Put it on in preop holding to get a room air unsedated baseline reading. Intraop keep it at least within 20%. If it's low, increase the delivery of oxygen to the brain.So when you do apply it to the patient, what are you looking for, and what do you do to make things 'normal'?
You've seen a massive stroke with normal Cerebral Oximeter numbers? Wow. I would right that up. That is kinda strange.So, I've seen massive strokes in people who had pristine cerebral sats all case.
I've seen people do just fine after very very concerning intraop cerebral sats.
So I think the sensitivity and specificity of this not-cheap monitor is unacceptably poor *for the indication people associate it with,* which is detection of a focal stroke.
Yes, the cerebral sats will drop in the setting of global hypoperfusion. You shouldn't need a cerebral sat monitor to know you're globally hypoperfusing.
The only thing the evidence really says is that if you have a misdirected cannula or something, this can pick it up. I submit that you should know if your cannula is misdirected in other ways.
The indication for beach chair positioning in a marginal patient is fine I think.
I think at the end of the day, perfusionists, much like ICU nurses, want numbers to reassure them. But since good numbers don't mean everything is good in the whole brain, and bad numbers don't mean the patient will wake up stroked out, I don't use these monitors routinely.