We do monitor for CO events in syndromic, although we've only ever had one detected (back when we were using BioSense 2.0). But there really wasn't any follow up necessary--it was a situation where a zamboni malfunctioned, and a bunch of people at a ice rink had to seek medical care. We were able to see the location and the reason from the free text chief complaint data. However, because there was a delay in our data at the time, it was more of an "oh, I guess this happened" thing for us. Everything was already taken care of two days later, and the facility had addressed the issue. We called the facility, they were like "yes, we know" and that was basically it. It was cool, though, to see that we could see events like that!
We've talked about doing what Caleb suggested, and use it to trigger messaging, if we can get our injury people on board.