Use of Transesophageal Echocardiography to Assess Left Ventricular Performance During Acute Normovolemic Hemodilution and Randomized Replacement With Intravenous Crystalloid or Hypertonic Saline

This investigator-initiated, single-center, prospective, randomized, clinical experimental design will enroll 30 patients scheduled for elective radical prostatectomy, cystectomy, or cystoprostatectomy, and anterior/posterior spinal fusions, which includes routine acute normovolemic hemodilution (ANH) as a technique to decrease the need for banked blood transfusions. The purpose of this study is to compare two methods of volume replacement during the ANH procedure. Patients will be randomized to receive either standard crystalloid replacement with Lactated Ringers (LR) or 5% hypertonic saline. Selected measurements will be obtained by transesophageal echocardiography (TEE) for assessing changes in left ventricular volume and function associated with blood loss and replacement. This study will use the Accuson Cypress Cardiovascular System and the V5M transesophageal echocardiography probe (Siemens Medical Solutions, Malvern, PA). The TEE measurements will be recorded on magnetic optical discs and assessed off-line by the researcher after the data collection is completed using the proprietary software included in the ultrasound system. In addition, stroke volume variation measurement (SVV), Cardiac Output (CO), Cardiac Index (CI), and Stroke Volume Index (SVI) will be measured using the Vigileo (TM) arterial pressure monitor with the FloTrac (TM) sensor (Edwards Lifesciences, Irvine, CA).