ZYNEX Cardiac Monitor in Patients Having Noncardiac Surgery

The investigators will titrate fluid administration to maintain a RI \> 90 over at least 85% of the intraoperative period lasting from induction until the end of anesthesia. Specifically, the investigator will consider titration to have been successful if 85% of patients in the RI group sustain a RI \> 90 over at least 85% of the intraoperative period.