Precedex Bolus- no loading dose.

[sevoflurane]

Who does it and what is your mcg/kg dose? Any side effects or problems? What cases?

I have a partner that does it all the time... puts 200mcgs into 100CC bag and uses it for a day or two. Just curious who else uses it this way. For long fusions I do the standard loading dose over 5-10 minutes and then switch to an infusion, +ketamine, +small amount of narcs. Other than that I use it very selectively as it's not a cheap drug. Wondering if anyone has had any problems with patients who are wired with a strong vagal system after a dex bolus.

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[cchoukal]

I'm using it primarily in the ICU for sedation, either on or off the vent. I don't load, although I typically start the infusion kind of high (1-1.2 mcg/kg/hr) and taper down, so it's sort of like a load.

As a resident, I used it a few times for sedation for awake FOBI. For that indication, I would load 20-40 mcg (20 at a time, slow IV push).

I also liked the 20-40 mcg bolus for sedation on short ortho cases with good blocks.

I did a fair amount of neuro (heads and backs) with dex and sufentanil, and I did not routinely load those cases.

 

[IN2B8R]

Had a partner push a significant bolus. Patient got brady (HR = 19) and hypotensive. Partner took my epi drip from the heart room. Patient did fine with pharmacologic pacing (epi). Precedex eventually wore off, but it took several hours....

Who does it and what is your mcg/kg dose? Any side effects or problems? What cases?

I have a partner that does it all the time... puts 200mcgs into 100CC bag and uses it for a day or two. Just curious who else uses it this way. For long fusions I do the standard loading dose over 5-10 minutes and then switch to an infusion, +ketamine, +small amount of narcs. Other than that I use it very selectively as it's not a cheap drug. Wondering if anyone has had any problems with patients who are wired with a strong vagal system after a dex bolus.

 

[sevoflurane]

I'm using it primarily in the ICU for sedation, either on or off the vent. I don't load, although I typically start the infusion kind of high (1-1.2 mcg/kg/hr) and taper down, so it's sort of like a load.

As a resident, I used it a few times for sedation for awake FOBI. For that indication, I would load 20-40 mcg (20 at a time, slow IV push).

I also liked the 20-40 mcg bolus for sedation on short ortho cases with good blocks.

I did a fair amount of neuro (heads and backs) with dex and sufentanil, and I did not routinely load those cases.

This is what I wanted to hear. One guy here uses it on almost all his ortho cases. He states that with blocks on board... narc requiremet is essentially nil and can decrease tachy/HTN with long tourniquet times.
He also uses Propofol + dex for quick gyn cases. Again, no narcs... wake up happy without N/V and are out the door quickly. Interesting application for dex. If you used 200mcg for 10 cases, it may be worth the extra cost.

 

[sevoflurane]

Had a partner push a significant bolus. Patient got brady (HR = 19) and hypotensive. Partner took my epi drip from the heart room. Patient did fine with pharmacologic pacing (epi). Precedex eventually wore off, but it took several hours....

This is my #1 reservation for using it as a bolus. There are plenty of documented reports of cardiac arrest with bolus delivery. Do you know how much the patient received? 20mcgs or 100mcgs?

Anyone bolusing the peds population?

 

[Ventil8]

We routinely bolus only for shorter (1-2hr) cases with a case total of 1mcg/kg. Used more for emergence delirium than anything else.

Slows wake ups until you get used to it.

Brady exceedingly rare (0.2/kg post induction).

 

[militarymd]

anyone ever use it subcutaneously?

Seems like a perfect way to administer it for a short procedure.

 

[IN2B8R]

He used a 1mcg/kg dose. If I remember correctly, patient was about 100kg, already on a moderate dose of BB and on an ACE-I. So I guess he started with bradycardia from the get go.... He said that after 6cc's were in, pt got severely Brady and hypotensive. He first bolused 40mcg of epi, but when that quickly wore off, he started epi gtt. That lasted about 3 hours. I guess it's safe to bolus for procedural sedation, just need good patient selection....

This is my #1 reservation for using it as a bolus. There are plenty of documented reports of cardiac arrest with bolus delivery. Do you know how much the patient received? 20mcgs or 100mcgs?

Anyone bolusing the peds population?

