[1] Virginia Commonwealth Univ, Dept Anesthesiol, Richmond, VA 23298 USA
[2] Virginia Commonwealth Univ, Dept Emergency Med, Richmond, VA 23298 USA
[3] Virginia Commonwealth Univ, Dept Physiol, Richmond, VA 23298 USA
[4] Virginia Commonwealth Univ, Reanimat Engn Shock Ctr VCURES, Richmond, VA 23298 USA
[5] Virginia Commonwealth Univ, Dept Chem, Richmond, VA 23298 USA