Outpatient Surgery Magazine

To Efficient Inhalational Anesthesia

Re: “Breathe In, Breeze Out” (May, page 59). Congratulations to Dr. Mayfield on a very
well-written summary on improving the efficiency of inhalational anesthesia. In
particular, I commend him on his recommendation to titrate the anesthesia to the
target organ (the brain) using the BIS monitor.
To get past the legitimate criticism that the BIS doesn’t predict patient movement,
select the EMG as a secondary trace from the advanced screen and select “save”
before exiting the screen. Although the EMG information is displayed in a bar graph
above the BIS trend, between the SQI (signal to noise ratio) and the EEG, one’s eye
tends to notice the change in the EMG relatively late. Having the EMG trace appear
below the BIS trend makes it obvious when the frontalis muscle is activated. A spike
in the EMG is instantaneous while the BIS is 30 seconds delayed from real time.
Eliminate midazolam from the premedication and administer po clonidine 0.2mg (to
patients weighing between 95 pounds and 175 pounds) 30 minutes to 60 minutes
pre-op. The decrease in pre-op elevated catecholamine levels provides a de facto
sense of tranquilization, reduces induction and maintenance anesthetic requirements
for both propofol and inhalational agents by about 25 percent, and decreases PONV,
post-operative shivering and pain management issues.