 

[GasDaddy]

I'm a resident but have used this drug quite a bit. I don't like to load, especially for long cases; your levels will build up with time. I think it's perfect for the obese/morbidly obese patient: you can use minimal narcotics and have a much smoother extubation/wake up. You can also keep it running in the PACU to decrease your narcotic requirements. I think it is overrated for FOI. Nothing beats topicalization + transtracheal block + superior laryngeal block + talking to the patient in advance and coaching them on the procedure.

 

[coprolalia]

I used Precedex a lot during residency. We currently do not have it on formulary where I'm currently practicing.

We used as an adjunct during balanced anesthesia. And, I think that's the take-home message. Some of the pediatric anesthesiologists picked-up on a Harvard paper regarding single-dose bolusing procedural sedation, and started giving it to kids undergoing MRI (etc.). That was all fine and dandy until one little, tiny kid had refractory bradycardia and this particular attending almost killed him. Fortunately, he had some epi drawn up.

I'm out of practice with this drug. We are currently trying to get it on formulary, as I think it is a great adjunct in (for example) neuro procedures as GasDaddy describes. But, it is a drug you have to get comfortable using, just like every other medication. It has a lot of benefit, but a lot of risk if used improperly IMHO.

-copro

 

[tucker27705]

I have only used it once since residency. Used it A LOT there. Limited here to cardiac pts due to cost.
The only times I saw it given in bolus form, it was typically in 20-40 mcg increments. These pts were often rough wake ups in the Pacu. Also, given for awake foi. Despite the above comment, it does wonders for an foi. Pts love it. They also like 5-700mcgs of fent with NO versed. To each his own, we have all developed the method we like and are most comfortable with. No pt arguing.

100mcg? sounds excessive. I would do 20 and see the response, then titrate to effect.

Tuck

 

[Fastrach]

I'm using it primarily in the ICU for sedation, either on or off the vent. I don't load, although I typically start the infusion kind of high (1-1.2 mcg/kg/hr) and taper down, so it's sort of like a load.

I thought Precedex had fallen out of vogue for ICU sedation. I know it was all sexed up for this purpose when it first came out, but then some studies came out against using it. Yes, it's a nice sedative, but it has basically nil amnestic properties, so all these poor people in the ICU had complete recall of their prolonged ICU stays on Precedex infusions. Is there newer data on this?

 

[cchoukal]

I thought Precedex had fallen out of vogue for ICU sedation. I know it was all sexed up for this purpose when it first came out, but then some studies came out against using it. Yes, it's a nice sedative, but it has basically nil amnestic properties, so all these poor people in the ICU had complete recall of their prolonged ICU stays on Precedex infusions. Is there newer data on this?

Most of the data are against midaz and loraz, and the results were favorable in terms of reduced benzos, reduced delirium, and, if I recall, more vent-free days, albeit at the cost of more fentanyl. SCCM continues to have loraz as their officially endorsed ICU sedative (probably because they're taking money from Hospira), which means that there never has to be a dex vs prop study. We all know that dex is inferior to prop for ICU sedation. That said, it's pretty good for moving the wild, thrashing patient toward extubation (the "dex"-tubation), and nice for the demented moaning old ladies who aren't on the vent. There are data in alcohol withdrawal as well, primarly with regard to lower benzo doses, and I use it a fair bit for that purpose. But as a first line vent sedative? Not typically my first choice.

 

[sevoflurane]

Most of the data are against midaz and loraz, and the results were favorable in terms of reduced benzos, reduced delirium, and, if I recall, more vent-free days, albeit at the cost of more fentanyl. SCCM continues to have loraz as their officially endorsed ICU sedative (probably because they're taking money from Hospira), which means that there never has to be a dex vs prop study. We all know that dex is inferior to prop for ICU sedation. That said, it's pretty good for moving the wild, thrashing patient toward extubation (the "dex"-tubation), and nice for the demented moaning old ladies who aren't on the vent. There are data in alcohol withdrawal as well, primarly with regard to lower benzo doses, and I use it a fair bit for that purpose. But as a first line vent sedative? Not typically my first choice.

I've seen it to wonders in the delerious, ETOH dependant ICU patient. FDA only approves it for 1 day last I remember (I don't know why??? withdrawl probably) That being said we will use it on selected patients for 3-4 days and sometimes longer.

 

[cchoukal]

I've seen it to wonders in the delerious, ETOH dependant ICU patient. FDA only approves it for 1 day last I remember (I don't know why??? withdrawl probably) That being said we will use it on selected patients for 3-4 days and sometimes longer.

