The executive commissioner by rule shall require that respiratory therapy services for ventilator-dependent persons furnished as part of a plan of care under this chapter be provided by a respiratory care practitioner authorized to practice respiratory care under Chapter 604, Occupations Code, when:
(1) respiratory therapy is determined by the recipient's treating physician to be the most effective method of treatment; and
(2) the use of a respiratory care practitioner is practicable and cost-neutral or cost-effective.