The two largest for-profit companies that provide dialysis treatment in Washington have unlawfully imposed noncompete agreements on medical directors in their centers, blocking competition and reducing treatment options for people with kidney failure, Attorney General Nick Brown alleged in a new lawsuit. Dialysis is a treatment to filter waste and fluid from the blood of people with kidney failure. About 9,000 people across Washington receive dialysis treatment, which usually occurs at a dialysis center three times a week for several hours at a time.