Care Team Model. CRNA's independent in practice, some supervision. Anesthesiologists do a combination of running their own rooms and supervising. The CRNA’s take OB call approximately 1:7 or 1:8 nights and weekends. The CRNA must be comfortable placing their own labor epidurals. They do about 660 births per year. Pre call day is off or 1st out. Post call day is OFF.