Excellent use for it. Hospira has been saying for almost a year that they have "new data" and a "new indication" coming, and many of my attendings thing it will be for longer duration of use. They say that when propofol came out, it had limited indications too. Of course, I wasn't around then, so I don't know.

We've used it for a week or more on some, and at doses well above the 1 mcg/kg/hr range.

 

[Gas girl123]

This is my #1 reservation for using it as a bolus. There are plenty of documented reports of cardiac arrest with bolus delivery. Do you know how much the patient received? 20mcgs or 100mcgs?

Anyone bolusing the peds population?

I know someone that uses uses precedex in pediatric tonsils. She gives .5 mcg per kg toward the end, and they wake up calm and sleeping.

 

[IlDestriero]

I know someone that uses uses precedex in pediatric tonsils. She gives .5 mcg per kg toward the end, and they wake up calm and sleeping.

That's a common use. I love it for palates. It may delay your pacu D/c though, so I don't use it at the ASC. The literature suggests it doesn't delay d/c, but I believe it does from my experience.

 

[psychbender]

At the children's hospital during residency, we gave precedex for pediatric tonsils all of the time, but not quite as a bolus. Often, we put 0.5-1mcg/kg precedex, 0.5-1mcg/kg fentanyl, decadron, and IV tylenol into a burretrol, then filled with IV fluid to a total volume of 100mL. This was then opened wide immediately after induction, and usually complete within ten minutes. Patients remained very calm and sedated for extubation, and for the next half hour or so in PACU. When they woke up further, they did have some opioid and tylenol on board, so there were not in severe pain. Based on suggestions from a few attendings, I tried it a few time with no opioid, just 2mcg/kg precedex, with the result of more sedation, but no analgesia when they eventually woke up an hour after surgery. I haven't tried in since I've been staff, as I do not trust my current PACU nurses to recover a child that is not wide awake (low volume of peds cases).

 

[sevoflurane]

Yup. I use it all the time as a bolus now days (this thread is from 2010). 20-40mcg bolus. Very safe.
I've used it on peds the population. Not in the tonsils room though. I really don't see a need for it there as we soak the tonsillar fossa with marcaine with epi and I give a little whiff of fentanyl. These cases are 10 minutes, so I try to keep it simple and have fast turnovers.

 

[San Marzano]

This is my #1 reservation for using it as a bolus. There are plenty of documented reports of cardiac arrest with bolus delivery. Do you know how much the patient received? 20mcgs or 100mcgs?

Anyone bolusing the peds population?

I had a patient arrest during an elective MAC case my second month of CA1. Young patient with zero health problems, not taking any meds. We had given the pt. a bolus of 0.5mcg/kg over 10 minutes (~35mcg total) and then ran the infusion at 0.7mcg/kg/hr. The arrest occurred about 30 minutes into the case. It was a very brief and benign event(around 30 seconds of asystole and pulselessness) and the pt recovered fully. It was a very hard way to learn to respect the potent bradycardia inducing effect of precedex though.

 

[IlDestriero]

What was the elective case? 20 min after the bolus doesn't sound like its Dex related to me. Sounds like a reaction to surgical stimulation.

 

[San Marzano]

What was the elective case? 20 min after the bolus doesn't sound like its Dex related to me. Sounds like a reaction to surgical stimulation.

Yeah that is also on my list of causes, hard to pin it solely on one thing. It was a small umbilical hernia repair, and the patient exhibited very strong vagal reaction to pulling on the peritoneum by the surgeon. Case was booked for a general, but the surgeon suggested that he could get a strong local field block and the patient was very motivated to have a MAC so thats what we chose to do.

 

[HollywdAnesth]

I love precedex. I use it frequently in my cases that I do under block. I give the loading dose (1 mcg/kg) along with fentanyl and/or versed and they snooze through the block itself and the entire case.
I like to use it in kids as well. You can put 5-6 mcg/kg into an atomizer and spray it into the kid's nose. Perfect for CT scans.
For any other peds case, give the child 1 mcg/kg as soon as they cry in recovery and it makes the nurses and parents super happy.

 

[Member12344]

This is an excellent discussion. I've used precedex in my pediatric anesthesiology practice for 8 years now for almost every case, with a few exceptions. The two primary reasons why I use it: emergence agitation prophylaxis; attenuation of a patient's transition through stage II after deep extubation. Bolus is 0.4 - 0.5 mcg/kg IV. No more than 12 mcg total for teens, unless they are quite autisic, because teens don't typically have emergence agitation after deep extubation. I've never had an untoward event of bradycardia. I use it to intubate, to place LMAs, for MRI sedations, everything. Happy to explain more if interested.

