[1] Med Coll Wisconsin, Med Sch, 8701 W Watertown Plank, Milwaukee, WI 53226 USA
[2] Rocky Vista Univ, Coll Osteopath Med, Sch Med, Greenwood Village, CO USA
[3] Harvard Med Sch, Beth Israel Deaconess Med Ctr, Dept Anesthesia Crit Care & Pain Med, Boston, MA 02115 USA
[4] Valley Anesthesiol & Pain Consultants, Phoenix, AZ USA
[5] Envis Phys Serv, Phoenix, AZ USA
[6] Univ Arizona, Coll Med, Dept Anesthesiol, Phoenix, AZ USA
[7] Creighton Univ, Sch Med, Dept Anesthesiol, Omaha, NE 68178 USA
[8] Louisiana State Univ Hlth, Dept Anesthesiol, Shreveport, LA USA