Assessment of Sv-O2 Monitoring after Open Heart Surgery / 日本心臓血管外科学会雑誌

ABSTRACT

A Pulmonary arterial flow-directed catheter (Oxymetry 93A-741-7.5F), combining the fiberoptic reflectometric system of continuous measurement of mixed venous blood oxygen saturation (SvO₂) was used for hemodynamic measurements including thermodilution cardiac output estimation and hemoglobin value in 21 cases of open heart surgery. Immediately after open heart surgery there was low correlation between Hb (hemoglobin value) and SvO₂ (r=0.513, <i>p</i><0.05). However there was no correlation between SvO₂ and cardiac function (pulmonary capillary wedge pressure and cardiac index). With almost normal Hb (10-13g/dl) the average cardiac index (CI) in cases of SvO₂ less than 60% was 2.47<i>l</i>/min/m² which was significantly lower than those with SvO₂ more than 60% (<i>p</i><0.01). With normal CI (2.5-4.0<i>l</i>/min/m²) the average Hb in cases of SvO₂ less than 60% was 7.40g/dl which was significantly lower than those of more than 60% (<i>p</i><0.01). This study suggested that there is low cardiac function or severe anemia in the state of SvO₂ less than 60%.