MO786: Monitoring of Arterio-Venous Fistula Maturation using Central-Venous Oxygen Saturation and Estimated Upper-Body Blood Flow: Impact on Catheter Residence Time

Abstract

Abstract BACKGROUND AND AIMS In hemodialysis patients, assessment of arterio-venous fistula (AVF) maturation is key to reduce the residence time of central venous catheters (CVC). We have introduced the use of central-venous oxygen saturation (ScvO2) and estimated upper-body blood flow (eUBBF) as means to monitor AVF maturation [1]. We now report CVC residence time in patients with and without ScvO2-based AVF maturation monitoring. METHOD We studied hemodialysis patients in who ScvO2-based AVF maturation monitoring was implemented within the framework of a clinical quality improvement project (QIP). ScvO2 and hematocrit were measured with Crit-Line (Fresenius Medical Care, Waltham, MA). eUBBF was computed as described previously [1]. We used time-to-event analysis to compare the CVC residence time post-AVF creation between patients who participated in the QIP (intervention group) and non-QIP patients (control group). Both groups were dialyzed in the same geography. Patients were censored at the time of death, change of dialytic modality, transplantation, lost to follow up, recovery of kidney function and end of the observation period (15 November 2021). RESULTS The intervention group comprised 44 patients [age 57 ± 17 years; 27 (61%) males]. In five patients, two AVF were created; in 34 (69%) CVC were removed. The control group comprised of 378 patients (age 59 ± 15 years, 61% males). CVC was removed in 199 (53%) control patients. In the intervention group, CVC were removed 125 days [95% confidence interval (95% CI): 102–171] after AVF creation. In the control group, this time was 236 days (95% CI: 173–404) (P < 0.0003; log rank test; Figure). CONCLUSION Compared to controls, the CVC residence time post AVF-creation was shortened significantly— by about 3.6 months—in patients who participated in a QIP that used ScvO2-baseed assessment of AVF maturation. Measurement of ScvO2 and computation of eUBBF are simple, non-invasive means to track AVF maturation, trigger timely interventions and AVF cannulation and shorten CVC residence time.