Pentobarb comas

RedBait · Sep 12, 2004

Okay, here is a big question. We are trying to develop a protocol for placing a pt in a pentobarb coma. After not doing it for a while the protocol became outdated, now that we have had two in the last few months we need a protocol. I have looked in Hickey for the general principles, I am hoping somebody out there has a protocol they would be willing to share a portion of to help us out or give us something to go by. Any ideas would be welcome. Thanks everyone! :)

Barbiturates are the most common class of drugs used to suppress cerebral metabolism. Barbiturate coma is typically induced with pentobarbital. A loading dose of 10 mg/kg is administered over 30 minutes, and then 5 mg/kg/h is administered for 3 hours. A maintenance infusion of 1-2 mg/kg/h is begun after loading is completed. The infusion is titrated to provide burst suppression on continuous electroencephalogram monitoring and a serum level of 3-4 mg/dL. Typically, the barbiturate infusion is continued for 48 hours, and then the patient is weaned off the barbiturates. If the ICP again escapes control, the patient may be reloaded with pentobarbital and weaned again in several days.

I'm sure you know, this is second tier treatment for intractable intracranial hypertension, refractory to other modalities. This patient will already be ventilated, sedated, perhaps pharmacalogically paralyzed, will likely need a PA cathether for hemodynamic management.

I have watched "barb" coma come in and out of favor a few times in my practice years. Everything old is new again, or something like that!

I found this on eMedicine, try a google.com search for more. The librarian in the medical library is an invaluable person for such a project. Try the pharmacist, as well.

bellehill, RN · Sep 12, 2004

Thanks redbait, looks like we did everything we were supposed to. How long should burst supression be? There are many different thoughts on this subject. I did google and found a couple good sites, the medical library is a great idea. Our patient was on pentobabr for almost three weeks, sounds like too long to me.

gwenith, BSN, RN · Sep 12, 2004

It has been a while since I did phenobarb coma and yes it has swung from in fashion to out and in again.

Dirk · Sep 12, 2004

Hello !

The use of Thiopental is not very often here - other methods of ICP-management are useful enough.

If you use Thiopental for such a long time, you have to think about the immuno-suppression effect.

This effect limits the useage for a long time.

(I really hope, you can understand, what I mean)

Greetings

Dirk

RedBait · Sep 12, 2004

Thanks redbait, looks like we did everything we were supposed to. How long should burst supression be? There are many different thoughts on this subject. I did google and found a couple good sites, the medical library is a great idea. Our patient was on pentobabr for almost three weeks, sounds like too long to me.

I am familiar with the notion of lightening the barbs every day and seeing what the ICP does...you can always put them down again. I once heard a trauma doc say that more than five to seven days only produces more patients in a vegetative state, but, in practice, I have not seen a limit set and kept. What happened to your patient who was down for almost three weeks?

bellehill, RN · Sep 12, 2004

Redbait, we are still trying to get the patient out and see what we have. Last time I worked she had been out for almost 96 hours will little effect, just movement to painful stim. We tried to wean her down a couple times and the ICP shot right back up. Her highest ICP was 72 which is what bought her the pentobarb.

Dirk, thanks for the tip on immunosupression, that would explain why her WBCs were trending down. Didn't even think of that!

Do you think there needs to be a 1:1 ratio when caring for a patient in a pentobarb coma?

RedBait · Sep 12, 2004

Redbait, we are still trying to get the patient out and see what we have. Last time I worked she had been out for almost 96 hours will little effect, just movement to painful stim. We tried to wean her down a couple times and the ICP shot right back up. Her highest ICP was 72 which is what bought her the pentobarb.
Dirk, thanks for the tip on immunosupression, that would explain why her WBCs were trending down. Didn't even think of that!
Do you think there needs to be a 1:1 ratio when caring for a patient in a pentobarb coma?

When I did barb coma, the patient was 1:1...continuous EEG to monitor burst suppression and titration of barbs, PA catheter for hemodynamic monitoring, usually pressors titrated to cardiac index, vent with close pCO2 management, careful maintenance of euthermia, probably a devastated family at the bedside...yup, that's a 1:1 in my book.

pedseducator · Jul 3, 2006

Burst suppression depends on the control of the ICP and how far "down" the patient needs to be along with BP control, etc.

Pediatric Critical Care Columnist · Jul 3, 2006

We aren't using pentobarb here anymore... can't get it from the manufacturer. I believe it has been discontinued in Canada. We used it for more than just barb comas, we also used it for sedation when all else failed, in much lower doses of course. (We SO overuse sedation in our unit... not uncommon to have patients on 200+ mcg/kg/hr morphine, and we've had kids up to 15 mcg/kg/min midazolam, plus chloral hydrate, plus lorazepam, plus pentobarb... Can't let them even twitch a toe, y'know!) So we're using phenobarb now in place of pentobarb. We have a morbidly obese 13 year old with a severe traumatic head injury currently being treated... I can't imagine how much she's getting!

NeuroMedic · Jul 10, 2006

take a look here:

http://www.trauma.org/anaesthesia/barbcoma.html

This could be of some use.

pedseducator · Jul 10, 2006

Thank you so much Neuro Medic! Very useful information.