Best practice to send update to a platform event that is using Comet

Hello, I was trying to figure out what are some of the ways to detect and send changes to an outside system and inform them of the type of change and what changes via PLE. So, for example, we will be Updating a record that will, in term, fire a PLE to an outside system that is subscribed via CometD. Lets say we update the same records status and maybe a field. How would we send that information to the outside system notifying them of the type of change and changes. I looked into Change Data Capture, but it didn't seem to be working.