Carotids and TIVA

Started by Ahmad Menari, January 20, 2005, 04:44:04 AM

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Ahmad Menari

Having done carotid endarterectomies for many years using isoflurane anesthesia, I have recently converted to remifentanil and propofol TCI. However, I will probably convert back soon.

My reasoning was that remi/propofol is more quickly titrated to BP than iso, and rapid wakening at the end should allow an earlier assessment of neurological function.

The titratability is fine, but the rapid wakening has not happened. My patient group is usually in their 60's, some ischemic heart disease, HT and LVH.

I induce with remi running at 1mcg/kg/min and propofol TCI 4-8mcg/mL then drop these to remi 0.15 mcg/kg/min and a propofol target of anywhere from 3-8, but usually 4-5mcg/mL. Surgery usually takes 2 to 2.5 hrs. During the clsing stages I turn remi down to 0.1mcg/kg/min and propofol down to 2-3mcg/mL

In the 6 patients I have used this technique, while being extremely stable intra-op, they have taken a long time to wake up. Much longer than with iso. Usually breathing after 5-10 minutes, but unresponsive for 15 or so minutes. Then rousable but not extubatable for a long time after, the longest being almost 2 hours! And even then, confused, agitated, uncooperative.

Needless to say, embarassing for me, surgeon pacing around waiting to test neuro function. None of us quite sure whether it is a cerebral event or just long emergence.

And this seems to be unique to CEA's. I also use this type of TIVA on my thoracic cases, with similar doses of drugs, and they are brightly awake within 5 minutes of turning off the remi/propofol.

Aany ideas why???

???

jetproppilot

No idea, dude.  Kind of an elementary question, but what is your propofol running at in mck/kg/min?

We started using Precedex for all hearts and carotids. really takes away the hemodynamic lability that seems to go hand in hand with CEAs. We started with the loading dose in holding followed by whatever infusion rate you pick. Usually see some hypotension very resposive to fluids or hespan. These patients are usually dry as you know because of their hypertension so fluids really evens them out. Intraoperatively the opiod requirement is low (50-150 mcg fentanyl) as well as volatile anesthetic requirement. Nice technique.
Same concept with CABGs and valves- we did about 475 pump cases in 2004. Precedex on every one. Usual fentanyl requirement 250 mcg or less. Because of the minimal opiod extubation times are quicker.