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N O V E M B E R 2 0 1 4 | O U T P AT I E N T S U R G E R Y M A G A Z I N E O N L I N E
ANESTHESIA ALERT
Flow.
I use the lowest, safest flow I can, depending on the surgery
being performed. These are the parameters I use to determine
what's safe:
• Is the patient's oxygen saturation staying at an acceptable level, and
what are the fraction of inspired oxygen (FiO
2
) requirements for the
anesthetic?
• Is the reservoir bag staying inflated, or is there a leak in the sys-
tem that I need to address?
• Is the end tidal carbon dioxide (EtCO
2
) level staying at an accept-
able level?
• Is the fraction of inspired carbon dioxide (FiCO
2
) staying low?
If all of these indicators allow for it, I usually keep the fresh gas flow
between 0.5 to 0.7 L/min.
It's not uncommon to see patients who receive 1.3 to 1.5 MAC of gas
and have their blood pressure supported by vasoactive drips or fre-
quent boluses. Sometimes we do have to take patients that deep. I use
the lowest MAC of agent that lets the patient be deep enough for that
specific surgery, but with a larger amount of narcotic to offset surgical
stimulus. The inhaled agent we use is bundled into the anesthetic
charge, so a more efficiently run anesthetic means more net revenue
from insurance reimbursement. The IV drugs, on the other hand,
are separate from the bundled charge. I find that with this technique,
patients usually wake up quicker and have less pain than those who
are more deeply anesthetized intraoperatively and then wake up in
recovery with a smaller narcotic load on board. Those patients seem
to have to stay in recovery longer while their pain is addressed and
also typically have more nausea.
Narcotics.
For TIVA cases, especially spine cases with neu-
romonitoring, I use remifentanil, instead of the much more com-
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