Bedside Resources to Gauge Intravascular Volume Status

A CardioQ-EDM probe will be placed on the day of surgery after induction of general anesthesia. The anesthesiologist will inform the investigator of plans to provide a fluid or blood bolus per clinical judgement in addition to the protocolized 10 ml/kg bolus provided after induction. While the anesthesiologist is preparing to administer volume expansion, a co-investigator will collect pre-fluid bolus data. Measurements will be recorded for data analysis at the completion of the trial. Additionally, a CipherOx-CRI probe will be placed on the patient's index finger (recorded data will be interpreted post hoc) and a bedside ultrasound will be performed by either the principal investigator (PI) or one of two co-investigators to measure the IVC CI. Ultrasound cine-loops will be recorded, and CI will be calculated post-hoc. Data will be recorded on the Data Collection Form for each fluid bolus administered. The PI and co-investigators will manage all aspects of investigational devices.