 

[IlDestriero]

It works great for MEG scans as well as the sole anesthetic.

 

[anes]

Had a partner push a significant bolus. Patient got brady (HR = 19) and hypotensive. Partner took my epi drip from the heart room. Patient did fine with pharmacologic pacing (epi). Precedex eventually wore off, but it took several hours....

I use it ALL the time. Never run infusions (even spine cases) just intermittently bolus. Usually will load them up with dexmedetomidine prior to intubation (on the way from preop to or) like 1-2 MCG per kilo. Bolus 10-20 mcgs at a time. Never ever get hypotension from it. Always always get hypertension. People do go bradycardic, but i have never had anyone so bradycardic that I was worried.

An hour later as the dexmed is wearing off, pressure may sag a bit. But never have I seen someone become hypotensive from a bolus dose.

In one of my old posts I mention an attending who bolused like 150 MCG on a ruptured AAA, whose blood pressure was 60/30. Guess what happened... Pressure improved to near normal range. Did EVAR with nothing but dexmedetomidine sedation.

Everybody is going to say how wrong it was etc. But my experience with the drug seems vastly different than it seems everyone else's.

 

[deleted171991]

The 1 mcg/kg "bolus" is actually a loading dose, and it's supposed to be given over 10 minutes. I haven't used it since residency, but back then I never saw severe bradycardia with a loading infusion. We also didn't run them at 0.7 mcg/kg/h, more like 0.2-0.4, never as a sole anesthetic.

The problem with that bradycardia is that it's supposedly atropine-resistant.

 

[dhb]

and they wake up calm and sleeping.

Waking up sleeping, i've gotta try it asap

 

[fakin' the funk]

I use it ALL the time. Never run infusions (even spine cases) just intermittently bolus. Usually will load them up with dexmedetomidine prior to intubation (on the way from preop to or) like 1-2 MCG per kilo. Bolus 10-20 mcgs at a time. Never ever get hypotension from it. Always always get hypertension. People do go bradycardic, but i have never had anyone so bradycardic that I was worried.

And this is doing what exactly for you?

Dexmedetomidine is a great drug in the ICU. It causes "gentle" sedation and is not very deliriogenic. Few patients get bradycardic from it, and those that do (young and vagal or old and sick sinus) generally can tolerate propofol or nothing just fine.

But in the OR it is nearly worthless. It has a long tail...its effect is subtle...it's difficult to titrate...and let's not forget that it CAUSES BRADYASYSTOLIC ARREST. Yeah, that sounds like a perfect drug for anesthesiologists.

And your story about the ruptured AAA whose severe hypotension was corrected by dexmedetomidine, that's complete BS.

 

[Arch Guillotti]

And your story about the ruptured AAA whose severe hypotension was corrected by dexmedetomidine, that's complete BS.

No way I would have treated hypotension this way. Too much precedex can cause hypertension though.

 

[deleted171991]

No way I would have treated hypotension this way. Too much precedex can cause hypertension though.

What's the mechanism? I would expect an alpha2 agonist to be hypotensive.

 

[anes]

What's the mechanism? I would expect an alpha2 agonist to be hypotensive.

Alpha 2a mediates sedation. Alpha 2b mediated vascular tone. High dose dexmed causes alpha 2b activation.

 

[deleted171991]

The α2-adrenergic receptor is classically located on vascular prejunctional terminals where it inhibits the release of norepinephrine (noradrenaline) in a form of negative feedback.[3] It is also located on the vascular smooth muscle cells of certain blood vessels, such as those found in skin arterioles or on veins, where it sits alongside the more plentiful α1-adrenergic receptor.[3] The α2-adrenergic receptor binds both norepinephrine released by sympathetic postganglionic fibers and epinephrine (adrenaline) released by the adrenal medulla, binding norepinephrine with slightly higher affinity.[

However, it's also this:

Common effects include:

• Suppression of release of norepinephrine (noradrenaline) by negative feedback.[3]
• Transient hypertension (increase in blood pressure), followed by a sustained hypotension (decrease in blood pressure).[5]
• Vasoconstriction of certain arteries

http://www.wikiwand.com/en/Alpha-2_adrenergic_receptor

I didn't know it can give transient hypertension before the hypotension, and the mechanism for it is not clear in my mind, unless it produces vasoconstriction in certain territories directly, before it gets to block norepi release.

