Reliability of continuous jugular venous bulb hemoglobin oxygen saturation during cardiac surgery

Abstract

Objective: To evaluate the accuracy and reliability of continuous measurement of jugular venous bulb hemoglobin oxygen saturation (SjvO 2) with a fiberoptic catheter (SjvO 2OX) during cardiac surgery versus simultaneous paired measurements of hemoglobin oxygen saturation by the Hemoximeter (SjvO 2HEM; Radiometer, Copenhagen, Denmark) and indirect estimations of hemoglobin oxygen saturation from measurements of partial pressure of oxygen in blood gases (SjvO 2BG). Design: A prospective study. Setting: American Hellenic Educational Progressive Association General Hospital, University Hospital of Thessaloniki, Greece. Patients: Thirty patients undergoing elective aortocoronary artery bypass surgery. Interventions: In addition to routine pressure monitoring, a 4F fiberoptic catheter was placed in the left jugular bulb by a retrograde internal jugular vein approach and SjvO 2OX was continuously measured. Before insertion, each catheter was calibrated in vitro. Measurements and Main Results: One hundred twelve simultaneous paired recordings between SjvO 2OX and SjvO 2BG were performed to define the accuracy of SjvO 2OX to SjvO 2BG. Sixty-one of 112 simultaneous paired recordings between SjvO 2OX and SjvO 2HEM and SjVO 2HEM and SjvO 2BG were performed to define the accuracy of SjvO 2OX to the reference SjVO 2HEM and the reliability of the SjVO 2BG measurement to SjVO 2HEM. The fiberoptic catheter readings varied from underestimating to overestimating hemoglobin saturation by a mean of −5.35% to +9.67% and of −3.22% to +7.81% versus Blood Gas Analyzer (Ciba-Corning) and Co-Oximeter (OSM 2b Hemoximeter, Radiometer) values, respectively. The mean underestimation and overestimation of CoOximeter versus Blood Gas Analyzer values were −3.18% and +4.17%, respectively. Conclusion: SjvO 2 values obtained continuously from a jugular venous bulb fiberoptic catheter may give relatively accurate readings provided they are duly interpreted and errors caused by wall artifact or blood sampling are avoided.