Tracking Arteriovenous Fistula Maturation: A Novel Approach

Abstract

Background: The time between the creation of an arteriovenous fistula (AVF) and its successful use is significantly longer in hemodialysis (HD) patients in the United States compared to those in other countries, and there is an urgent need to reduce the residence time of central-venous catheters (CVC). Methods: Successful AVF creation and maturation results in typical hemodynamic changes, such as an increase in cardiac output and upper body blood flow (UBBF). In patients with CVC as vascular access, we measured once per minute intradialytic central-venous oxygen saturation (ScvO₂) and hemoglobin levels simultaneously using the Crit-Line Monitor. Under conditions of stable upper body oxygen consumption and arterial oxygen saturation, ScvO₂ and hemoglobin concentration allows the calculation of estimated UBBF (eUBBF). In a quality improvement project, we used ScvO₂ and eUBBF to track the hemodynamic changes accompanying AVF maturation. Results: Out of 11 patients (9 incident to HD, 1 female, age 61 ± 13 years), AVF maturation was successful in 9. In 1 patient, the AVF did not mature. One patient died from sudden cardiac death with a maturing AVF. In the 9 patients with successful AVF maturation, ScvO₂ increased from 60.9 ± 2.7% prior to AVF creation to 73.4 ± 3.6% a week after AVF creation (19.6 ± 6.3% increase). eUBBF increased from 1.3 ± 0.3 to 2.2 ± 0.6 L/min (62.7 ± 37.5% increase); no material ScvO₂ or eUBBF changes occurred in the other 2 patients. Conclusion: Our results indicate the potential utility of ScvO₂ and eUBBF to track the hemodynamic response to AVF maturation. To what extent these insights translate into shortening of the time between AVF creation and successful cannulation warrants further investigations.