentanyl bolus, not necessarily the amount
well exactly, if your pushing 800 mcg for induction there is only so much time you have before you need to put the tube in. i've heard of rigid chest with 200 mcg, when pushed fast. i've never seen it.
so this brings a good point, how fast do you push 800 mcg for induction?
while i like the idea of high-dose narcotics - giving a patient 700mcg of fentanyl for a 20 minute case? give me a break.... while i agree the less volatile you use, the better the wake up, I find that using such high doses of fentanyl unnecessary....
- don't tell me to read the literature on context sensitive half-life when you clearly don't understand context sensitive half-life: it is the time for plasma concentration to fall by 50% following steady-state infusion and constant blood levels (which for most drugs is about 2-3 hours)... which is totally unrelated to single-dose boluses at the beginning of the case. Not to mention that the context sensitive half-life of fentanyl after infusion is >100 mins!!! and in some reports can be close to 400-500 minutes! Which is the main reason that a fentanyl infusion is pointless, might as well just use a dilaudid infusion.
I work in recovery the best wake ups I've seen were with bolus doses of fent up front then using small amts every 15 mins to prevent the drug from wearing off and switching to morphine near the end for the longer pain relief effects, and always versed at the beginning of the case waking up in recovery is scary best to be sleepy and forgetful. Our CRNA does a great job with this I've never had a single respiratory or pain issue with his work
I've only been in clinical for a week and thus have had nausea, vomiting and diarhea for a week. one week and I am on call for the first time on sunday. yeesh.
anyway. durring a confernce this week we talked about neonate emergencies ie gastrochesis or diaphragmatic hernia. The instructor whos is an Author of a pediatric text book stated that studies have shown that you could give up to 50mcg/kg to these neonates and they wake up and breathe just fine. when he said this I thought "no way" I was thinking of context sensitve half time. but he said that as long as its all in one whack it will come off quick.
the next day I was with him in a 15 day old PDA ligation and we used almost 60mcg/kg fent and the patient woke up and was breathing after a case that lasted only about an hour.
I am new and barley know what I am talking about but i think it fits here. of course I don't remember what we did for amnestic.
but as I remember Dr. Iger saying if they don't rememeber then there was no pain. ????? all these schools of thought are reaking havoc in my brain.
Finally.. Someone with a little experience and cajones (spanish slang-for b_lls) knows how to dose narcotics. Good for you AND your patients. Gotta start another case..I'll jump on the computer another time..and we'll talk. Later
Snakebitten - you are exactly 100% dead-on-the-money correct in how you are dosing your Fentanyl. One of the attendings that I work with on an almost daily basis did much of the early animal studies on the pharmacokinetics of Fentanyl and wrote the Opiod chapter in Barash when I was a student in 1990. He taught me that dosing Fentanyl 8-12 mcg/kg at induction provided very predictable results and stable hemodynamics. I only dose in this manner if I'm fairly confidant that the case will last 1 hour or more although I have always been able to wake up patients when I have misjudged. Like you, I can't remember the time that I had to resort to Narcan. My typical regimen for TAH as an example is 500 - 700 mcg Fent on induction followed in about 30 min by 10mg MSO4. As the Fentanyl levels start to tail off during the second half hour of the case, the MSO4 is reaching peak efficacy. The end result is a great preemptive analgesia anesthetic with the patient waking up very quickly and absolutely pain free. PACU time is paradoxically decreased with this technique because the nurses are not having to give pain meds to keep the patient comfortable. I have been using this technique for many years and constantly get the question - "what is it that you are doing different??" because my patients wake up so smoothly and quickly and are easy to recover.
Pre-emptive analgesia is the key to a truely elegant anesthetic. Dose your narcotic preemptively instead of reactively (BP and HR changes) and you will get a consistently smooth anesthetic course and a really great wakeup.
OK don't read..You are probably some tube monkey supervised by an MDA, try working alone and making Your OWN decisions someday. Blah ,Blah Blah with all the literature.Have you ever noticed the ones who talk the most, read the most and think they know the most , can't deliver an anesthetic if their life depended on it.. Thats where your headed...Experience is the best educator. Listen once in awhile without erupting AND you will probably learn something. I have found that the CRNA's that are supervised are usually trying to prove something-get over it or come out to the boonies and make your own decisions unsupervised.."Give me a break"
while i like the idea of high-dose narcotics - giving a patient 700mcg of fentanyl for a 20 minute case? give me a break.... while i agree the less volatile you use, the better the wake up, I find that using such high doses of fentanyl unnecessary....
- don't tell me to read the literature on context sensitive half-life when you clearly don't understand context sensitive half-life: it is the time for plasma concentration to fall by 50% following steady-state infusion and constant blood levels (which for most drugs is about 2-3 hours)... which is totally unrelated to single-dose boluses at the beginning of the case. Not to mention that the context sensitive half-life of fentanyl after infusion is >100 mins!!! and in some reports can be close to 400-500 minutes! Which is the main reason that a fentanyl infusion is pointless, might as well just use a dilaudid infusion.
there is nothing wrong with high-dose narcotic techniques - especially in neonates or in cardiac or even in neuro patients.... but to use high dose fentanyl for other cases that are short (ie: tonsillectomy) is kinda pointless... you could get the same results with much lower doses, trust me...
by the way, I am not supervised, I am an MD, I teach pharmacology at med school, 80% of time do my own cases - I was just responding to your inappropriate use of a principle of pharmacology to support your narcotic management...
there is nothing wrong with high-dose narcotic techniques - especially in neonates or in cardiac or even in neuro patients.... but to use high dose fentanyl for other cases that are short (ie: tonsillectomy) is kinda pointless... you could get the same results with much lower doses, trust me...
by the way, I am not supervised, I am an MD, I teach pharmacology at med school, 80% of time do my own cases - I was just responding to your inappropriate use of a principle of pharmacology to support your narcotic management...
I also do not advocate high dose narcotics for very short cases. But for cases that most would consider to be relatively painful (abdominal incisions, total joints, major spine etc), then I do consider it a great technique. The key is to give the big dose up front and then maintain a constant narcotic level either by infusion or switching to a longer lasting drug before the Fentanyl has worn off. I do not wait to see changes in BP or heart rate to give more narcotic, but see these changes as an indication that I'm not dosing appropriately. Studies have shown that pre-emptive dosing techniques such as this cause patients perception of post-operative pain to be less and consequently they will require less analgesics to remain comfortable.
snakebitten
39 Posts
Never had a rigid chest that Sux won't cure. Obviously I would never push all those narcs without wanting to secure the airway. Never had rigid chest with Fentanyl but Sufenta/Alfenta on the other hand will cause a rigid chest in large doses.
I use the actual weight for narcotic boluses. Fat is a great reservoir for Fentanyl. Again, every situation and patient is different. I use these large amounts on ASA 1-2 without COPD, Hx of severe sleep apnea etc.. ..