title: Clinical comparison of two- and three-wavelength systems for continuous measurement of venous oxygen saturation.
abstract: OBJECTIVE
  To evaluate clinically the accuracy of continuous SvO2 systems to reflect reference SvO2 values over a 24-hour period.
  
  
  METHODS
  Randomized clinical trial.
  
  
  METHODS
  Six-bed cardiac surgical intensive care unit of a 540-bed federal facility.
  
  
  METHODS
  Sixty postoperative cardiac patients.
  
  
  METHODS
  Random assignment to a two- or three-wavelength continuous SvO2 catheter for postoperative SvO2 monitoring. At 4-hour intervals over a 24-hour period, mixed venous blood samples were analyzed with a reference cooximeter and compared with the monitor value of the SvO2 catheter.
  
  
  METHODS
  A reference cooximeter method to measure SvO2 in mixed venous blood; SvO2 as measured by the in-line, SvO2 catheter system.
  
  
  RESULTS
  SvO2 measured by the three-wavelength system did not differ significantly from the reference SvO2 measurement. In contrast, SvO2 measured by the two-wavelength system was significantly lower than the reference SvO2 measurement within 4 hours of admission to the critical care unit and remained significantly lower throughout the 24-hour study period.
  
  
  CONCLUSIONS
  The results of this clinical study confirmed a previous study in dogs, showing that SvO2 is measured more accurately by the three-wavelength continuous monitoring system.
authors.affiliation: Critical Care Nursing Service, Warren Grant Magnuson Clinical Center, Bethesda, MD.
authors.forename: M
authors.initials: M
authors.lastname: Chulay
authors.forename: J
authors.initials: J
authors.lastname: Palmer
authors.forename: J
authors.initials: J
authors.lastname: Neblett
authors.forename: A R
authors.initials: AR
authors.lastname: Nancherla
authors.forename: D
authors.initials: D
authors.lastname: Tripodi
authors.forename: D
authors.initials: D
authors.lastname: Caden
mesh_terms: D000328:Adult; D000368:Aged; D000704:Analysis of Variance; D002138:Calibration; D006348:Cardiac Surgical Procedures; D002407:Catheterization, Swan-Ganz / Q000295:instrumentation / Q000379:methods*; D003422:Critical Care; D005163:Factor Analysis, Statistical; D006801:Humans; D008875:Middle Aged; D008991:Monitoring, Physiologic / Q000295:instrumentation / Q000379:methods*; D010092:Oximetry / Q000295:instrumentation / Q000379:methods*; D010100:Oxygen / Q000097:blood*; D011182:Postoperative Care; D015203:Reproducibility of Results; D013815:Thermodilution / Q000295:instrumentation / Q000379:methods*
chemical_list: D010100:Oxygen