I would check it, I am quite familiar with that specific peritoneal machine. It's awfully awkward and heavy. And considering the need for sterility, I would never want that to see the inside of an airplane.
you will be especially doomed if you are on an UX flight.
Talk to your dialysis provider, especially if it is one of the majors (davita, fersenius, etc) most have off the shelf programs where they will send in equipment to your destination.
Finally, if there are any travel hiccups, each of the majors have contingency plans if you have a delay or issues while in transit.