title: A comparison of two pulmonary artery mixed venous oxygen saturation catheters during the changing conditions of cardiac surgery.
abstract: Continuous mixed venous oxygen saturation (SvO2), using modified pulmonary artery (PA) catheters, can assist in the management of cardiac surgery patients. Two FDA-approved catheters are available for SvO2 monitoring. One system uses two wavelengths of light and the other is a three-wavelength system. The present study was designed to determine the accuracy of the two catheters during cardiac surgery. Sixty-five consecutive patients were assigned to one of the two catheter groups. Data were collected pre- and post-induction, after sternotomy, and after extracorporeal circulation. An updated hematocrit was entered in the two-wavelength system preceding the last two measurements. Patient demographics, severity of preoperative cardiac disease, and intraoperative hemodynamics were comparable between groups. Two-wavelength determinations varied inconsistently from cooximeter values, while three-wavelength measurements did not differ significantly. Changes in hematocrit were responsible in part for the variability in two-wavelength measurements. In summary, three-wavelength measurements by the Shaw system were more accurate than two-wavelength measurements by the Edwards system.
authors.affiliation: Department of Anesthesiology, Virginia Mason Medical Center, Seattle, WA 98111.
authors.forename: B R
authors.initials: BR
authors.lastname: Hecker
authors.forename: D L
authors.initials: DL
authors.lastname: Brown
authors.forename: D
authors.initials: D
authors.lastname: Wilson
mesh_terms: D000368:Aged; D006348:Cardiac Surgical Procedures / Q000295:instrumentation; D002407:Catheterization, Swan-Ganz / Q000295:instrumentation*; D005112:Extracorporeal Circulation; D005260:Female; D005336:Fiber Optic Technology / Q000295:instrumentation; D006400:Hematocrit; D006438:Hemodilution; D006801:Humans; D007442:Intubation, Intratracheal; D008297:Male; D008875:Middle Aged; D010092:Oximetry / Q000295:instrumentation*; D010100:Oxygen / Q000097:blood*; D011651:Pulmonary Artery; D013249:Sternum / Q000601:surgery; D013908:Thoracotomy; D013997:Time Factors
chemical_list: D010100:Oxygen