These guys might be able to help. I saw about half way down the page that they have a Dialysis Club (Coming Soon). They say they have agreements with hospitals in Cancun and Playa del Carmen. Who knows how often they update their page, so it might be worth shooting them an email.
Cancún Accesible
Here is the paragraph in English:
Dialysis Club (soon)
Cancun access has an agreement with first-level hospitals in the cities of Cancun and Playa del Carmen.
The Hemodialysis Unit has the latest technology and comfort. The hospital also has the services of interpreters in several languages.
This Club Dialysis allows Cancun and the Riviera Maya to become a tourist destination accessible to all patients in the world that require dialysis and want to spend their holidays in the Mexican Caribbean.