[1] Tufts Med Ctr, Dept Anesthesiol, Boston, MA USA
[2] Brigham & Womens Hosp, Dept Anesthesiol Perioperat & Pain Med, 75 Francis St, Boston, MA 02115 USA
[3] Salzburg Gen Hosp, Dept Anesthesiol Perioperat Med & Gen Intens Care, Salzburg, Austria
[4] Paracelsus Private Med Univ, Salzburg, Austria
[5] Missoula Anesthesiol, Missoula, MT USA
[6] Int Heart Inst Montana, Missoula, MT USA
[7] Tufts Univ, Tufts Clin & Translat Sci Inst, Boston, MA 02111 USA
[8] Tufts Med Ctr, Inst Clin Res & Hlth Policy Studies, Boston, MA USA
[9] Univ Massachusetts, Sch Med, Dept Family Med, Worcester, MA USA