 

[anes]

And this is doing what exactly for you?

Dexmedetomidine is a great drug in the ICU. It causes "gentle" sedation and is not very deliriogenic. Few patients get bradycardic from it, and those that do (young and vagal or old and sick sinus) generally can tolerate propofol or nothing just fine.

But in the OR it is nearly worthless. It has a long tail...its effect is subtle...it's difficult to titrate...and let's not forget that it CAUSES BRADYASYSTOLIC ARREST. Yeah, that sounds like a perfect drug for anesthesiologists.

And your story about the ruptured AAA whose severe hypotension was corrected by dexmedetomidine, that's complete BS.

Long half life...that's why it's better as bolus dose instead of infusion. I've found dexmedetomine to smooth hemodynamics intraoperatively. It significantly reduces opioid requirements. We do kidney transplants with literally zero opioids because of dexmedetomidine.

Never have I seen anything close to bradysystolic arrest with dexmedetomidine. Remifentanil will for sure cause Brady arrest with large bolus dose.

 

[fakin' the funk]

However, it's also this:

http://www.wikiwand.com/en/Alpha-2_adrenergic_receptor

I didn't know it can give transient hypertension before the hypotension, and the mechanism for it is not clear in my mind, unless it produces vasoconstriction in certain territories directly, before it gets to block norepi release.

Yeah, that's all well and good. But let's not miss the MAIN THING hemodynamically that dex does: cause bradycardia.

And let's also not forget the fact that Anes claimed he successfully treated hypovolemic shock in a patient with a ruptured AAA with dexmedetomidine.

Younguns out there: do not do this; you will regret it.

 

[deleted171991]

Yeah, that's all well and good. But let's not miss the MAIN THING hemodynamically that dex does: cause bradycardia.

The main thing is hypotension since, after all, this is the same class as clonidine (just 200 times more alpha2 specific).

Adverse Reactions
The most significant adverse reactions associated with dexmedetomidine are hypotension and bradycardia, resulting from its sympatholytic activity. In clinical trials of adults, 28% of patients receiving dexmedetomidine experienced hypotension, compared to 13% of patients given placebo. Bradycardia was seen in 7% of treated patients versus 3% of controls. While a reduction in the infusion rate or administration of IV fluids is often adequate to alleviate these symptoms, administration of atropine may be necessary in cases of significant bradycardia. Transient hypertension has been reported with the administration of the loading dose due to initial peripheral vasoconstriction. In clinical trials, the rate of hypertension was similar in treated patients and controls (16% compared to 18%). Hypertension rarely requires intervention beyond slowing the infusion rate.[2,3]

Other adverse reactions reported with dexmedetomidine during clinical trials included nausea (11%), fever (5%), vomiting (4%), hypoxia (4%), tachycardia (3%), and anemia (3%). It is recommended that dexmedetomidine be used with caution in patients with advanced heart block or severe ventricular dysfunction, as well as in hypovolemic patients or those with chronic hypertension.[2,3]

http://www.medscape.com/viewarticle/524752_6

And let's also not forget the fact that Anes claimed he successfully treated hypovolemic shock in a patient with a ruptured AAA with dexmedetomidine.

I am also intrigued, but I remember the quote from Wikipedia which says that dex causes temporary hypertension before causing hypotension.

 

[Ignatius J]

I use 0.5 mcg/kg pretty frequently and have never had any issues.

Gotten away from using it as it's expensive and other meds can do the trick. But yeah, it's a great drug. Do bolus and then 0.2-1 mcg/kg/hr.

 

[Ignatius J]

The main thing is hypotension since, after all, this is the same class as clonidine (just 200 times more alpha2 specific).

http://www.medscape.com/viewarticle/524752_6


I am also intrigued, but I remember the quote from Wikipedia which says that dex causes temporary hypertension before causing hypotension.

It does, but I've never seen it be clinically significant. Everyone is different, but the top of the bell curve (just ball parking) maybe increases MAPS 10-20% for a few BP cycles. Never seen anything close to a hypertensive crisis or anything.

 

[Libertas]

Had it happen to me recently during a vascular bypass case....patient had been moderately hypertensive throughout case requiring a couple doses of anti hypertensives previously. Towards ends of case I gave 0.5mcg/kg of precedex and the patient abruptly went from 140 sbp to 230 sbp. Over 5-10 minutes it drifted back down without much intervention. Didn't experience any bradycardia or hypotension in that particular patient.

