Registered nurses at Hi-Desert Medical Center voted Tuesday night to join California’s largest nurses’ union. In a secret ballot, the nurses voted 77-4, or 95 percent, to join the California Nurses Association/National Nurses United. Hi-Desert Medical Center is part of Tenet Healthcare. The nurses will now seek wage parity with other Tenet hospitals and a contract that requires the hospital to comply with the state’s mandated nurse-to-patient ratio law.