Prediction of intradialytic hypotension based on oxygen saturation variations

Hemodialysis sessions are often complicated by the occurrence of intradialytic hypotension (IDH), mainly due to the decrease of central blood volume. Blood oxygen content may play a role in hypotension onset and can reflect changes in cardiac output and tissue perfusion. Currently, there is an increasing interest in intradialytic monitoring, through the development of biofeedback based technologies aimed to IDH prevention. Blood Oxygen saturation (SO₂) is a patient parameter easy to monitor during hemodialysis thanks to optical noninvasive sensors placed on blood line. The aim of this study was to analyze SO₂ variations in relationship with IDH in ten hypotension prone patients with central venous vascular access. A higher decrease of SO₂ was found in sessions complicated by hypotension, in comparison with stable sessions (p<;0.001). The existence of predictive information in SO₂ variations in relationship with IDH was evidenced through ROC analysis (AUC=0.631, CI95% 0.564-0.690). Our results suggest that SO₂ decrease can characterize sessions complicated with hypotension and monitoring SO₂ could be useful in clinical practice to prevent IDH occurrence.