 

[Gas girl123]

That's a common use. I love it for palates. It may delay your pacu D/c though, so I don't use it at the ASC. The literature suggests it doesn't delay d/c, but I believe it does from my experience.

Although she made a med error and instead of giving 2mg of zofran , she gave 100mcg of precedex undiluted. Yikes!. The heart rate dropped but not too low. the child was around 8 years old. I guess he slept for 2 hours in pacu. They ended up transferring him to a childrens hospital to monitor him overnight .There was no other adverse effects.

 

[deleted9493]

Yesterday afternoon I took care of a child having a open partial nephrectomy through a typical subcostal incision. The surgeon was thinking that the kiddo could go home the following night, so felt that an epidural might not be the best option. I ran a dexmedetomidine infusion at .5mcg/kg/h (total dose for the case 1.5mcg/kg). .15mg/kg morphine, IV tylenol, lidocaine infusion and some mag sulfate for good measure. The child received one dose of morphine 10hrs after case's end and had good pain control with prn hycet today.

I believe that dex. has a significant opioid-sparing effect which typically seems to last 3-4 half lives of the drug (6-8hrs). I have done this on big, painful cases not amenable to regional (spine fusions for scoliosis where surgeon not a fan of laying an epidural catheter in the field) and consistently, when I see these kids on the floor...their pain becomes more typical (what you'd expect with traditional opioid pain management) at the 6-8hr timeframe. I tell families that this will be the case and they seem appreciative and tempered by the forewarning.

To further illustrate it's analgesic properties, I have also used dex. as the sole analgesic (beyond an intubating dose of fentanyl) for laparoscopic gastric restrictive procedures in morbidly obese patients with sleep apnea (.2mcg/kg/h based on actual body weight). I can't say that I've ever needed to titrate opioid after extubation. They emerge so smoothly.

The naysayers can hate but PACU nurses and postop. opioid consumption (or lack thereof), don't lie...at least not that often.

 

[deleted171991]

It makes perfect sense to be opioid-sparing. Even N2O is opioid-sparing intraop, so why not a much stronger analgesic that is also long-acting on top of it?

On the other hand, I think some people are way too obsessed with avoiding opiates at all costs, even at low dose in the opiate naive. Everything in moderation, that's my motto. There is no wonder drug, and the best drugs are those which one knows best and serve the purpose.

 

[deleted9493]

Oh, and I will do the same thing with dex. in the buretrol for tonsils. I do this on days in which I have several patients who I feel will benefit from it as an adjuvant. Our pediatric pharmacy is working on fractionating vials into syringes because it is growing in popularity with both our anesthesiologists and PACU nurses.

 

[deleted9493]

I think pain management needs to be viewed in much the same way as we view 'balanced anesthesia'. Lower doses of different drugs to reach your goal...avoiding the side effects of higher doses of any single drug. I mean, the evidence is out there to support a practice that is not defined by simply gorking patients with opioids. They do have their role and in the foreseeable future, opioids will be primary but we can do better.

 

[dhb]

Yesterday afternoon I took care of a child having a open partial nephrectomy through a typical subcostal incision.

Many ways to skin a cat, i'd just do a TAP and the kid wouldn't even have needed morphine...

 

[Promethean]

In our peds OR, almost the only question about precedex is whether to give it before or after extubation. Virtually every patient gets a little, unless there is a definite contraindication. The PACU nurses ask for it by name, and they get really peeved if we deliver a patient that didn't get any at all. Residents are advised to bring a syringe of it with them when delivering the patient to PACU, just in case. I see boluses given in 4-8 mcg aliquots, and for many smaller or calmer kids, 4-8 mcgs will be the total dose. If a patient is larger or waking up wild, 16-24 mcg is not unheard of, and I have seen some heroic (40+mcg) doses given to delirious teens. I'm sure that mcgs/kg calculations are considered, but I almost never hear them discussed. Rather, there is a quick titration to effect over the course of a minute or two.

A very few of our anesthesiologists will work in a little precedex into their premed. I've seen it used as the only premed for patients with a history of paradoxical reaction to versed, and it seemed to work very well. I can't comment on those doses at all.

 

[deleted9493]

If you were having part of your kidney taken out via a lateral subcostal incision, would you want a TAP or paravertebral block? I submit this question to those who have a reasonable amount of experience following patients after these types of blocks...

