Central venous oxygen saturation: a potential new marker for circulatory stress in haemodialysis patients?

Abstract

BACKGROUND/AIMS: Haemodialysis causes recurrent haemodynamic stress with subsequent ischaemic end-organ dysfunction. As dialysis prescriptions/schedules can be modified to lessen this circulatory stress, an easily applicable test to allow targeted interventions in vulnerable patients is urgently required. METHODS: Intra-dialytic central venous oxygen saturation (ScvO2) and clinical markers (including ultrafiltration, blood pressure) were measured in 18 prevalent haemodialysis patients. RESULTS: Pre-dialysis ScvO2 was 63.5 ± 13% and fell significantly to 56.4 ± 8% at end dialysis (p = 0.046). Ultrafiltration volume, a key driver of dialysis-induced myocardial ischaemia, inversely correlated to ScvO2 (r = -0.680, p = 0.015). CONCLUSIONS: This initial study demonstrates ScvO2 sampling is practical, with a potential clinical utility as an indicator of circulatory stress during dialysis.