Delta perfusion rate predicts the development of adverse outcome in cardiopulmonary bypass patients

Despite the advances in CPB, various complications may occur. Prediction and anticipation of these undesirable outcomes is of great importance. For this reason, various markers have been tried to be determined.

The aim of this retrospective study was to evaluate whether the delta perfusion ratio, i.e. (v-a)CO₂/(av) O₂ ratio, and other perfusion markers are good indices for predicting adverse postoperative outcomes in patients undergoing cardiac surgery with CPB.

This study retrospectively included data from 169 adult patients aged 20 to 85 years who underwent consecutive CPB-guided isolated CABG surgery after applying exclusion criteria. Perfusion indices were compared between patients with and without adverse outcomes after CPB.

There was a statistically significant correlation between the (v-a)CO₂/(a-v)O₂ ratio at CPB output and ICU admission (p < 0.001; p = 0.004, respectively); ScvO2 and CO₂ deficit after ACC and at CPB output and adverse outcomes after CPB (p = 0.010; p = 0.007; p = 0.000; p = 0.008, respectively). In ROC curve analysis, the cut-off value for CPB output (v-a)CO₂/(a-v)O₂ value was 2.27 (67.9% sensitivity, 65.9% specificity). The cut-off value for ICU entry (v-a)CO₂/(a-v)O₂ value was 2.6 (62.6% sensitivity, 73.3% specificity).

There was a statistically significant correlation between the (v-a)CO₂/(a-v)O₂ ratio after CPB and at ICU admission, ScvO2 and CO₂ deficit after ACC and after CPB and adverse outcomes after CPB. Therefore, we think that these are reliable perfusion indices in CPB-guided cardiac surgery.