 

[Arch Guillotti]

Saudi J Anaesth. 2011 Oct-Dec; 5(4): 395–410.

Hypertension has also been reported during the loading dose. This hemodynamic effect is thought to be mediated via peripheral α2B-adrenergic agonism leading to vasoconstriction prior to the onset of the central effects. Other investigators have reported the potential for the development of bradycardia with dexmedetomidine although in most cases the blood pressure is well maintained.

Anesth Analg. 2010 December ; 111(6): 1490–1496.

Introduction—Dexmedetomidine is a highly selective α2-adrenoceptor agonist with sedative,
anxiolytic and analgesic properties that has minimal effects on respiratory drive. Its sedative and
hypotensive effects are mediated via central α2A and imidazoline type 1 receptors while activation
of peripheral α2B–adrenoceptors result in an increase in arterial blood pressure and systemic
vascular resistance (SVR). In this randomized, prospective, clinical study we attempted to quantify
the short-term hemodynamic effects resulting from a rapid IV bolus administration of
dexmedetomidine in pediatric cardiac transplant patients.

Results—There were 6 patients in each group. Investigation suggested that systolic blood
pressure, diastolic blood pressure, systolic pulmonary artery pressure, diastolic pulmonary artery
pressure, pulmonary artery wedge pressure and systemic vascular resistance all increased at 1
minute after rapid IV bolus for both doses, and decreased significantly to near baseline for both
doses by 5 minutes. The transient increase in pressures was more pronounced in the systemic
system than in the pulmonary system. In the systemic system there was a larger percent increase in
the diastolic pressures than the systolic pressures. Cardiac output, CVP and pulmonary vascular
resistance did not change significantly. HR decreased at 1 min for both doses and was, within the
0.5 mcg/kg group, the only hemodynamic variable still changed from baseline at the 5 min time
point

 

[dhb]

If you were having part of your kidney taken out via a lateral subcostal incision, would you want a TAP or paravertebral block? I submit this question to those who have a reasonable amount of experience following patients after these types of blocks...

If open i guess epidural > TAP - paravertebral if robot or laparoscopic TAP> paravertebral

 

[asmith1121]

Hi, I'm a resident and have a few questions on using precedex. Please be patient! Most of my attendings don't use it and don't know how to use it, but have been open to trying. I've been doing a lot of reading on how to use it. When I tried using it alone for deep sedation, it was not possible to achieve the same sedation as with propofol (I know...sedation is sedation, not general anesthesia, but there is still a certain expectation by surgeons and even anesthesia attendings). So I combined with propofol, and I have been in love for awhile. I don't struggle with apnea anymore, as it reduces the propofol requirement, and luckily I've never experienced problems with bradycardia or hypotension. If anything, I used it to my advantage in a FESS case w/GA, and never had to bother with labetalol and labile pressures. I usually give a very small loading dose(20-40mcg over 10min), because regardless of sedation or GA, I usually bolus propofol. If I'm doing an EVAR or angio case, and I'm only using dex, then I use 0.5mcg/kg, and start as soon as possible. I have never really had a problem with it until recently. Pts seem oversedated in the PACU, possibly bc I have been using higher amounts? Lately I've been doing 0.5+mcg/kg with small amount of propofol. And then I suggested using it on a bariatric case. As most of these patients besides being large, have OSA and I thought it would reduce the narcotic requirement intraoperatively and postop, and allow for a smooth wakeup. Well, my attending wanted to use remi too and bolused 1mg hydromorphone at the end, which kind of defeated the purpose. We used a BIS and kept MAC at 0.4. He got a total of 110mcg over 2hr, got a bolus dose of 40mcg and was kept at 0.2mcg/kg/hr. Although he woke up smooth, was breathing on his own, and was following commands (head lift, hand grip, answering questions, etc), my attending didn't want to extubate bc he said he looked sleepy and could stop breathing if he fell back asleep without the tube. He said it was because of the precedex, which I understand can cause oversedation, but what about the fact that he was 350lb, with OSA, and had gotten 1mg dilaudid at the end? And now I'm concerned about oversedation, that I don't really want to use it, even though it makes my life so much easier in deep sedation cases, and patients seem to wake up smoother, with less narcotic requirement. What is the max total dose you would give a patient? How many hours? In a 3hr case, when would you consider shutting it off, and just running propofol? Thanks.